PUBLIC HEALTH ASSESSMENT
NORFOLK NAVAL SHIPYARD
PORTSMOUTH, VIRGINIA
Norfolk Naval Shipyard (NNSY), in Portsmouth, Virginia, is one of the largest ship repair facilities in the world. It is on approximately 800 acres, with 4 miles of waterfront along the Southern Branch of the Elizabeth River. Approximately 8 miles north of NNSY is Hampton Roads, the tidal basin at the confluence of the Elizabeth and James Rivers, a major area for commercial and naval ship traffic. Parts of NNSY are along Paradise Creek, which flows approximately 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. Two of the annexes are still used for activities associated with NNSY, but operate under a separate Navy command. They are called Scott Center Annex, located along Paradise Creek, and Southgate Annex, located along the Southern Branch of the Elizabeth River. The third former annex (St. Helena Annex) is now owned by a shipbuilding company, and the fourth (St. Juliens Creek Annex) was transferred to Naval Station Norfolk and is being evaluated by ATSDR separately. Activities associated with NNSY also extend to two noncontiguous areas-the New Gosport 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 Elizabeth River.
In 1983, efforts began to identify contamination resulting from the handling and disposal of
products used in areas currently or formerly part of NNSY. Many locations that historically
received waste products are south of the main Shipyard, including five in the Paradise Creek
Disposal 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's
Installation Restoration Program (IRP) resulted in the identification of additional potential IRP
sites 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. Many
environmental assessments have been conducted since. Appendix A reviews the areas under
investigation.
The Agency for Toxic Substances and Disease Registry (ATSDR) visited NNSY in 1999 and 2002 to collect information about how people on site and off site might be exposed to environmental contamination, to review environmental sampling data, and to learn about community health concerns. This public health assessment evaluates past, current, and potential future exposures to contaminants originating from NNSY. Table 1 provides a summary of the primary exposure pathways evaluated in this public health assessment. Those pathways involve the surface water and sediment of Paradise Creek, soil in and near Southgate Annex that was until July 2003 contaminated with calcium hydroxide, lead-contaminated soil in and around the New Gosport area, lead at other Navy family housing areas, and emissions from the former shipyard foundry.
Exposure to Contaminated Sediment and Surface Water in Paradise Creek
ATSDR evaluated available samples collected by the Navy from Paradise Creek, which is affected 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 of other chemical contaminants commonly associated with industrial activities, and trace levels of pesticides. Public access to the creek near NNSY is limited by landscape features, such as reeds and mud along its banks. No regular exposures to Paradise Creek surface water and sediment have 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 northern portion 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, ATSDR recommended during site visits that the Navy better inform anyone who might have access to the area about the potential effects of contact with calcium hydroxide. The Navy adopted this recommendation in April 2002 and indicated to ATSDR that there had been no reports of anyone coming into contact with the calcium hydroxide. ATSDR believes that the measures taken by the Navy 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 which children may have had access on Navy property in the New Gosport area and on adjacent private property. ABM and soil samples have contained elevated levels of lead. The affected area was not fenced until 2000. Contamination was remediated in 2001. Detected concentrations of lead were associated with the past disposal of ABM, but other sources can also contribute to lead in soil, including lead-based exterior paint. Navy-owned residences in the New Gosport Housing complex contained lead-based paint and were demolished in the mid-1990s. At least some of the nearby 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 to children.Because of the possibility of past lead exposure from multiple sources and critical data gaps (including uncertainty associated with individual exposures to lead and the absence of blood lead data), a definitive conclusion about past exposure to lead in the New Gosport area cannot be drawn.
Recent investigative and remedial actions in the New Gosport area, completed in 2001, have reduced the potential for exposure to lead in soil. Infrequent and incidental exposure to any lead remaining in soil would not, in and of itself, pose a public health concern, currently or in the future. Because of the possibility of exposure to lead from multiple sources, ATSDR recommends 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 substantially elevated levels of lead in soil in NNSY family housing areas. Quarters A-O, Quarters P-Z (the Horseshoe Area), and Stanley Court were affected. Since that time, the Navy has taken several measures to reduce the potential for exposure to lead in family housing areas. In 1997, the Navy invited all families to a meeting where the lead testing results were presented. Residents were advised 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 following actions at NNSY housing areas: covering exterior surfaces that had lead-based paint, repainting interior surfaces that had damaged paint areas, covering bare soil with mulch, leaving units vacant 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 been or 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 with brochures 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 about lead. As part of our review of potential sources of lead to which the community might be or have been exposed, ATSDR reviewed information about the former Shipyard foundry. Records indicate that foundry emissions may have been at their peak during World War II, but no data quantifying production levels or air emissions were available. Thus, ATSDR cannot make a determination about possible past effects of those emissions on public health. Available data about foundry emissions between the end of World War II and the late 1980s (when the foundry stopped operating), while limited, suggest that emissions from the foundry after 1945 did not reach levels associated with adverse health effects.
A. Site Description and History
Norfolk Naval Shipyard (NNSY or the Shipyard) is devoted to ship repair and overhaul. It is located in Portsmouth, Virginia (see Figure 1, an overview map). Situated on approximately 800 acres, with 4 miles of waterfront along the Southern Branch of the Elizabeth River, it is one of the largest ship repair facilities in the world (NNSY 2001a). NNSY opened on 12 acres in 1767 as 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 in 1779. The federal government started using the Shipyard in 1794. Five years later, the United States 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 Shipyard commander 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 the Shipyard in 1861 and 1862. The Shipyard was burned later in 1862 by departing Confederate forces. It was rebuilt after the Civil War, and construction of the first U.S. battleship began in 1889 (NNSY 2001a; Water and Air Research 1983).
Major expansion occurred at the Shipyard during both World Wars. In 1922, the Navy completed its first aircraft carrier, converted from a collier, at NNSY. One hundred ships were built at the Shipyard through 1953, when ship construction ceased (NNSY 2001a). After World War II, the facility'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 and submarines. This work is performed under the authority of the Naval Nuclear Propulsion Program, 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, and
testing work are also performed at the Shipyard. It also provides logistics support and hosts
approximately 36 tenant commands (GlobalSecurity.org 2001a; NNSY 2001b). Wastes generated
from Shipyard activities include oils, solvents and cleaners, paint, thinners, plating wastes,
blasting residue, scrap metal, batteries, and asbestos (EPA 2000a). Solid waste associated with
activities at the Shipyard, including blasting grit, sludge from the wastewater treatment plant , and
fly ash, have been disposed of in the southern portion of the Shipyard, primarily at sites along
Paradise Creek (EPA 2000a). Five of these sites are in an area known as the Paradise Creek
Disposal Area that is not contiguous with the main portion of the Shipyard. Another site is in the
New Gosport area, which is south of Paradise Creek, north of Greenwood Drive, and east of
Lincoln Memorial Cemetery.
Figure 2 depicts NNSY and vicinity, including former annexes to the Shipyard. Southgate Annex and Scott Center Annex are still used for activities associated with NNSY, but operate under a separate command. Southgate Annex contains warehousing facilities and a radioactive material storage area and houses inactive defueled nuclear-powered ships. Scott Center Annex contains recreational facilities for Navy personnel, bachelor quarters, a Navy Exchange store, and a service station. It also contains a former disposal site known as Scott Center Landfill, which is along Paradise Creek.
Between 1977 and 1995, the St. Juliens Creek Annex was part of NNSY. It previously served as an ordnance and material storage and loading facility and includes offices, storage facilities, and a radar testing range. This annex is currently part of Naval Station Norfolk and is being evaluated by ATSDR separately (ATSDR 2000b; Baker 1994; GlobalSecurity.org 2001a; VDEQ-ORP 2000). Until October 2001, St. Helena Annex was part of the Shipyard. St. Helena Annex is on the eastern side of the Southern Branch of the Elizabeth River, just north of NNSY. On October 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 of contamination at St. Helena Annex. Localized groundwater contamination was identified, but the Navy and EPA determined that groundwater remediation was not necessary. Deed restrictions will prohibit future use of groundwater at the former annex (EPA 1999, 2000a). Because the site is adjacent to the Elizabeth River, St. Helena's Annex could have contributed to Elizabeth River contamination.
NNSY is surrounded by a fence, and no public access is allowed. Security personnel are stationed at the Shipyard gates. Within the gates are waterfront facilities, including dry docks; a fenced controlled industrial area; administration, supply, and public works facilities; and housing and personnel support areas. Approximately 8 miles north of NNSY is Hampton Roads, the tidal basin 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 of
Defense program known as the Installation Restoration Program (IRP). The purpose of the IRP at
NNSY is to assess environmental contamination associated with Shipyard operations. An initial
assessment study published in 1983 identified 19 potentially contaminated sites (Water and Air
Research 1983). Subsequent investigations and evaluations identified a total of approximately
140 additional potential sites of contamination at NNSY and made recommendations about
appropriate follow up actions at these sites. Analysis of data associated with these sites resulted
in the Navy's determination, with the concurrence of regulatory agencies, that the majority of the
potential sites identified did not require further action. See Figure 2 for the approximate locations
of the IRP sites. In 1998, sites requiring further action (both IRP sites and other solid waste
management units [SWMUs]) were grouped into four operable units (OUs) based on their
locations, as shown in Table 2. In January 2000, a Site Screening Assessment that evaluated
potential waste sites at NNSY recommended additional investigations (either document review
or soil sampling) at 17 sites. An additional 50 sites are considered by the Navy to be active
SWMUs and will be reevaluated if they become (or are scheduled to become) inactive (Baker
2000; 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 the
creek (CH2M HILL 2001a).
In March 1998, the U.S. Environmental Protection Agency (EPA) proposed adding NNSY to the National Priorities List (NPL). EPA's primary concern about NNSY was potential impacts to Paradise Creek and the Elizabeth River (EPA 1999). NNSY was formally added to the NPL on July 22, 1999 (EPA 2000a). As of July 2003, the Navy and EPA were negotiating a Federal Facilities Agreement (FFA) governing investigation and remediation activities at NNSY (J. Nielsen, personal communication, July 10, 2003). The proposed FFA lists seven active OUs and/or IRP sites. Appendix A summarizes available information about these sites. The proposed FFA also identifies two site screening areas (SSAs) for further investigation and nine areas of concern (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 previously been identified. For more detailed information on the Navy's plans to address contamination at NNSY, refer to documents available at the Shipyard's public repository at the Portsmouth Public Library (NNSY and LANTDIV 2002).
In July 1999, the Agency for Toxic Substances and Disease Registry (ATSDR) conducted an initial site visit and met with representatives of NNSY, the Atlantic Division of the Naval Facilities Engineering Command, and the Navy Environmental Health Center, as well as representatives of other interested governmental agencies. In May 2000, ATSDR released a health 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 this site, blasting grit and paint chips contaminated with lead had been placed in a 1-acre area and covered 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 contained lead-based paint had also been present in the area until it was demolished, beginning in 1992. To prevent possible exposures to lead, ATSDR recommended that the Navy evaluate the need to fence the area and increase public awareness about the access restrictions. The Navy adopted this recommendation and fenced the site in January 2000. In 2001, removal of the blasting grit and associated contamination at the New Gosport Landfill was completed (ATSDR 2000a, NNSY 2001c).
In February 2002, ATSDR conducted another site visit to gain an understanding of current site
conditions and of the status of remedial actions, as well as to collect site-related documents and
environmental data. As part of gathering information about the Shipyard and any associated
community 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 were
contaminated with calcium hydroxide waste from an NNSY acetylene gas manufacturing plant
that operated from 1942 to 1971. As a result of historical waste disposal practices, soil
contaminated with calcium hydroxide (similar to lime) was on both NNSY property and Atlantic
Wood Industries, Inc. (Atlantic Wood) property. Fencing was present, but it did not surround all
of the contaminated soil. The affected area included the Calcium Hydroxide Lagoon , which
stretches across both properties, and nearby IRP Site 9, a bermed impoundment area entirely on
Navy property where calcium hydroxide contamination had been covered with soil. Site 9 is
adjacent to a parking lot at Southgate Annex used primarily by Navy personnel or contractors. At
the time of the site visit, low concrete barriers separated parking spaces from Site 9. Signs posted
along these barriers noted: "No Trespassing: IR Site."
During the 1999 and 2002 site visits, ATSDR expressed concern about the potential for Atlantic Wood employees or people using the parking lot to come into contact with calcium hydroxide and that the signs posted at the time did not adequately convey the potential effects of any such exposure. Thus, ATSDR recommended that the Navy post new signs to convey this information and distribute fact sheets to persons who work or park in the area. The Navy adopted these recommendations in April 2002 and posted new signs and fact sheets at Southgate Annex and Atlantic Wood. The Navy also provided training to personnel responsible for coordinating the use of the parking area about the potential hazards posed by exposure to calcium hydroxide and the measures that should be taken if contact occurs. In July 2003, clean up of the calcium hydroxide was completed, and wetlands restoration was completed in fall 2003. This issue is discussed further in the Evaluation of Environmental Contamination, Exposure Pathways, and Public Health Implications section of this report.
ATSDR examines demographic data (i.e., population information) to determine the number of people potentially exposed to environmental chemicals and to determine the presence of sensitive populations, such as children (age 6 and younger), women of childbearing age (age 15-44), and the 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 environmental chemicals.
During World War I, the Shipyard employed more than 11,000 workers. At its peak in 1943 during World War II, the Shipyard employed nearly 43,000 workers. In 1999, NNSY had approximately 6,750 employees. Several thousand additional Navy personnel might be aboard ships 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 for only 1 to 3 years (NNSY and NEHC 2003). However, some personnel may reside there for longer periods of time because they are assigned to NNSY for more than 3 years or because they remain in NNSY housing after being transferred to another Navy installation in the Hampton Roads area.
In the northeast corner of the main Shipyard, five residences are currently occupied by officers and their families. These units are part of a housing area called Quarters A-O Housing, which is currently partially vacant. In the past, additional family housing units, designated NNSY Quarters P-Z, were occupied. These units were built on the western side of the main Shipyard off of Lee Street, near where George Washington Street intersects Effingham Street. They were laid out along a roughly U-shaped court and are sometimes referred to as the Horseshoe area. Demolition of 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 its intersection 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 Housing complex was occupied by up to 247 families between approximately 1941 and 1992, when the units were demolished. Bachelor's quarters in Scott Center Annex and at the Callaghan Center within the main Shipyard accommodate approximately 1,200 naval employees. The Navy is evaluating the possibility of re-opening additional quarters within the main Shipyard, at Quarters M-1 (NNSY-IRP 2002a, 2002b).
Two child care centers are on site, one near the entrance of Scott Center Annex and the other in the 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 center serves primarily children ages 5 to 12 and can accommodate up to 85 people. It replaced an earlier youth center, also within the New Gosport area, which had operated for approximately 12 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 other side of the Elizabeth River is the city of Chesapeake, portions of which are also located approximately 1 mile south of NNSY. Directly to the south of NNSY is Paradise Creek, and beyond the creek are homes and businesses, including the Cradock community. Residential and downtown areas of Portsmouth are to the north and west of the Shipyard. Homes are within approximately 400 feet of potential NNSY contamination in Cradock, southwest of a landfill known as Scott Center Landfill (Site 2), and in Effingham Plaza, north of the Shipyard's metal plating shop (Building 195, investigated as Site 17). Northeast of the Shipyard is the city of Norfolk (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 4a and 4b. According to the 2000 census, approximately 26,010 persons live within 1 mile of the Shipyard 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 Center Landfill (Site 2), across Paradise Creek (Baker 1994).
Adjacent to NNSY is the Atlantic Wood NPL site, south of Elm Avenue and east of Victory Boulevard. Between 1926 and the late 1980s, the Atlantic Wood site was used for refining coal tar, treating wood products (primarily with the preservatives creosote and pentachlorophenol), and storing treated wood products. In approximately 1990, the site was converted to an operation that manufactures concrete pilings. As of 2000, 13 employees worked at Atlantic Wood. EPA and Atlantic Wood are planning to evaluate remedial alternatives, including soil and sediment removal and treatment, as well as the use of recovery wells to remove sources of groundwater contamination. Because waste from NNSY is thought to have been transported onto Atlantic Wood property, the Navy is considered as an additional potentially responsible party for contamination at the Atlantic Wood site. In addition, some groundwater contamination from Atlantic 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 of NNSY. From 1928 to 1978, a brass and bronze foundry at the site melted old railroad car bearings and recast them into new bearings. The waste sand generated was left in open areas near the foundry. Elevated levels of metals, particularly lead, have been found nearby. Remediation of the Abex Corporation site began in 1986. Contaminated soil, foundry buildings, and vacant homes 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, is being removed, and all residents of this complex have been relocated. Additional soil and groundwater sampling, as well as an evaluation of whether foundry-related contamination is affecting the Elizabeth River, is underway or planned (EPA 2002c).
Hampton Roads Area
Numerous naval installations are in the area, including Naval Station Norfolk; Naval
Amphibious 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 are
on 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 largest
naval hospital on the east coast. Although these figures fluctuate, from 80,000 to 120,000
military employees and 30,000 to 40,000 civilian employees of the Navy are in the Hampton
Roads 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 and natural resource use to determine what activities might put people at risk for exposure. This information is important because land use affects people's exposures to contamination by controlling the types and frequencies of activities in those areas. ATSDR uses this information as part 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 the fate and transport of environmental contaminants. For additional information about these features, see Figure 5 (a topographical map showing NNSY and vicinity, including IRP sites) and Figure 6 (a map of soil types at NNSY and in the New Gosport area). Natural processes such as the movement of surface water and groundwater also affect the migration of contaminants. See Figure 7 for a map and Appendix C for information on flood plains in the vicinity of NNSY. See Figure 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 approximately 10 feet above mean sea level. Shallow groundwater is encountered less than 1 foot below ground surface 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 shallow groundwater is part of an aquifer known as the water-table aquifer or Columbia Aquifer. Near the Shipyard, the thickness of the aquifer is approximately 20 to 30 feet, and groundwater is recharged primarily by the infiltration of precipitation (Water and Air Research 1983; NNSY and LANTDIV 2002). The groundwater in the shallow aquifer near NNSY is brackish (salty) and consequently is not viewed as a suitable drinking water source. Most shallow groundwater in the water-table aquifer flows to Paradise Creek, the Southern Branch of the Elizabeth River, or to drainage ditches that empty into these waterways. No drinking water intakes draw from surface water 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 a confining layer that helps minimize the amount of transport from the water-table aquifer to the formation beneath it, the Yorktown Formation. The upper part of the formation, encountered from approximately 50 to 150 feet below ground surface, is known as the Yorktown Aquifer and holds groundwater. The confining layer between the water-table aquifer and the Yorktown Aquifer is discontinuous and may be absent in some areas. Two additional aquifers beneath the Yorktown Aquifer hold brackish water. These aquifers are much deeper and not considered likely to 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 Kilby Water Treatment Plant. The water is drawn from a system of four lakes and five deep wells in the city of Suffolk, more than 10 miles from the Shipyard. In compliance with the Safe Drinking Water Act (SDWA), water is treated and regularly sampled before being distributed (City of Portsmouth n.d.). According to Navy reports, the water-table and Yorktown aquifers are not used for drinking water in the vicinity of NNSY, but groundwater from the two aquifers might be used for watering lawns in some areas near the Shipyard. The only identified private and public consumption wells within 4 miles are east of NNSY; they are separated from the Shipyard by the Southern Branch of the Elizabeth River. Some local industries also reportedly use groundwater for cooling and process water (Baker 1994; Water and Air Research 1983). There are no regulations in effect that restrict which aquifer wells may draw from. Since 1984, the Virginia Department 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 Eastern
Branch approximately 1 mile north of the site. Approximately 2 miles further north is the mouth
of the Western Branch of the river, where it empties into the main stem of the river. Elizabeth
River 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 a
great 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 the
Elizabeth River. This wastewater might contain small amounts of metals and other pollutants.
Before the 1970s, no regulatory requirements limited discharges. Contamination from a variety
of sources, ranging from past waste disposal practices, to existing point sources (e.g., permitted
discharges from facilities), to nonpoint sources (i.e., runoff), resulted in EPA's Chesapeake Bay
Program (CBP) designating the Elizabeth River a Region of Concern in 1993 (Alliance for the
Chesapeake Bay n.d.; Chesapeake Bay Program 1999).
A number of agencies, both government and nonprofit, have been working on characterizing and reducing contaminant levels in the river for the past two decades. This work is further described in the Community Health Concerns section of this document. In late 1999, Dr. Daniel Dauer of the Biological Sciences Department of Old Dominion University in Norfolk offered the following assessment: "the Elizabeth River system is still in the worst condition of any other river system on the [Chesapeake] Bay, but it also shows the most improving trends" (Army CBP 2000; ERP 1996; VDEQ-CBP 2002).
Elizabeth River Use
Several cooperative committees studying the Elizabeth River advise against swimming in the river 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 the river than that on which NNSY is situated. However, public access to the river across from NNSY, near the Jordan Bridge, is allowed; during site visits, ATSDR staff saw people using the boat 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 the Elizabeth River. Particularly abundant seasonal fish include bluefish, spot, and Atlantic croaker. American eel and striped bass, particularly juveniles, are also common (NOAA 1999). No fishing advisory is in effect for the river. A variety of shellfish species can also be found in the Southern Branch, 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, this prohibition is based on elevated levels of bacteriologic contamination in these waterways (R. Barker, VDH Division of Shellfish Sanitation, personal communication, 2002). During site visits, ATSDR staff saw that locations near NNSY, including downstream of Site 9 (in Southgate Annex), 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 Southern Branch of the Elizabeth River. The creek begins at Eliot Street, less than ½ mile northeast of the former New Gosport Landfill (Site 1). The Navy calls the part of the creek that flows from this area to the George Washington Highway bridge Upper Paradise Creek and refers to the part of the creek below this bridge as Lower Paradise Creek. Between its headwaters and the Scott Center Landfill (Site 2), approximately 1,000 feet south of the George Washington Highway bridge, the creek is relatively shallow and narrow. In most of this area, it is less than about 2 to 4 feet deep and 100 feet wide. It widens to approximately 200 feet wide where it is crossed by the Victory Boulevard bridge. It is approximately 500 feet wide at its mouth, where it enters into the Southern Branch of the Elizabeth River. The lower part of Paradise Creek is deep enough for small boats to navigate and would be expected to support many of the same seafood species as the Elizabeth River (CH2M HILL 2001a; NNSY and LANTDIV 2002).
North of Lower Paradise Creek, land use is industrial. From northwest to southeast are Scott Center Annex, a parcel owned by the Southeastern Public Service Authority, Peck Iron and Metal, NNSY's Paradise Creek Disposal Area (OU 2), and a parcel owned by Vane Marine Terminal. Just north of this last parcel (once owned by British Petroleum) is a site used by the Portsmouth School Board for its buses and the Atlantic Wood site. No trespassing is allowed on Navy property adjacent to the creek. Any access to the creek from the neighboring industrial parcels would be expected to be limited. South of the creek is private property, including residences. Public access to Paradise Creek is somewhat limited by landscape features, such as reeds and mud along its banks. During site visits, ATSDR observed crab pots in Lower Paradise Creek (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 extent to which boating, fishing, and crabbing in the lower part of the creek occur has not been well documented. Some people might swim or wade in the creek or sunbathe along it. However, the creek 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 to clean up and restore wetlands and vegetation along the shoreline of Paradise Creek by 2007. This effort is considered part of a larger effort to restore the Elizabeth River and its tributaries. The Navy has received praise for creating almost 2 acres of new wetlands along Paradise Creek in the New Gosport area (after a removal action at the former New Gosport Landfill addressing blasting grit, associated paint chips, and other debris). During an April 2002 cleanup, community members removed trash from Paradise Creek in the Cradock neighborhood and Navy volunteers planted trees, shrubs, and bushes in the New Gosport wetlands area (Harper 2001a, 2002).
Before the 1970s, waste generated at NNSY was often dumped onto the ground, into storm drains, or into the Southern Branch of the Elizabeth River (EPA 1999). Water that comes into contact with waste products can gradually "leach" chemicals from the waste; the resulting contaminated water is typically carried to groundwater or surface water. Many of NNSY's landfills and other disposal areas are near Paradise Creek or the Elizabeth River and were not constructed with effective liners or were not lined at all. Therefore, over the years, waste products left in these areas might have leached or migrated (e.g., from contact with rainwater or by tidal flushing) to these water bodies. The types of waste products that might have been released from NNSY over its history are outlined in this document and described in greater detail in 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 Navy has held under the National Pollutant Discharge Elimination System (NPDES), issued by the state of Virginia. In 1979, an industrial waste treatment plant began treating waste related to shop and maintenance operations from the Controlled Industrial Area at NNSY. Sanitary wastewater generated at NNSY is discharged to the Hampton Roads Sanitation District. On-site treatment of dry dock wastewater and bilge water from Shipyard vessels (previously discharged to the Hampton Roads Sanitation District) began in 1994. In February 2001, a study of the NNSY wastewater treatment system, including its condition, capacity, and efficiency, was completed. NNSY recently constructed a new system to collect and treat bilge water and dry dock wastewater. It became operational in August 2003 (CH2M HILL 2001c; NNSY and NEHC 2003).
Most storm water runoff at NNSY is routed to the Elizabeth River, except runoff from the Paradise Creek Disposal Area, Scott Center Annex, and the western side portion of the main Shipyard, which is routed to Paradise Creek. Paradise Creek also receives storm water discharge from the city of Portsmouth, Atlantic Wood, and other sources not associated with NNSY, including industrial, commercial, and urban activities. Discharges to the Elizabeth River watershed 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 for which monitoring requirements or discharge limitations exist. ATSDR has not reviewed NNSY's historical NPDES permits, but expects that regulatory requirements have become more stringent over time. NNSY has more than 75 outfalls (i.e., discharge pipes) that empty into the Elizabeth River. Many of them release untreated storm water from nonindustrial areas. Outfalls for storm water from industrial areas are monitored regularly for selected metals and total petroleum hydrocarbons, as well as a number of general water quality parameters (such as flow, total suspended solids, and pH). Treated wastewater, cooling water, and storm water from selected industrial processes and areas (such as dry docks) is monitored weekly, bimonthly, or quarterly for general water quality parameters and oil and grease. At certain outfalls, VDH requires NNSY to 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 for all 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 to reduce the potential for contaminant releases and to design and implement a storm water pollution 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 be exposed to harmful levels of contaminants in the environment. The conservative exposure evaluation process used by ATSDR is illustrated in Figure 9. ATSDR considers how individuals might come into contact with contaminated media, as well as the duration and frequency of exposure.
If it is possible that exposure has occurred or does occur, ATSDR then considers whether contaminants were or are present at harmful levels. This is accomplished by screening the concentration of each contaminant in an environmental medium (e.g., soil or water) against health-based screening values. These screening values are contaminant concentrations that are not likely to cause adverse effects, even when very conservative exposure scenarios are assumed. Environmental levels that exceed available screening values will not necessarily produce adverse health effects. If a contaminant is found in the environment at levels exceeding applicable screening values, ATSDR examines potential exposure variables and the toxicology of the contaminant. ATSDR emphasizes that regardless of the level of contamination, a public health hazard exists only if people come into contact with, or are otherwise exposed to, harmful levels of contaminants in site media.
This section describes three exposure pathways associated with NNSY: Paradise Creek surface water and sediment, calcium hydroxide in and around Southgate Annex, and lead in soil in and near the New Gosport Area. For each pathway, ATSDR provides an assessment of whether human 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 be associated with surface water or sediment contamination in Paradise Creek. Paradise Creek is tidally influenced and is affected by pollution from a number of point and nonpoint sources of contamination 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 and sediment have been reported. Surface water and sediment samples from the creek have contained metals, low levels of other chemical contaminants commonly associated with industrial activities, and trace levels of pesticides. The detected concentrations of these contaminants would not cause adverse health effects to people from infrequent, short-term, incidental contact with the water or sediment (see Table 1).
Background
As noted previously, several NNSY IRP Sites are along Paradise Creek (see Figure 10). The former New Gosport Landfill (Site 1) is south of Upper Paradise Creek. It was used as a disposal area for blasting grit and associated paint-chip waste created during paint removal activities; this waste is referred to as abrasive blast material (ABM). Scott Center Landfill (Site 2 or OU 1), in Scott Center Annex, is north of Lower Paradise Creek, downstream of the George Washington Highway 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 further downstream. A variety of types of waste products have been associated with this OU, including sanitary 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 for further information about the IRP sites.
The Navy is addressing potential sources of Paradise Creek contamination originating from NNSY. It holds a state permit for surface water discharges and uses best management practices to reduce pollution. In 2000 and 2001, the Navy removed ABM and associated soil and debris from Site 1. The excavated area was filled with soil, grass seed, and marsh plants to create a 1.9-acre wetland along Paradise Creek. The Navy is also studying whether covering the former landfills at OUs 1 and 2 would meet its remediation goals, including reducing the potential for exposure to buried 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 that serves the western part of the main Shipyard and the industrial facilities between it and Lower Paradise Creek discharges to the creek. Some of these facilities are described in the Paradise Creek Use subsection of the Natural Resources section of this document. A variety of chemical contaminants may be associated with activities conducted at these sites. For example, Atlantic Wood is a potential source of wood preservatives, including creosote and pentachlorophenol, metals, polycyclic aromatic hydrocarbons (PAHs), and dioxins (EPA 2000b). Chemicals now used or previously used as gasoline additives or in petroleum-related products (including lead and benzene, among others) might be associated with the former BP site (now Vane Marine Terminal), the parcel used by Portsmouth School Board buses, and other nearby areas in which vehicles are used or serviced.
As described in the Natural Resources section of this document, leachate migration and storm water runoff have undoubtedly caused some chemical contaminants from land owned by NNSY and from other activities conducted near Paradise Creek to enter the water and sediment of the creek. High and low tides greatly affect surface water flow in Paradise Creek. Particularly in Lower Paradise Creek, water and sediment might be carried into the creek from the Elizabeth River. Tidal action causes chemicals released from NNSY to mix with those released from other nearby upstream and downstream sources. This mixing makes it difficult to attribute contaminant concentrations in surface water and sediment to any specific source.
The Navy has sampled surface water and sediment in Upper Paradise Creek and Lower Paradise Creek as part of several investigations conducted between 1986 and 2000. These data are presented in the Navy's ecological risk assessment for Paradise Creek, finalized in December 2001, and earlier investigations conducted as part of the IRP. Surface water samples collected during investigations of the IR sites along Paradise Creek contained relatively low levels of some metals, as well as selected volatile organic compounds (VOCs) and semivolatile organic compounds (SVOCs). One surface water sample also contained trace amounts of pesticides. Most of the sediment samples collected over time have contained metals, which were generally detected at higher concentrations in Lower Paradise Creek than in Upper Paradise Creek. Most of the sediment samples also contained SVOCs, primarily PAHs. Some samples also contained VOCs, 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 the following 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 of creek quality and plans to share the results with the community. One of these efforts is a study by Dr. Daniel Dauer of Old Dominion University of the benthic (bottom-dwelling) community in Paradise Creek (CH2M HILL n.d.a.; Elizabeth River Project n.d.a.). ERP also initiates associated outreach programs, including a "River Stars" program to enlist industry and organizations in pollution 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. The only 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 creek are fenced. Little, if any, access would be expected from the industrial areas north of Lower Paradise Creek. Any public access to the creek would be expected to occur primarily from residential areas. The most likely types of exposures would occur while people walk along the creek, or if they wade, sunbathe, or play at its edge. As noted previously, Paradise Creek is not a very attractive place for swimming. There are reportedly few, if any, sandy spots adjacent to the creek. In most areas, the land adjacent to the creek is marshy or covered with vegetation. Some people may also take small boats into the lower part of the creek. Crabbing is discussed in the Community Health Concerns section of this document.
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 on neighboring Atlantic Wood property. Calcium hydroxide can be corrosive, and it can irritate or burn the eyes, skin, and respiratory system. The Navy and Atlantic Wood worked together to develop an approach to remediate calcium hydroxide contamination, as well as other cross-border contamination resulting from wood-treating operations at Atlantic Wood and sandblasting 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 with calcium hydroxide. We therefore recommended that the Navy and Atlantic Wood ensure that anyone who might have access to the area be advised of the potential health effects of any such contact. In April 2002, the Navy posted new signs in the affected parts of Southgate Annex and Atlantic Wood, distributed fact sheets, and provided associated training to selected naval personnel. 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 the potential hazard that contact with calcium hydroxide might pose, until site clean-up activities were completed in early July 2003. After the calcium hydroxide was removed, the Navy and Atlantic Wood restored the nearby wetland area and planted additional trees. Any past incidental exposures to the detected concentrations of other chemical contaminants (such as PAHs or metals) would not be of sufficient duration to pose a health concern (see Table 1).
Background
As noted previously, the Navy operated an acetylene gas manufacturing plant within Southgate
Annex from 1942 to 1971. The plant was near the annex border with Atlantic Wood and west of
the Southern Branch of the Elizabeth River. One of the waste products from the manufacturing
process was calcium hydroxide (also known as hydrated lime). ATSDR received information about two separate areas affected by
calcium hydroxide contamination: (1)
IRP Site 9, the Calcium Hydroxide
Disposal Area (originally called the
Waste Lime Pit), which is entirely
within Southgate Annex; and (2) the
Calcium Hydroxide Lagoon, part of
which is on naval property and part of
which is on Atlantic Wood property.
Site 9 was a semi-aboveground, bermed impoundment that was used from approximately 1965 to 1971 to hold waste calcium hydroxide. The berm was constructed partially from used ABM, and blasting (of paint off ships) is reported to have taken place nearby. Thus, the used ABM was mixed with metal-contaminated paint chips. For some years and through 2002, Site 9 was covered with more than one foot of soil, according to the Navy (NNSY and LANTDIV 2002). From 1944 to approximately 1965, NNSY discharged waste calcium hydroxide from its acetylene gas plant through a pipe to an inlet on the Southern Branch of the Elizabeth River. The area containing leftover calcium hydroxide sludge was referred to as the Calcium Hydroxide Lagoon. According to the Navy, approximately one-third of the affected area was on NNSY property, and the other two-thirds was on Atlantic Wood property (Baker 1996a, 1996b; NAVSEA 2002).
Historical practices at Atlantic Wood and NNSY have contributed to additional cross-border contamination, primarily with PAHs and metals. The PAHs are believed to be from chemicals used for wood treating at Atlantic Wood. The metals detected near the boundary between the two sites is thought to be partially attributable to transport of blast grit from Navy property by storm water runoff, but contributions coming from the two properties have not been determined (LANTDIV 2001; NNSY and LANTDIV 2002).
Southgate Annex is surrounded by a guarded fence, and the perimeter of Atlantic Wood is partially 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 the fence to corrode). Beyond this fence and on Atlantic Wood property, there was exposed calcium hydroxide in the Calcium Hydroxide Lagoon (Baker 1996b; NAVSEA 2002; NNSY and LANTDIV 2002). At the time of ATSDR's 2002 site visit, part of Southgate Annex near Site 9 was being used as a parking lot for employees of Navy contractors. At that time, concrete barriers separated Site 9 (a soil-covered mound of calcium hydroxide) from nearby parking spaces. Signs on 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 to calcium sulfate (LANTDIV 1994). Thus, if people came into contact with material from these areas, they might not contact pure calcium hydroxide. In 1996, the Navy measured the pH of two calcium hydroxide samples collected from near the surface of the calcium hydroxide waste on Atlantic Wood property. The pH value for both samples was 12.8. In a report associated with this sampling, it was noted that natural degradation would have been expected to cause the other samples to have lower pH values (Baker 1996b).
In early 2002, the Navy conducted an assessment to delineate the full extent of calcium hydroxide contamination at Southgate Annex and Atlantic Wood. Later, an Engineering Evaluation/Cost Analysis was conducted to assess ways to remediate this contamination. In addition, the Navy and Atlantic Wood, with EPA and Virginia Department of Environmental Quality (VDEQ) oversight, jointly studied how best to address and remediate cross-border contamination. As of late 2001, a joint proposal called for removing the calcium hydroxide from the Calcium Hydroxide Lagoon, creating a wetland along the Southern Branch of the Elizabeth River, and capping soils areas affected by PAHs and ABM (LANTDIV 2001; NNSY 2002). A calcium hydroxide removal action at both Site 9 and the Calcium Hydroxide Lagoon was completed 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 around the areas contaminated with calcium hydroxide, posted and distributed fact sheets, and provided training about potential health concerns related to the calcium hydroxide to selected naval personnel. The new signs read, "NO TRESPASSING. Caution: Environmental Investigation Site. Soil Contains Caustic Material. Potential Acute Eye and Skin Irritant. NO TRESPASSING." The Navy also posted new fact sheets on both Navy and Atlantic Wood property and provided additional copies to staff who coordinate the use of the parking area and to representatives of Atlantic Wood. The fact sheets contained background information about Site 9 and the Calcium Hydroxide Lagoon, advised people to avoid contact with the calcium hydroxide, and provided information about the potential health effects of exposure to calcium hydroxide and measures to take if exposure occurs. The fact sheets also provided Navy and Atlantic Wood employees with contacts who can address questions and provide more information. The training, provided to the Supervisor of Ships and Navy personnel who coordinate the use of the parking area, covered information 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 site clean-up was completed, to advise people who work or park near Site 9 of the potential hazard that contact with calcium hydroxide might pose. The Navy indicated to ATSDR that it has not received any reports of people coming into contact with calcium hydroxide or questions about exposure to calcium hydroxide (NEHC 2002b). Other contaminants (particularly metals and PAHs) have been detected in soils at Atlantic Wood and Southgate Annex, but any incidental exposures to these contaminants would be short-term and infrequent. Such short-duration exposure to the detected levels of these contaminants would not pose a health concern. Measures to remediate the calcium hydroxide and chemical contamination designed to prevent any future exposures were implemented. Calcium hydroxide removal and cleanup was completed in July 2003 (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 1969 and 1970. Historical records show that the waste was present in areas that neighborhood children might have had access to, including behind Wainwright Avenue (part of the New Gosport Housing complex, which has since been demolished), north of the New Gosport youth center, in the wetlands area south of Paradise Creek (now known as Area C), and in the backyard of a neighboring private residence. The full extent of the ABM disposal area (called the New Gosport Landfill or Site 1) was not delineated and fenced until 2000. A removal action addressing ABM and associated waste was completed in 2001. After remediation, part of the fencing was removed.
Because of the remedial actions completed by the Navy in the New Gosport area in 2001, the potential 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 of itself, is not expected to cause adverse health effects (see Table 1). Our review of information on past exposures shows that not only could people have been exposed to ABM, but residences in and 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 regularly visit could contribute to children's total lead exposure. Blood lead data would provide information on the extent and effects of lead exposure to children living within and near the New Gosport area, but blood lead data collection began after the years that the housing area was occupied. Because of (1) the possibility of lead exposure from multiple sources; (2) the absence of blood lead data for affected populations; and (3) the uncertainty associated with individual exposures to lead (including site-specific information about the fate and transport of lead and its bioavailability), insufficient information is available to determine whether past exposure to lead in and near the New Gosport area might have caused adverse health effects (see Table 1).
Background
This section describes the history and land
use of the New Gosport area, followed by information about investigations conducted.
History and Land Use
The New Gosport area is a 56-acre Navy parcel separate from the main Shipyard, south of Paradise Creek, north of Greenwood Drive, east of Lincoln Memorial Cemetery, and west of Ansell Avenue. From 1942 until the mid-1990s, much of the New Gosport area was occupied by the 247-unit New Gosport Housing (NGH) complex, which served families of NNSY personnel (LANTDIV 1991; Navy Public Works Center 1996a). Because of the age and condition of the units, the Navy demolished the NGH complex between 1992 and 1995 (CH2M HILL 2000a; NNSY and LANTDIV 2000a). Most of the Navy residences were south and west of Wainwright Drive. This road, along with most other roads and driveways within the housing complex (except Alabama Avenue and Stack Street), was removed as part of the demolition (CH2M HILL 2000a; Navy Public Works Center 1998). Stack Street is along the eastern edge of the New Gosport area, which is surrounded by private homes on three sides. While Navy homes on the western side of Stack Street have been demolished, Stack Street is still used to access the rear of private residences to its east, on Treakle Terrace and Ansell Avenue (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 south of Paradise Creek. The waste (used for fill) was primarily ABM, which refers to both spent blasting grit and commingled paint chips. (See text box for more information about ABM.) The Navy later called this ABM disposal area the New Gosport Landfill, IRP Site 1. No ABM disposal is thought to have taken place at Site 1 after 1970 (CH2M HILL 2000d; Water and Air Research 1983). Between October 2000 and June 2001, the Navy removed ABM and associated soil and debris at the Site 1 ABM disposal area. This removal action is discussed in further detail in the following subsections.
In addition to housing, the New Gosport
area contained other facilities where
community members often gathered.
Examples include a community center and a
self-help center on the western side of the
housing area, near the intersection of
Alabama Avenue and Morningside Drive.
Originally, the community center served
young people, among other groups. After
the NGH complex was demolished, the self-help center was converted to a new youth
center, which opened in 2001. A child care
center was built nearby in 1985 and
continues to serve Navy families (Navy
Public Works Center 1998; NNSY-IRP
2002a, 2002c). Playgrounds and playing
fields were also in the New Gosport area
during the time that NNSY families lived in
the housing area (CH2M HILL n.d.b.).
Currently, children using the youth center sometimes play in adjacent grassy areas (within the
New 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 in soil, 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, mostly metals (and low levels of some pesticides, which are not considered to be associated with ABM disposal activities), have been detected at Site 1 and are listed in Appendix A. ATSDR focused our evaluation on potential exposure to lead in soil because lead was the only contaminant detected at levels that might pose a health risk to persons coming into contact with contaminated soil. This subsection reviews the history of investigations and remediation of lead contamination in the New Gosport area, both at the NGH complex and at Site 1. It also presents information about ATSDR's 1999 site visit to the New Gosport area. Table 3 presents the results of samples analyzed for lead as part of the investigations described below.
Navy Activities at the NGH Complex
In the late 1980s and early 1990s, the Navy assessed the condition of the NGH complex and decided to demolish existing buildings, which had been built in 1942 (Navy Public Works Center 1996a, NNSY and LANTDIV 2002). Demolition and removal of these residences was carried out between 1992 and 1995 (CH2M HILL 2000a). The following paragraphs provide information about samples collected at the NGH complex and discussed in a 1996 lead management plan, as well as activities conducted by the Navy as part of the demolition of the NGH complex.
Lead sampling at the NGH complex. In 1994, as part of its effort to assess lead-based paint across NNSY housing areas, the Navy collected soil, paint, and dust samples from randomly selected residences in the New Gosport area. The purpose of this sampling was to characterize household levels of lead, both indoor and outdoor, and was 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 and are discussed later in this section (in the Discussion section addressing lead-based paint). The soil 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 all Navy-owned housing units in the New Gosport area.) Approximately 85% of the 38 samples collected, including five background samples, contained concentrations of lead below 400 parts per million (ppm). The exceptions were five soil samples from four residences, which contained levels of lead between 400 and 800 ppm (Navy Public Works Center 1996a). For more information about these samples, see Table 3.
Demolition of the NGH complex. Because the Navy had identified the possibility of lead in soil posing 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:
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 following paragraphs 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 disposal area. In a 1983 Initial Assessment Study report, the Navy indicated that there were large areas of exposed ABM behind the northernmost houses on Wainwright Drive and Stack Street, perhaps fewer than 50 or 100 feet behind some of the houses. In areas where ABM was exposed, little or no vegetation was present. ABM was visible within 30 to 60 feet of Paradise Creek and adjacent to drainage ditches discharging to the creek (Water and Air Research 1983). The Navy analyzed two samples of ABM, which contained 560 and 1,730 ppm of lead. Two additional samples were analyzed using the extraction procedure toxicity test, which indicated that metals would not be expected to easily leach from the ABM (Water and Air Research 1983). To reduce the potential for people to come into contact with ABM, the Navy took immediate action to regrade areas where 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 had eroded and that it had proven difficult to maintain a vegetative cover in other areas. Some exposed ABM was visible (particularly near the northwestern boundary of the New Gosport area); 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 of these 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 collecting the 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 Site Investigation (SI) at Site 1 to determine the nature and extent of contamination associated with the disposal of ABM (ATSDR 2000a). In August 1999, the Navy adopted ATSDR's recommendation to distribute a fact sheet about Site 1 to community members living in the vicinity of the New Gosport area. The fact sheet noted that EPA and VDEQ concurred with the Navy's assessment that exposed blasting grit at Site 1 did not pose an immediate health threat because 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 the ABM suggested that there was approximately 9,100 cubic yards of ABM present, surrounded by 20,300 cubic yards of miscellaneous fill material, primarily construction-related fill (CH2M HILL 2000b). During the SI, the Navy determined that ABM disposal activities were not limited to a linear band parallel to Paradise Creek, as had been suggested by historical records. A smaller amount 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 was understood to encompass this smaller disposal area, later termed Area A, and the primary disposal area (later termed Area C). Because part of the primary disposal area was on private property, this subset of Area C was termed Area B. Areas A, B, and C, which together cover approximately 5.5 acres, are depicted in Figure 12 (CH2M HILL 2000a). A short description of each area follows.
Area A. Area A is a discrete area south of the former Wainwright Drive and north of the current youth center (at the end of Alabama Avenue). In this 130-by-150-foot area, ABM was found up to 6 feet deep along a former drainage channel to Paradise Creek; in the rest of 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 a subset 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 ABM extends onto the backyard of one private residence. In this area, the maximum depth of ABM encountered was 9 feet. The private residence affected is on Treakle Terrace. Stack Street, which is on Navy property, runs behind this and neighboring properties on Treakle Terrace 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. It begins less than 50 feet west of Stack Street and extends approximately 1,100 feet to a drainage ditch that flows northward to Paradise Creek. The blasting grit encountered was approximately 150 to 200 feet wide and at depths up to 11 feet. Near the southern edge of this band, the thickness of ABM was generally less than 1 foot. ABM was encountered as close as approximately 40 feet north of the former Wainwright Drive. No ABM was found along the banks of Paradise Creek itself, but ABM 0.5 to 1 foot deep was found extending 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 high potential for human exposure might exist: north of the youth center (near the perimeter of Area A), the Stack Street cul-de-sac (near the eastern edge of Area B), and in Area C adjacent to the Paradise Creek wetlands, west of the Stack Street cul-de-sac, near a crude tree fort that the Navy thought might suggest a potential play area for children. Samples were biased for the presence of paint chips so that they might indicate the highest potential (i.e., "worst-case") concentrations of lead. The detected concentrations of lead ranged from 176 to 1,260 ppm. Four of the five samples contained concentrations of lead exceeding 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. Seven subsurface samples collected immediately beneath ABM contained concentrations of lead ranging 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 contained concentrations of lead ranging from 5 to 315 ppm; 11 of them contained less than 100 ppm. Another six subsurface soil samples collected outside the perimeter of Site 1 contained concentrations of lead below 10 ppm. Subsurface samples collected as part of the Site 1 removal action are discussed below.
Wetland soil samples collected adjacent to Paradise Creek. Thirteen samples were collected from the marshy banks of Paradise Creek. The maximum detected concentration was 408 ppm. In general, the samples collected furthest downstream contained the highest levels of lead; however, the Navy notes that this trend might be due, at least in part, to the difference in the composition of different soil samples. See Figure 6 and Appendix 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 on wetland 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 of Site 1, in the former Navy housing area, to provide baseline information about soil quality. Lead concentrations in the surface soil samples ranged from 19 to 76 ppm; lead levels 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 Navy determined that remediation goals could be met by covering or removing all of the ABM (CH2M HILL 2000c; NNSY 2000).
In October 2000, with EPA and VDEQ concurrence, the Navy began a removal action during which 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 members updating 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 were updated 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, and associated debris (approximately 55,000 tons of material) at Site 1. The excavated area was filled with clean soil, grass seed, and marsh plants to create a 1.9-acre wetland (Harper 2001b; NFESC 2001; OHM 2001). In the area where ABM was present on private property, the Navy removed the ABM and restored the property to its original condition (NFESC 2001). Most of the fencing surrounding 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 were analyzed for lead after initial excavation had been completed. The purpose of collecting and analyzing these samples was to determine to what extent lead contamination remained in soil. In any locations where concentrations of lead exceeded 400 ppm, additional excavation was conducted, and then additional samples were collected to ensure that remaining soil did not contain concentrations of lead exceeding 400 ppm. After initial excavation of Areas A, B, and C had been completed, lead concentrations exceeded 400 ppm in nine of 139 samples. Among these samples, the maximum detected concentration of lead was 2,940 ppm. After additional excavation was performed in the nine affected areas, resampling indicated that they all contained concentrations of lead below 400 ppm (OHM 2001, 2002; NNSY and LANTDIV 2002). For more 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-based paint and ABM to occur (and have occurred) in the past, present, and future. Such an assessment is mostly limited to the information provided in historical records. ATSDR also visited the New Gosport 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 materials from the demolished housing units (such as shingles and asphalt), throughout the New Gosport area. Some bare spots of soil were seen, but most of the New Gosport area was covered with grass, bushes, and some trees. Signs were posted that read, "U.S. Government Property. No Trespassing. Residents and Guests Only. No Soliciting." Nonetheless, ATSDR observed evidence 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 drink cans 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-contaminated soil, 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 additional recommendations was that measures be taken to increase public awareness of the importance of observing the posted access restrictions (ATSDR 2000a). During the 2002 site visit, ATSDR observed the status of the New Gosport area after the Site 1 remedial action. Although fencing was present between the New Gosport area and the residential area near the child care and youth centers, other fencing that had been put up during the SI had been removed. ATSDR observed that there were sporadic areas in which very small amounts of black surface grit were present in parts of the New Gosport area closest to Site 1. Visual examination of the very small bits of grit did not reveal whether any of it was ABM.
ATSDR reviewed the chronology of events affecting the potential for exposure to lead in and near the New Gosport area, including the following:
Table 4 summarizes the potential for exposure to lead in and near the New Gosport area over time. This table addresses only exposures associated with lead-based paint in housing units and ABM. Potential exposure to lead from other sources is discussed elsewhere in this document.
Discussion
In this section, ATSDR evaluates whether exposures to lead might affect or have affected the
health of people living at or near the New Gosport area. This evaluation considers a number of
factors, including who might be
exposed, how often and for how long
any exposure might occur, and the
contaminant concentrations to which
people might be exposed.
Concerns About Potential Exposure
Although lead can cause adverse effects in persons of all ages, ATSDR is concerned about the potential for children (6 years of age and younger) to come into contact with lead because they are especially vulnerable to its effects (see text box). Lead in soil and dust from lead-based paint are often the primary sources of potential exposure to lead for children. When playing outdoors in areas where lead contamination exists, children can come into contact with lead through handling soil or grit. Children, particularly those of preschool age, sometimes inadvertently ingest soil through hand-to-mouth activity. Lead can be absorbed through ingestion more readily than through inhalation or dermal contact (ATSDR 1992, 1999).
Important factors that can affect the extent to which exposure to any soil contamination might occur include the following:
Whether the contamination is covered or exposed. Children would be expected to come into contact with more soil in areas with bare ground or exposed grit than in areas that 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 of age are more likely to put their hands and toys in their mouths. However, the behavior of individual children varies. The symptoms of exposure to lead are not always clear. With a simple blood test, physicians can find out how much lead is circulating in a person's bloodstream. Correlations between blood lead levels and health effects have been studied extensively to evaluate the potential for lead exposure to cause adverse health effects. The Centers for Disease Control and Prevention (CDC) recommends follow up and/or treatment for children with blood lead levels greater than or equal to 10 micrograms/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 where ABM was present on private property) and as part of the demolition of the NGH complex have reduced the likelihood for current or future exposure to lead in soil. During site visits in 1999 and 2002, ATSDR observed tiny amounts of grit in portions of the New Gosport area, which is now partially covered with grass. Some grit might be ABM, which could have been blown by the wind or carried by surface water runoff outside of the area defined as Site 1, and some might be remnants 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 remediation has been conducted with EPA and VDEQ oversight and concurrence to ensure the protection of human health and the environment (OHM 2001, 2002). All 20 samples collected by the Navy outside of Site 1 in 2000 (collected outside the perimeter of Site 1 and in the former housing area to reflect "background" concentrations) contained levels of lead below 400 ppm; in fact, 19 of the 20 samples contained levels of lead below 100 ppm. Thus, although the level of lead that might be present now or in the future in any given patch of surface soil in the New Gosport area cannot be known, the available soil sampling data suggest that levels in most places are probably lower than 400 ppm.
On the basis of the investigative and remedial activities conducted and the presence of vegetation covering most of the soil, current exposures to any lead contamination remaining in soil in the New Gosport area would likely occur only infrequently and incidentally. Exposures to relatively low concentrations of lead (below 400 ppm) in soil-assuming there are not other concurrent sources of exposure to lead-are not expected to elevate blood lead levels in the body above CDC health 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 to lead, ATSDR reviewed information about two important considerations:
Exposure point concentrations. In reviewing analytical data reflecting concentrations of lead in soil and ABM samples, ATSDR considered which samples reflect the concentrations of lead in soil at locations of likely exposure. In general, children would be more likely to come into contact with surface material than subsurface material.
The nature of access restrictions. Access restrictions that might reduce the potential for exposure to contaminated soil include signs, fencing, and natural physical barriers. Children are not expected to necessarily be aware of or obey posted signs, but effective fencing (or other natural or man-made barriers) can prevent them from entering areas where contamination is present.
ABM disposal in the New Gosport area began in 1969. ABM samples have contained concentrations of lead ranging from 176 to 1,730 ppm to 2,940 ppm (collected below the surface of Site 1). In available surface soil samples collected from outside of Site 1, the maximum detected concentration of lead was 408 ppm (CH2M HILL 2000a; OHM 2001, 2002; Water and Air Research 1983). Historical records indicate that, at times, there were substantial amounts of exposed 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 coming into contact with ABM or lead-contaminated soil were not put in place until 2000 (CH2M HILL 2000a; Kearney 1987; Water and Air Research 1983).
As discussed previously, it is possible that detected lead levels in soil are not attributable entirely to 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 not phased 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 was banned in 1978) (ATSDR 1999).
It is difficult to reconstruct past conditions, particularly information about where children played and the condition of the areas in which they played. Designated play areas in the New Gosport area included playgrounds and fields. Soil samples collected in 1995 from play areas and background locations at playgrounds in the New Gosport area contained only very low levels of lead (below 65 ppm). At that time, none of the playgrounds contained painted playground equipment (Navy Public Works Center 1996b). Although these data provide information about the condition of playgrounds in the New Gosport area in the mid-1990s, they do not provide information about historical conditions at playgrounds. Reportedly, a baseball field or fields were near Site 1 in the past, but the Navy reported in 2000 that ABM disposal did not affect former ball fields (CH2M HILL n.d.b.; Kearney 1987; Navy Public Works Center 1996b; Water and Air Research 1983). However, ABM disposal occurred behind some of the homes in the New Gosport area and in the wetlands area south of Paradise Creek. Children would be expected to play in their backyards and are often attracted to open space and creeks. The presence of a tree fort (house) in the wetlands area south of Paradise Creek further supports the possibility that children 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 highlight the potential for people living in or near the New Gosport area to have been exposed to sources of lead other than ABM at Site 1. Although a thorough review of sources of lead exposure is outside the scope of this document, readers interested in more information can consult ATSDR's Toxicological 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 built before 1978) is the most important risk factor for lead exposure in children. Children can be exposed to lead-based paint by chewing or mouthing painted surfaces or by accidentally ingesting 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, or peeling) 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 many housing complexes built before 1978 (Navy Public Works Center 1996a). Therefore, residents could have been exposed to lead from lead-based paint. However, the extent of individual exposures is unknown. In the mid-1990s, the Navy prepared a lead management plan for the NGH complex to evaluate the potential presence of lead-based paint and recommend methods to minimize any potential hazards. As part of its this assessment, the Navy analyzed the lead content in samples of paint, dust, and soil from selected housing units in 1994. The paint at 52 of the 247 housing units in the NGH complex was inspected and analyzed. Almost 70% of the paint samples 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 Public Works Center 1996a). Because floors and windowsills are among the surfaces that are most likely to be accessible to young children, the Navy also analyzed samples of lead in dust on those surfaces from 12 of the housing units. In all of the dust samples, lead levels were consistently below the applicable EPA standards (Navy Public Works Center 1996a).
As previously noted, the Navy also collected soil samples outside of 12 residences in 1994 (the same 12 residences from which dust samples were collected). Only 5 soil samples out of the 38 collected contained lead concentrations exceeding 400 ppm. The maximum concentration detected was 795 ppm (Navy Public Works Center 1996a). However, none of the samples were identified as having come from residential yards, which may have been a frequent play area for children. (As noted previously, children living in or visiting the New Gosport area in the past might have regularly used other areas for play. Available information about any such play areas is extremely limited.)
The levels of lead in soil detected in the samples collected as part of the preparation of the lead management plans for the NGH complex are not unusually high. EPA has reported that soil adjacent to houses with exterior lead-based paint can contain lead concentrations greater than 10,000 ppm (ATSDR 1999). The Navy reports that sample locations within the housing area were selected conservatively (i.e., from areas where soil contamination might be highest, such as those 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 most likely other sources of lead exposure to residents living at or near the New Gosport area include lead 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 long distances before it settles to the ground, where it usually sticks to soil particles. The burning of leaded gasoline was responsible for most of the lead emissions to the atmosphere before the use of lead as an additive to motor vehicle fuel was phased out in the 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 soil beside well-traveled roadways can contain lead levels between 30 and 2,000 ppm higher than naturally occurring levels, but these levels drop as distance from roadways increases. Emissions from point sources, such as smelters and industrial operations dealing with lead-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 or closely monitored before the 1970s (ATSDR 1999).
Lead in drinking water. Most of the Portsmouth area, including NNSY, receives public water from the city of Portsmouth. Lead was used in solder and pipes in the past and can leach into water from corroding plumbing. Although the federal government banned the use of new leaded pipes and solder in public water systems in 1986, it did not require replacement of all existing pipes and solder containing lead. Instead, public water systems have been required to evaluate the presence of lead in drinking water both at points of distribution (e.g., treatment plants) and points of exposure (e.g., faucets in selected homes) to make sure that lead levels meet Safe Drinking Water Act requirements. These analyses also allow public water systems to select appropriate measures to reduce the potential for exposure to lead (such as reducing the likelihood for water passing through the 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 drinking water at NNSY is discussed further in the Community Health Concerns section of this document. Data provided by the Navy indicate that sampling of tap water from selected locations at NNSY began in December 1992. However, no samples were collected in the New Gosport area, most likely because demolition of the NGH complex was already underway (NNSY n.d.).
Evaluating Potential Health Effects of Exposure
Since the 1980s, CDC and the American Academy of Pediatrics have recommended that physicians evaluate potential lead exposure to children (aged 9 months to 6 years) and perform blood lead screening when appropriate (AAP 1998; ATSDR 1999). Data from earlier decades are often sparse, if they exist at all. Results from blood lead screening conducted over the past approximately 25 years have the potential to provide information about whether children have been exposed to lead. However, no blood lead data are available for children who lived in or near the New Gosport area. The following section discusses the importance of this data gap and describes current blood lead screening programs. It is followed by information on how potential increases in blood lead levels can be estimated from soil lead concentrations and a discussion of the uncertainties associated with these estimates.
Blood Lead Screening Data
Two applicable blood lead screening programs serve families who live in or near the New Gosport area:
The Navy's Pediatric Lead Poisoning Prevention (PLPP) program. Since approximately 1992, the Navy has operated a PLPP program that calls for physicians to administer 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 all children 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 screen children and promote lead education complement its efforts to evaluate and remediate residential lead paint hazards (NEHC 2002c). Because the PLPP program began after the NGH complex was vacated, no Navy records of blood lead screening are available to contribute to an assessment of whether past exposure to lead may have posed a health hazard. Any Navy personnel who know they lived in the NGH complex and whose children had their blood sampled are encouraged to contact the Navy, VDH, or ATSDR.
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
The absence of blood lead screening data for the exposed population is an important data gap in any analysis of potential exposure to lead. Blood lead data would provide more information about the potential for occurrence of adverse health effects as a result of exposure to lead in and around the New Gosport area. Without these data, we can only estimate potential exposures.
Evaluating Potential Increases in Blood Lead Levels From Soil Lead Concentrations
ATSDR
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 its bioavailability includes the following:
Nutritional status. Studies have shown that deficiencies of calcium can enhance lead absorption in children. Researchers have noted that zinc has a protective effect against lead toxicity in some animal species. Nutritional deficiencies in several other essential nutrients (e.g., iron, copper, and phosphorous) 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 are more soluble than others. The chemical form of lead that people ingest affects the rate at which it is 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 to different 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 the concentrations of lead present and the condition of contaminated areas. These estimates are intended to provide perspective about exposures that might have occurred. They are not intended to suggest that exposure to lead in soil in the New Gosport area actually caused particular increases in blood lead levels. Relating levels of lead found in environmental samples to blood lead levels is complex, and scientists are still studying approaches for doing so. As we have suggested, uncertainties that are difficult to account for in any estimates include the following:
Conclusions
ATSDR concludes that available data indicate that people, particularly children, living in or near the New Gosport area were potentially exposed to lead. Further information about the time periods of potential exposure to ABM (1969 to 2000) and to lead-based paint in housing both within 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 not currently available, including blood lead data for affected children, information on concurrent exposures 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 does not pose a current or future health concern, in and of itself, concurrent exposures to other sources of lead are possible. Cumulative exposures to lead have the potential to cause adverse health effects. Other possible sources of lead in the area include lead-based paint from homes built before 1978 and soils contaminated with emissions deposited from point and nonpoint sources such as automobile exhaust, smelters, and industrial operations dealing with lead-containing products.
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