PETITIONED PUBLIC HEALTH ASSESSMENT
EGLIN AIR FORCE BASE
(a/k/a EGLIN AIR FORCE BASE ARMAMENT DIVISION
EGLIN AIR FORCE BASE, OKALOOSA COUNTY, FLORIDA
Eglin Air Force Base (AFB) is in the Florida Panhandle between Pensacola and Panama City. Itis the largest forested military reservation in the United States, covering approximately 464,000acres. Most of the Eglin Reservation is undeveloped, with small pockets of developed and semi-developed areas. Since 1935 it has been the Air Force's primary munitions testing and trainingfacility.
Munitions training and testing, other standard defense missions and related activities, and wastehandling practices have contaminated some areas on Eglin. In 1981, the Department of Defenseinitiated the Installation Restoration Program to identify, evaluate, and clean up contaminationfrom past military activities. Throughout the history of the program, the Air Force has completedsite investigations, interim measures, and removal/remedial actions at Eglin AFB, resulting in a"no further action"(1) status for many of these sites.
In February 1998, the Agency for Toxic Substances and Disease Registry (ATSDR) waspetitioned to assess Eglin AFB for potential public health hazards. On April 6-8, 1998, and againon August 20-23, 2001, ATSDR visited Eglin AFB to evaluate the petitioner's concerns as wellas other concerns identified during the public health evaluation process.
From talking with the petitioner and other community members, ATSDR identified five mainissues of concern that are addressed in this public health assessment. To determine whetherpeople are being exposed to levels of contamination that might cause health problems, ATSDRconsiders how people might come into contact with a chemical, what levels people mightencounter, and for how long. If the environmental data show that people have or could come intocontact with harmful chemicals at the site, ATSDR reviews the existing scientific information todetermine if exposures are expected to result in harmful health effects. Based on a thoroughreview of the available information, data, modeling analyses, and calculated assumptions,ATSDR reached the following conclusions:
- Transport of contaminants via air to off-base areas: Would there be adverse healtheffects to off-base residents from harmful substances being transported through the airduring herbicide spraying, open burning/open detonation (OB/OD) activities, wildfires,prescribed burns, and a past structural fire?
ATSDR reviewed information characterizing the magnitude and duration of relevant chemicalreleases from Eglin AFB, including those from herbicide spraying, OB/OD activities, prescribedburns, wildfires, and a past structural fire (C-6 Radar Facility). ATSDR determined that previousherbicide and pesticide spraying activities, current OB/OD operations, and a past structural firedo not pose a public health hazard. Contaminant levels in off-base residential areas would havebeen lower than levels expected to cause harmful health effects.
A prescribed burn is an intentional controlled fire. A wildfire is a fire caused by an accidental actof nature or man. To address whether on-base prescribed burns or wildfires pose a health hazard to off-base residents, ATSDR considered two different aspects of on-base fires. First, ATSDRevaluated whether fires in areas where soil contamination exist could cause contaminants tobecome airborne and transported to off-base residential areas. Then, exposure to chemicalsreleased during the burning of plant material (trees, grasses, shrubs, etc.) was considered.Uncontrolled wildfires present much greater threat because their uncontrolled nature can causethem to burn longer and much greater area thus producing more hazardous substances into theair.
The findings indicate that the contaminants in soils (depleted uranium and herbicides, includingHerbicide Orange(2)) would not reach off-base areas at levels associated with harmful healtheffects. Therefore, off-base residents would not come in contact with those contaminants.
However, the burning of plant material causes a release of particles and natural combustionproducts (smoke) that could cause some short-term adverse health effects (e.g., burning, itchingor watery eyes; nausea; breathing difficulty; and asthma-like symptoms) in those people exposed.The frequency of such burns is low and the duration is very short (personal communication withEglin AFB personnel, July 2002). Airborne emissions from prescribed burns and wildfires havenot been measured. This evaluation is based on health effects seen from other wildfires.Individuals highly sensitive to the effects would be anyone with previous respiratory conditionssuch as asthma or emphysema, children, and the elderly. Health effects would likely be of shortduration, i.e., developing within a few days of exposure and lasting no more than two or threeweeks after exposure stopped.
Depleted uranium would not be an airborne contaminant from the burning of plant material since plants have a minimal uptake of uranium from soil.
During prescribed burns, Eglin takes several measures to minimize the impacts of fires on residential neighborhoods. ATSDR recommends that Eglin AFB continue notifying the entire community (especially potentially impacted communities) when the prescribed burns are scheduled. This allows people to take measures to reduce potential exposures. If people are experiencing respiratory problems, they should seek the attention of their personal medical care provider.
- Transport of contaminants via surface waters: Are dangerous chemicals seeping into waterways on and off base, and would contact with those chemicals via swimming or eating fish be harmful to people's health? (Water-bodies evaluated: Tom's Bayou; Weekly Pond; Pocosin Pond; Mullet, Trout, and Basin Creeks; and an unnamed pond near the North Gate of Eglin Main Base).
No. Based on ATSDR's review of available data, Air Force documents, and scientific literature, the chemicals detected in the surface water bodies, sediments, and fish are below levels of health concern. Contact with the water or eating fish from those water bodies presents no public health hazard.
Information on the unnamed pond near the North Gate could not confirm whether it might have contained Herbicide Orange. The presence of a sign in the pond indicating Herbicide Orange use is unsupported by the Air Force historical documents and herbicide testing information. Nevertheless, access to this area is limited and any potential exposure would be minimal.
- Transport of contamination to private drinking water wells via groundwater: Is groundwater contamination from the C-6 Radar Facility reaching off-base residential wells?
No. The C-6 Radar Facility is located approximately 3 miles north of the town of Portland. The site is in an undeveloped section of Eglin AFB that is closed to the public. During a 2000 site investigation, the extent of the trichloroethylene (TCE) contamination was defined to be entirely on Eglin AFB property. To ensure that the contamination does not migrate to areas where people are using groundwater wells, long-term monitoring of the groundwater is conducted at the site on an annual basis. Therefore, this site poses no past, present, or future public health hazard.
- Contact with herbicide contamination: Could people be exposed to harmful levels of herbicide contamination at sites in the Herbicide Exposure Unit (SS-25/DP-09), C-52A Aerial Overspray Area (AOC-24), Upper Memorial Lake (LF-51), and Hardstand 7 (SS-26) (reported Herbicide Orange sites)?
No. Human exposure to herbicide contamination on Eglin AFB is minimal. Access to the Herbicide Exposure Unit (DP-09 and SS-25), the C-52A Aerial Overspray Area (AOC-24), and Hardstand 7 (SS-26) has been, is, and will continue to be restricted by locked gates, fences, security personnel, and topography. Even though people have access to Upper Memorial Lake (LF-51), the herbicide contamination was detected in the subsurface soil, and contact with subsurface soil would be minimal since Eglin AFB has implemented land use controls to minimize exposure. In addition, remedial activities have removed or contained, or both, the contamination formerly present at Mullet Creek Drum Disposal Site (DP-09) and Hardstand 7. Therefore, because contact with contamination is minimal, these sites pose no past, present, or future public health hazard.
- Contact with radioactive contamination: Could people be exposed to harmful levels of radioactive contamination from the Isotope Burial Area (AOC-63/-67), Test Area C-64 (RW-40), Test Area C-74L (RW-41), and the Low-Level Radioactive Waste Site (RW-42)?
No. Access to the Isotope Burial Area (AOC-63/AOC-67), Test Area C-64 (RW-40), and Test Area C-74L (RW-41) is restricted by locked gates, fences, and security guards. Furthermore, because of the nature (chemical and physical forms) of the depleted uranium and other radioactive contamination, ATSDR does not expect that anyone would be exposed to radioactive contamination present at these sites. In addition, remedial activities have removed or reduced the contamination that was once present. Therefore, these sites pose no public health hazard. Still, although access is restricted, the Low-level Radioactive Waste Site (RW-42) is not fenced and trespassing by boat could occur. However, the measured radiation levels were at or near normal background levels. Thus, despite the fact exposure is possible, the frequency and duration would be minimal. Accordingly, this site poses no public health hazard.
|Community and ATSDR Questions on Possible Exposures||Did Exposure Occur?||Hazard Category(3)||Comments|
|Are air releases from herbicide spraying and open burning/open detonation (OB/OD) exposing off-base populations to unsafe chemical levels? |
(Herbicide Exposure Unit, Ranges C-62/C-52N)
|In the past, present, and possibly in the future, people would be exposed.||The exposure presents no apparent public health hazard.|| |
• Available data for the most extensive herbicide spraying activities suggest that air concentrations did not reach unsafe levels at off-base locations.
• All of the chemicals released to the air during OB/OD activities did not exceed EPA's regulatory standards.
|Are air releases from prescribed burns and wildfires harmful to off-base populations?||In the past, present, and possibly in the future, people would be exposed.||The exposure presents a public health hazard, short-term effects.|| |
• Winds could occasionally blow plumes of potentially unhealthy smoke toward residential neighborhoods. If, however, harmful health effects occur, they are typically short-term, reversible, and subside after fires are extinguished.
|Were air releases from a structural fire at C-6 Radar Facility in 1965 harmful to off-base residents?||People were possibly exposed in the past.||The exposure presents no apparent public health hazard.|| |
• The C-6 Radar Facility is 3 miles from Portland; therefore, contaminants that could have been in the smoke would have been significantly dispersed. The fire lasted only one day; therefore, inhalation exposures to contaminants were extremely short-lived.
|Are chemicals from Eglin AFB seeping into Tom's Bayou and if so, would swimming, wading, or eating fish from the bayou be harmful to my family's health?||In the past, present, and possibly in the future, people would be exposed.||The exposure presents no apparent public health hazard|| |
• Even though contamination is present at sites on Eglin Main Base that are within the Tom's Bayou drainage basin, the levels detected are too low to be of health concern at these source areas.
|Are people exposed to harmful contamination via swimming or fishing in Weekly Pond; Pocosin Pond; Mullet, Trout, and Basin Creeks; and a pond near the North Gate?||In the past, people were exposed. Currently and in the future, exposure is not likely.||The exposure presents no apparent public health hazard.|| |
• Even though pesticides were detected in the fish from Weekly Pond, the levels detected were too low to be of health concern for anyone eating the fish in the past. Currently, people are not allowed to eat fish from this pond.
• People are not allowed to catch and eat fish from Pocosin Pond and no appreciable contamination exits.
• Even though contamination is present in Mullet, Trout, and Basin Creeks, the levels detected are too low to be of health concern.
• It is not expected that anyone could come in contact with Herbicide Orange at the unnamed pond near the North Gate often enough or in high enough doses to be a cause for health concern.
|Is groundwater contamination from the C-6 Radar Facility reaching off-base residential wells?||No, not in the past or currently and not likely in the future would people be exposed.||No public health hazard|| |
• Although contamination is present in the groundwater at the C-6 Radar Facility, it is not affecting the nearest down-gradient wells. To ensure that the contamination does not migrate to areas where people are using groundwater wells and for restoration purposes, the Air Force is conducting long-term monitoring of the groundwater at the site on an annual basis.
|Could people be exposed to harmful levels of herbicide contamination at the Herbicide Exposure Unit (SS-25/DP-09), C-52A Aerial Overspray Area (AOC-24), and Hardstand 7 (SS-26) (reported Herbicide Orange sites)?||No, not in the past or currently, and not likely in the future would people be exposed.||No public health hazard|| |
• Even though contamination is present at these sites, public access is restricted.
|Could people be exposed to harmful levels of herbicide contamination at Upper Memorial Lake (LF-51), a reported Herbicide Orange site?||No, not in the past or currently, and not likely in the future would people be exposed.||The exposure presents no apparent public health hazard.|| |
• Even though contamination is present in the subsurface soil at this site, people who have access to the area would have minimal contact with subsurface soils, since Eglin AFB has implemented land use controls to minimize exposure. Could people be exposed to harmful levels of herbicide contamination at Upper Memorial Lake (LF-51), a reported Herbicide Orange site?
|Could people be exposed to harmful levels of radioactive contamination from the Isotope Burial Area (AOC-63/-67), Test Area C-64 (RW-40), Test Area C-74L (RW-41)?||No, not in the past or currently, and not likely in the future would people be exposed.||No public health hazard|| |
• Even though contamination is present at these sites, public access is restricted and available information indicates that the contamination is localized within some of these areas.
|Could people be exposed to harmful levels of radioactive contamination at the Low-Level Radioactive Waste Site (RW-42)?||Possibly in the past, present, and future people would be exposed.||The exposure presents no apparent public health hazard.|| |
• Although access is restricted, the Low-level Radioactive Waste Site is not fenced and trespassing by boat from the Gulf of Mexico or Santa Rosa Sound could occur. However, radiation levels are not at levels of health concern.
Eglin Air Force Base (AFB) is an active military base located in Okaloosa, Walton, and SantaRosa counties on the Florida Panhandle between Pensacola and Panama City (see Figure 1). TheEglin Reservation, as it is called, is the largest forested military reservation in the United States,covering approximately 464,000 acres (725 square miles) (EA Engineering, Science, andTechnology 1997; Eglin AFB 2000c).
Eglin AFB was founded in 1935, as the headquarters for a bombing and gunnery base. In 1941,the Air Proving Ground Center was established at the base. During 1942, the Air Force begantesting combat aircraft and equipment. Throughout and after World War II, Eglin AFB was thecenter for developing and testing new techniques and tactics in air armament. In 1968, the AirProving Ground Center was renamed the Armament Development and Test Center, but EglinAFB continued to research, develop, and test nonnuclear munitions. In 1989, the ArmamentDevelopment and Test Center was renamed, to the Munitions Systems Division and, in 1990, tothe Air Force Development Test Center. The Center tests and evaluates nonnuclear munitions,guided munitions, and electronic combat systems (Eglin AFB 2000c).
Standard defense missions or other related activities at Eglin AFB, such as storage, maintenance,and shipping of war material; research and development; and aircraft operations andmaintenance, have contaminated some areas on Eglin AFB property. In 1981, the Department ofDefense initiated the Installation Restoration Program (IRP) to identify, evaluate, and clean upcontamination from past military activities. The Defense Environmental Restoration Accountfunds the IRP (EA Engineering, Science, and Technology 1997). As of March 2000, Eglin AFBidentified 118 IRP and 17 compliance sites found to contain harmful materials (Eglin AFB2000c). In addition, based on limited historical or circumstantial information, Eglin AFB hasidentified 236 areas of concern (AOCs) and 202 points of interest (POIs) which are pre-regulatory sites with the potential for contamination (Eglin AFB 2000c). Throughout the historyof the IRP at Eglin AFB, the Air Force has completed numerous site investigations, interimmeasures, and removal/remedial actions that have resulted in a No Further Action status formany of these sites.
For detailed information on the Air Force's continued environmental investigation andremediation plans at Eglin AFB, refer to Eglin AFB's documents at the following three publicrepositories: the Learning Resource Center at Okaloosa-Walton Community College, NicevilleCampus; Eglin Air Force Base AAC/EMR (207 N. Second Street, Bldg. 216); and at the FloridaDepartment of Environmental Protection (FDEP), Twin Towers Office Building (2600 BlairStone Road) in Tallahassee, Florida.
In February 1998, a private citizen petitioned (see text box for definition), the Agency for ToxicSubstances and Disease Registry (ATSDR) to assesscontamination from Eglin AFB for potential public healthhazards. ATSDR is responding to this petition in adocument known as a public health assessment. Throughthe public health assessment process ATSDR examineswhat chemicals enter the environment, how they movethrough the environment, whether people are being exposed to these chemicals, and the levels ofchemicals that people might encounter. ATSDR uses this information to determine whetherpeople are exposed to levels of contamination that might cause health problems. ATSDR'sevaluation focuses on public exposure and does not address exposure of base personnel who haveaccess to the areas of concern.
After receiving the petition letter and speaking with the petitioner, ATSDR on April 6-8, 1998,made a site visit to Eglin AFB. ATSDR staff scientists toured the multiple sites referred to by thepetitioner and met with representatives from the base, Air Force, and the United StatesEnvironmental Protection Agency (EPA). On August 20-23, 2001, ATSDR toured the site for asecond time to further evaluate the sites referred to by the petitioner as well as other sitesATSDR identified during the public health assessment process.
From talking with the petitioner and other community members, ATSDR identified five potentialexposure pathways. They are listed below and addressed in detail in this public healthassessment:
- Transport of contaminants via air to off-base areas: Would there be adversehealth effects to off-base residents from harmful substances being transportedthrough the air during herbicide spraying, open burning/open detonation(OB/OD) activities, wildfires, prescribed burns, and a past structural fire?
- Transport of contaminants via surface waters: Are dangerous chemicalsseeping into waterways on and off base, and would contact with those chemicalsvia swimming or eating fish be harmful to people's health? (Water bodies include:Tom's Bayou; Weekly Pond; Pocosin Pond; Mullet, Trout, and Basin Creeks; andan unnamed pond near the North Gate of Eglin Main Base).
- Transport of contamination to private drinking water wells via groundwater:Is groundwater contamination from the C-6 Radar Facility reaching off-baseresidential wells?
- Contact with herbicide contamination: Could people be exposed to harmfullevels of herbicide contamination at the Herbicide Exposure Unit (SS-25/DP-09),the C-52A Aerial Overspray Area (AOC-24), Upper Memorial Lake (LF-51), andHardstand 7 (SS-26) (reported Herbicide Orange sites)?
- Contact with radioactive contamination: Could people be exposed to harmfullevels of radioactive contamination from the Isotope Burial Area (AOC-63/-67),Test Area C-64 (RW-40), Test Area C-74L (RW-41), and the Low-LevelRadioactive Waste Site (RW-42)?
ATSDR examines demographic data (i.e., population information) to determine the number ofpeople potentially exposed to environmental chemicals and to determine the presence of sensitivepopulations, such as women of childbearing age (age 15-44), children (age 6 and younger), andthe elderly (age 65 and older), see Figure 4. Demographic data also provide details on populationmobility which, in turn, helps ATSDR evaluate how long residents might have been exposed toenvironmental chemicals. ATSDR also examines land and natural resource use to determinewhat activities might put people at risk for exposure. Some of the general information used inthat analysis is provided below.
Okaloosa, Santa Rosa, and Walton Counties
Eglin AFB is located in portions of Okaloosa, Santa Rosa, and Walton counties. According to the2000 United States (US) Census, Okaloosa County has the largest population (170,498 people),but is the smallest county in area (936 square miles); this results in the highest population density(182 people/square mile) of the three counties. Santa Rosa County is the next smallest county(1,016 square miles) with a population of 117,743 people; resulting in a population density of116 people/square mile. Walton County has a considerably smaller population (40,601 people)and an area of 1,058 square miles; resulting in a much smaller population density (38people/square mile) than the other two counties.
Demographics within one mile of Eglin AFB
A combination of commercial, residential, and undeveloped land surrounds Eglin AFB (EAEngineering, Science, and Technology 1997). According to the 2000 US Census, 101,792 peoplelive within one mile of Eglin AFBâ€“9,727 people are children aged 6 years and younger, 22,154people are women of child-bearing age, and 11,014 people are adults aged 65 and older (seeFigure 4). The total number of housing units within a one-mile buffer is 44,406.
Freeport and Portland
Freeport and Portland are small communities located within 2Â½ miles of the southeastern borderof Eglin AFB. According to the 2000 US Census, nearly 1,100 people live in Freeportâ€“106people are children aged 6 and younger, 205 people are women of child-bearing age, and 159people are adults aged 65 and older. Portland has a population of nearly 200 peopleâ€“17 peopleare children aged 6 and younger, 31 people are women of child-bearing age, and 21 people areadults aged 65 and older.
Most of the Eglin Reservation is undeveloped (458,400 acres) with small pockets of developed(1,400 acres) and semi-developed areas (4,200 acres), see Figure 2 (EA Engineering, Science,and Technology 1997). Eglin Main Base is the largest developed complex on the reservation (seeFigure 3). It is located in the south central portion of Eglin Reservation and employs about15,000 military and civilian workers. Hurlburt Field is about 11 miles west of the Main Base andemploys about 6,000 people. Duke Field and Camp Rudder are smaller areas that employ 50 and300 workers, respectively.
About 65% (280,000 acres) of the Eglin's 464,000 acre reservation is open to the general publicfor outdoor recreation (Eglin AFB 2000d). Members of the public, as well as off-duty militarymembers, can purchase recreational permits for a variety of activities from hunting to hiking.Approximately 12,000-14,000 people apply for permits to fish, hunt, camp, hike, or bike on thereservation every year (Daily News 2000a). In addition, every permit purchaser must watch aneducational video and accept a brochure on the hazards of unexploded ordnance (UXO) and theproper procedure to take should they encounter one (Eglin AFB 2000d). Areas that have beendetermined to contain a known potential for UXO are closed to the public. To date, Eglinreservation has no recorded incidents involving a recreational user and UXO on the reservation(personal communication with Eglin AFB personnel, July 2002). The sections of the reservationthat are restricted to all forms of public access are clearly posted with "Do Not Enter" signs andare marked in red on the Outdoor Recreation, Hunting, and Fresh Water Fishing Map (Eglin AFB2000b). Those who purchase permits receive this map with an extensive list of regulationsoutlining permitted recreational activities on the Eglin Reservation.
With the appropriate permits, fishing is permitted in several lakes and ponds on the EglinReservation, as indicated below.
|JackÂ§,Â¶||Jr. Walton||Kepner||Lost Boyâ€¡||Lower MemorialÂ§|
|Upper MemorialÂ§,Â¶||Pocosinâ€ â€||Speck||Roberts||Timberlake|
|WeeklyÂ§,Â¶|| * Handicap accessible fishing pier and nature trail |
â€ Special Creel limits apply
â€¡ Currently closed for renovation
Â§ Restricted to DOD-affiliated personnel and their guests
Â¶ Catch-and -release fishing only
** The only pond open to fishing on Hurlburt Field
â€ â€ Fishing is not allowed
Source: Eglin AFB 2000b
Nearby Off-Base Areas
Tom's Bayou is in Valparaiso, Florida, and receives drainage from surface water bodies on EglinMain Base. People reside around Tom's Bayou and engage in various recreational activities inthe bayou (e.g., fishing, swimming, and boating). While fishing and crabbing occur in the bayou,harvesting shellfish is not approved by FDEP (personal communication with Florida Departmentof Health personnel, September 2002). Several IRP sites were identified within the Tom's Bayoudrainage basin (see Figure 3).
Three significant hydrogeologic units underlie Eglin Reservation: the surficial sand and gravelaquifer, the Pensacola Clay confining layer, and the Floridan aquifer (EA Engineering, Science,and Technology 1997). Groundwater flow in the sand and gravel aquifer is toward larger streamsor the Choctawhatchee Bay. The Pensacola Clay is a thick confining layer that hydraulicallyisolates the sand and gravel aquifer from the Floridan aquifer. The Floridan aquifer is rechargedto the north of Eglin AFB where the Pensacola Clay is thinner or absent. Groundwater flow in theFloridan aquifer is south toward the Gulf of Mexico (EA Engineering, Science, and Technology1997).
Eglin AFB receives its drinking water from deep groundwater wells (about 600 feet below meansea level) that draw water from the Floridan aquifer, the primary source of public water innorthwest Florida (EA Engineering, Science, and Technology 1997). As noted above, thePensacola Clay forms a competent confining layer between the surficial aquifer and the Floridanaquifer. There are approximately 111 water supply wells on the Eglin Reservation. Twenty activewells are located on Eglin Main Base and another 20 wells have been capped, abandoned, or areinactive (EA Engineering, Science, and Technology 1997). The remaining 61 wells are assumedto be in areas other than the Main Base and active since they have not been categorized as capped, abandoned, or are inactive.
The majority of residents living near Eglin AFB are supplied with public water from OkaloosaCounty, Niceville, or Valparaiso water supplies. Some people use private groundwater wells andsome communities or businesses have limited use commercial or community systems that requirea permit from the Florida Department of Health (personal communication with FloridaDepartment of Health personnel, September 2002).
ATSDR investigated a contaminated groundwater plume originating from the C-6 Radar Facility.The nearest downgradient drinking water wells from this site are located off base, 3 miles south,in the town of Portland, Florida. The extent of the trichloroethylene (TCE) contamination wasdefined to be entirely on Eglin AFB property. To ensure that the contamination does not migrateto Portland, the Air Force conducts long-term monitoring of the groundwater at the site on anannual basis (Earth Tech 2000a).
In preparing this public health assessment, ATSDR reviewed and evaluated information providedin the referenced documents. Documents prepared for the IRP program must meet specificstandards for adequate quality assurance and control measures for chain-of-custody procedures,laboratory procedures, and data reporting. The environmental data presented in this public healthassessment are from the referenced reports. The limitations of these data have been identified inthe associated reports. After evaluating the data, ATSDR determined that the quality ofenvironmental data available in site-related documents for Eglin AFB is adequate to make publichealth decisions.
ATSDR evaluated a number of areas identified by the petitioner and other community members to determine whether potential exposure to contaminated media would result in past, present, or future public health hazards. ATSDR identified five main ways people were concerned that they would be exposed to hazardous levels of contaminants. Table 1 provides a summary of the exposure pathways at Eglin AFB that were evaluated in this public health assessment. Figures 2 and 3 provide the locations of the sites evaluated. For reference, Appendix A defines some of the technical terms used in this public health assessment and a List of Acronyms is available after the Table of Contents.
OUTLINE OF IDENTIFIED EXPOSURE CONCERNS
ATSDR obtained information characterizing the magnitude and duration of relevant chemicalreleases from Eglin AFB, including those from herbicide spraying, OB/OD activities, prescribedburns, wildfires, and a past structural fire (C-6 Radar Facility). Figure 2 shows the sitelocations.
ATSDR determined that previous herbicide spraying activities, current OB/OD operations, and apast structural fire did not pose public health hazards. Contaminant levels in off-base residentialareas would have been much lower than levels shown to cause adverse health effects.
In order to address whether on-baseprescribed burns or wildfires pose a healthhazard to off-base residents ATSDRconsidered two different aspects of on-basefires. First, an evaluation of whether fires inareas where soil contamination exist couldcause contaminants to become air-borne andbe transported to off-base residential areas.Next, a consideration of exposure tocontaminants released during the burning ofplant material (trees, grasses, shrubs, etc.).
Findings indicate that the contaminants insoils (depleted uranium and herbicides,including Herbicide Orange(4)) would notreach off-base areas at levels associated withharmful health effects. Therefore, off-baseresidents would not come in contact withthose contaminants.
Still, the burning of plant material causes arelease of particles and natural combustionproducts (smoke) that could cause someshort-term adverse health effects (e.g.,burning, itching or watery eyes, nausea,breathing difficulty and asthma-likesymptoms) in those people exposed. Airborne emissions from prescribed burns and wildfireshave not been measured. This evaluation is based on health effects seen from other burns.Individuals highly sensitive to the effects would be anyone with previous respiratory conditionssuch as asthma or emphysema, children, and the elderly. Health effects would likely be of shortduration, developing within a few days of exposure and lasting no more than 2 or 3 weeks afterexposure stopped. The base takes several measures to minimize the impacts of fires onresidential neighborhoods. Fires can, however, present a public health hazard to people who aresensitive to the effects of smoke.
Herbicides and pesticides have been sprayed at locations throughout Eglin AFB periodically forat least 40 years (Eglin AFB 2000c). Winds might have blown some of these chemicals tooff-base locations. Measuring airborne levels of these chemicals is not a general practice and notrequired by regulation. Thus, airborne levels of herbicides or pesticides have never beenmeasured in residential areas. To evaluate this concern, ATSDR estimated exposures based onwhat was sprayed, the distance to populated areas, and the wind speed and direction.
The base does not have comprehensive records that document exactly when, where, and thequantity of chemicals sprayed throughout the base. But it does have records that summarizespraying activities for the Herbicide Exposure Unit, where herbicides were sprayed from 1962 to1970 (Eglin AFB 2000c) (for more details about this site see the Herbicide Exposure Unitdiscussion in the Herbicide Contamination concern). Though pesticides and herbicides havebeen, and continue to be, sprayed in other areas of the base, the amounts sprayed are notablylower when compared to those sprayed at the Herbicide Exposure Unit. Therefore, thisevaluation is conservatively based on air exposures resulting from spraying activities at theHerbicide Exposure Unitâ€“the area on Eglin AFB believed to be sprayed with the greatestquantities of potentially toxic chemicals.
ATSDR evaluated a simple and overestimated exposure situation: What would have happened ifthe entire amount of chemicals used at the Herbicide Exposure Unit continuously blew directlytoward the closest off-base location, instead of mostly depositing on the ground at the HerbicideExposure Unit? Though obviously unrealistic, this scenario provides an extreme upper boundestimate of what the actual ambient air concentrations might have been during relatively intensespraying activities.
ATSDR used an air dispersion model (the SCREEN3 Model; EPA 1995) together with EglinAFB chemical use data to estimate off-base air concentrations at the nearest base boundary(about 2 miles). The model, agency assumptions, and the results are described in Appendix B.Even with the extremely conservative assumptions in this analysis, the estimated averageoff-base concentrations were lower than levels expected to be harmful to humans. In other words,spraying activities at the Herbicide Exposure Unit did not cause concentrations of chemicals toreach levels of health concern at off-base locations. For example, the estimated average airconcentration for arsenic at off-base locations (0.009 micrograms per cubic meter, or Âµg/m3) issubstantially lower than levels expected to be harmful to humans (0.7-613 Âµg/m3; ATSDR2000a). Further, this estimated arsenic concentration overstates the actual air concentration, thatis ATSDR used the extremely conservative assumption that all of the arsenic that was sprayed atthe Herbicide Exposure Unit blew directly to, and only to, off-base locations. See Appendix B forATSDR's evaluation of additional chemicals sprayed at the Herbicide Exposure Unit.
Past herbicide spraying at the Herbicide Exposure Unit does not appear to have posed a pastpublic health hazard. Therefore, current and future spraying activities, which use notably loweramounts and less toxic mixtures than past herbicide spraying, are not expected to pose current orfuture public health hazards to off-base residents.
In October 1996, Eglin AFB obtained a permit to conduct OB/OD operations at Range C-62 andRange C-52N (EA Engineering, Science, andTechnology 1999). These ranges are located in thenortheast and east central sections of EglinReservation, respectively (see Figure 2). Range C-62 is about 14,500 feet from Eglin's east boundaryand Range C-52N is about 25,000 feet from Eglin'snorth boundary. Range C-62 contains OB/OD unitsin the south-central portion of the range and RangeC-52N contains an OD unit in the middle of the range.
From October 1997 to October 1998, the Air Force monitored six OB/OD events at Range C-62for total suspended particulates (TSP), barium, magnesium, and leadâ€“all of which werepreviously identified during a human health risk assessment as the air quality compounds ofconcern. Ambient air sampling activities were pre-approved by EPA and FDEP (EA Engineering,Science, and Technology 1999).
The upwind and downwind ambient air samples showed that the chemical concentrations in theair did not exceed EPA's National Ambient Air Quality Standards (NAAQS) for TSP (75 Âµg/m3)and the Florida ambient reference concentrations (ARCs) for barium (1.2 Âµg/m3), magnesium (24Âµg/m3), and lead (0.09 Âµg/m3); with the exception of one lead sample (0.15 Âµg/m3) during oneevent (EA Engineering, Science, and Technology 1999). But, average lead results (0.03 Âµg/m3)were below Florida's ARCs for lead.
The air quality monitoring was conducted within the range and the airborne contamination isexpected to be substantially dispersed before reaching residential neighborhoods. The chemicalsreleased during OB/OD operations are at levels too low to be of health concern on base and arenot expected to be concentrated in off-base areas. Therefore, they pose no health hazard to off-base populations.
To reduce the likelihood and severity of wildfires, base personnel have since the 1900sconducted periodic prescribed (i.e., controlled) burns of vegetation (Eglin AFB 1999). Most openareas of Eglin AFB are burned at least once every 10 years through a series of prescribed burns.These burns normally are conducted in the spring, and sometimes in the fall. Each individualburn typically lasts less than 24 hours and spans an area of 1,500 acres or less (Eglin AFB1997-98).
To prevent smoke plumes from reaching residential neighborhoods, the base approves prescribedburns only after detailed computer simulations show that potential impact of the fire on nearbyresidents is minimal (Eglin AFB 1999). Eglin AFB conducts prescribed burns under controlledconditions and follows procedures outlined in the US Forest Service's A Guide for PrescribedFires in Southern Forests, which describes appropriate weather conditions, fire ignition methods,and other parameters for conducting successful prescribed burns and minimizing their adverseenvironmental effects. The Guide emphasizes the importance of managing smoke and avoidingrisk to smoke-sensitive areas to the greatest extent possible (USFS 1989). According to EPA,prescribed burns are generally accepted as an "ecologically sound tool for forest, range, andwetland management," and prescribed burns are believed to release a "relatively smallerquantity" of air pollution than wildfires (EPA 1996).
Beginning in 2001, Eglin officials committed to improving the ways they inform the communitywhen prescribed burns are scheduled (Daily News 2000b). Notifying potentially impactedcommunity members, especially sensitive populations, through timely and informative pressreleases and radio announcements when the prescribed burns are scheduled affords thesepopulations the opportunity to reduce potential exposures.
Wildfires occur in many parts of Florida, including Eglin AFB. Severe wildfires can spread overlarger areas, and burn for durations much longer than those of typical prescribed burns.Therefore, wildfires are capable of producing a much greater volume of air pollution thanprescribed burns. Furthermore, wildfires can have greater impacts on residential areas near EglinAFB than prescribed burns, primarily because wildfires can occur when winds are blowing in anydirection. Given the base's policy of conducting regular prescribed burns to minimize theconsequences of wildfires, however, the chance that a severe wildfire would occur at Eglin AFBis very low (especially in comparison to other parts of Florida where prescribed burns are notpracticed).
Components of Air Releases from Fires
To determine the health impact of prescribed burns or wildfires on nearby residents and workers,ATSDR relied on information from other forest fires and wildfires across the country todetermine possible components of the fire and smoke at Eglin AFB. Additional informationabout the fire components possibly released into the air were also ascertained from surface soilcontaminants (e.g., herbicides and depleted uranium) found at Eglin AFB.
The main components of fire that could pose the greatest hazard by way of inhalation are carbonmonoxide, carbon dioxide, aldehydes (i.e., formaldehyde and acrolein), ozone, and respirableparticulates.
Carbon Monoxide: Carbon monoxide is a colorless, odorless gas released during incompletecombustion (i.e., fire) which primarily affects the nervous system. Exposure to carbon monoxidecan cause headaches, dizziness, and lightheadedness. Exposure to low to moderate levels canaffect concentration, cause memory and vision problems, loss of muscle coordination, temporaryreduction in lung function, bronchitis, and asthma-like symptoms (New Jersey HazardousSubstance Fact Sheets; Ottmar and Reinhardt 1989; Reinhardt et al. 1999; Sharkey 1997).
Carbon Dioxide: Carbon dioxide is a colorless, odorless gas which, in addition to being acomponent released during fire, is released by our bodies when exhaled. Exposure to moderateamounts of carbon dioxide can cause lightheadedness, confusion, and loss of consciousness(New Jersey Hazardous Substance Fact Sheets).
Formaldehyde: Formaldehyde is a colorless, flammable gas with a strong, pungent odor. It canform explosive mixtures with air and oxygen. As an important industrial chemical of majorcommercial use, formaldehyde is found throughout the environment. It is also naturally producedin very small amounts in our bodies as part of our normal, everyday metabolism (ATSDR1999a). In solution, it has a wide range of uses. Examples include the manufacture of resins andtextiles, disinfectants, and laboratory fixatives or preservatives. Formaldehyde is formed duringincomplete combustion of hydrocarbons (Reinhardt and Ottmar 2000). In outdoor air it canoriginate from many sources such as incinerators, photochemical smog, and engine exhaust.Atmospheric levels of formaldehyde have been reported to range from less than 0.005 ppm to0.06 ppm near industrial outlets or in areas of heavy smog (Reinhardt et al. 2000). Workers whosmoke are exposed to additional levels of formaldehyde, cigarette smoke contains as much as 40ppm of formaldehyde by volume (Sharkey 1996). The first signs or symptoms noticed fromexposure to formaldehyde at concentrations ranging from 0.1 to 5 ppm are burning of the eyes,tearing, and general irritation to the upper respiratory passages. Higher exposures (10 to 20 ppm)could produce coughing, tightening in the chest, a sense of pressure in the head, and palpitationof the heart (NIOSH 2000; New Jersey Hazardous Substance Fact Sheets; Reinhardt et al. 1994;USDA 1999).
Acrolein: Acrolein is a colorless to yellow liquid that produces vapors characterized by a foulchoking odor. It is released from the burning of natural materials, such as plants. People can alsobreathe acrolein when near automobiles, because burning gasoline forms acrolein, which entersthe air (New Jersey Hazardous Substance Fact Sheets; Reinhardt and Ottmar 2000; Reinhardt etal. 2000). Oil or coal power plants also release small amounts of acrolein. Acrolein is formedwhen fats are heated. Small amounts of acrolein can also be found in foods such as fried foods,cooking oils, and roasted coffee. In several large cities acrolein has been measured at levels of0.009 ppm (Reinhardt et al. 1994). The levels in inside air can be much higher when tobacco isburning. For example, in a car with three people smoking and the windows closed, a personcould breathe in 0.300 ppm. Acrolein can be smelled at levels above 0.160 ppm. Thus, a personsmelling acrolein would probably notice eye, nose, and throat irritation before any lung damageoccurred (Reinhardt et al. 1994).
Ozone: Ozone is a colorless gas with a sharp odor which can be smelled well below thepermissible levels of exposure. At low exposure doses, an individual could experience irritationof the eyes, dryness of the nose and throat, and a cough. At moderate levels, headache, stomachache and vomiting can occur. In addition, ozone is the main component in smog that can causebreathing problems, aggravate asthma, and increases the severity and incidence of respiratoryinfections (New Jersey Hazardous Substance Fact Sheets; Reinhardt et al. 1999).
Particulates: Particulates are small pieces of material released from combustion or from physicalrelease. The effect particulates have when breathed in depends on the size of the particles. Largerparticles (greater than 10 microns) get trapped by the nasal passages. Particles greater than 5microns travel down the airway to the bronchioles and are removed by the cilia and by coughing.Respirable particles (0.5-5 microns) can travel deeper into the alveolar region of the lungscausing irritation, bronchitis and respiratory effects. Many particles smaller than 0.5 micronsremain suspended in the air and are exhaled, however some are deposited in the alveolar region(Levy and Wegman 1988; Williams et al. 1985). These smaller particles are cleared bymacrophages, lymphatics, and the bloodstream (Amdur et al. 1991). The legal airbornepermissible exposure limit for workers is 50 ppm averaged over an 8-hour period (Reinhardt etal. 1994).
Other Chemical Considerations: If fires reach sufficiently high temperatures, they can also causecontaminants in soils, like metals and herbicides, to become airborne. Therefore, depending onthe location of a fire, smoke from the fires can also contain metals and other pollutants. As ahypothetical example(5), ATSDR evaluated whether a wildfire near the Herbicide Exposure Unitcould release trace amounts of the chemicals that were tested in this area to the air, assuming thatthey are in the soil. To evaluate the public health implications of these emissions, ATSDRconsidered an extremely conservative exposure situation to determine whether smoke containsunhealthy levels of contaminants that were once in the soil(6). From such analyses, ATSDRconcluded that soil contaminants that might be released during wildfires are not expected toreach levels associated with adverse health effects at off-base locations. Appendix B containsmore details about how this conclusion was reached.
Depleted Uranium: Depleted uranium (DU) describes a waste product from the production ofnuclear fuel for energy production or weapons. Typically DU is approximately 50% lessradioactive than naturally occurring uranium, yet it is just as dense. This density allows the wastematerial to be used in military applications such as armor and armor piercing munitions. Duringthe use of DU munitions at Eglin, the areas where the DU were used was localized and studiessuggest the majority of the DU remains in the areas (White 1981; Becker and Vanta 1995).
If the DU is in fine particles in the surface soils, it would have oxidized either by the original useof the munitions or by exposure to the environment. Uranium oxides do not vaporize (Moses1978). Because DU particles are extremely dense, any particles in the soil that could get airbornewould quickly settle to the ground in the area of use. Conceivably, very small particulates coulddisperse at greater distances from the source. However, deposition of these fine particles wouldbe widely scattered, and consequently, measurable amounts of DU would not occur in localizedareas distant from the source (ATSDR 1997). Also, if the DU is in large metal pieces, it wouldnot get airborne during a prescribed burn or wildfire. Studies suggest that the munitions (largeDU metal pieces) penetrated the ground surface to a depth of 6 inches (Earth Tech 2001b) which,if a prescribed burn or wildfire occurred, would not result in temperatures sufficient to affect theDU metal. Also, plants in the area would not be contaminated with uranium since uranium isminimally transferred from soil to vegetation (the uranium transfer factor from soil to vegetationis 0.0085); therefore, burning vegetation would not contribute to airborne DU (Baes et al. 1984).
Public Health Implications
The likelihood of becoming sick from chemical exposure increases as the amount of chemicalexposure increases. This is determined by the length of time and the amount of chemicals towhich someone is exposed. Short-term exposure typically refers to contact with a contaminant(e.g., by breathing it in, eating or drinking it, or touching it to the skin or eyes) for a short periodof time, less than 1 year. Long-term exposure typically refers to contact with a contaminant formore than one year (New Jersey Hazardous Substance Fact Sheets; Reinhardt and Ottmar 2000;Sharkey 1996). Short-term health effects (also called acute health effects) are conditions,symptoms, or health changes that can occur immediately or shortly after exposure and last forless than 2 to 3 weeks (New Jersey Hazardous Substance Fact Sheets; Reinhardt and Ottmar2000; Sharkey 1996). Long-term health effects (also called chronic health effects) are conditions,symptoms, or health changes that can occur at some time after exposure and can last for monthsor years. Short-term health effects can occur from exposure to high or low amounts of chemicalcontaminants and can also occur from short- or long-term exposures. Most long-term healtheffects, however, result from repeated exposures to a chemical (New Jersey Hazardous SubstanceFact Sheets).
Health-related research shows that firefighters can experience both reversible, short-term healtheffects, such as eye and respiratory tract irritation, and long-term adverse health effects, such asdecreased lung function and increased incidence of respiratory illness (Reinhardt 1991; Reinhardtet al. 1995; Reinhardt and Ottmar 1997). Long-term adverse health effects have been seen in asmall portion of firefighters who were exposed to fire components on a daily basis for more than1 year (Reinhardt 1991; Sandber 1999; Sharkey 1999). Data from studies show that between 1and 10% of firefighters have exposures to fire and smoke components which exceedrecommended Time Weighted Averages(7) for a normal 8-hour day/40 hour work week. Less than5% of these smoke exposures exceed Occupational Safety and Health Administration (OSHA)permissible exposure limits, which are less stringent than the recommended limits, but which arelegally applicable to federal agencies (Sharkey 1999). The exposures of firefighters to smoke andfire components have been identified by both the respired air from the lungs of firefighters andfrom actual air samples collected by monitors worn on the neck and chest of firefighters. Reportsof studies conducted since 1988 show consistent results. In several studies, firefighters, who weregiven questionnaires after days of exposure, reported headaches, cough, shortness of breath,lightheadedness, and wheezing (Ottmar and Reinhardt 1989; Reinhardt et al. 1999; Reinhardt1991; Sandber 1999).
Airborne emissions from prescribed burns and wildfires have not been measured in the countiessurrounding Eglin AFB. Nevertheless, to provide perspective about health problems reported inthe general population, ATSDR spoke with nurses from several counties where severe wildfiresoccurred during 2000. Most of the fire and smoke related cases reported eye, nose, and throatirritation that subsided within a few hours after exposures stopped. None of the county nursesreported adverse pregnancy or birth outcomes related to the fire and smoke. They noted that mostphone calls were not related to health, but to how to get the smell of smoke out of the furnitureand carpeting (ATSDR 2000c, 2000d, 2000e, 2000f, 2000g, 2000h).
That said, however, recent studies suggest that the incidence of certain acute respiratory healtheffects (e.g., asthma-like symptoms, acute bronchitis, and chest pain) among selected Floridaresidents is greater when large wildfires occur, as compared to when wildfires do not occur or areless severe (CDC 1999). The likelihood of observing these effects during a prescribed burn isbelieved to be much reduced because the base makes every effort to conduct prescribed burnsonly during meteorological conditions that favor rapid dispersion of smoke in directions awayfrom residences. In addition, once emitted by fires, these pollutants gradually disperse as smokeplumes blow downwind.
Even though Eglin AFB takes several measures to minimize the impacts of fires on residentialneighborhoods, components (chemical and physical) released from prescribed burns andwildfires could cause some short-term adverse health effects (such as burning, itching, or wateryeyes and sinuses; headache; nausea; breathing difficulty; and asthma-like symptoms) in thosepeople exposed, especially sensitive populations (such as anyone with previous respiratoryconditions such as asthma or emphysema, children, and the elderly). Although, health effectswould be of short duration, developing within a few days of exposure and lasting no more than 2or 3 weeks after exposure stopped.
The Air Force should continue to notify community members when the prescribed burns arescheduled. This allows people to take measures to reduce potential exposures. If people areexperiencing respiratory problems, they should seek the attention of their personal medical careprovider.
The C-6 Radar Facility was built in the mid-1960s to monitor the southeastern United Statesairspace (Earth Tech 2000a; Eglin AFB 2000c). It is located in the eastern portion of Eglin AFB,approximately 3 miles north of the town of Portland in an undeveloped section, see Figure 2 (Earth Tech 2000a). On January 5, 1965, during the final phases of its construction, the mainbuilding of the C-6 Radar Facility caught fire and was destroyed (Rust International 1996; EglinAFB 1999, 2000). The main building was made of wood, but it housed high-voltage transformersand radar/surveillance equipment that contained polychlorinated biphenyls (PCBs) and otherenvironmentally persistent materials (Earth Tech 2000a; Rust International 1996).
There are conflicting reports of the remedial activities following the fire. An Eglin employee incharge of operations reported that the entire facility and contents (e.g., transformers andradar/surveillance equipment) were buried in an unlined pit in the front of the remainingfoundation slab. A second employee claimed to be an eyewitness to the disposal activities,reported that most of the recyclable materials were removed from the site and only inert debris(e.g., concrete fragments and steel beams) were buried on site (Earth Tech 2000a; RustInternational 1996).
Because the fire at the C-6 Radar Facility lasted only 1 day, inhalation exposures to contaminantsfrom this fire, if any, were short term. No air sampling was conducted in the vicinity of the C-6Radar Facility during or after the fire, and a detailed inventory of the original contents of themain building is not available.
Some observations can help put potential exposures from this fire into perspective. For instance,meteorological data collected at a nearby air field on Eglin AFB indicate that wind blewpredominantly from the east and northeast (or toward the west and southwest) on the date of thefire, thus suggesting that residents southwest of the site could have been briefly exposed to thesmoke from the fire (NOAA 1965). Because the C-6 Radar Facility is 19,260 feet from thenearest boundary of the base (about 3 miles from Portland), contaminants in the smoke thatreached residential neighborhoods were expected to be substantially dispersed and notconcentrated. Though neither of these observations quantify actual exposures to smoke andfumes from the fire, they both suggest that the fire had little impact on residential neighborhoodsnear the C-6 Radar Facility.
To address this concern, ATSDR obtained information that characterizes the nature and extent ofcontamination and the potential for human exposure at the following surface water bodies:Tom's Bayou; Weekly Pond; Pocosin Pond; Mullet, Trout, and Basin Creeks; and an unnamedpond near North Gate; see Figures 2 and 3 for site locations.
ATSDR determined that although contamination from Eglin AFB is potentially migrating intoTom's Bayou, it would not cause a past, present, and future public health hazard for peopleliving near, recreating in, or eating fish from Tom's Bayou.
ATSDR determined that eating fish from Weekly and Pocosin Ponds is not likely to present apast, current, and future public health hazard. As a precautionary measure, fishing is currentlynot allowed in Pocosin Pond and is designated as catch-and-release only in Weekly Pond. Basedupon the available information, ATSDR determined that people who ate fish from Weekly Pondin the past were not exposed to unsafe levels of chemicals.
Recreating in Mullet, Trout, and Basin Creeks is also not likely to present a public health hazardbecause the chemicals detected in the surface water, sediment, and fish tissues were below levelsof health concern.
One community member wanted information on whether Herbicide Orange was present in anunnamed pond near the North Gate of Eglin Main Base. The Air Force has no records ofHerbicide Orange in this unnamed pond. Access to the unnamed pond near the North Gate iscurrently limited by the location of the pond and the presence of building rubble between an off-base stable and the pond; thus any potential exposures would have been minimal.
Tom's Bayou is in Valparaiso, Florida, and is used for various recreational activities (e.g.,fishing, swimming and boating) by those who reside near the bayou. There are several smallponds and streams located on Eglin Main Base to the south and west of Tom's Bayou, whichdrain into the bayou (e.g., small unnamed beaver ponds to the south and Tom's Creek to thewest). Several IRP sites are at the headwaters or along these surface water bodies, potentiallycontributing to contamination in Tom's Bayou (see Figure 3). Table 2 provides site descriptionsand remedial activities for these IRP sites. For the purposes of this evaluation, these sites weregrouped into four areas according to location and flow into Tom's Bayou. These sites range fromabout 2,000-11,000 feet upstream of the bayou.
- The first set of sites (named Group 1 for the purposes of this document) is located nearseveral beaver ponds to the south of Tom's Bayou and drains into a small unnamedstream, which flows into the southwest corner of the bayou. These sites include: LF-08(Receiver Area Landfill), DP-07 (A-19 Drum Disposal Site), DP-96 (Taxiway 9eDisposal Area), ST-64 (Aero Club/Building 68), ST-112 (Base Operations GeneratorTank, Building 60), POI-324 (First Baptist Church of Valparaiso/Napalm Site), and POI-390 (Transmission Building Site).
- The second group (named Group 2 for the purposes of this document) includes AOC-98(Hardfill 01 End of Runway Disposal Area) and is located along the south shore of Tom'sCreek, which flows directly into Tom's Bayou.
- The third set of sites (named Group 3 for the purposes of this document) is located nearHardstand Pond and Beaver Pond. Hardstand Pond is a marsh area with two surface waterbodies flowing into a small stream, which in turn flows north for about 3,300 feet toBeaver Pond (Engineering & Services Laboratory 1987). Beaver Pond is dammed atPerimeter Road; only a small amount of surface water enters a culvert under the road andfeeds into a wetland area near Tom's Creek, which flows into Tom's Bayou. Surfacewater within the ponds is reported to be essentially stagnant (Earth Tech 2001c). Thisthird set of sites includes: SS-26 (Hardstand 7), DP-261 (Building 914 Disposal Area),AOC-88 (Hardstand 8 Alternate Loading Area), SS-32 (High Explosives Research &Development [HERD] PCE Spill), POI-412 (HERD Facility Building 1206), and POI-358 (Water Tower No. 1205).
- The fourth set of sites (named Group 4 for the purposes of this document) include OT-29(Missile Maintenance Paint Stripper Pit) and POI-408 (SAC Munitions Maintenance/33rdFlight Munitions Area). These two sites are located to the south of Tom's Creek,upstream of AOC-98. Tom's Creek drains directly into Tom's Bayou.
ATSDR extensively investigated whether any sampling had been conducted in Tom's Bayou.The US Fish and Wildlife Service, as part of Eglin AFB's stream monitoring program, collectedwater quality data in Tom's Bayou, including dissolved oxygen levels, turbidity, andconductivity. They have also collected aquatic insects to determine taxa richness and diversity.Based on the information collected, Tom's Bayou is considered to be a healthy system (personalcommunication with US Fish and Wildlife Service personnel, April 2002).
In February 1997, FDEP sampled a site in Tom's Bayou during an environmental assessment ofsediment quality in Boggy Bayou (Butts 1997). FDEP collected water quality data in Tom'sBayou and reported that the results indicate good water quality (with the exception of nitrate plusnitrite levels, however, according to ATSDR's evaluation the concentrations are below levels ofhealth concern). FDEP also collected two sediment samples from Tom's Bayou and analyzedthem for metals and volatile organic compounds. ATSDR reviewed the analytical data anddetermined that the chemical concentrations present in the sediment are not at levels of healthconcern for people using Tom's Bayou for recreational activities (i.e., all the concentrations weredetected below levels known to cause harmful health effects, assuming that people were exposedto the chemicals present every day for 70 years, see Appendix C for more details about howATSDR reached this conclusion). Finally, FDEP also evaluated the benthic macroinvertebratecommunity structure at the sample location in Tom's Bayou and reported a good assemblage oforganisms present, especially in the more productive shallow zone (Butts 1997).
Because limited chemical data are available for Tom's Bayou, ATSDR evaluated the level ofcontamination present at the Eglin AFB sites located in the drainage basin that potentiallycontribute to contamination in Tom's Bayou. As a conservative approach, ATSDR assumed thatthe contaminant concentrations present at these sites are equivalent to the level of contaminationthat people are being exposed to in Tom's Bayou, even though these areas of Eglin Main Baseare closed to all forms of recreation (Eglin AFB 2000b). ATSDR evaluated whether exposure tothese contaminant concentrations could result in exposure levels high enough to cause harmfulhealth effects, assuming people were being exposed every day for 70 years. Appendix C describes in greater detail the methods and assumptions ATSDR used to estimate humanexposure doses and determine health effects.
The Air Force has conducted several investigations at many of the IRP sites within the Tom'sBayou drainage basin. ATSDR determined that the available information adequately defines theextent of the contamination at the sites in the drainage basin and can be used to evaluate healthconcerns in the bayou.
- Group 1 sites are located to the south of Tom's Bayou in a drainage basin that does notreceive additional contamination from Group 2, 3, or 4 sites. In 1994, 1995, 1996, and2000, the Air Force collected surface water and sediment samples from the beaver pondsnear the Group 1 sites and analyzed them for metals, volatile organic compounds,pesticides, herbicides, and PCBs (CH2MHILL 1996; Earth Tech 2001a; Eglin AFB2000c; O'Brien & Gere Engineers 1996). ATSDR reviewed the available data anddetermined that the detected chemicals were not at levels of health concern for peopleusing Tom's Bayou for recreational activities.
- The Group 2 site is located west of Tom's Bayou, along an area of Tom's Creekdownstream of the Group 3 and 4 sites. In 1995 the Air Force conducted a siteinvestigation at this site, and sampled groundwater and subsurface soil for metals, volatileorganic compounds, pesticides, herbicides, and PCBs (Earth Tech 2001e). It should benoted that because surface water and sediment data were not available for this area,ATSDR assumed that the levels of chemicals present in the groundwater and subsurfacesoil were representative of contamination present at the surface. Using this conservativeapproach, ATSDR determined that the detected chemicals were not at levels of healthconcern for people using Tom's Bayou for recreational activities.
- The Group 3 sites are located to the south of Tom's Creek in a drainage basin that doesnot receive additional contamination from Group 1, 2, or 4 sites. From 1974 to 1980, theAir Force and the Florida Game and Freshwater Fish Commission collected soil,sediment, and biological samples from this area for 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD) analysis (Harrison et al. 1979; Harrison and Crews 1981). The results of thesediment sampling revealed that TCDD had migrated into the ponds. TCDD, however,was not detected in the one sample collected from Tom's Bayou. In addition, the AirForce sampled Hardstand Pond and Beaver Pond in 1994, 1999, and 2001 for metals,volatile organic compounds, pesticides, herbicides, and TCDD (Earth Tech 2001c; EglinAFB 1994). ATSDR evaluated the data and determined that all detected concentrationswere below levels of health concern. Moreover, because only a small amount of surfacewater and sediment flow into Tom's Creek from Hardstand Pond and Beaver Pond, verylittle contamination is expected to leave the ponds and flow into Tom's Creek (andeventually Tom's Bayou). Therefore, ATSDR determined that contamination from Group3 sites would not cause harmful health effects in people using Tom's Bayou forrecreational activities. As a note, Hardstand Pond, Beaver Pond, and the surroundingwooded areas are closed to all recreational activitiesâ€“in 1985, the entire area was fenced to prevent trespassing and signs were posted to ban fishing (Eglin AFB 2000b, 2000c).
- The Group 4 sites are located west of Tom's Bayou, along an area of Tom's Creek that isfarther upstream from the Group 2 site. In 1995, the Air Force collected surface water andsediment samples near these sites (EA Engineering, Science, and Technology 1997). Thesamples were analyzed for volatile organic compounds, pesticides, PCBs, and metals.ATSDR evaluated the data and determined that the chemicals that were detected are notat levels that would cause harmful health effects to people using Tom's Bayou forrecreational activities.
In summary, ATSDR determined that all of the chemicals detected at the four areas that draininto Tom's Bayou are below levels of health concern and would not cause harmful health effectsin people using Tom's Bayou for recreational activities in the past, present, and future. ATSDR'sconclusions are based on calculated exposures that overstate actual exposures occurring in Tom'sBayou because (1) people are not expected to be exposed consistently to the maximumconcentration on a daily basis and for an extended period of time. More realistically peoplewould encounter a range of concentrations, including no concentrations, given that everychemical was not detected in every sample, (2) adults and children are not expected to berecreating in the bayou as often as 365 days of the year, and (3) the majority of the data are fromsites that are located on Eglin Main Base and it is expected that the concentrations would belower in the bayou than at the source areas.
It should be noted that ATSDR considered exposure to multiple chemicals during this evaluation.Several studies, including those conducted by the National Toxicology Program in the UnitedStates and the TNO Nutrition and Food Research Institute in the Netherlands, among others,generally support the conclusion that if each individual chemical is at a concentration not likelyto produce harmful health effects (as is the case here), exposures to multiple chemicals are alsonot expected to be of health concern (for reviews, see Seed et al. 1995; Feron et al. 1993).
Fish from Tom's Bayou have not been sampled and analyzed for contamination. Without actualdata, ATSDR can not definitively draw conclusions about whether eating fish from the bayouwould be expected to cause harmful health effects. Still, based on the available information aboutthe water and ecosystem quality in Tom's Bayou and the type of contamination present at the IRPsites within the drainage basin, ATSDR does not expect high levels of contamination toaccumulate in fish in the bayou. FDEP and US Fish and Wildlife Service conducted water qualitysurveys in Tom's Bayou and concluded that the water quality is good and that the bayou is ahealthy system, ecologically. The levels and types of contamination found at the sites on EglinMain Base do not pose a health hazard to people, including those exposed directly to thecontamination.
Weekly Pond is a small 6-acre pond located southeast of the runways on Eglin Main Base (seeFigure 3). The pond is about 4,460 feet from the Lewis Junior High School, which is just outsideEglin AFB's East Gate (Eglin AFB 2001b). Fishing is limited to Air Force personnel and theirguests, and Eglin AFB's Natural Resources Branch requires a permit to fish on base (Eglin AFB2000b). While Weekly Pond was open to recreational fishing in the past, it currently has a catch-and-release policy with signs posted (Water and Air Research 1984). In 1996, the NaturalResource Department found trace amounts of dichlorodiphenyltrichloroethane (DDT) anddichlorodiphenyldichloroethylene (DDE) in fish samples. Even though the levels were belowhealth concern, Weekly Pond was posted catch-and-release as a precautionary measure. Also,Eglin AFB was concerned that new quantities of contaminants from a nearby landfill couldincrease levels in the future (personal communication with Eglin AFB personnel, July 2002).
ATSDR evaluated whether contaminant concentrations could result in exposure doses highenough to cause harmful health effects in people who in the past might have eaten fish fromWeekly Pond. In the mid-1980s, Eglin AFB sampled fish tissue and detected pesticides (DDT,DDD, and DDE) (Eglin AFB 1989). Other contaminants have not been identified in WeeklyPond. To calculate exposures, ATSDR assumed that adults and children ate seven meals of fishfrom Weekly Pond each month (adults were estimated to eat 8 ounces of fish every meal andchildren were estimated to eat 4 ounces of fish every meal). The resulting exposure doses werewell below levels of health concern when compared to values documented in the medical,toxicologic, and epidemiologic literature (ATSDR 2000b). Therefore, adverse health effects arenot expected to have occurred from eating fish from Weekly Pond in the past. Thus, whileexposure was possible, Weekly Pond poses no past public health hazard. Additionally, becausepeople are not allowed to eat fish from Weekly Pond, people are not being exposed, and nocurrent or future public health hazard is present. Appendix C describes in greater detail themethods and assumptions ATSDR used to estimate human exposure doses and determine healtheffects.
Pocosin Pond covers approximately 10-13 acres and is in the north-central section of the EglinReservation (see Figure 2), about 32,000 feet from the nearest base boundary (Earth Tech 2001b;Eglin AFB 2001b). In the past, the Air Force used this area for jungle-environment ballistictesting, air drops, and static detonation of conventional munitions (USACE August 1999 as citedin Earth Tech 2001b). Sometime between July 1969 and February 1970, during one exercise,approximately 500 rounds of DU ammunition were fired at a cloth target marker located in themiddle of Pocosin Pond (Earth Tech 2001b).
Pocosin Pond is located in an area open to the public during designated hunting seasons but isrestricted to the use of primitive weapons only; however, the thick brush surrounding the pondmakes it unlikely that hunters would actually use the area near the pond (Earth Tech 2001b; EglinAFB 2000b). Members of the Natural Resources Branch and US Fish and Wildlife Servicesampled fish and amphibians in 1997. Pocosin Pond was found to be very acidic and no fish werepresent at that time (personal communication with Eglin AFB personnel, July 2002). Fishing isnot allowed at Pocosin Pond and signs are posted to notify the public.
The Low-Level Radioactive Materials Partnering Team recommended No Further Action for thesite with current land use controls in place. Even though DU fragments were not removed, thepartnering team decided that further investigation would be impractical due to (1) the minimalnumber of rounds used, (2) the remoteness of the pond, (3) the thickness of the brush, and (4) theexpense to remove the brush (Earth Tech 2001b).
Pocosin Pond receives surface water runoff from the area surrounding the Cattle Dipping Vat(OT-83; formerly AOC-113), which is located about 230 feet south of the pond. The cattledipping vat was used from 1917 to 1944 during the National Cattle Tick Fever EradicationProgram (Woodward-Clyde 1995 as cited in Eglin AFB 2000a). The cattle dip solutionscommonly consisted of sodium carbonate, arsenic trioxide, pine tar, and water (Eglin AFB2000c). Arsenic in soil is the primary contaminant detected at the Cattle Dipping Vat. In 1998,the Air Force excavated arsenic-contaminated soil and the concrete vat to remove the source ofcontamination. The Air Force recommended No Further Investigative Action with current landuse controls for this site (Eglin AFB 2000a).
In general, the procedure used during a Preliminary Assessment in October 2000 to evaluate thelevels of radioactivity associated with the Pocosin Pond area did not detect any radioactivematerial or radiation levels elevated above the investigation limit and, by definition, abovenatural background levels in site soils and dry sediments of Pocosin Pond (Earth Tech 2001b). Inaddition, documentation exists suggesting that the DU has not migrated from the area (Beckerand Vanta 1995; White 1981). Furthermore, no visual evidence of depleted uranium fragmentswere found in or around a 50 to 100-foot perimeter of the pond. But because the penetratorscould have been below the ground surface, this is not surprising. The surveyors also noted thatthe thick trees and brush surrounding Pocosin Pond make it unlikely that DU fragments would befound (Earth Tech 2001b).
Additionally, surface water and sediment samples were taken from Pocosin Pond as part of aResource Conservation and Recovery Act (RCRA) Facility Investigation for the Cattle DippingVat. Contaminants were not detected above screening levels (Eglin AFB 2000a). Mostimportantly, Pocosin Pond is located in an area only open to licensed hunters during designatedhunting seasons and fishing is not allowed (see the Community Concern section for a discussionabout eating venison caught in the vicinity of the Eglin Reservation). Therefore, because peopleare not allowed to catch and eat fish from Pocosin Pond and no appreciable contamination exits,Pocosin Pond poses no public health hazard.
Mullet, Trout, and Basin Creeks are in the southeastern section of the Eglin Reservation (seeFigure 3) and receive surface water runoff from the Herbicide Exposure Unit (i.e., C-52AHerbicide Test Grid (SS-25) and the Mullet Creek Drum Disposal Site (DP-09)) and the C-52AAerial Overspray Area (AOC-24). For more details about these sites see the HerbicideContamination section of this document. The headwaters of all three creeks are located in areasclosed to all forms of public access, but flow into areas that are open to seasonal recreationalactivities (with appropriate Eglin AFB permits). Mullet and Trout Creeks flow through the FredGannon Rocky Bayou State Recreational Area and all three creeks eventually drain into theChoctawhatchee Bay.
According to the Baseline Risk Assessment, none of the creeks are visited very often (EAEngineering, Science, and Technology 1997). The highest use was characterized as one or morepersons visiting the area seasonally for Basin Creek (downstream of the Herbicide ExposureUnit) and lower Mullet Creek. The headwaters of Mullet Creek(8) and lower Trout Creek arevisited even less (1 or more people annually) and the headwaters of Trout Creek are not expectedto receive visitors (EA Engineering, Science, and Technology 1997).
The Air Force sampled surface water, sediment, and fish from Mullet, Trout, and Basin Creeksfor organic compounds, pesticides and herbicides, dioxins and furans, PCBs, and inorganics (EAEngineering, Science, and Technology 1997; Engineering-Science 1993). Because contaminationis present and people do have contact with the surface water, sediment, and fish in these creeks,ATSDR evaluated whether concentrations of chemicals were at levels that would be expected tocause harmful health effects in people who might swim, wade in, or eat fish from the creeks.
To determine if people were, are, or will be exposed to unsafe levels of the chemicals present,ATSDR calculated recreational exposure to the maximum concentrations detected in the surfacewater and sediment by conservatively assuming that adults and children visit the creeks 365days/year, even though actual exposure is much lower (EA Engineering, Science, andTechnology 1997). ATSDR also calculated exposure doses for catching and eating fish from thecreeks by assuming that adults and children consume seven meals of fish from the creeks eachmonth (adults were estimated to eat 8 ounces of fish every meal and children were estimated toeat 4 ounces of fish every meal). Appendix C describes in greater detail the methods andassumptions ATSDR used to estimate human exposure doses and determine health effects.
The resulting exposure doses were below levels of health concern when compared to valuesdocumented in the medical, toxicologic, and epidemiologic literature (ATSDR 2000a, 2002a;EPA 2002). For instance, the estimated dose from recreational exposure to the maximumconcentration of arsenic in the surface water is 6.4 x 10-6 milligrams per kilogram per day(mg/kg/day) for adults and 2.8 x 10-5 mg/kg/day for children, which are orders of magnitudebelow doses known to cause harmful cancer and noncancer health effects (0.01 to 0.05mg/kg/day; ATSDR 2000a). Further, the calculated exposures overstate the actual exposuresoccurring at Mullet, Trout, and Basin Creeks because (1) people are not expected to be exposedconsistently to the maximum concentration on a daily basis and for an extended period of time.More realistically, people would encounter a range of concentrations, including none, becausenot every chemical was detected in every sample and (2) adults and children are not expected tobe visiting the creeks as often as 365 days of the year.
Therefore, even though contamination was detected in Mullet, Trout, and Basin Creeks, adversehealth effects are not expected from people engaging in recreational activities in the past, present,or future. For health evaluations concerning exposure at the Herbicide Exposure Unit in otherenvironmental media, please see the Herbicide Contamination and Air Contamination Concerns.
An unnamed pond near the North Gate of Eglin Main Base is in a remote area with limitedaccessibility (e.g., access roads are not maintained), about 2,000 feet from the nearest non-baseresident (Eglin AFB 2001b). A community member was concerned that Herbicide Orange waspresent in the pond. About 20 years ago, the community member would ride a horse from thestable to the pond and reported seeing a sign that warned of Herbicide Orange contamination.The Air Force has no records of ever placing a sign at this unnamed pond and the sign is nolonger present. There are no historical Air Force documents that indicate Herbicide Orange wasever present at this pond (personal communication with Eglin AFB personnel, April 2002).
If Herbicide Orange was present, people would need to have contact with either the surface wateror sediment in the pond to be exposed (e.g., either through touching the water or sediment ordrinking water from the pond). If people are not being exposed, no harmful health effects canoccur. Currently, there is no fence surrounding the pond or preventing access to the pond. Aprivate off-base riding stable in Valparaiso, Florida is about 450 to 600 feet from the unnamedpond. The area between the stable and the pond is currently filled with building rubble, whichseverely limits access to the pond.
This unnamed pond is not an ideal location for recreational activities (e.g., swimming).Therefore, it is unlikely that anyone actually had contact with potential contamination in thepond, even in the past when people reportedly rode their horses to it. Because access to the pondis currently limited, there is a low chance that anyone is or will be exposed to high levels ofcontamination for a long time and on a regular basis. Consequently, harmful health effects are not expected to occur.
1 "No further action" indicates that sufficient data is available to determine the site poses no human or ecological health concern and that no additional remediation or sampling is necessary (personal communication with Eglin AFB personnel, July 2002).
2 Herbicide Orange: an herbicide used by the military until the 1970s for various purposes (e.g., used in Vietnam to remove leaves from trees). It is a 50:50 mixture of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and 2,4-dichlorophenoxyacetic acid (2,4-D). The 2,4,5-T was contaminated during the manufacturing process with dioxin (VA 2000). See Section III. Community Concerns for additional information about Herbicide Orange and exposure at Eglin AFB.
3 See Appendix A for ATSDR's Conclusion Categories.
4 See Section III. Community Concerns for additional information about Herbicide Orange and exposure at Eglin AFB.
5 Eglin AFB does not conduct prescribed burning at the Herbicide Exposure Unit.
6 ATSDR assumed that soils throughout a 5-acre area in the Herbicide Exposure Unit are contaminated at the maximum concentrations reported for a given chemical and assumed that a fire releases all chemicals found in the top 3 inches of the soil.
7 Time weight averages are threshold limit values consisting of the average airborne concentration of the substance over a specified time limit.
8 The headwaters of Mullet Creek are not open to the public. During the Baseline Risk Assessment, however, there was evidence of infrequent use, probably by base employees (EA Engineering, Science, and Technology 1997).