PUBLIC HEALTH ASSESSMENT
MCCLELLAN AIR FORCE BASE
SACRAMENTO, SACRAMENTO COUNTY, CALIFORNIA
McClellan Air Force Base (McAFB), an active aircraft maintenance facility since 1936, is located approximately seven miles northeast of Sacramento, in Sacramento County, California, and covers 2,952 acres. Operations at the base have involved the use, storage, and disposal of hazardous materials, including industrial solvents, caustic cleaners, electroplating chemicals, heavy metals, polychlorinated biphenyls (PCBs), low-level radioactive wastes, and various fuel oils and lubricants. For remedial purposes, the base is divided geographically into eight operable units (OUs); contaminant characterization is ongoing. McAFB has identified 239 locations as confirmed or potential sources of contamination.
In 1979, volatile organic compounds (VOCs) were detected in groundwater. Contaminated groundwater plumes emanating from McAFB are responsible for the closing of two municipal wells and several base supply wells. In 1986, approximately 550 homes west of the site were connected to municipal water supplies. In addition, groundwater at McAFB has been treated with an activated carbon filter system to remove contaminants from the groundwater.
Contaminants of concern [including VOCs, polychlorinated biphenyls (PCBs) and heavy metals] have been detected on site in groundwater, surface soil, subsurface soil, air, sediment, and surface water, and off site in groundwater, sediment, surface soil, and air. People have been, are being, or may be exposed through inhalation and ingestion of, or dermal contact with, the contaminants. Past exposure pathways have been identified for private wells and base supply wells. Because the locations and use status of all private wells are not known, unidentified private wells pose potential exposure pathways. Past, present, and potential future exposures exist for surface soil, sediment, and ambient air pathways. The listing of contaminants of concern in a human exposure pathway does not mean that adverse health effects will result from those exposures. ATSDR evaluated the exposures for each chemical in each completed exposure pathway to determine if there is a public health concern.
The community, including off-site property owners and on-site workers, is concerned about exposures to contaminants from McAFB. Off-site residents are concerned about health effects from exposures to contaminants in the groundwater and sediment and surface water in Magpie Creek.
ATSDR's toxicological evaluation of the chemicals in the human exposure pathways indicated several areas of concern. Those concerns are discussed in detail in the Toxicologic Evaluation Section of the public health assessment.
Past off-site exposures by the private well pathway indicate an increased risk of developing cancer (for the VOCs 1,2-DCA, 1,1-DCE, TCE, and vinyl chloride, and arsenic) and an increased risk of developing adverse noncancerous health effects from exposures to vinyl chloride and cadmium. Past and present exposures of children to cadmium by incidental ingestion of and dermal contact with contaminated sediments in Magpie Creek may result in an increased risk of developing adverse noncancerous health effects.
Past and present inhalation exposures to benzene, 1,1-DCE, and TCE in the ambient air at Stations 2 and 4, and incidental ingestion and dermal contact with PCBs in surface soil at the DRMO yard are of public health concern and may result in an increased risk of developing cancer. In addition, there is an increased risk of developing adverse noncancerous health effects as a result of inhalation exposures to mercury in building 252.
Because of the contaminant concentrations emanating from the southern and western portions of McAFB and the completed human exposure pathways, ATSDR has concluded that the site is a public health hazard. (This conclusion category is defined in Table 21.) ATSDR is unable to completely evaluate the public health implications of several of the on-site OUs because contamination has not been characterized. To further characterize the OUs, ATSDR recommends additional sampling of on- and off-site soil gas, on-site surface soil and ambient air, off-site sediment and surface water in Magpie Creek, ambient air (breathing zone) in nearby homes, and biota. In addition, ATSDR recommends surveying residents in the identified groundwater plume areas about their well use, and continued monitoring of base water supply wells.
The ATSDR Health Activities Recommendation Panel (HARP) has evaluated the data and information in this public health assessment and determined several health actions are necessary for this NPL site. Health actions include health education for health professionals and the community, community health investigations, comprehensive epidemiologic studies, and a community assistance panel (CAP). The public health action plan defines the implementation of those health actions.
McClellan Air Force Base (McAFB) is approximately seven miles northeast of downtown Sacramento, Sacramento County, California (Fig. 1). The main base covers 2,952 acres and is bounded by the City of Sacramento to the west and southwest, the unincorporated areas of the towns of Rio Linda/Elverta to the northwest, and the town of North Highlands to the east. McAFB, formerly the Sacramento Air Depot, was established in 1936 as an Army Air Corps air repair depot and supply base. In the early 1950s, McAFB changed from a bomber depot to a jet fighter maintenance depot. McAFB now operates as an Air Force Logistics Command Base; its units include the 2852nd Air Base Group, the 2951st Combat Logistics Support Squadron, and the USAF Clinic. Several tenant units, including the Air Force Systems Command, Air Training Command, Tactical Air Command, Air Force Communications Command, and Military Airlift Command are also stationed at McAFB. McAFB's current mission is to maintain and repair aircraft, missiles, space vehicles, and electronics and communication equipment. Because of its current and past missions, the base has engaged in a wide variety of operations involving the use, storage, and disposal of hazardous materials, including industrial solvents, caustic cleaners, electroplating chemicals, heavy metals, polychlorinated biphenyls (PCBs), low-level radioactive wastes, and a variety of fuel oils and lubricants. Most of the contaminated areas on site are burial pits which were used for disposal and/or burning of wastes.
The use of open burial pits for waste disposal was discontinued in March, 1980. After many years of using the solvent trichloroethene (TCE), the base in the fall of 1978 banned its use because of air pollution considerations (1). In 1979, McAFB officials began to suspect that these past disposal practices might have contaminated area groundwater. A McClellan Groundwater Task Force, with members from McAFB, the California Regional Water Quality Control Board (CRWQCB), the city and county of Sacramento, and the California Department of Health Services (CDHS), was organized to study the potential contamination.
Groundwater investigations identified volatile organic compounds (VOCs) in on-base production wells and off-base residential wells. The source of the contamination was burial pits on the northwestern boundary of the base. Groundwater and soil samples collected on and near the base were contaminated; VOCs and metals were detected. Groundwater contamination plumes have been identified in four areas.
In 1981, the United States Department of Defense (DoD) developed the Installation Restoration Program (IRP) to investigate hazardous material disposal sites at DOD facilities, and the McAFB investigations were revised to conform with the IRP. On July 22, 1987, McAFB was listed on the U.S. Environmental Protection Agency's (EPA) National Priorities List (NPL). On May 2, 1990, an Interagency Agreement (IAG) between McAFB, Cal EPA (formerly CDHS), and EPA became effective. The IAG sets schedules for completing specific tasks and establishes the process for involving federal and state regulatory agencies, and the public, in McAFB's ongoing remediation process.
To date, 239 areas of concern are identified on the base, including 112 potential release locations (PRL), 74 study areas (SA), and 53 confirmed sites (CS) (Appendix A). Additional PRLs will be added as characterization progresses in areas not yet studied. The base has been divided into eight geographical operable units (OU), labelled A through H (Appendix A and Fig. 2); a basewide groundwater OU may also be incorporated into the workplan.
OU A is in the southeastern portion of McAFB and does not include off-base areas. Base production wells 1, 2, and 12 have been closed because of TCE contamination. The area includes offices, industrial shops, maintenance buildings, and some base housing. Previous activities in the area generated hazardous materials including refuse and refuse ash, ethylene dichloride, cresylic acid, skimming pond sludges, and industrial wastewater sludge.
OU B includes both the southwestern portion of McAFB and some residential off-base areas. About half of OU B's on-base surface area is occupied by open storage lots and warehouses. Also on site are former waste storage, disposal, and treatment areas, maintenance buildings, underground storage tanks (USTs), pipelines, a dismantled plating shop, and a former laboratory.
Base production well 18, near the southwestern boundary of the base, is still used for drinking water and other purposes; an activated carbon treatment system removes VOCs so that the water is safe to drink (2). Raw groundwater from well 18 is filtered through two carbon beds before being treated with chlorine. The well is sampled once a week for volatile organic compounds and once every two weeks for bacteriological analysis. The only compound of concern has been TCE. TCE has been detected in the raw well water at 15-20 parts per billion. After treatment, TCE is usually not detectable with an analytical detection limit of 0.37 parts per billion. If the level of TCE in the finished (treated water) exceeds 2-3 parts per billion (the maximum contaminant level for the State of California is 5 parts per billion), the well is taken off-line until the carbon beds can be replaced.
The off-base section of OU B includes single-family residential housing, open fields, and some commercial and light industrial operations. Groundwater studies in OU B have identified three VOC plumes within the five uppermost geohydrologic zones. Two of those plumes have migrated off base, resulting in the closing of City Well 150, and are now progressing toward City Well 132 southeast of the base. A remedial investigation sampling and analysis plan for OU B was initiated in October 1991. Groundwater extraction is currently taking place in OU B to limit offbase subsurface migration. A Groundwater Treatment Plant was built in the mid-1980s on the west side of the base near building 655. The plant receives water from the five extraction wells located within OU B. The plant uses air stripping processes to remediate groundwater and granular activated carbon processes to treat air emissions.
OU C is in the western-central portion of the base, between OU B and OU D. OU C includes several CSs and was used in the past for disposal of solid waste, industrial waste sludges, waste solvents, oil, and other chemicals. From the 1940s until the early 1970s, wastes were discarded into large excavated trenches which were then covered with fill. Also during that period, the area contained several waste oil storage ponds that probably also contained large quantities of solvents. Four groundwater extraction wells are in operation in OU C. The Groundwater Treatment Plant near building 655 receives the contaminated groundwater drawn from these wells. The OU B and OU C extraction systems capture approximately 90 gallons of groundwater per minute.
OU D, in the northwest part of the base, includes disposal area D, which covers approximately 140 acres, and surrounding areas including off-base residential neighborhoods north and west of the waste sites. On-base activities in OU D that produced wastes in the late 1950s through 1981 included disposal of industrial sludge in pits; burning of waste oil, fuel, and solvent in pits; landfarming of industrial waste treatment sludge; and fire-training exercises. From the late 1940s to the early 1950s, areas in OU D were used for burying sodium valves from aircraft engines. No disposal currently takes place in OU D. The area now has an engineered cap. The cap consists of three feet of cover soil over a 40 mil (0.040 inch) synthetic liner which overlies one and one half feet of low permeability soil. Below the low permeability soil is a highly permeable layer of soil which has a piping system installed in it to collect soil vapor. A woven textile layer underlies the soil collection layer and provides support and strength to the cap. Contaminated groundwater is pumped from six extraction wells in OU D to a the Groundwater Treatment Plant near building 655. Because of their high levels of contaminants and the proximity of residences, the pits were the first areas sampled for media contamination. A groundwater plume was identified in 1979.
OU E is east of OU D and north/northwest of the flightline. Contamination at OU E has not been characterized. The area includes a part of the drainage ditch for the flightline area, a paint waste landfill, and a storage area believed to contain solvent and radiation waste.
OU F is a large, open, grassy area north of the flightline that has not been studied. The area includes a section of the open drainage system for the base; waste could have been disposed there in the past.
OU G is a light industrial area bounded by the flightline on the west and base family housing and recreational areas on the east. Although environmental sampling data are not yet available, contaminants may be or may have been released from USTs, aircraft washracks, the base hobby shop and other maintenance shops, and the industrial wastewater line in the OU.
OU H is between OU A and OU G on the east-central side of the base. The area includes dormitory-style troop housing, troop service buildings, and maintenance shops. Environmental contamination may have resulted from past disposal of solvents, metals, and petroleum products. OU H has not been characterized.
The order in which the OUs will be investigated has been agreed upon by the parties to the IAG; priority is determined by potential risks, community concerns, statutory environmental obligations, and Air Force Logistics Command mission requirements. The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980 process is being followed sequentially at each of the Ous. Records of decision (RODs) for the Ous are scheduled in the following order through the year 2003: OU B, OU A, OU C, OU D, followed by OUs E, F, G, and H (3). The workplan is being updated and priorities will be reevaluated as necessary by the parties to the IAG.
Additionally, interim removal actions have taken place on base. Expedited response actions (ERAs) can be implemented during the CERCLA process when contamination at a site poses a threat to public health or the environment. ERAs currently being implemented at McAFB are the OU B extraction system and the well abandonment program for base and municipal production wells contaminated with VOCs. Completed ERAs at McAFB include installation of the Area C groundwater extraction system, demolition of building 666 in OU B, and mercury decontamination at building 252 in OU A.
Building 666 (site 47), an electroplating shop from 1957-1980 and hazardous waste storage structure from 1980-1982, was contaminated beyond the point at which rehabilitation would be cost effective. Soil borings at this site and the affiliated industrial wastewater treatment plant (IWTP, site 48) indicated that the contaminants (primarily solvents and heavy metals) had migrated 80 feet below ground surface. Demolition of the two sites, completed in 1988, included removing the building, capping the sumps, and filling the trenches and floor drains with concrete. Removal of the foundations and sumps and further remediation of contaminated media will be addressed during the OU B remedial action process. The contaminants detected at this site are discussed in the Environmental Contamination section of this document.
Building 252 was used for more than 20 years as an aircraft instrument maintenance shop. Test equipment containing mercury, such as gauge pressure devices, was used to repair guidance system parts. During conversion of the building to office space, mercury contamination in the vacuum system (which had several leaks) was discovered. Metal deposits were found in the ceiling, walls, and on surfaces of the building, as well as outside near the doorways and in the workers' break area between buildings 251 and 252. Emergency removal of mercury outside the building was completed in December 1990. The vacuum system has been removed from Building 252, but internal cleanup to Occupational Safety and Health Administration (OSHA) standards has not been completed (3). The building is currently sealed and unoccupied; OSHA is to be notified 30 days prior to occupancy of the building.
Remedial Designs and Remedial Actions (RDs/RAs) that have taken place at OU D during the IRP include the installation of the OU D groundwater extraction and treatment system, provision of an alternative water supply to off-base residences (approximately 550 homes now have municipal water), and repair of the industrial wastewater line. Additional RAs on base are coordinated with the UST program and the soils management program. Sixty six USTs were removed from June 1985 to December 22, 1988; 33 USTs from December 22, 1988, through September 30, 1990; and 10 from October 1, 1990, to September 30, 1991. Contaminated soil is managed according to federal and state requirements, using a two-phase approach. The first phase requires temporary storage of the soils before off-site disposal. The long-term second stage, which is needed during the basewide proposed RAs, is development of on-site treatment capability.
An Agency for Toxic Substances and Disease Registry (ATSDR) preliminary public health assessment for McAFB was released March 17, 1989. That assessment concluded that McAFB was of public health concern because people probably were exposed to hazardous substances in groundwater by way of direct contact, ingestion, and inhalation. Potential exposure pathways described in the preliminary assessment were inhalation of volatilized contaminants by base employees and area residents, and ingestion of bioaccumulated contaminants in the food chain by area residents. Recommendations included conducting a compliance survey of area wells west of the base for backflow prevention devices; collecting information on contaminants in irrigation water; characterizing the area's hydrogeology, and further characterizing the site and site contaminants.
ATSDR initiated a health consultation for McAFB in August 1991. The purposes of the consultation were to request sampling and analysis of private groundwater supply wells west of OU D; to perform the heavy metals analyses using unfiltered samples; and to determine if the heavy metals concentrations reported for samples collected in 1983-1985 reflected current groundwater contamination. The results of the consultation are discussed in the Off-site Groundwater Contamination section of this public health assessment.
The first McAFB site visit was conducted by ATSDR on January 30-31 and February 1, 1991. Base environmental management (EM) staff provided an overview of the IRP/NPL process at McAFB. Staff from base bioenvironmental engineering (BEE) discussed occupational health issues and monitoring performed to comply with OSHA regulations. Meetings were also held with staff from base natural resources, the clinic, and the public affairs office. ATSDR staff also discussed community relations and community concerns with representatives from the state and county health departments. EM and BEE staff led the tour of the hazardous waste areas.
McAFB is an active maintenance facility; large sections of the base are devoted to industrial operations. Most of the identified areas of concern on base were not recognizable during the site visit because of changes in land use. Most areas have not been sampled or characterized. OU D, the source of the groundwater TCE plume that migrated off site and resulted in residences being connected to municipal water supplies in the mid-1980s, was adjacent to the western base boundary. The Air Force constructed a cap over the area in 1987. No former pits or other disposal areas were seen during the site visit. Residential properties abutted the base boundary adjacent to OU D (Fig. 1). Homes were within 200-300 feet of the fence. Other residential land use, gardens and stables, were closer to the fence.
The entire base is fenced; gates are guarded, restricting access. Because the base is a maintenance facility, there are many sources of potential occupational exposures for workers in the shops and industrial buildings on the base. Most CSs were in the industrial, limited-access section of the base, which is removed from base housing, schools, and recreational areas where children are allowed. ATSDR staff noted no physical hazards during the site visit.
ATSDR staff also conducted a tour of residential communities around the base, making observations on land use, surface water drainage (two creeks, Magpie and Don Julio, that flow west off base), and locations of schools and recreation areas. It has been reported that children play in Magpie Creek (see Community Concerns section), but no children were seen during the site visit.
On April 15-16, 1991, ATSDR staff met with Cal EPA, and CRWQCB to acquire additional environmental data on the base and drainage creeks that flow through the site. A meeting with the McClellan Community Relations Steering Committee resulted in ATSDR scheduling of a series of public availability sessions with communities on and off base during the week of July 15, 1991. Results of those sessions are discussed in the Community Health Concerns section.
McAFB is seven miles northeast of downtown Sacramento, the capital of California and a rapidly growing city of approximately 350,000 located in north-central California.
The base worker population in 1982 was 13,243 civilian and 1,227 military personnel. The total in 1992 is similar with proportionally more military.
Currently 11,176 civilian and 3,105 military are assigned to McAFB. The on-base residential population includes 669 military personnel in dormitory-style housing; military staff plus their dependents total 556 in Wherry Housing and 162 in Corps Housing. Capehart Family Housing, located about three miles from the main base, has 2,946 residents. All on-base housing and recreational areas are located on the east side of the installation, upgradient of the contaminant plumes.
Several neighborhoods to the northwest, west, and southwest of the base are in the path of the groundwater plumes that originate on the base; contaminants have been detected in private wells in those areas. In the mid-1980s McAFB identified the area possibly affected by groundwater contamination and provided 550 homes in the impact area with municipal water for potable purposes. Many of the homes are adjacent to the base boundary, while the homes farthest from the base in the impact area are approximately 1.5 miles from the boundary (see Fig. 4 for impact area).
Appendix B has demographic information for the impacted area; data are presented in tables with a map to define the discussion areas. Comparisons are made of the north and south subareas of the impact area. The North Area (close to OU D and most affected by the early 1980s groundwater contamination) is a largely rural area to the northwest of the base while the South Area is a much more densely populated area bordering the base to the southwest (near OU B where current groundwater plumes have led to the closure of one city production well and threaten the safety of another).
According to the 1990 Census 6,604 persons live in the Impact Area; 4,847 of those residents live in the South Area while 1,757 reside in the North Area. There are approximately six times more persons per square mile in the South Area than the North Area, which reflects the more rural nature of the region to the northwest of the base. There are no substantial differences in gender, race, Hispanic origin, or age between the two areas. There is a slightly higher percentage of owner occupied homes in the North Area and considerably more mobile homes in the South Area. Median value of owner occupied housing is less than half the county median in the South Area, with the North Area median being considerably higher than the neighborhoods to the south but still well under the county median.
Appendix B, Table III provides information from the 1990 Census on when householders moved into their current residences. Just over 52 percent of all householders in 1990 in the census tracts in both the North and South Area moved into their current housing unit since 1985. As expected, homeowners have generally lived in their homes for a longer period of time than have renters; in 1990 approximately half of homeowners in both the North Area and South Area had lived in their household since prior to 1980. In contrast, over 80 percent of renters in both areas in 1990 had moved into their current household between 1985 and 1990. Since nearly two-thirds of households are owner occupied, a substantial portion of the impact area population appears to have lived there for many years; interviews with residents during ATSDR public availability sessions provided similar information.
Before 1936, McAFB land was used for low-density residential and agricultural purposes. Since that time, the land has been devoted to Air Force aircraft maintenance; that use is expected to continue. About 40% of the on-base surface area is covered by building foundations, parking areas, runways, roads, and other paved surfaces. The base is divided into three areas. The eastern portion is densely developed with offices, housing for base personnel, repair and maintenance facilities, and aircraft hangars. The western portion is less densely occupied and has large grassy areas. The northern portion of the base is primarily open fields, except for the aircraft runway and service roads.
The land surrounding the base is devoted to a mixture of industrial, commercial, residential, and agricultural uses. East of the base are low-density residential areas; some commercial and light industrial areas are along Watt Avenue. Commercial and office areas and I-80 are along the southern boundary. The Rio Linda community north and northwest of McAFB consists mainly of large-lot residential tracts, but there is also some industry immediately adjacent to the northern base boundary. Residential neighborhoods west of the base include small farms with some farm animals and private gardens.
Natural Resource Uses
Groundwater, surface water, and game birds are the primary natural resources used on and near McAFB. Groundwater supplies all sources of potable water near McAFB. Surface water is used for irrigation and livestock watering, and for play areas by some young children. Limited hunting of pheasant and quail is allowed on base.
Groundwater resources near McAFB are at depths of 90-1400 feet. The groundwater system has been the sole source of potable water for the base and the surrounding communities. McAFB obtains water from on-base groundwater supply wells. Three wells are currently in use; well 18 is the principal supply well. During times of high water demand, the base obtains supplemental water from the Northridge Water District (5).
Water is drawn from production wells depths of approximately 145-400 feet below ground surface. Because of complex sedimentary deposits, water-bearing zones may be hydrologically separated over large areas, but are also locally interconnected where there are no impermeable clay and silt deposits. Such localized changes allow groundwater to move vertically between shallow and deeper groundwater zones. Because of increased use of groundwater for irrigation, industry, and municipal and domestic purposes, a major pumping depression centered under McAFB has been created. The depression has caused a change in regional flow from a westerly flow gradient to a southerly gradient (Fig. 2). Also, flow directions in the immediate vicinity of the base change in response to groundwater withdrawals (during production well use and implementation of groundwater treatment plant systems) and to seasonal changes in the water table (2).
Surface water from McAFB is directed into four small creeks, Magpie, Don Julio, Robla, and Arcade. Robla, Don Julio, and Magpie creeks originate east of the base and carry surface water onto the base. Don Julio Creek merges with Magpie Creek just west of the base. Arcade Creek, south of the base, receives drainage from the southern part of the base. All four creeks flow into the Natomas East Drainage Canal, which flows into the American River southwest of McAFB. Base effluent from the groundwater treatment plant and other drainages are the major sources of water volume to Magpie Creek, particularly in the summer. ATSDR received reports from several sources, including community members and the Community Relations Plan, of children playing in and along Magpie Creek.
On-base streams do not have sufficient water volume to support consumable fish or other aquatic biota. A report in 1987 by the U.S. Department of Interior stated that releases from McAFB have not affected endangered or threatened species, or migrating fish (6). Regulated game fowl are hunted at McAFB; no hunting is reported in surrounding communities.
CDHS maintains a Department of Vital Statistics, the California Tumor Registry of the Cancer Surveillance Section, and the California Birth Defects Monitoring Program. The Department of Vital Statistics gathers information on numbers of deaths, births, marriages, and divorces for the State of California. Variables included in the database are geographic location (city, county, town), age, sex, race, and cause of death.
The California Tumor Registry database is the central repository for all data on cancer cases gathered from the State's 10 regions. The registry is a statewide, population-based cancer surveillance system that monitors the incidence of and mortality associated with specific cancers over time. The database was designed to permit detection of risks of cancer by geographic region, age, race, sex, occupation, type of cancer, extent of disease, treatment, and demographics. This information is currently available for Region 3, Sacramento County, for 1987 - 1990.
The California Birth Defects Monitoring Program is a registry of children who were diagnosed with serious birth defects before their first birthday. The database contains information by 47 diagnostic categories of birth defects and by four demographic factors: region of residence, sex, race, and mother's age. Data for births in military hospitals are not included in the program. As of December 1992, information was available for four regions: the Coastal Region, the Bay Area Region, North Central Valley Region, and South Central Valley Region. The birth defects information for Sacramento County in the North Central Valley Region is for 1986 and 1987 only.
In 1984, the Epidemiological Studies Section of CDHS prepared a report on the feasibility of conducting an epidemiologic study of the West Sacramento community, which is adjacent to McAFB (7). Two parameters were used to determine the feasibility and practicality of conducting such a study: 1) Were the chemical contaminants to which people were exposed of high enough concentrations to induce any measurable medical symptoms? 2) Were the demographic characteristics of the exposed population adequate to provide the statistical power necessary to detect an increase in adverse health effects?
The McAFB occupational health staff provided ATSDR with a medical surveillance packet for Building 252 workers exposed to mercury (8) and workers exposed to polychlorinated biphenyls (PCBs) at site 12A (OU B1) (9). That information, the CDHS report, and other health outcome data are discussed further in the Health Outcome Data Evaluation section of this public health assessment.
In October 1992, the Air Force provided ATSDR with the 1991 Report of the California Birth Defects Monitoring Program for Sacramento County. At that time ATSDR also received a copy of a California Department of Health Services report evaluating cancer incidence data for Sacramento County census tract numbers 63, 65, 72.02, 74.04, and 73.
Through public availability sessions held on July 16 and 17, 1991, ATSDR representatives met with the public, on base and off base, to determine health concerns related to exposures to hazardous substance releases from McAFB. During those meetings, area residents and on-base employees presented ATSDR with numerous questions and concerns. ATSDR's response to these concerns are in the Community Health Concerns Evaluation section.
1. There appear to be cancer clusters on Barbara Street and other locations west of the base. Could the high number of cancer deaths in the residential area west of the base be related to the groundwater contamination or other contaminated media at McClellan?
2. Is there a risk of contamination to my vegetable garden if Magpie Creek overflows? Is it safe to use water from Magpie Creek for irrigation?
3. In the past, citizens have seen barrels in Magpie Creek and have heard reports of vats of TCE being dumped into the creek. One child who used to play in the creek has a cancerous tumor; could it be related to the past waste disposal into the stream? Are the levels of contamination in Magpie Creek dangerous to the health of children playing in and around the creek? Will overflow from the creek onto private property contaminate the soil where children play?
4. Is there any danger to the livestock that graze around creeks?
Is groundwater from irrigation wells safe for livestock?
5. Is there increased incidence of brain cancers on base?
6. Could chemical exposures of employees who used to work in Building 252 be causing an increased rate of gout?
7. Why are so many people who worked in Building 252 getting cancer?
8. Why are so many on-base workers suffering from chemically induced hepatitis, and why hasn't anything been done to prevent it?
9. Could any of the chemicals used in Building 252 cause bone deterioration?
10. What health effects, both short and long-term, are associated with on- and off-site contaminants?
11. What is the significance of finding vinyl chloride in the crawl spaces of homes west of the base ?
12. Do any of the contaminants of concern cause Graves' disease?
13. Can any of the contaminants be linked to major depression at McAFB?
14. What are the effects on our health of combined exposures to the chemicals? Is there an increased risk of damage to the body following exposure to a combination of any 2 or more of the chemicals?
15. Asbestos was recently removed from Hangars 360 and 362A. Are there health risks to workers who might have been exposed to the dust during removal?
16. Is groundwater being tested enough to ensure that residents still using residential wells are protected?
17. Were contract employees exposed to PCBs in Building 624D during the months of January and February of 1985? Could those exposures have resulted in illnesses? If so, will health studies be conducted?
The following community health concerns were collected from residents at McAFB during the public comment period for this PHA. These concerns are addressed in the Community Health Concerns Evaluation section.
1. What are the immediate and long term health effects of mercury?
2. What are the health effects associated with exposure to BTEX and other solvents?
3. What are the immediate and long term health effects of TERCO?
4. Is bladder cancer associated with JP 4, Naptha, TCE or TERCO?
5. Is hydraulic fluid associated with arthritis?
6. Are naptha, polysulfide primer or TERCO associated with headaches, panic attacks, or depression?
7. Can contaminated well water or air contribute to allergies, colds, or bronchitis?
8. Could learning disabilities/attention deficit disorder be associated with environmental contamination?
9. Are heart attacks associated with nickel plating work or other chemical exposures?
10. Could asthma, COPD and nasal polyps be associated with stripping paint off of aircraft?
11. Was the equipment that was moved form building 252 to building 237 decontaminated prior to moving?
12. Are private wells near 26th and I Streets contaminated?
13. Could a municipal well or private well near Magpie Creek be contaminated; would past dumping of heavy metals into the creek effect crops, fruit trees and well water?
14. Are city water systems, such as Rio Linda water, tested for the contaminants?
15. Was a study made of workers on base related to the drinking water and chemical exposures in the workplace; will there be investigations of possible cancer clusters on and off base?
16. Base well 17 reportedly remained in use, even though contaminated, until 1985; why was that well not discussed in the section on base drinking water in the PHA?
17. Is ATSDR going to assist people who have health problems associated with toxic substances at McAFB?
18. What are the health risks of eating contaminated frog legs and crawfish from Magpie Creek?
19. What are the health effects of air contamination off-base from the burning pits and fuel dumping by aircraft taking off and landing at McAFB?
20. Could dioxins and furans form in overheated/burned transformers; how about smoking, space heaters, electrical filament heaters or gasoline/diesel powered fork lifts being operated in PCB-contaminated air?