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PUBLIC HEALTH ASSESSMENT

NORFOLK NAVAL SHIPYARD
PORTSMOUTH, VIRGINIA


SUMMARY

Norfolk Naval Shipyard (NNSY), in Portsmouth, Virginia, is one of the largest ship repairfacilities in the world. It is on approximately 800 acres, with 4 miles of waterfront along theSouthern Branch of the Elizabeth River. Approximately 8 miles north of NNSY is HamptonRoads, the tidal basin at the confluence of the Elizabeth and James Rivers, a major area forcommercial and naval ship traffic. Parts of NNSY are along Paradise Creek, which flowsapproximately 2 stream miles before emptying into the Southern Branch of the Elizabeth River.Activities conducted at NNSY include the construction, conversion, overhaul, repair,maintenance, and outfitting of ships and other craft. Public access to NNSY is not allowed.

In the past, NNSY included the main Shipyard, four annexes, and two noncontiguous areas. Twoof the annexes are still used for activities associated with NNSY, but operate under a separateNavy command. They are called Scott Center Annex, located along Paradise Creek, andSouthgate Annex, located along the Southern Branch of the Elizabeth River. The third formerannex (St. Helena Annex) is now owned by a shipbuilding company, and the fourth (St. JuliensCreek Annex) was transferred to Naval Station Norfolk and is being evaluated by ATSDRseparately. Activities associated with NNSY also extend to two noncontiguous areas-the NewGosport area, south of the headwaters of Paradise Creek, and the Paradise Creek Disposal Area,located north of Paradise Creek, near where it empties into the Southern Branch of the ElizabethRiver.

In 1983, efforts began to identify contamination resulting from the handling and disposal ofproducts used in areas currently or formerly part of NNSY. Many locations that historicallyreceived waste products are south of the main Shipyard, including five in the Paradise CreekDisposal Area, a landfill within Scott Center Annex, and a landfill in the New Gosport area.Subsequent investigations and evaluations conducted under the U.S. Department of Defense'sInstallation Restoration Program (IRP) resulted in the identification of additional potential IRPsites and the inactivation of other IRP sites that did not require further action. In 1999, the U.S.Environmental Protection Agency (EPA) added NNSY to the National Priorities List. Manyenvironmental assessments have been conducted since. Appendix A reviews the areas underinvestigation.

The Agency for Toxic Substances and Disease Registry (ATSDR) visited NNSY in 1999 and2002 to collect information about how people on site and off site might be exposed toenvironmental contamination, to review environmental sampling data, and to learn aboutcommunity health concerns. This public health assessment evaluates past, current, and potentialfuture exposures to contaminants originating from NNSY. Table 1 provides a summary of theprimary exposure pathways evaluated in this public health assessment. Those pathways involvethe surface water and sediment of Paradise Creek, soil in and near Southgate Annex that wasuntil July 2003 contaminated with calcium hydroxide, lead-contaminated soil in and around theNew Gosport area, lead at other Navy family housing areas, and emissions from the formershipyard foundry.

Exposure to Contaminated Sediment and Surface Water in Paradise Creek

ATSDR evaluated available samples collected by the Navy from Paradise Creek, which isaffected not only by NNSY, but also by other upstream and downstream sources of pollution.Surface water and sediment samples from Paradise Creek have contained metals, low levels ofother chemical contaminants commonly associated with industrial activities, and trace levels ofpesticides. Public access to the creek near NNSY is limited by landscape features, such as reedsand mud along its banks. No regular exposures to Paradise Creek surface water and sedimenthave been reported. Infrequent, short-term contact with the detected contaminant concentrations in water or sediment from Paradise Creek would not result in any adverse health effects.

Exposure to Calcium Hydroxide from Southgate Annex

Calcium hydroxide, a by-product of NNSY manufacturing activities, was present in the northernportion of the Southgate Annex and on neighboring property owned by Atlantic Wood Industries,Inc. (Atlantic Wood) until 2003. Calcium hydroxide is corrosive and can irritate or burn the eyes,skin, and respiratory system. Because the contaminated area was not fully fenced, ATSDRrecommended during site visits that the Navy better inform anyone who might have access to thearea about the potential effects of contact with calcium hydroxide. The Navy adopted thisrecommendation in April 2002 and indicated to ATSDR that there had been no reports of anyonecoming into contact with the calcium hydroxide. ATSDR believes that the measures taken by theNavy were reasonable until site clean-up was completed in July 2003.

Exposure to Lead in Soil in the New Gosport Area

Lead-based paint chips mixed with abrasive blast material (ABM) were present in areas to whichchildren may have had access on Navy property in the New Gosport area and on adjacent privateproperty. ABM and soil samples have contained elevated levels of lead. The affected area wasnot fenced until 2000. Contamination was remediated in 2001. Detected concentrations of leadwere associated with the past disposal of ABM, but other sources can also contribute to lead insoil, including lead-based exterior paint. Navy-owned residences in the New Gosport Housingcomplex contained lead-based paint and were demolished in the mid-1990s. At least some of thenearby private residences were built during the time lead-based paint was used (until 1978).Cumulative exposures to lead have the potential to cause adverse health effects, particularly tochildren.Because of the possibility of past lead exposure from multiple sources and critical datagaps (including uncertainty associated with individual exposures to lead and the absence of bloodlead data), a definitive conclusion about past exposure to lead in the New Gosport area cannot bedrawn.

Recent investigative and remedial actions in the New Gosport area, completed in 2001, havereduced the potential for exposure to lead in soil. Infrequent and incidental exposure to any leadremaining in soil would not, in and of itself, pose a public health concern, currently or in thefuture. Because of the possibility of exposure to lead from multiple sources, ATSDRrecommends that area families participate in blood lead screening programs.

Exposure to Lead at Other NNSY Family Housing Areas

In the mid-1990s, the Navy found evidence of damaged lead-based paint and substantiallyelevated levels of lead in soil in NNSY family housing areas. Quarters A-O, Quarters P-Z (theHorseshoe Area), and Stanley Court were affected. Since that time, the Navy has taken severalmeasures to reduce the potential for exposure to lead in family housing areas. In 1997, the Navyinvited all families to a meeting where the lead testing results were presented. Residents wereadvised about how to reduce potential lead exposures and were advised not to plant gardens.Families were also offered free blood lead tests. Subsequently, the Navy took the followingactions at NNSY housing areas: covering exterior surfaces that had lead-based paint, repaintinginterior surfaces that had damaged paint areas, covering bare soil with mulch, leaving unitsvacant after residents moved, and informing residents of ways to help reduce lead exposures.Many of the units were left vacant after families moved out of them. Some of the units have beenor are slated to be demolished, including Quarters P-Z. Stanley Court, an off-site housing area,has been closed for renovations. Only five of the quarters at NNSY remain in use (Quarters A, B,C, I and K). Residents of these units have been informed of the hazards and provided withbrochures discussing lead hazards and measures homeowners can take to control exposures.

Because of the remediation efforts and the apparent decreases in numbers of children with elevated blood levels, ATSDR believes that the potential for lead exposure in the remaining quarters has been eliminated or reduced. However, no information is available about whether all children with potential exposures to lead to have been or are being tested. Continued screening and follow-up–consistent with Navy, VDH, and CDC guidance–is recommended.

Exposure to Emissions from the Former Shipyard Foundry

During the public health assessment process, ATSDR also identified a community concern aboutlead. As part of our review of potential sources of lead to which the community might be or havebeen exposed, ATSDR reviewed information about the former Shipyard foundry. Recordsindicate that foundry emissions may have been at their peak during World War II, but no dataquantifying production levels or air emissions were available. Thus, ATSDR cannot make adetermination about possible past effects of those emissions on public health. Available dataabout foundry emissions between the end of World War II and the late 1980s (when the foundrystopped operating), while limited, suggest that emissions from the foundry after 1945 did not reach levels associated with adverse health effects.


I. BACKGROUND

A. Site Description and History

Norfolk Naval Shipyard (NNSY or the Shipyard) is devoted to ship repair and overhaul. It islocated in Portsmouth, Virginia (see Figure 1, an overview map). Situated on approximately 800acres, with 4 miles of waterfront along the Southern Branch of the Elizabeth River, it is one ofthe largest ship repair facilities in the world (NNSY 2001a). NNSY opened on 12 acres in 1767as the Gosport Shipyard and is the oldest continuously operating shipyard in the United States.Confiscated by the state of Virginia during the Revolutionary War, it was burned by the British in1779. The federal government started using the Shipyard in 1794. Five years later, the UnitedStates Navy launched the frigate U.S.S. Chesapeake, built at the Shipyard (Baker 1994).

The first dry dock in the country was built at the Shipyard in 1833. In 1861, the Shipyardcommander ordered the burning of the facility before it was taken over by Confederate forces.The partly burned frigate U.S.S. Merrimac was converted to the ironclad C.S.S. Virginia at theShipyard in 1861 and 1862. The Shipyard was burned later in 1862 by departing Confederateforces. It was rebuilt after the Civil War, and construction of the first U.S. battleship began in1889 (NNSY 2001a; Water and Air Research 1983).

Major expansion occurred at the Shipyard during both World Wars. In 1922, the Navy completedits first aircraft carrier, converted from a collier, at NNSY. One hundred ships were built at theShipyard through 1953, when ship construction ceased (NNSY 2001a). After World War II, thefacility's primary focus became ship overhaul and repair. With seven operational dry docks,including the one built in 1833, NNSY can accommodate any vessel in the U.S. fleet(GlobalSecurity.org 2001a). In 1963, the facility was authorized to overhaul nuclear ships andsubmarines. This work is performed under the authority of the Naval Nuclear PropulsionProgram, a joint Navy and U.S. Department of Energy program (GlobalSecurity.org 2001a;LANTDIV 1994; NNSY 2001a).

Activities at the Shipyard are not limited to construction, conversion, overhaul, repair,maintenance, and outfitting ships and other craft. Manufacturing, research, development, andtesting work are also performed at the Shipyard. It also provides logistics support and hostsapproximately 36 tenant commands (GlobalSecurity.org 2001a; NNSY 2001b). Wastes generatedfrom Shipyard activities include oils, solvents and cleaners, paint, thinners, plating wastes,blasting residue, scrap metal, batteries, and asbestos (EPA 2000a). Solid waste associated withactivities at the Shipyard, including blasting grit, sludge from the wastewater treatment plant , andfly ash, have been disposed of in the southern portion of the Shipyard, primarily at sites alongParadise Creek (EPA 2000a). Five of these sites are in an area known as the Paradise CreekDisposal Area that is not contiguous with the main portion of the Shipyard. Another site is in theNew Gosport area, which is south of Paradise Creek, north of Greenwood Drive, and east ofLincoln Memorial Cemetery.

Figure 2 depicts NNSY and vicinity, including former annexes to the Shipyard. Southgate Annexand Scott Center Annex are still used for activities associated with NNSY, but operate under aseparate command. Southgate Annex contains warehousing facilities and a radioactive materialstorage area and houses inactive defueled nuclear-powered ships. Scott Center Annex containsrecreational facilities for Navy personnel, bachelor quarters, a Navy Exchange store, and aservice station. It also contains a former disposal site known as Scott Center Landfill, which isalong Paradise Creek.

Between 1977 and 1995, the St. Juliens Creek Annex was part of NNSY. It previously served asan ordnance and material storage and loading facility and includes offices, storage facilities, anda radar testing range. This annex is currently part of Naval Station Norfolk and is being evaluatedby ATSDR separately (ATSDR 2000b; Baker 1994; GlobalSecurity.org 2001a; VDEQ-ORP2000). Until October 2001, St. Helena Annex was part of the Shipyard. St. Helena Annex is onthe eastern side of the Southern Branch of the Elizabeth River, just north of NNSY. OnOctober 2, 2001, the annex was transferred to the Norfolk Shipbuilding and Drydock Corporation(also known as NORSHIPCO), a private shipyard that had been leasing the site (NEHC 2002a).Around the time of property transfer, the Navy investigated the nature and extent ofcontamination at St. Helena Annex. Localized groundwater contamination was identified, but theNavy and EPA determined that groundwater remediation was not necessary. Deed restrictionswill prohibit future use of groundwater at the former annex (EPA 1999, 2000a). Because the siteis adjacent to the Elizabeth River, St. Helena's Annex could have contributed to Elizabeth Rivercontamination.

NNSY is surrounded by a fence, and no public access is allowed. Security personnel are stationedat the Shipyard gates. Within the gates are waterfront facilities, including dry docks; a fencedcontrolled industrial area; administration, supply, and public works facilities; and housing andpersonnel support areas. Approximately 8 miles north of NNSY is Hampton Roads, the tidalbasin at the confluence of the Elizabeth and James Rivers, a major area for commercial and naval ship traffic (CH2M HILL 2000b).

B. Remedial and Regulatory History

Investigation of potentially contaminated sites at NNSY began in 1982 as part of a Department ofDefense program known as the Installation Restoration Program (IRP). The purpose of the IRP atNNSY is to assess environmental contamination associated with Shipyard operations. An initialassessment study published in 1983 identified 19 potentially contaminated sites (Water and AirResearch 1983). Subsequent investigations and evaluations identified a total of approximately140 additional potential sites of contamination at NNSY and made recommendations aboutappropriate follow up actions at these sites. Analysis of data associated with these sites resultedin the Navy's determination, with the concurrence of regulatory agencies, that the majority of thepotential sites identified did not require further action. See Figure 2 for the approximate locationsof the IRP sites. In 1998, sites requiring further action (both IRP sites and other solid wastemanagement units [SWMUs]) were grouped into four operable units (OUs) based on theirlocations, as shown in Table 2. In January 2000, a Site Screening Assessment that evaluatedpotential waste sites at NNSY recommended additional investigations (either document reviewor soil sampling) at 17 sites. An additional 50 sites are considered by the Navy to be activeSWMUs and will be reevaluated if they become (or are scheduled to become) inactive (Baker2000; NNSY and LANTDIV 2002). An ecological risk assessment (ERA) of Paradise Creek,evaluating potential impacts from IRP sites along the creek, was completed in December 2001.The ERA presented surface water, sediment, and biota samples collected by the Navy from thecreek (CH2M HILL 2001a).

In March 1998, the U.S. Environmental Protection Agency (EPA) proposed adding NNSY to theNational Priorities List (NPL). EPA's primary concern about NNSY was potential impacts toParadise Creek and the Elizabeth River (EPA 1999). NNSY was formally added to the NPL onJuly 22, 1999 (EPA 2000a). As of July 2003, the Navy and EPA were negotiating a FederalFacilities Agreement (FFA) governing investigation and remediation activities at NNSY (J.Nielsen, personal communication, July 10, 2003). The proposed FFA lists seven active OUsand/or IRP sites. Appendix A summarizes available information about these sites. The proposedFFA also identifies two site screening areas (SSAs) for further investigation and nine areas ofconcern (AOCs) for which a document evaluation and/or limited sampling would be appropriate.These SSAs and AOCs comprise multiple sites of potential contamination that had previouslybeen identified. For more detailed information on the Navy's plans to address contamination atNNSY, refer to documents available at the Shipyard's public repository at the Portsmouth Public Library (NNSY and LANTDIV 2002).

C. ATSDR Involvement

In July 1999, the Agency for Toxic Substances and Disease Registry (ATSDR) conducted aninitial site visit and met with representatives of NNSY, the Atlantic Division of the NavalFacilities Engineering Command, and the Navy Environmental Health Center, as well asrepresentatives of other interested governmental agencies. In May 2000, ATSDR released ahealth consultation summarizing potential public health issues at NNSY (ATSDR 2000a).

During the 1999 site visit, ATSDR saw evidence of trespassing in the New Gosport Landfill area,despite signs indicating that it was government property and trespassing was not allowed. At thissite, blasting grit and paint chips contaminated with lead had been placed in a 1-acre area andcovered with fill in 1969 and 1970. Although the Navy had planted grass on top of the landfill,ATSDR saw bare spots and small amounts of blasting grit in the area. Housing that containedlead-based paint had also been present in the area until it was demolished, beginning in 1992. Toprevent possible exposures to lead, ATSDR recommended that the Navy evaluate the need tofence the area and increase public awareness about the access restrictions. The Navy adopted thisrecommendation and fenced the site in January 2000. In 2001, removal of the blasting grit andassociated contamination at the New Gosport Landfill was completed (ATSDR 2000a, NNSY2001c).

In February 2002, ATSDR conducted another site visit to gain an understanding of current siteconditions and of the status of remedial actions, as well as to collect site-related documents andenvironmental data. As part of gathering information about the Shipyard and any associatedcommunity concerns, ATSDR also attended a Restoration Advisory Board (RAB) meeting.During a tour of NNSY, ATSDR visited the northern part of Southgate Annex, where soils werecontaminated with calcium hydroxide waste from an NNSY acetylene gas manufacturing plantthat operated from 1942 to 1971. As a result of historical waste disposal practices, soilcontaminated with calcium hydroxide (similar to lime) was on both NNSY property and AtlanticWood Industries, Inc. (Atlantic Wood) property. Fencing was present, but it did not surround allof the contaminated soil. The affected area included the Calcium Hydroxide Lagoon , whichstretches across both properties, and nearby IRP Site 9, a bermed impoundment area entirely onNavy property where calcium hydroxide contamination had been covered with soil. Site 9 isadjacent to a parking lot at Southgate Annex used primarily by Navy personnel or contractors. Atthe time of the site visit, low concrete barriers separated parking spaces from Site 9. Signs postedalong these barriers noted: "No Trespassing: IR Site."

During the 1999 and 2002 site visits, ATSDR expressed concern about the potential for AtlanticWood employees or people using the parking lot to come into contact with calcium hydroxideand that the signs posted at the time did not adequately convey the potential effects of any suchexposure. Thus, ATSDR recommended that the Navy post new signs to convey this informationand distribute fact sheets to persons who work or park in the area. The Navy adopted theserecommendations in April 2002 and posted new signs and fact sheets at Southgate Annex andAtlantic Wood. The Navy also provided training to personnel responsible for coordinating theuse of the parking area about the potential hazards posed by exposure to calcium hydroxide andthe measures that should be taken if contact occurs. In July 2003, clean up of the calciumhydroxide was completed, and wetlands restoration was completed in fall 2003. This issue isdiscussed further in the Evaluation of Environmental Contamination, Exposure Pathways, and Public Health Implications section of this report.

D. Demographics

ATSDR examines demographic data (i.e., population information) to determine the number ofpeople potentially exposed to environmental chemicals and to determine the presence of sensitivepopulations, such as children (age 6 and younger), women of childbearing age (age 15-44), andthe elderly (age 65 and older). Demographic data also provide details on population mobility,which helps ATSDR evaluate how long residents might have been exposed to environmentalchemicals.

NNSY

During World War I, the Shipyard employed more than 11,000 workers. At its peak in 1943during World War II, the Shipyard employed nearly 43,000 workers. In 1999, NNSY hadapproximately 6,750 employees. Several thousand additional Navy personnel might be aboardships undergoing repair on site at any given time (GlobalSecurity.org 2001a, NNSY 2001d).Because of the nature of Navy assignments, many employees reside in NNSY housing areas foronly 1 to 3 years (NNSY and NEHC 2003). However, some personnel may reside there forlonger periods of time because they are assigned to NNSY for more than 3 years or because theyremain in NNSY housing after being transferred to another Navy installation in the HamptonRoads area.

In the northeast corner of the main Shipyard, five residences are currently occupied by officersand their families. These units are part of a housing area called Quarters A-O Housing, which iscurrently partially vacant. In the past, additional family housing units, designated NNSY QuartersP-Z, were occupied. These units were built on the western side of the main Shipyard off of LeeStreet, near where George Washington Street intersects Effingham Street. They were laid outalong a roughly U-shaped court and are sometimes referred to as the Horseshoe area. Demolitionof Quarters P-Z is underway (NNSY-IRP 2002a, 2002b).

Stanley Court is an NNSY housing area south of the Shipyard, off Deep Creek Boulevard near itsintersection with Victory Boulevard; it accommodates approximately 120 families. Built in 1953,it was closed for renovations in 2001 and has not yet reopened. The New Gosport Housingcomplex was occupied by up to 247 families between approximately 1941 and 1992, when theunits were demolished. Bachelor's quarters in Scott Center Annex and at the Callaghan Centerwithin the main Shipyard accommodate approximately 1,200 naval employees. The Navy isevaluating the possibility of re-opening additional quarters within the main Shipyard, at QuartersM-1 (NNSY-IRP 2002a, 2002b).

Two child care centers are on site, one near the entrance of Scott Center Annex and the other inthe New Gosport area. Both were built in 1982 and can accommodate approximately 57 children.Adjacent to the New Gosport facility is a youth center that opened in 2001. The youth centerserves primarily children ages 5 to 12 and can accommodate up to 85 people. It replaced anearlier youth center, also within the New Gosport area, which had operated for approximately12 years. It also operates some teen programs (NNSY-IRP 2002a, 2002b). No schools are on site.

Community Within 1 Mile of NNSY

The Southern Branch of the Elizabeth River is directly to the east of the Shipyard. On the otherside of the Elizabeth River is the city of Chesapeake, portions of which are also locatedapproximately 1 mile south of NNSY. Directly to the south of NNSY is Paradise Creek, andbeyond the creek are homes and businesses, including the Cradock community. Residential anddowntown areas of Portsmouth are to the north and west of the Shipyard. Homes are withinapproximately 400 feet of potential NNSY contamination in Cradock, southwest of a landfillknown as Scott Center Landfill (Site 2), and in Effingham Plaza, north of the Shipyard's metalplating shop (Building 195, investigated as Site 17). Northeast of the Shipyard is the city ofNorfolk (Baker 1994; LANTDIV 1994). Figure 3, an aerial photo map of NNSY and vicinity,shows some of the features of the surrounding community.

Census data from 1990 and 2000 for the area within 1 mile of NNSY are depicted in Figures 4aand 4b. According to the 2000 census, approximately 26,010 persons live within 1 mile of theShipyard boundary, including 2,637 children under 6 years old. The nearest school is the A.J.Mapp Junior High School, which is approximately 800 feet southwest of the Scott CenterLandfill (Site 2), across Paradise Creek (Baker 1994).

Adjacent to NNSY is the Atlantic Wood NPL site, south of Elm Avenue and east of VictoryBoulevard. Between 1926 and the late 1980s, the Atlantic Wood site was used for refining coaltar, treating wood products (primarily with the preservatives creosote and pentachlorophenol),and storing treated wood products. In approximately 1990, the site was converted to an operationthat manufactures concrete pilings. As of 2000, 13 employees worked at Atlantic Wood. EPAand Atlantic Wood are planning to evaluate remedial alternatives, including soil and sedimentremoval and treatment, as well as the use of recovery wells to remove sources of groundwatercontamination. Because waste from NNSY is thought to have been transported onto AtlanticWood property, the Navy is considered as an additional potentially responsible party forcontamination at the Atlantic Wood site. In addition, some groundwater contamination fromAtlantic Wood is thought to have migrated onto NNSY and drained into the Elizabeth River(ATSDR 1994; EPA 2000b; NNSY and LANTDIV 2002).

Another NPL site, the Abex Corporation site, is approximately one-third of a mile north ofNNSY. From 1928 to 1978, a brass and bronze foundry at the site melted old railroad carbearings and recast them into new bearings. The waste sand generated was left in open areas nearthe foundry. Elevated levels of metals, particularly lead, have been found nearby. Remediation ofthe Abex Corporation site began in 1986. Contaminated soil, foundry buildings, and vacanthomes within the NPL site have been removed. A fire station was built in their place.Contaminated soil in off-site areas, particularly in the Washington Park Housing Development, isbeing removed, and all residents of this complex have been relocated. Additional soil andgroundwater sampling, as well as an evaluation of whether foundry-related contamination isaffecting the Elizabeth River, is underway or planned (EPA 2002c).

Hampton Roads Area

Numerous naval installations are in the area, including Naval Station Norfolk; NavalAmphibious Base, Little Creek; Naval Weapons Station, Yorktown; Naval Air Station, Oceana;and Fleet Combat Training Center Atlantic, Dam Neck. All of these sites except the last two areon the NPL. Additional information about NPL sites in Virginia can be found on the Internet at www.epa.gov/reg3hwmd/super/VA/ . Also nearby is the Portsmouth Naval Hospital, the largestnaval hospital on the east coast. Although these figures fluctuate, from 80,000 to 120,000military employees and 30,000 to 40,000 civilian employees of the Navy are in the HamptonRoads area, which includes the cities of Norfolk, Chesapeake, Suffolk, Virginia Beach,Portsmouth, Newport News, Hampton, and Yorktown (Baker 1993; GlobalSecurity.org 2001b).

E. Land and Natural Resource Use

Persons near NNSY use the land and natural resources in many ways. ATSDR examines land andnatural resource use to determine what activities might put people at risk for exposure. Thisinformation is important because land use affects people's exposures to contamination bycontrolling the types and frequencies of activities in those areas. ATSDR uses this information aspart of the evaluation of contamination and exposure in this document. Below, we provide the information used in our analysis.

Hydrogeology

The physical characteristics of NNSY and vicinity (such as topography and geology) affect thefate and transport of environmental contaminants. For additional information about thesefeatures, see Figure 5 (a topographical map showing NNSY and vicinity, including IRP sites) andFigure 6 (a map of soil types at NNSY and in the New Gosport area). Natural processes such asthe movement of surface water and groundwater also affect the migration of contaminants. SeeFigure 7 for a map and Appendix C for information on flood plains in the vicinity of NNSY. SeeFigure 8 for a map and Appendix D for information on wetlands in the area.

Topographically, NNSY is relatively flat. The elevation ranges from sea level to approximately10 feet above mean sea level. Shallow groundwater is encountered less than 1 foot below groundsurface near surface water bodies (such as the Elizabeth River or Paradise Creek). Further inland,the depth to shallow groundwater may be up to 5 to 10 feet below ground surface. The shallowgroundwater is part of an aquifer known as the water-table aquifer or Columbia Aquifer. Near theShipyard, the thickness of the aquifer is approximately 20 to 30 feet, and groundwater isrecharged primarily by the infiltration of precipitation (Water and Air Research 1983; NNSY andLANTDIV 2002). The groundwater in the shallow aquifer near NNSY is brackish (salty) andconsequently is not viewed as a suitable drinking water source. Most shallow groundwater in thewater-table aquifer flows to Paradise Creek, the Southern Branch of the Elizabeth River, or todrainage ditches that empty into these waterways. No drinking water intakes draw from surfacewater downstream of the Shipyard (Baker 1995; NOAA 1999; CH2M HILL 2000a).

Beneath the water-table aquifer is 20 to 40 feet of silt, clay, and sandy clay, which serves as aconfining layer that helps minimize the amount of transport from the water-table aquifer to theformation beneath it, the Yorktown Formation. The upper part of the formation, encounteredfrom approximately 50 to 150 feet below ground surface, is known as the Yorktown Aquifer andholds groundwater. The confining layer between the water-table aquifer and the YorktownAquifer is discontinuous and may be absent in some areas. Two additional aquifers beneath theYorktown Aquifer hold brackish water. These aquifers are much deeper and not considered likelyto be impacted by any contamination originating from NNSY (Baker 1995; CH2M HILL 2000b;Water and Air Research 1983).

The city of Portsmouth provides water to NNSY and most city residences from its Lake KilbyWater Treatment Plant. The water is drawn from a system of four lakes and five deep wells in thecity of Suffolk, more than 10 miles from the Shipyard. In compliance with the Safe DrinkingWater Act (SDWA), water is treated and regularly sampled before being distributed (City ofPortsmouth n.d.). According to Navy reports, the water-table and Yorktown aquifers are not usedfor drinking water in the vicinity of NNSY, but groundwater from the two aquifers might be usedfor watering lawns in some areas near the Shipyard. The only identified private and publicconsumption wells within 4 miles are east of NNSY; they are separated from the Shipyard by theSouthern Branch of the Elizabeth River. Some local industries also reportedly use groundwaterfor cooling and process water (Baker 1994; Water and Air Research 1983). There are noregulations in effect that restrict which aquifer wells may draw from. Since 1984, the VirginiaDepartment of Health (VDH) has required permits for most new well construction projects (R.Ussery, Portsmouth Health Department, personal communication, 2002).

Surface Water

Elizabeth River Description

NNSY is along the Southern Branch of the Elizabeth River, which is joined by the EasternBranch approximately 1 mile north of the site. Approximately 2 miles further north is the mouthof the Western Branch of the river, where it empties into the main stem of the river. ElizabethRiver flow is often sluggish, and sediment movement (i.e., turnover) is expected to be slow.However, periodic dredging of channels for ships can stir up contaminants. The river hosts agreat deal of shipping traffic, and there is extensive industrial activity along its banks. Currently,approximately 80 industrial and municipal facilities hold permits to discharge wastewater to theElizabeth River. This wastewater might contain small amounts of metals and other pollutants.Before the 1970s, no regulatory requirements limited discharges. Contamination from a varietyof sources, ranging from past waste disposal practices, to existing point sources (e.g., permitteddischarges from facilities), to nonpoint sources (i.e., runoff), resulted in EPA's Chesapeake BayProgram (CBP) designating the Elizabeth River a Region of Concern in 1993 (Alliance for theChesapeake Bay n.d.; Chesapeake Bay Program 1999).

A number of agencies, both government and nonprofit, have been working on characterizing andreducing contaminant levels in the river for the past two decades. This work is further describedin the Community Health Concerns section of this document. In late 1999, Dr. Daniel Dauer ofthe Biological Sciences Department of Old Dominion University in Norfolk offered thefollowing assessment: "the Elizabeth River system is still in the worst condition of any otherriver system on the [Chesapeake] Bay, but it also shows the most improving trends" (Army CBP2000; ERP 1996; VDEQ-CBP 2002).

Elizabeth River Use

Several cooperative committees studying the Elizabeth River advise against swimming in theriver near its shores. However, the river is used for other types of recreation, including boating,water skiing, and jet skiing. Much of this activity might occur in less-industrial stretches of theriver than that on which NNSY is situated. However, public access to the river across fromNNSY, near the Jordan Bridge, is allowed; during site visits, ATSDR staff saw people using theboat ramp there and jet skiing near the NNSY waterfront (ERP 1996; ATSDR 1994, 2000b).

Commercial and recreational fishing and crabbing also takes place in the Southern Branch of theElizabeth River. Particularly abundant seasonal fish include bluefish, spot, and Atlantic croaker.American eel and striped bass, particularly juveniles, are also common (NOAA 1999). No fishingadvisory is in effect for the river. A variety of shellfish species can also be found in the SouthernBranch, including crabs and hard clams (northern quahogs). However, since approximately 1926,VDH has prohibited harvesting of most shellfish (species other than crabs, including oysters,clams, and mussels) from the Elizabeth River and its tributaries. According to VDH, thisprohibition is based on elevated levels of bacteriologic contamination in these waterways(R. Barker, VDH Division of Shellfish Sanitation, personal communication, 2002). During sitevisits, ATSDR staff saw that locations near NNSY, including downstream of Site 9 (in SouthgateAnnex), are among the areas used for crabbing in the Elizabeth River system (ATSDR 2000a).

Paradise Creek Description

Paradise Creek is tidal and flows approximately 2 miles before emptying into the SouthernBranch of the Elizabeth River. The creek begins at Eliot Street, less than ½ mile northeast of theformer New Gosport Landfill (Site 1). The Navy calls the part of the creek that flows from thisarea to the George Washington Highway bridge Upper Paradise Creek and refers to the part ofthe creek below this bridge as Lower Paradise Creek. Between its headwaters and the ScottCenter Landfill (Site 2), approximately 1,000 feet south of the George Washington Highwaybridge, the creek is relatively shallow and narrow. In most of this area, it is less than about 2 to4 feet deep and 100 feet wide. It widens to approximately 200 feet wide where it is crossed by theVictory Boulevard bridge. It is approximately 500 feet wide at its mouth, where it enters into theSouthern Branch of the Elizabeth River. The lower part of Paradise Creek is deep enough forsmall boats to navigate and would be expected to support many of the same seafood species asthe Elizabeth River (CH2M HILL 2001a; NNSY and LANTDIV 2002).

Paradise Creek Use

North of Lower Paradise Creek, land use is industrial. From northwest to southeast are ScottCenter Annex, a parcel owned by the Southeastern Public Service Authority, Peck Iron andMetal, NNSY's Paradise Creek Disposal Area (OU 2), and a parcel owned by Vane MarineTerminal. Just north of this last parcel (once owned by British Petroleum) is a site used by thePortsmouth School Board for its buses and the Atlantic Wood site. No trespassing is allowed onNavy property adjacent to the creek. Any access to the creek from the neighboring industrialparcels would be expected to be limited. South of the creek is private property, includingresidences. Public access to Paradise Creek is somewhat limited by landscape features, such asreeds and mud along its banks. During site visits, ATSDR observed crab pots in Lower ParadiseCreek (near its mouth) and learned that local residents sometimes fish in Lower Paradise Creek.ATSDR also observed small boats moored along different sections of Paradise Creek. The extentto which boating, fishing, and crabbing in the lower part of the creek occur has not been welldocumented. Some people might swim or wade in the creek or sunbathe along it. However, thecreek is not currently an attractive location for these types of activities (CH2M HILL 2001b;EPA 1997; Harper 2002; NNSY-IRP 2002a).

 

A nonprofit organization known as the Elizabeth River Project (ERP) is conducting an effort toclean up and restore wetlands and vegetation along the shoreline of Paradise Creek by 2007. Thiseffort is considered part of a larger effort to restore the Elizabeth River and its tributaries. TheNavy has received praise for creating almost 2 acres of new wetlands along Paradise Creek in theNew Gosport area (after a removal action at the former New Gosport Landfill addressing blastinggrit, associated paint chips, and other debris). During an April 2002 cleanup, communitymembers removed trash from Paradise Creek in the Cradock neighborhood and Navy volunteersplanted trees, shrubs, and bushes in the New Gosport wetlands area (Harper 2001a, 2002).

Discharges to Surface Water

Before the 1970s, waste generated at NNSY was often dumped onto the ground, into stormdrains, or into the Southern Branch of the Elizabeth River (EPA 1999). Water that comes intocontact with waste products can gradually "leach" chemicals from the waste; the resultingcontaminated water is typically carried to groundwater or surface water. Many of NNSY'slandfills and other disposal areas are near Paradise Creek or the Elizabeth River and were notconstructed with effective liners or were not lined at all. Therefore, over the years, wasteproducts left in these areas might have leached or migrated (e.g., from contact with rainwater orby tidal flushing) to these water bodies. The types of waste products that might have beenreleased from NNSY over its history are outlined in this document and described in greater detailin ATSDR's 2000 health consultation summarizing potential public health issues at NNSY(ATSDR 2000a).

Since 1975, all surface water discharges from NNSY have been governed by permits the Navyhas held under the National Pollutant Discharge Elimination System (NPDES), issued by thestate of Virginia. In 1979, an industrial waste treatment plant began treating waste related to shopand maintenance operations from the Controlled Industrial Area at NNSY. Sanitary wastewatergenerated at NNSY is discharged to the Hampton Roads Sanitation District. On-site treatment ofdry dock wastewater and bilge water from Shipyard vessels (previously discharged to theHampton Roads Sanitation District) began in 1994. In February 2001, a study of the NNSYwastewater treatment system, including its condition, capacity, and efficiency, was completed.NNSY recently constructed a new system to collect and treat bilge water and dry dockwastewater. It became operational in August 2003 (CH2M HILL 2001c; NNSY and NEHC2003).

Most storm water runoff at NNSY is routed to the Elizabeth River, except runoff from theParadise Creek Disposal Area, Scott Center Annex, and the western side portion of the mainShipyard, which is routed to Paradise Creek. Paradise Creek also receives storm water dischargefrom the city of Portsmouth, Atlantic Wood, and other sources not associated with NNSY,including industrial, commercial, and urban activities. Discharges to the Elizabeth Riverwatershed originating from sources outside of NNSY are discussed further in the Community Health Concerns section of this document.

ATSDR reviewed NNSY's current NPDES permit to determine the types of contaminants forwhich monitoring requirements or discharge limitations exist. ATSDR has not reviewed NNSY'shistorical NPDES permits, but expects that regulatory requirements have become more stringentover time. NNSY has more than 75 outfalls (i.e., discharge pipes) that empty into the ElizabethRiver. Many of them release untreated storm water from nonindustrial areas. Outfalls for stormwater from industrial areas are monitored regularly for selected metals and total petroleumhydrocarbons, as well as a number of general water quality parameters (such as flow, totalsuspended solids, and pH). Treated wastewater, cooling water, and storm water from selectedindustrial processes and areas (such as dry docks) is monitored weekly, bimonthly, or quarterlyfor general water quality parameters and oil and grease. At certain outfalls, VDH requires NNSYto periodically monitor discharges of cadmium, chromium, copper, lead, mercury, nickel, silver,zinc, and cyanide. Once every 5 years, NNSY samples its treated process wastewater outfall forall types of chemical contaminants that it might contain and for other water quality parameters.NNSY's current NPDES permit also requires the Navy to use best management practices toreduce the potential for contaminant releases and to design and implement a storm waterpollution prevention plan for NNSY (EPA 1999, 2000a, 2002b; VDEQ 2000).

F. Quality Assurance and Quality Control

In preparing this public health assessment (PHA), ATSDR reviewed and evaluated information provided in the referenced documents. Documents prepared for the IRP, the Comprehensive Emergency Response, Compensation, and Liability Act, and Resource Conservation and Recovery Act (RCRA) programs must meet specific standards for adequate quality assurance and control measures for chain-of-custody procedures, laboratory procedures, and data reporting. The environmental data presented in this PHA are from the referenced reports. The limitations of these data have been identified in the associated reports. As a result of our evaluation, ATSDR determined that the quality of environmental data available was adequate to make public health decisions discussed in this document.


II. EVALUATION OF ENVIRONMENTAL CONTAMINATION, EXPOSURE PATHWAYS, AND PUBLIC HEALTH IMPLICATIONS

In this section, ATSDR evaluates whether community members have been, are, or could beexposed to harmful levels of contaminants in the environment. The conservative exposureevaluation process used by ATSDR is illustrated in Figure 9. ATSDR considers how individualsmight come into contact with contaminated media, as well as the duration and frequency ofexposure.

If it is possible that exposure has occurred or does occur, ATSDR then considers whethercontaminants were or are present at harmful levels. This is accomplished by screening theconcentration of each contaminant in an environmental medium (e.g., soil or water) againsthealth-based screening values. These screening values are contaminant concentrations that arenot likely to cause adverse effects, even when very conservative exposure scenarios are assumed.Environmental levels that exceed available screening values will not necessarily produce adversehealth effects. If a contaminant is found in the environment at levels exceeding applicablescreening values, ATSDR examines potential exposure variables and the toxicology of thecontaminant. ATSDR emphasizes that regardless of the level of contamination, a public healthhazard exists only if people come into contact with, or are otherwise exposed to, harmful levelsof contaminants in site media.

This section describes three exposure pathways associated with NNSY: Paradise Creek surfacewater and sediment, calcium hydroxide in and around Southgate Annex, and lead in soil in andnear the New Gosport Area. For each pathway, ATSDR provides an assessment of whetherhuman exposure to potentially-harmful levels of contaminants might have occurred or occur.

A. Exposure to Paradise Creek Surface Water and Sediment

ATSDR evaluated available data to evaluate whether past, current, or future hazards might beassociated with surface water or sediment contamination in Paradise Creek. Paradise Creek istidally influenced and is affected by pollution from a number of point and nonpoint sources ofcontamination upstream and downstream of NNSY. Public access to the creek is limited.Although some boating and wading might occur, no regular exposures to surface water andsediment have been reported. Surface water and sediment samples from the creek have containedmetals, low levels of other chemical contaminants commonly associated with industrialactivities, and trace levels of pesticides. The detected concentrations of these contaminantswould not cause adverse health effects to people from infrequent, short-term, incidental contactwith the water or sediment (see Table 1).

Background

As noted previously, several NNSY IRP Sites are along Paradise Creek (see Figure 10). Theformer New Gosport Landfill (Site 1) is south of Upper Paradise Creek. It was used as a disposalarea for blasting grit and associated paint-chip waste created during paint removal activities; thiswaste is referred to as abrasive blast material (ABM). Scott Center Landfill (Site 2 or OU 1), inScott Center Annex, is north of Lower Paradise Creek, downstream of the George WashingtonHighway bridge. This landfill was used during the 1950s for NNSY industrial and sanitary waste.The Paradise Creek Disposal Area (OU 2, comprising Sites 3-7 and SWMU 22) is furtherdownstream. A variety of types of waste products have been associated with this OU, includingsanitary waste, asbestos, boiler ash, grit and paint chips left over from blasting operations,industrial wastewater treatment plant sludge, paints, solvents, petroleum products, other liquids,and hydraulic fill (CH2M HILL 2001a, 2001b, 2002a; NNSY-IRP 2002a). See Appendix A forfurther information about the IRP sites.

The Navy is addressing potential sources of Paradise Creek contamination originating fromNNSY. It holds a state permit for surface water discharges and uses best management practices toreduce pollution. In 2000 and 2001, the Navy removed ABM and associated soil and debris fromSite 1. The excavated area was filled with soil, grass seed, and marsh plants to create a 1.9-acrewetland along Paradise Creek. The Navy is also studying whether covering the former landfills atOUs 1 and 2 would meet its remediation goals, including reducing the potential for exposure toburied contaminants (both future contact with waste on land and future effects on groundwater,surface water, and sediment caused by infiltration of rainwater) (CH2M HILL 2001a, 2001b,2002a; Harper 2001b).

Several other industrial facilities are near Paradise Creek (see Figure 11). A storm drain thatserves the western part of the main Shipyard and the industrial facilities between it and LowerParadise Creek discharges to the creek. Some of these facilities are described in the ParadiseCreek Use subsection of the Natural Resources section of this document. A variety of chemicalcontaminants may be associated with activities conducted at these sites. For example, AtlanticWood is a potential source of wood preservatives, including creosote and pentachlorophenol,metals, polycyclic aromatic hydrocarbons (PAHs), and dioxins (EPA 2000b). Chemicals nowused or previously used as gasoline additives or in petroleum-related products (including leadand benzene, among others) might be associated with the former BP site (now Vane MarineTerminal), the parcel used by Portsmouth School Board buses, and other nearby areas in whichvehicles are used or serviced.

As described in the Natural Resources section of this document, leachate migration and stormwater runoff have undoubtedly caused some chemical contaminants from land owned by NNSYand from other activities conducted near Paradise Creek to enter the water and sediment of thecreek. High and low tides greatly affect surface water flow in Paradise Creek. Particularly inLower Paradise Creek, water and sediment might be carried into the creek from the ElizabethRiver. Tidal action causes chemicals released from NNSY to mix with those released from othernearby upstream and downstream sources. This mixing makes it difficult to attribute contaminantconcentrations in surface water and sediment to any specific source.

The Navy has sampled surface water and sediment in Upper Paradise Creek and Lower ParadiseCreek as part of several investigations conducted between 1986 and 2000. These data arepresented in the Navy's ecological risk assessment for Paradise Creek, finalized in December2001, and earlier investigations conducted as part of the IRP. Surface water samples collectedduring investigations of the IR sites along Paradise Creek contained relatively low levels of somemetals, as well as selected volatile organic compounds (VOCs) and semivolatile organiccompounds (SVOCs). One surface water sample also contained trace amounts of pesticides.Most of the sediment samples collected over time have contained metals, which were generallydetected at higher concentrations in Lower Paradise Creek than in Upper Paradise Creek. Most ofthe sediment samples also contained SVOCs, primarily PAHs. Some samples also containedVOCs, pesticides, and polychlorinated biphenyls (PCBs) (CH2M HILL 2001a, 2001b, 2002a).More information about the contaminants that have been detected is in the text box on thefollowing page.

As previously noted, ERP is working to foster partnerships among interested agencies, industries,and community members to clean up Paradise Creek. It sponsors efforts to monitor indicators ofcreek quality and plans to share the results with the community. One of these efforts is a study byDr. Daniel Dauer of Old Dominion University of the benthic (bottom-dwelling) community inParadise Creek (CH2M HILL n.d.a.; Elizabeth River Project n.d.a.). ERP also initiates associatedoutreach programs, including a "River Stars" program to enlist industry and organizations inpollution prevention and habitat restoration initiatives (Elizabeth River Project n.d.a.).

Discussion

No one drinks the water from Paradise Creek or uses it as a water supply for any purpose. Theonly exposures to surface water and sediment that would be expected are incidental exposures(via dermal contact or ingestion) during recreational use of the creek. IRP sites along the creekare fenced. Little, if any, access would be expected from the industrial areas north of LowerParadise Creek. Any public access to the creek would be expected to occur primarily fromresidential areas. The most likely types of exposures would occur while people walk along thecreek, or if they wade, sunbathe, or play at its edge. As noted previously, Paradise Creek is not avery attractive place for swimming. There are reportedly few, if any, sandy spots adjacent to thecreek. In most areas, the land adjacent to the creek is marshy or covered with vegetation. Somepeople may also take small boats into the lower part of the creek. Crabbing is discussed in theCommunity Health Concerns section of this document.

What contaminants have been detected in samples from Paradise Creek? -- Metals. Metals are naturally occurring. However, certain metals found in the environment are also by-products of industrial activity (including iron, lead, mercury, and zinc). Arsenic, lead, and thallium are among the metals detected above background concentrations in surface water and sediment samples from Paradise Creek. Some arsenic compounds are used as wood preservatives and in pesticides. Lead has been used in paints, ceramic products, batteries, ammunition, and other metal products such as solder. In the past, some lead compounds were added to gasoline, but these products have been phased out since the 1980s. Thallium enters the environment primarily as a result of emissions from coal-burning and smelting, as well as cement factories. -- Pesticides. Pesticides are chemicals that were developed to destroy pests such as insects. Not all types of pesticides are still in use. Some pesticides have been used so extensively that they are found throughout the environment at very low levels. Some surface water and sediment samples contained trace amounts of certain pesticides (e.g., chlordane, dieldrin, heptachlor epoxide, and DDT). -- Polychlorinated biphenyls (PCBs). PCBs are synthetic oils once widely used as coolants and lubricants in transformers and other electrical equipment. PCBs are persistent in the environment and bind strongly to soil and sediment. Approximately one-fifth of sediment samples contained one or more PCBs. -- Volatile organic compounds (VOCs). VOCs are organic chemicals that readily evaporate. A few VOCs (e.g., benzene, cyclohexane, and 1,2-dibromoethane) were detected at very low levels in surface water samples. Some of these VOCs are commonly found as a result of burning fossil fuels. Others are used in cleaning products, solvents, degreasing agents, and other industrial and household products. -- Semivolatile organic compounds (SVOCs). SVOCs are similar to VOCs, but they evaporate less readily. Low levels of two phthalates, which are commonly added to plastics, were detected in surface water samples. Polycyclic aromatic hydrocarbons (PAHs) are a class of SVOCs. PAHs are formed during the burning of organic substances, including fossil fuels such as oil, gas, coal, and wood. They can be found in tar, oil, and creosote, among other substances, and are sometimes used to make dyes, plastics, and pesticides. PAHs generally occur as complex mixtures. Like PCBs, they adhere to solid particles and have been detected in sediment samples. -- For more information about the contaminant concentrations detected, see the final entry of the table appearing in Appendix A. For more information about these contaminants, see the Agency for Toxic Substances and Disease Registry's Toxicological Profiles and ToxFAQs, which are available on the Internet at www.atsdr.cdc.gov/toxpro2.html and www.atsdr.cdc.gov/toxfaq.html, respectively, or by contacting the National Technical Information Service at 1-800-553-6847. -- How does ATSDR interpret Paradise Creek sampling data? -- The types of contaminants found in Paradise Creek are often present in streams affected by point sources (such as industrial facilities) and non-point sources (such as a runoff from lawns and highways). As explained in the Discussion section of this document, the detected levels of contaminants would not cause adverse health effects to people with infrequent and incidental exposure to surface water and sediment while swimming, wading, or boating in Paradise Creek.

ATSDR has been advised that Paradise Creek might be infrequently used for recreation. However, no regular exposures to surface water or sediment have been reported or documented. Recreational activities conducted along or in Paradise Creek would be expected to occur primarily during the warmer months of the year. Those activities do not involve swallowing large quantities of surface water or sediment. Accidental ingestion or contact with chemical contaminants in Paradise Creek and its sediments is probably minimal. Any incidental, infrequent, and short-term exposures to the detected levels of contaminants would not result in adverse health effects. (For additional perspective on reasons that these types of exposures are not expected to pose a health concern, see Appendix F, Response to Comment #21.) Efforts by the Navy, ERP, and other agencies, organizations, and community members to restore Paradise Creek quality would be expected to result in reductions of contaminant levels over time.

B. Exposure to Calcium Hydroxide from Southgate Annex

Calcium hydroxide, a waste product from a former NNSY acetylene gas manufacturing plant,was present on both Navy property in the northern portion of Southgate Annex and onneighboring Atlantic Wood property. Calcium hydroxide can be corrosive, and it can irritate orburn the eyes, skin, and respiratory system. The Navy and Atlantic Wood worked together todevelop an approach to remediate calcium hydroxide contamination, as well as other cross-border contamination resulting from wood-treating operations at Atlantic Wood andsandblasting and the disposal of sandblast grit at Southgate Annex.

Because fencing previously did not surround all of the calcium hydroxide-contaminated soil,ATSDR noted that trespassers or workers on either property might come into contact withcalcium hydroxide. We therefore recommended that the Navy and Atlantic Wood ensure thatanyone who might have access to the area be advised of the potential health effects of any suchcontact. In April 2002, the Navy posted new signs in the affected parts of Southgate Annex andAtlantic Wood, distributed fact sheets, and provided associated training to selected navalpersonnel. As of May 2002, no one had reported coming into contact with calcium hydroxide,and the Navy had not received any questions or concerns about exposure to calcium hydroxide.ATSDR believes the measures taken by the Navy were sufficient to advise affected parties of thepotential hazard that contact with calcium hydroxide might pose, until site clean-up activitieswere completed in early July 2003. After the calcium hydroxide was removed, the Navy andAtlantic Wood restored the nearby wetland area and planted additional trees. Any pastincidental exposures to the detected concentrations of other chemical contaminants (such asPAHs or metals) would not be of sufficient duration to pose a health concern (see Table 1).

Background

What is calcium hydroxide?: Calcium hydroxide is a strong base and has a pH, when it is pure, of approximately 12.2–12.4. Calcium hydroxide is corrosive and can irritate or burn the eyes, skin, and respiratory system. The extent of damage calcium hydroxide can cause depends on the duration of contact, and medical attention may be necessary. -- What health effects could result from contact with calcium hydroxide?: Skin contact with calcium hydroxide can cause severe burns and blistering. Eye contact might result in irritation or swelling, and prolonged contact can damage the surface layer of the cornea, which can lead to blindness. Inhaling calcium hydroxide can irritate mucous membranes or the respiratory tract or cause a burning sensation, coughing, laryngitis, shortness of breath, headache, nausea, or vomiting. -- What should people do if they come into contact with calcium hydroxide?: Follow procedures outlined in the material safety data sheet (MSDS) sheet for exposure to calcium hydroxide. In the event of eye or skin contact with calcium hydroxide, the affected area should be flushed with water for at least 15 minutes. Any contaminated clothing or footwear should be removed and washed. In the event of inhalation of calcium hydroxide dust, move the victim to fresh air. Immediate medical care and attention should also be sought for other severe exposures or if irritation becomes apparent. If calcium hydroxide is swallowed, do not induce vomiting.As noted previously, the Navy operated an acetylene gas manufacturing plant within SouthgateAnnex from 1942 to 1971. The plant was near the annex border with Atlantic Wood and west ofthe Southern Branch of the Elizabeth River. One of the waste products from the manufacturingprocess was calcium hydroxide (also known as hydrated lime). ATSDR received information about two separate areas affected bycalcium hydroxide contamination: (1)IRP Site 9, the Calcium HydroxideDisposal Area (originally called theWaste Lime Pit), which is entirelywithin Southgate Annex; and (2) theCalcium Hydroxide Lagoon, part ofwhich is on naval property and part ofwhich is on Atlantic Wood property.

Site 9 was a semi-aboveground, bermedimpoundment that was used fromapproximately 1965 to 1971 to holdwaste calcium hydroxide. The berm wasconstructed partially from used ABM,and blasting (of paint off ships) isreported to have taken place nearby.Thus, the used ABM was mixed withmetal-contaminated paint chips. Forsome years and through 2002, Site 9 wascovered with more than one foot of soil,according to the Navy (NNSY andLANTDIV 2002). From 1944 toapproximately 1965, NNSY dischargedwaste calcium hydroxide from itsacetylene gas plant through a pipe to aninlet on the Southern Branch of theElizabeth River. The area containingleftover calcium hydroxide sludge wasreferred to as the Calcium HydroxideLagoon. According to the Navy,approximately one-third of the affectedarea was on NNSY property, and theother two-thirds was on Atlantic Woodproperty (Baker 1996a, 1996b;NAVSEA 2002).

Historical practices at Atlantic Woodand NNSY have contributed toadditional cross-border contamination, primarily with PAHs and metals. The PAHs are believedto be from chemicals used for wood treating at Atlantic Wood. The metals detected near theboundary between the two sites is thought to be partially attributable to transport of blast gritfrom Navy property by storm water runoff, but contributions coming from the two propertieshave not been determined (LANTDIV 2001; NNSY and LANTDIV 2002).

Southgate Annex is surrounded by a guarded fence, and the perimeter of Atlantic Wood ispartially fenced. There is also a chain-link fence between Southgate Annex and Atlantic Wood(reportedly set back from the property line because calcium hydroxide would have caused thefence to corrode). Beyond this fence and on Atlantic Wood property, there was exposed calciumhydroxide in the Calcium Hydroxide Lagoon (Baker 1996b; NAVSEA 2002; NNSY andLANTDIV 2002). At the time of ATSDR's 2002 site visit, part of Southgate Annex near Site 9was being used as a parking lot for employees of Navy contractors. At that time, concrete barriersseparated Site 9 (a soil-covered mound of calcium hydroxide) from nearby parking spaces. Signson the barriers read, "No Trespassing: IR Site."

Calcium hydroxide can absorb carbon dioxide from the atmosphere and form calcium carbonate(Mallinckrodt Baker 2001). Natural weathering also can convert some calcium hydroxide tocalcium sulfate (LANTDIV 1994). Thus, if people came into contact with material from theseareas, they might not contact pure calcium hydroxide. In 1996, the Navy measured the pH of twocalcium hydroxide samples collected from near the surface of the calcium hydroxide waste onAtlantic Wood property. The pH value for both samples was 12.8. In a report associated with thissampling, it was noted that natural degradation would have been expected to cause the othersamples to have lower pH values (Baker 1996b).

In early 2002, the Navy conducted an assessment to delineate the full extent of calciumhydroxide contamination at Southgate Annex and Atlantic Wood. Later, an EngineeringEvaluation/Cost Analysis was conducted to assess ways to remediate this contamination. Inaddition, the Navy and Atlantic Wood, with EPA and Virginia Department of EnvironmentalQuality (VDEQ) oversight, jointly studied how best to address and remediate cross-bordercontamination. As of late 2001, a joint proposal called for removing the calcium hydroxide fromthe Calcium Hydroxide Lagoon, creating a wetland along the Southern Branch of the ElizabethRiver, and capping soils areas affected by PAHs and ABM (LANTDIV 2001; NNSY 2002). Acalcium hydroxide removal action at both Site 9 and the Calcium Hydroxide Lagoon wascompleted in early July 2003, and restoration of the wetland was completed in October fall 2003(NNSY and LANTDIV 2002; J. Nielsen, personal communication, July 10, 2003).

Discussion

On the basis of ATSDR's recommendations, in April 2002, the Navy posted new signs aroundthe areas contaminated with calcium hydroxide, posted and distributed fact sheets, and providedtraining about potential health concerns related to the calcium hydroxide to selected navalpersonnel. The new signs read, "NO TRESPASSING. Caution: Environmental Investigation Site.Soil Contains Caustic Material. Potential Acute Eye and Skin Irritant. NO TRESPASSING." TheNavy also posted new fact sheets on both Navy and Atlantic Wood property and providedadditional copies to staff who coordinate the use of the parking area and to representatives ofAtlantic Wood. The fact sheets contained background information about Site 9 and the CalciumHydroxide Lagoon, advised people to avoid contact with the calcium hydroxide, and providedinformation about the potential health effects of exposure to calcium hydroxide and measures totake if exposure occurs. The fact sheets also provided Navy and Atlantic Wood employees withcontacts who can address questions and provide more information. The training, provided to theSupervisor of Ships and Navy personnel who coordinate the use of the parking area, coveredinformation similar to that included in the fact sheets (NAVSEA 2002; NNSY-IRP 2002b).

ATSDR believes that the measures taken by the Navy in April 2002 were sufficient until siteclean-up was completed, to advise people who work or park near Site 9 of the potential hazardthat contact with calcium hydroxide might pose. The Navy indicated to ATSDR that it has notreceived any reports of people coming into contact with calcium hydroxide or questions aboutexposure to calcium hydroxide (NEHC 2002b). Other contaminants (particularly metals andPAHs) have been detected in soils at Atlantic Wood and Southgate Annex, but any incidentalexposures to these contaminants would be short-term and infrequent. Such short-durationexposure to the detected levels of these contaminants would not pose a health concern. Measuresto remediate the calcium hydroxide and chemical contamination designed to prevent any futureexposures were implemented. Calcium hydroxide removal and cleanup was completed in July2003 (J. Nielsen, personal communication, July 10, 2003).

C. Exposure to Lead in Soil in and Near the New Gosport Area

Lead-based paint chips mixed with ABM were used as fill in the New Gosport area between 1969and 1970. Historical records show that the waste was present in areas that neighborhoodchildren might have had access to, including behind Wainwright Avenue (part of the NewGosport Housing complex, which has since been demolished), north of the New Gosport youthcenter, in the wetlands area south of Paradise Creek (now known as Area C), and in thebackyard of a neighboring private residence. The full extent of the ABM disposal area (called theNew Gosport Landfill or Site 1) was not delineated and fenced until 2000. A removal actionaddressing ABM and associated waste was completed in 2001. After remediation, part of thefencing was removed.

Because of the remedial actions completed by the Navy in the New Gosport area in 2001, thepotential for current and future exposure to lead in soil has been greatly reduced. Today,infrequent and incidental exposure to the soil in and around the New Gosport area, in and ofitself, is not expected to cause adverse health effects (see Table 1). Our review of information onpast exposures shows that not only could people have been exposed to ABM, but residences inand near the New Gosport area are of an age such that they were probably painted with lead-based paint. Lead-based paint from homes built before 1978 that children live in or regularlyvisit could contribute to children's total lead exposure. Blood lead data would provideinformation on the extent and effects of lead exposure to children living within and near the NewGosport area, but blood lead data collection began after the years that the housing area wasoccupied. Because of (1) the possibility of lead exposure from multiple sources; (2) the absenceof blood lead data for affected populations; and (3) the uncertainty associated with individualexposures to lead (including site-specific information about the fate and transport of lead and itsbioavailability), insufficient information is available to determine whether past exposure to leadin and near the New Gosport area might have caused adverse health effects (see Table 1).

Background

New Gosport Area: The New Gosport area is owned by the Navy and is approximately 56 acres. It includes the New Gosport Landfill and the New Gosport Housing (NGH) complex. Privately owned homes are also in adjacent neighborhoods. The Navy's NGH complex was built in 1942 to accommodate 247 families. It was demolished between 1992 and 1995. The New Gosport Landfill, or Site 1, is near the northern border of the New Gosport area. Navy disposal of abrasive blast material (ABM; see text box on the following page) took place at Site 1 in 1969 and 1970. The disposal area was originally thought to be approximately 1 acre in size, but investigations conducted around 2000 revealed that ABM disposal affected approximately 5.5 acres. Sources: CH2M HILL 2000a; LANTDIV 1991; Navy Public Works Center 1996aThis section describes the history and landuse of the New Gosport area, followed by information about investigations conducted.

History and Land Use

The New Gosport area is a 56-acre Navyparcel separate from the main Shipyard,south of Paradise Creek, north ofGreenwood Drive, east of Lincoln MemorialCemetery, and west of Ansell Avenue. From1942 until the mid-1990s, much of the NewGosport area was occupied by the 247-unitNew Gosport Housing (NGH) complex,which served families of NNSY personnel(LANTDIV 1991; Navy Public WorksCenter 1996a). Because of the age andcondition of the units, the Navy demolishedthe NGH complex between 1992 and 1995(CH2M HILL 2000a; NNSY and LANTDIV2000a). Most of the Navy residences weresouth and west of Wainwright Drive. Thisroad, along with most other roads anddriveways within the housing complex (except Alabama Avenue and Stack Street), was removedas part of the demolition (CH2M HILL 2000a; Navy Public Works Center 1998). Stack Street isalong the eastern edge of the New Gosport area, which is surrounded by private homes on threesides. While Navy homes on the western side of Stack Street have been demolished, Stack Streetis still used to access the rear of private residences to its east, on Treakle Terrace and AnsellAvenue (NNSY and LANTDIV 2000a).

In 1969 and 1970, the Navy disposed of waste created during paint removal from ships in dry-dock in the New Gosport area, north of the northernmost houses on Wainwright Drive and southof Paradise Creek. The waste (used for fill) was primarily ABM, which refers to both spentblasting grit and commingled paint chips. (See text box for more information about ABM.) TheNavy later called this ABM disposal area the New Gosport Landfill, IRP Site 1. No ABMdisposal is thought to have taken place at Site 1 after 1970 (CH2M HILL 2000d; Water and AirResearch 1983). Between October 2000 and June 2001, the Navy removed ABM and associatedsoil and debris at the Site 1 ABM disposal area. This removal action is discussed in further detailin the following subsections.

What is abrasive blast material (ABM)?: In the past, the Navy used a product called Black Beauty as an abrasive when blasting paint off ships at the Norfolk Naval Shipyard. Because it is made from coal slag, Black Beauty contains heavy metals, including lead. The blasting grit is black and granular and thus can be visually distinguished from soil. ABM refers to the waste generated after blasting, which includes used blasting grit and paint chips. The paint chips contain lead because it was commonly added to paint at that time (the text box on the following page describes where lead in soil comes from). Sources: CH2M HILL 2000a; Reed Minerals 1993In addition to housing, the New Gosportarea contained other facilities wherecommunity members often gathered.Examples include a community center and aself-help center on the western side of thehousing area, near the intersection ofAlabama Avenue and Morningside Drive.Originally, the community center servedyoung people, among other groups. Afterthe NGH complex was demolished, the self-help center was converted to a new youthcenter, which opened in 2001. A child carecenter was built nearby in 1985 andcontinues to serve Navy families (NavyPublic Works Center 1998; NNSY-IRP2002a, 2002c). Playgrounds and playingfields were also in the New Gosport areaduring the time that NNSY families lived inthe housing area (CH2M HILL n.d.b.).Currently, children using the youth center sometimes play in adjacent grassy areas (within theNew Gosport area, but outside of Site 1) (NNSY-IRP 2002a).

At the time of this writing, the Navy had not determined the future use of the New Gosport area.In light of the measures it has taken to reduce the potential for lead contamination to remain insoil, the Navy is considering building new residences in the area formerly occupied by housing(CH2M HILL n.d.d.).

Nature and Extent of Contamination

The primary contaminant of concern in the New Gosport area is lead. Other contaminants, mostlymetals (and low levels of some pesticides, which are not considered to be associated with ABMdisposal activities), have been detected at Site 1 and are listed in Appendix A. ATSDR focusedour evaluation on potential exposure to lead in soil because lead was the only contaminantdetected at levels that might pose a health risk to persons coming into contact with contaminatedsoil. This subsection reviews the history of investigations and remediation of lead contaminationin the New Gosport area, both at the NGH complex and at Site 1. It also presents informationabout ATSDR's 1999 site visit to the New Gosport area. Table 3 presents the results of samplesanalyzed for lead as part of the investigations described below.

Where does lead in soil come from?: Lead is a metal present in the earth's crust, and low levels of lead are found naturally in soils. Lead levels in soil might be elevated above naturally occurring levels for a variety of reasons. For many years, lead was a component of or an additive to many manufactured products, including paint and gasoline. Lead was added to gasoline to improve its octane rating. It was added to paint to give it pigment (color), make the paint more durable, and improve its spreadability. In later years, awareness of the potential hazards posed by exposure to lead resulted in a reduction in its use in these products. Lead in soil does not biodegrade or dissipate; thus, its presence might be attributable to motor vehicle emissions, waste associated with industrial facilities, and deteriorating lead-based paint, among many other sources. Sources: ATSDR 1999; CH2M HILL 2000a; EPA 2000cNavy Activities at the NGH Complex

In the late 1980s and early 1990s, the Navyassessed the condition of the NGH complexand decided to demolish existing buildings,which had been built in 1942 (Navy PublicWorks Center 1996a, NNSY and LANTDIV2002). Demolition and removal of theseresidences was carried out between 1992and 1995 (CH2M HILL 2000a). Thefollowing paragraphs provide informationabout samples collected at the NGHcomplex and discussed in a 1996 leadmanagement plan, as well as activitiesconducted by the Navy as part of thedemolition of the NGH complex.

Lead sampling at the NGH complex. In1994, as part of its effort to assess lead-based paint across NNSY housing areas, theNavy collected soil, paint, and dust samplesfrom randomly selected residences in theNew Gosport area. The purpose of thissampling was to characterize householdlevels of lead, both indoor and outdoor, andwas not to measure the nature and extent of lead contamination associated with ABM disposal.The paint and dust samples revealed the presence of lead-based paint in the NGH complex andare discussed later in this section (in the Discussion section addressing lead-based paint). Thesoil samples analyzed for lead as part of this project were collected outside of 12 residences.(Those residences, none of which were on Wainwright Drive, represent approximately 5% of allNavy-owned housing units in the New Gosport area.) Approximately 85% of the 38 samplescollected, including five background samples, contained concentrations of lead below 400 partsper million (ppm). The exceptions were five soil samples from four residences, which containedlevels of lead between 400 and 800 ppm (Navy Public Works Center 1996a). For moreinformation about these samples, see Table 3.

Demolition of the NGH complex. Because the Navy had identified the possibility of lead in soilposing a potential future hazard, the Navy took the following measures to reduce the potential for future exposure to lead during demolition and removal of the complex:

  • Removed all internal and external wood trim coated with lead-based paint beforedemolition.
  • After demolition, removed foundation footings and backfilled areas.
  • Removed all existing roads and driveways.
  • Graded all disturbed areas with fill, covered the fill with 4 inches of topsoil, thenseeded the disturbed areas so that grass would grow (ATSDR 2000a).

Navy Activities at Site 1

Over the last 25 years, the Navy has extensively studied the effects of ABM disposal at Site 1.These investigations culminated in a large clean-up project in 2000 and 2001. The followingparagraphs present a chronology of key events at Site 1.

In April 1982, as part of its initial assessment of NNSY, the Navy inspected the ABM disposalarea. In a 1983 Initial Assessment Study report, the Navy indicated that there were large areas ofexposed ABM behind the northernmost houses on Wainwright Drive and Stack Street, perhapsfewer than 50 or 100 feet behind some of the houses. In areas where ABM was exposed, little orno vegetation was present. ABM was visible within 30 to 60 feet of Paradise Creek and adjacentto drainage ditches discharging to the creek (Water and Air Research 1983). The Navy analyzedtwo samples of ABM, which contained 560 and 1,730 ppm of lead. Two additional samples wereanalyzed using the extraction procedure toxicity test, which indicated that metals would not beexpected to easily leach from the ABM (Water and Air Research 1983). To reduce the potentialfor people to come into contact with ABM, the Navy took immediate action to regrade areaswhere there was exposed ABM, cover the exposed ABM with clean soil, and plant new grass(Water and Air Research 1983; NNSY 1999).

In 1987, Navy personnel investigated Site 1 and noted that the soil cover in some areas haderoded and that it had proven difficult to maintain a vegetative cover in other areas. Someexposed ABM was visible (particularly near the northwestern boundary of the New Gosportarea); the Navy covered it with additional clean fill (Kearney 1987; NNSY 1999).

An April 1999 Navy inspection of Site 1 revealed that the site was well vegetated in most places.The Navy noted three spots with exposed ABM. A single soil sample was collected from each ofthese spots; the maximum lead concentration measured was 929 ppm (CH2M HILL 2000a;NNSY 1999). For additional information about this sampling event, see Table 3. After collectingthe samples, the Navy covered the exposed ABM with clean soil (NNSY 1999).

By summer 1999, the Navy was in the process of developing a plan to complete a SiteInvestigation (SI) at Site 1 to determine the nature and extent of contamination associated withthe disposal of ABM (ATSDR 2000a). In August 1999, the Navy adopted ATSDR'srecommendation to distribute a fact sheet about Site 1 to community members living in thevicinity of the New Gosport area. The fact sheet noted that EPA and VDEQ concurred with theNavy's assessment that exposed blasting grit at Site 1 did not pose an immediate health threatbecause of the types of limited (i.e., incidental and infrequent) exposures expected (NNSY 1999).

In January 2000, the Navy erected a 6-foot chain-link fence around Site 1 as part of SI activities.These activities included delineating the extent of ABM visually, analyzing five ABM samples,drilling approximately 175 borings, and analyzing soil and sediment samples. Delineation of theABM suggested that there was approximately 9,100 cubic yards of ABM present, surrounded by20,300 cubic yards of miscellaneous fill material, primarily construction-related fill (CH2MHILL 2000b). During the SI, the Navy determined that ABM disposal activities were not limitedto a linear band parallel to Paradise Creek, as had been suggested by historical records. A smalleramount of ABM disposal was also discovered near a drainage channel south of Paradise Creek,within several hundred feet north of the current youth center. After this investigation, Site 1 wasunderstood to encompass this smaller disposal area, later termed Area A, and the primarydisposal area (later termed Area C). Because part of the primary disposal area was on privateproperty, this subset of Area C was termed Area B. Areas A, B, and C, which together coverapproximately 5.5 acres, are depicted in Figure 12 (CH2M HILL 2000a). A short description ofeach area follows.

Area A. Area A is a discrete area south of the former Wainwright Drive and north of thecurrent youth center (at the end of Alabama Avenue). In this 130-by-150-foot area, ABMwas found up to 6 feet deep along a former drainage channel to Paradise Creek; in the restof Area A, ABM was generally less than 1 foot deep (CH2M HILL 2000a).

Area B. Area B is the easternmost area affected by ABM disposal. Although actually asubset of Area C, Area B was characterized separately because it is on private property.Area B is an 100-by-75-foot area off the cul-de-sac at the end of Stack Street where ABMextends onto the backyard of one private residence. In this area, the maximum depth ofABM encountered was 9 feet. The private residence affected is on Treakle Terrace. StackStreet, which is on Navy property, runs behind this and neighboring properties on TreakleTerrace and is used to access the rear of these properties (NNSY and LANTDIV 2002).

Area C. Area C is the principal blast grit disposal area, parallel to Paradise Creek. Itbegins less than 50 feet west of Stack Street and extends approximately 1,100 feet to adrainage ditch that flows northward to Paradise Creek. The blasting grit encountered wasapproximately 150 to 200 feet wide and at depths up to 11 feet. Near the southern edge ofthis band, the thickness of ABM was generally less than 1 foot. ABM was encountered asclose as approximately 40 feet north of the former Wainwright Drive. No ABM wasfound along the banks of Paradise Creek itself, but ABM 0.5 to 1 foot deep was foundextending approximately 15 feet into the Paradise Creek wetland.

The results of ABM and soil sampling conducted in January and February 2000, as part of the SI,can be summarized as follows (CH2M HILL 2000a). (See Table 3 for additional detail.)

ABM samples. Five ABM samples were collected from three areas where a highpotential for human exposure might exist: north of the youth center (near the perimeter ofArea A), the Stack Street cul-de-sac (near the eastern edge of Area B), and in Area Cadjacent to the Paradise Creek wetlands, west of the Stack Street cul-de-sac, near a crudetree fort that the Navy thought might suggest a potential play area for children. Sampleswere biased for the presence of paint chips so that they might indicate the highestpotential (i.e., "worst-case") concentrations of lead. The detected concentrations of leadranged from 176 to 1,260 ppm. Four of the five samples contained concentrations of leadexceeding the 400 ppm action level.

Soil samples collected below ABM and outside the perimeter of Site 1. In most spots,blasting grit mixed in with soil beneath or outside of Site 1 was not visible. Sevensubsurface samples collected immediately beneath ABM contained concentrations of leadranging from 0.7 to 350 ppm; most of these samples contained less than 100 ppm of lead.Similarly, 12 surface soil samples collected outside the perimeter of Site 1 containedconcentrations of lead ranging from 5 to 315 ppm; 11 of them contained less than100 ppm. Another six subsurface soil samples collected outside the perimeter of Site 1contained concentrations of lead below 10 ppm. Subsurface samples collected as part ofthe Site 1 removal action are discussed below.

Wetland soil samples collected adjacent to Paradise Creek. Thirteen samples werecollected from the marshy banks of Paradise Creek. The maximum detected concentrationwas 408 ppm. In general, the samples collected furthest downstream contained thehighest levels of lead; however, the Navy notes that this trend might be due, at least inpart, to the difference in the composition of different soil samples. See Figure 6 andAppendix C for the location and information on soils present near the New Gosport area.See Figure 8 and Appendix D for locations of wetlands, wetland soils and information onwetland codes in place (mapped) before the restoration activities.

Background soil samples collected within the New Gosport area, outside of Site 1.Eight surface soil samples and co-located subsurface soil samples were collected south ofSite 1, in the former Navy housing area, to provide baseline information about soilquality. Lead concentrations in the surface soil samples ranged from 19 to 76 ppm; leadlevels in the subsurface soil samples were all below 5 ppm (CH2M HILL 2000a).

Because lead levels in soil samples collected both beneath the ABM and outside of Areas A, B,and C were consistently below the 400 ppm action level and often substantially lower, the Navydetermined that remediation goals could be met by covering or removing all of the ABM (CH2MHILL 2000c; NNSY 2000).

In October 2000, with EPA and VDEQ concurrence, the Navy began a removal action duringwhich it planned to remove ABM from Areas A and B, as a first step in remediating Site 1.Before the removal action began, the Navy distributed new fact sheets to community membersupdating them on Navy clean-up plans (NNSY 2000). During the course of removal activities,the Navy determined a cost-effective way to remove all of the ABM in Areas A, B, and C. Thus,plans were amended to remove all of the ABM, rather than some of it; community members wereupdated on the revised plans by means of an additional fact sheet, distributed in March 2001(NNSY 2001c). By June 2001, the Navy completed its removal of ABM, contaminated soil, andassociated debris (approximately 55,000 tons of material) at Site 1. The excavated area was filledwith clean soil, grass seed, and marsh plants to create a 1.9-acre wetland (Harper 2001b; NFESC2001; OHM 2001). In the area where ABM was present on private property, the Navy removedthe ABM and restored the property to its original condition (NFESC 2001). Most of the fencingsurrounding Site 1 was removed after the removal action was completed.

As part of the removal action, approximately 140 samples collected from Areas A, B, and C wereanalyzed for lead after initial excavation had been completed. The purpose of collecting andanalyzing these samples was to determine to what extent lead contamination remained in soil. Inany locations where concentrations of lead exceeded 400 ppm, additional excavation wasconducted, and then additional samples were collected to ensure that remaining soil did notcontain concentrations of lead exceeding 400 ppm. After initial excavation of Areas A, B, and Chad been completed, lead concentrations exceeded 400 ppm in nine of 139 samples. Amongthese samples, the maximum detected concentration of lead was 2,940 ppm. After additionalexcavation was performed in the nine affected areas, resampling indicated that they all containedconcentrations of lead below 400 ppm (OHM 2001, 2002; NNSY and LANTDIV 2002). Formore information about these samples, see Table 3.

Chronology of Events Affecting Potential Exposure

ATSDR evaluated available information about the potential for exposure to lead from lead-basedpaint and ABM to occur (and have occurred) in the past, present, and future. Such an assessmentis mostly limited to the information provided in historical records. ATSDR also visited the NewGosport area during site visits in July 1999 and February 2002. During the 1999 site visit,ATSDR noted small pieces of grit that appeared to be ABM, as well as remnants of materialsfrom the demolished housing units (such as shingles and asphalt), throughout the New Gosportarea. Some bare spots of soil were seen, but most of the New Gosport area was covered withgrass, bushes, and some trees. Signs were posted that read, "U.S. Government Property. NoTrespassing. Residents and Guests Only. No Soliciting." Nonetheless, ATSDR observedevidence of community use of open areas within the New Gosport area and inside Site 1,including dirt roads, well-worn paths, and trash (such as lawn chairs, shoes and socks, and drinkcans and bottles). At that time, no perimeter fence existed around Site 1 (ATSDR 2000a).Concerned about the potential for people to come into contact with ABM and lead-contaminatedsoil, ATSDR suggested that the Navy evaluate the effectiveness of the existing signs and fencing.A fence was constructed in 2000 on the southern side of Site 1. One of ATSDR's additionalrecommendations was that measures be taken to increase public awareness of the importance ofobserving the posted access restrictions (ATSDR 2000a). During the 2002 site visit, ATSDRobserved the status of the New Gosport area after the Site 1 remedial action. Although fencingwas present between the New Gosport area and the residential area near the child care and youthcenters, other fencing that had been put up during the SI had been removed. ATSDR observedthat there were sporadic areas in which very small amounts of black surface grit were present inparts of the New Gosport area closest to Site 1. Visual examination of the very small bits of gritdid not reveal whether any of it was ABM.

ATSDR reviewed the chronology of events affecting the potential for exposure to lead in andnear the New Gosport area, including the following:

  • the construction of the NGH complex in 1942,
  • the construction of nearby non-Navy housing units by the 1970s,
  • the disposal of ABM in the New Gosport area and adjacent private property in1969 and 1970,
  • the construction of fencing around Site 1 in 2000,
  • the Site 1 remedial action on Navy property and at an adjacent private residence in2000 and 2001, and
  • the removal of some of the fencing in the New Gosport area after Site 1 remedialactions were completed in 2001.

Table 4 summarizes the potential for exposure to lead in and near the New Gosport area overtime. This table addresses only exposures associated with lead-based paint in housing units andABM. Potential exposure to lead from other sources is discussed elsewhere in this document.

Discussion

How does lead affect human health?: Exposure to lead can affect most organs and systems in the human body, particularly the central nervous system. Exposure to children is of particular concern because children's brains and nervous systems are sensitive to the damaging effects of lead, and their growing bodies absorb more lead. Children who have high lead levels in their bodies might suffer from behavioral problems, learning disabilities, and delayed growth, among other effects. Sources: ATSDR 1992, 1999In this section, ATSDR evaluates whether exposures to lead might affect or have affected thehealth of people living at or near the New Gosport area. This evaluation considers a number offactors, including who might beexposed, how often and for how longany exposure might occur, and thecontaminant concentrations to whichpeople might be exposed.

Concerns About Potential Exposure

Although lead can cause adverseeffects in persons of all ages, ATSDRis concerned about the potential forchildren (6 years of age and younger)to come into contact with leadbecause they are especially vulnerable to its effects (see text box). Lead in soil and dust fromlead-based paint are often the primary sources of potential exposure to lead for children. Whenplaying outdoors in areas where lead contamination exists, children can come into contact withlead through handling soil or grit. Children, particularly those of preschool age, sometimesinadvertently ingest soil through hand-to-mouth activity. Lead can be absorbed through ingestionmore readily than through inhalation or dermal contact (ATSDR 1992, 1999).

Important factors that can affect the extent to which exposure to any soil contamination mightoccur include the following:

Whether the contamination is covered or exposed. Children would be expected tocome into contact with more soil in areas with bare ground or exposed grit than in areasthat are covered with grass or other vegetation, or in paved areas.

The age and behavior patterns of children. As a group, children who are 2 to 3 years ofage are more likely to put their hands and toys in their mouths. However, the behavior ofindividual children varies. The symptoms of exposure to lead are not always clear. With asimple blood test, physicians can find out how much lead is circulating in a person'sbloodstream. Correlations between blood lead levels and health effects have been studiedextensively to evaluate the potential for lead exposure to cause adverse health effects. TheCenters for Disease Control and Prevention (CDC) recommends follow up and/ortreatment for children with blood lead levels greater than or equal to 10micrograms/deciliter (µg/dL).

Potential for Current Exposure to Lead in Soil

The measures taken by the Navy to investigate and remediate Site 1 (including the area whereABM was present on private property) and as part of the demolition of the NGH complex havereduced the likelihood for current or future exposure to lead in soil. During site visits in 1999 and2002, ATSDR observed tiny amounts of grit in portions of the New Gosport area, which is nowpartially covered with grass. Some grit might be ABM, which could have been blown by thewind or carried by surface water runoff outside of the area defined as Site 1, and some might beremnants of shingles or asphalt from former roads or houses.

The Navy has been required to remediate lead levels in soil to below 400 ppm, and remediationhas been conducted with EPA and VDEQ oversight and concurrence to ensure the protection ofhuman health and the environment (OHM 2001, 2002). All 20 samples collected by the Navyoutside of Site 1 in 2000 (collected outside the perimeter of Site 1 and in the former housing areato reflect "background" concentrations) contained levels of lead below 400 ppm; in fact, 19 ofthe 20 samples contained levels of lead below 100 ppm. Thus, although the level of lead thatmight be present now or in the future in any given patch of surface soil in the New Gosport areacannot be known, the available soil sampling data suggest that levels in most places are probablylower than 400 ppm.

On the basis of the investigative and remedial activities conducted and the presence of vegetationcovering most of the soil, current exposures to any lead contamination remaining in soil in theNew Gosport area would likely occur only infrequently and incidentally. Exposures to relativelylow concentrations of lead (below 400 ppm) in soil-assuming there are not other concurrentsources of exposure to lead-are not expected to elevate blood lead levels in the body above CDChealth guidelines or cause adverse health effects.

Potential for Past Exposure to Lead in Soil Related to ABM Disposal at Site 1

In evaluating whether ABM disposal at Site 1 might have resulted in potential past exposure tolead, ATSDR reviewed information about two important considerations:

Exposure point concentrations. In reviewing analytical data reflecting concentrations oflead in soil and ABM samples, ATSDR considered which samples reflect theconcentrations of lead in soil at locations of likely exposure. In general, children would bemore likely to come into contact with surface material than subsurface material.

The nature of access restrictions. Access restrictions that might reduce the potential forexposure to contaminated soil include signs, fencing, and natural physical barriers.Children are not expected to necessarily be aware of or obey posted signs, but effectivefencing (or other natural or man-made barriers) can prevent them from entering areaswhere contamination is present.

ABM disposal in the New Gosport area began in 1969. ABM samples have containedconcentrations of lead ranging from 176 to 1,730 ppm to 2,940 ppm (collected below the surfaceof Site 1). In available surface soil samples collected from outside of Site 1, the maximumdetected concentration of lead was 408 ppm (CH2M HILL 2000a; OHM 2001, 2002; Water andAir Research 1983). Historical records indicate that, at times, there were substantial amounts ofexposed ABM with which people might have come into contact. Effective access restrictions(primarily fencing) to prevent children living or playing in the New Gosport area from cominginto contact with ABM or lead-contaminated soil were not put in place until 2000 (CH2M HILL2000a; Kearney 1987; Water and Air Research 1983).

As discussed previously, it is possible that detected lead levels in soil are not attributable entirelyto ABM disposal activities. Lead contamination in surface soil can be caused by other sources,such as emissions from motor vehicles (because the use of lead additives to gasoline was notphased out until the late 1980s and early 1990s) and deteriorating lead-based paint on buildings(because lead-based paint was used widely until its presence in residential and toy paint wasbanned in 1978) (ATSDR 1999).

It is difficult to reconstruct past conditions, particularly information about where children playedand the condition of the areas in which they played. Designated play areas in the New Gosportarea included playgrounds and fields. Soil samples collected in 1995 from play areas andbackground locations at playgrounds in the New Gosport area contained only very low levels oflead (below 65 ppm). At that time, none of the playgrounds contained painted playgroundequipment (Navy Public Works Center 1996b). Although these data provide information aboutthe condition of playgrounds in the New Gosport area in the mid-1990s, they do not provideinformation about historical conditions at playgrounds. Reportedly, a baseball field or fields werenear Site 1 in the past, but the Navy reported in 2000 that ABM disposal did not affect formerball fields (CH2M HILL n.d.b.; Kearney 1987; Navy Public Works Center 1996b; Water and AirResearch 1983). However, ABM disposal occurred behind some of the homes in the NewGosport area and in the wetlands area south of Paradise Creek. Children would be expected toplay in their backyards and are often attracted to open space and creeks. The presence of a treefort (house) in the wetlands area south of Paradise Creek further supports the possibility thatchildren might have played in areas where ABM was present.

Potential for Exposure to Lead From Other Sources

People can be exposed to lead in a variety of media, including ambient air, drinking water, food,soil, paint, and dust. ATSDR reviews some of the potential sources of lead exposure to highlightthe potential for people living in or near the New Gosport area to have been exposed to sourcesof lead other than ABM at Site 1. Although a thorough review of sources of lead exposure isoutside the scope of this document, readers interested in more information can consult ATSDR'sToxicological Profile for Lead (ATSDR 1999), among other publications.

Lead-Based Paint

Public health screening for lead in children indicates that lead paint in older homes (those builtbefore 1978) is the most important risk factor for lead exposure in children. Children can beexposed to lead-based paint by chewing or mouthing painted surfaces or by accidentallyingesting paint chips, lead dust, or lead-contaminated soil through hand-to-mouth activity. Lead-based paint is considered a potential hazard if it is damaged (i.e., chipping, cracking, chalking, orpeeling) or if it is on a surface subject to impact or friction (such as stairs, doors, and windows)(ATSDR 1999; EPA 2001b).

Lead-based paint was used on the interior and exterior of houses in the NGH complex, like manyhousing complexes built before 1978 (Navy Public Works Center 1996a). Therefore, residentscould have been exposed to lead from lead-based paint. However, the extent of individualexposures is unknown. In the mid-1990s, the Navy prepared a lead management plan for theNGH complex to evaluate the potential presence of lead-based paint and recommend methods tominimize any potential hazards. As part of its this assessment, the Navy analyzed the leadcontent in samples of paint, dust, and soil from selected housing units in 1994. The paint at 52 ofthe 247 housing units in the NGH complex was inspected and analyzed. Almost 70% of the paintsamples contained lead. In most of the locations inspected, the paint was in good condition.However, 20% of the locations sampled contained paint that appeared damaged (Navy PublicWorks Center 1996a). Because floors and windowsills are among the surfaces that are mostlikely to be accessible to young children, the Navy also analyzed samples of lead in dust on thosesurfaces from 12 of the housing units. In all of the dust samples, lead levels were consistentlybelow the applicable EPA standards (Navy Public Works Center 1996a).

As previously noted, the Navy also collected soil samples outside of 12 residences in 1994 (thesame 12 residences from which dust samples were collected). Only 5 soil samples out of the 38collected contained lead concentrations exceeding 400 ppm. The maximum concentrationdetected was 795 ppm (Navy Public Works Center 1996a). However, none of the samples wereidentified as having come from residential yards, which may have been a frequent play area forchildren. (As noted previously, children living in or visiting the New Gosport area in the pastmight have regularly used other areas for play. Available information about any such play areas isextremely limited.)

The levels of lead in soil detected in the samples collected as part of the preparation of the leadmanagement plans for the NGH complex are not unusually high. EPA has reported that soiladjacent to houses with exterior lead-based paint can contain lead concentrations greater than10,000 ppm (ATSDR 1999). The Navy reports that sample locations within the housing areawere selected conservatively (i.e., from areas where soil contamination might be highest, such asthose bare of vegetation or beneath roof drip lines) (NNSY and LANTDIV 2002).

Other Sources of Lead

Data on lead concentrations in other media are incomplete. Aside from lead-based paint, the mostlikely other sources of lead exposure to residents living at or near the New Gosport area includelead emitted to the air and deposited on soil, as well as lead in drinking water.

Lead emitted to the air and deposited on soil. Lead released to the air can travel longdistances before it settles to the ground, where it usually sticks to soil particles. Theburning of leaded gasoline was responsible for most of the lead emissions to theatmosphere before the use of lead as an additive to motor vehicle fuel was phased out inthe late 1980s and early 1990s. Lead was added to fuel to increase its octane rating (i.e.,to make it more resistant to knocking in high-compression engines). EPA reports that soilbeside well-traveled roadways can contain lead levels between 30 and 2,000 ppm higherthan naturally occurring levels, but these levels drop as distance from roadways increases.Emissions from point sources, such as smelters and industrial operations dealing withlead-containing products, also can be important sources of lead releases to the air.Although emissions from point sources are currently regulated, they were not regulated orclosely monitored before the 1970s (ATSDR 1999).

Lead in drinking water. Most of the Portsmouth area, including NNSY, receives publicwater from the city of Portsmouth. Lead was used in solder and pipes in the past and canleach into water from corroding plumbing. Although the federal government banned theuse of new leaded pipes and solder in public water systems in 1986, it did not requirereplacement of all existing pipes and solder containing lead. Instead, public water systemshave been required to evaluate the presence of lead in drinking water both at points ofdistribution (e.g., treatment plants) and points of exposure (e.g., faucets in selectedhomes) to make sure that lead levels meet Safe Drinking Water Act requirements. Theseanalyses also allow public water systems to select appropriate measures to reduce thepotential for exposure to lead (such as reducing the likelihood for water passing throughthe distribution system to be corrosive, a measure taken by the city of Portsmouth) (T.Dongarra, City of Portsmouth Department of Public Utilities, personal communication,2002; EPA 2002a; city of Portsmouth n.d.). The potential presence of lead in drinkingwater at NNSY is discussed further in the Community Health Concerns section of thisdocument. Data provided by the Navy indicate that sampling of tap water from selectedlocations at NNSY began in December 1992. However, no samples were collected in theNew Gosport area, most likely because demolition of the NGH complex was alreadyunderway (NNSY n.d.).

Evaluating Potential Health Effects of Exposure

Since the 1980s, CDC and the American Academy of Pediatrics have recommended thatphysicians evaluate potential lead exposure to children (aged 9 months to 6 years) and performblood lead screening when appropriate (AAP 1998; ATSDR 1999). Data from earlier decades areoften sparse, if they exist at all. Results from blood lead screening conducted over the pastapproximately 25 years have the potential to provide information about whether children havebeen exposed to lead. However, no blood lead data are available for children who lived in or nearthe New Gosport area. The following section discusses the importance of this data gap anddescribes current blood lead screening programs. It is followed by information on how potentialincreases in blood lead levels can be estimated from soil lead concentrations and a discussion ofthe uncertainties associated with these estimates.

Blood Lead Screening Data

Two applicable blood lead screening programs serve families who live in or near the NewGosport area:

The Navy's Pediatric Lead Poisoning Prevention (PLPP) program. Sinceapproximately 1992, the Navy has operated a PLPP program that calls for physicians toadminister annual questionnaires to guardians of children 6 years of age and younger,starting at the check-up conducted at age 1. It also calls for blood lead testing of allchildren at age 1 and of older children categorized as high risk on the basis of the questionnaire responses (NAVOSH n.d.; NNSY-IRP 2002a). The Navy's efforts to screenchildren and promote lead education complement its efforts to evaluate and remediateresidential lead paint hazards (NEHC 2002c). Because the PLPP program began after theNGH complex was vacated, no Navy records of blood lead screening are available tocontribute to an assessment of whether past exposure to lead may have posed a healthhazard. Any Navy personnel who know they lived in the NGH complex and whosechildren had their blood sampled are encouraged to contact the Navy, VDH, or ATSDR.

Blood Lead Levels

The Lead-Safe Virginia program. VDH's childhood lead poisoning prevention program, called Lead-Safe Virginia, includes health departments in both Portsmouth and Norfolk. Currently, the program recommends that physicians evaluate the risk for exposure to lead in all children. A blood lead screening test is recommended for all at-risk children at 1 year of age, again at 2 years of age, and for children 3 to 6 years of age who have not previously been evaluated. At risk children include those living with an adult whose job or hobby involves exposure to lead; children living in a home built before 1978 that is undergoing renovation or has deteriorating paint; and children whose parent or physician believes they may have been exposed to lead. VDH also recommends that the blood lead levels of all children living in "high-risk" ZIP codes–defined as those where 27% or more of the housing was built before 1950 or where 12% or more of tested children have elevated blood lead levels–be tested (VDH 2002; Virginia Register of Regulations 2002). Additional information on the Lead-Safe Virginia program can be found on the Internet at www.vahealth.org/leadsafe/index.htm . At this Web site, there is a link to the current list of "high-risk" ZIP codes. Please see Figure 13 for a map of the ZIP codes near NNSY. Blood lead samples from the Cradock neighborhood (southwest of the New Gosport area) show elevated blood lead levels for a higher than expected number of children, but these data could not be sorted in a manner that reveals which of the children in this neighborhood lived closest to the New Gosport area (VCU 1996). The Lead-Safe Virginia program has the potential to serve area families who use non-Navy doctors. However, it does not call for universal screening and therefore would not necessarily reach all of the potentially affected families.

The absence of blood lead screening data for the exposed population is an important data gap inany analysis of potential exposure to lead. Blood lead data would provide more informationabout the potential for occurrence of adverse health effects as a result of exposure to lead in andaround the New Gosport area. Without these data, we can only estimate potential exposures.

Evaluating PotentialIncreases in Blood LeadLevels From Soil LeadConcentrations

Bioavailability means the amount of a compound that can be (or has been) absorbed from a particular medium (such as soil). It is the degree of ability to be absorbed and ready to interact in a person's or other organism's metabolism.Bioaccumulants: Substances that increase in concentration in living organisms as they take in contaminated air, water, or food because the substances are very slowly metabolized or excreted.Bioconcentration: The accumulation of a chemical in tissues of a fish or other organism to levels greater than in the surrounding medium.Biological Magnification: Refers to the process whereby certain substances such as pesticides or heavy metals move up the food chain, work their way into rivers or lakes, and are eaten by aquatic organisms such as fish, which in turn are eaten by large birds, animals or humans. The substances become concentrated in tissues or internal organs as they move up the chain.Source: EPA Terms of the Environment http://www.epa.gov/OCEPAterms/bterms.htmlATSDR reviewed available toxicologic literature on the relationship between exposure to lead in soil and potential health effects. Research indicates that it is difficult to predict the amount that regular exposure to a known concentration of lead in soil might cause blood lead levels to rise based on the detected concentration alone. Variability exists not only in the hand-to-mouth behavior of individual children, but also in how their bodies react to the lead. A comprehensive review of factors that affect the amount of lead that persons uptake (or absorb) is outside the scope of this document. These issues are discussed in greater detail in other publications, including ATSDR's Toxicological Profile for Lead (ATSDR 1999).

However, the list of some of the factors that affect the fate and transport of lead and itsbioavailability includes the following:

Nutritional status. Studies have shown that deficiencies of calcium can enhance lead absorptionin children. Researchers have noted that zinc has a protective effect against lead toxicity in someanimal species. Nutritional deficiencies in several other essential nutrients (e.g., iron, copper, andphosphorous) have also been shown to impact the effects of lead in animal studies.

Form of lead. Lead can form compounds with other elements. Some of these compounds aremore soluble than others. The chemical form of lead that people ingest affects the rate at which itis absorbed by the body.

Particle size. Smaller particles of lead are absorbed at higher rates in the gastrointestinal tract than are larger particles of lead. Researchers have noted that smaller particles adhere more readily to hands. In addition, several studies have shown that the lead content of soil and dust increases as particle size decreases (ATSDR 1992, 1999). Although factors such as these affect the absorption of lead, several comprehensive literature reviews indicate that blood lead levels might rise 3 to 7 µg/dL for every 1,000 ppm increase in soil lead concentrations (ATSDR 1999). Using this information, ATSDR estimated the hypothetical amount that blood lead levels might increase if anyone had regular contact with, via incidental ingestion, some of the concentrations of lead that have been detected in the New Gosport area. Our estimates suggest that regular contact with or incidental ingestion of lead at the maximum concentration detected in abrasive blasting material (ABM), 1,730 ppm, would correspond to an increase of 5 to 12 µg/dL in blood lead levels. This estimate was calculated as a conservative measure, to reveal the effects that might result from regular exposure to the highest detected concentration of lead. By comparison, regular exposure via incidental ingestion to the average concentration of lead detected at Site 1 prior to its remediation, approximately 740 parts per million, is estimated to correspond to an increase of 2 to 5 µg/dL in blood lead levels.

Table 5 provides perspective on the rise in blood lead levels predicted by regular exposure todifferent concentrations of lead measured in soil samples from New Gosport area.

Uncertainties Associated With This Assessment

In making these conservative estimates, ATSDR used available information about theconcentrations of lead present and the condition of contaminated areas. These estimates areintended to provide perspective about exposures that might have occurred. They are not intendedto suggest that exposure to lead in soil in the New Gosport area actually caused particularincreases in blood lead levels. Relating levels of lead found in environmental samples to bloodlead levels is complex, and scientists are still studying approaches for doing so. As we havesuggested, uncertainties that are difficult to account for in any estimates include the following:

  • Exposure frequency and duration. As noted previously, we do not know the frequencywith which any children actually came into contact with lead in soil. We also do not knowhow long any children were exposed to lead in soil.

  • Exposure point concentrations. The concentrations we used in our estimates do notrepresent the only levels of lead to which children might have been exposed. Childrenmight have been exposed to higher or lower concentrations of lead in soil.

  • Information about the exposed population. ATSDR does not have information aboutwhether any children lived in the houses closest to the ABM disposal area. Informationon the ages of any such children, their behavior patterns, and their nutritional status isalso missing.

  • Information on lead fate and transport and bioavailability. Without a study of thechemical and physical properties of the lead in soil in the New Gosport area, anyestimates of increases in blood lead levels can only be approximated.

  • Concurrent exposures. Perhaps the most important factor that our estimates cannotaccount for is the possibility of concurrent exposure to lead in other media. People livingat or near the New Gosport area could have been exposed to lead in media other than soil.Lead-based paint is considered the most important source of potential exposure to lead toanyone living in or regularly visiting a home built before 1978. The presence of lead-based paint at residences, day care centers, and playgrounds at NNSY was evaluated inthe mid-1990s. However, existing data provide only very limited information about theextent to which individuals might have been exposed to lead-based paint and lead fromother sources and are not factored into these estimates.

Conclusions

ATSDR concludes that available data indicate that people, particularly children, living in or nearthe New Gosport area were potentially exposed to lead. Further information about the timeperiods of potential exposure to ABM (1969 to 2000) and to lead-based paint in housing bothwithin the New Gosport area and in nearby neighborhoods is provided in Table 4. However,critical data that would allow ATSDR to assess the extent to which exposure occurred are notcurrently available, including blood lead data for affected children, information on concurrentexposures to lead, and information on the fate, transport, and bioavailability of lead in soil.

Although ATSDR believes that exposure to lead in soil in and near the New Gosport area doesnot pose a current or future health concern, in and of itself, concurrent exposures to other sourcesof lead are possible. Cumulative exposures to lead have the potential to cause adverse healtheffects. Other possible sources of lead in the area include lead-based paint from homes builtbefore 1978 and soils contaminated with emissions deposited from point and nonpoint sourcessuch as automobile exhaust, smelters, and industrial operations dealing with lead-containing products.


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