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1. ATSDR > Public Health Assessments & Consultations

PUBLIC HEALTH ASSESSMENT

MARCH AIR FORCE BASE
(a.k.a. MARCH AIR FORCE BASE)
MARCH AIR FORCE BASE, RIVERSIDE COUNTY, CALIFORNIA

TABLES

TABLE 1. GREEN ACRES MILITARY FAMILY HOUSING-ASBESTOS, LEAD, AND PESTICIDES

PATHWAY NAME	CONTAMINANTS	EXPOSURE PATHWAYS ELEMENTS					TIME	COMMENTS
		SOURCE	ENVIRONMENTAL MEDIA	POINT OF EXPOSURE	ROUTE OF EXPOSURE	EXPOSED POPULATION
Green Acres Military Family Housing	Pesticides in living area	Crawl space air	air, contaminated interior surfaces	Inside houses	Inhalation, ingestion from contact with interior surfaces	Residents including sensitive subpopulations such as children (particularly ages six and under) and pregnant and nursing women, and women of childbearing age. About 300 to 500 people may have been living at Green Acres at any one time in the 128 houses depending on the number of dependents	Past: duration of exposure approx. 5 to 9 years per rotation starting in the 1940s. Future exposure unknown pending reuse and home improve-ments	The houses are currently leased to the MJPA. In turn, the MJPA is renting the houses. ATSDR reviewed the pesticide sampling data together with past, current, and future exposure scenarios, use of the Green Acre Houses, and the toxicology of the pesticides. Based on this review, we have concluded that past, current, and future exposure to indoor air contaminated with pesticides poses no (apparent) public health hazard. Although we have made this conclusion, ATSDR recommends the placement of barriers in the crawl space to prevent or lower pesticide migration into the houses.
	Pesticides in crawl space	Unknown but probably pesticide application	soil, air	Crawl space	Ingestion inhalation	Residents, maintenance workers		ATSDR concluded that the past, current, and future exposures poses no (apparent) public health hazard. ATSDR recommends future prevention of exposure by maintaining restricted access to the crawl space.
	Lead	Interior and exterior lead paint	soil, air	Lead contaminated household dusts, paint chips, painted surfaces, and soils	Inhalation (of lead contaminated dusts) Ingestion (paint chips, children teething on wood surfaces, dusts and chips ingested via hand-mouth and toy-mouth activity	Residents and sensitive subpopulations discussed above.		No apparent public health hazard based on limited blood lead sampling data. ATSDR recommends exposure prevention. The AFBCA or MJPA should maintain lawns and shrubs adjacent to the houses including the roof driplines and all bare soils should be replanted to prevent access to the lead in the soils by children. Gardens adjacent to the houses should be prohibited to limit contact with the lead in the soil. Children should not be allowed to play next to the homes because of lead contaminated soils identified in the drip soil samples. Playground equipment or fenced areas for children should not be located next to the homes. ATSDR also recommends that MJPA and AFBCA follow the protective public health measures identified in 66 Federal Register 1206 for lead in residential soils.
	Asbestos	Building materials	air	Inside house	inhalation	Residents		A visual inspection and a review of the types of building materials present indicate that asbestos is present but in good condition. The AFBCA or MJPA should maintain and routinely inspect the asbestos in the houses.

TABLE 2. PESTICIDE CONCENTRATIONS IN CRAWL SPACE SOIL, GREEN ACRES MILITARY FAMILY HOUSING

Pesticide	Range of Concentrations Detected1 (mg/kg)	Number of Sampled Houses with Pesticides above Detection Limits	ATSDR's Comparison Values2
			Value (mg/kg)	Criteria
Chlordane (alpha)	<0.0005 to 31 J3	6	0.5	Chronic Oral CREG
Chlordane (gamma)	<0.0008 to 26 J	5	0.5	Chronic Oral CREG
Dieldrin	<0.0009 to 54 J	2	0.04	Chronic Oral CREG
4-4'-DDD	<0.0017 to 65 J	11	3	Chronic Oral CREG
4,4'-DDE	<0.0030 to 77 J	18	2	Chronic Oral CREG
4,4'-DDT	<0.18 to 440 J	20	2	Chronic Oral CREG
Methoxychlor	< 0.015 to 0.047	1	10	Chronic Oral Pica Child

1. Tetra Tech, Inc. 1996.
2. ATSDR 1997.
3. J - indicates that the concentration value is an estimated quantity because the analytical methods used to quantify the chemical concentrations were not sufficiently precise. Precision is based on detection limits of the sampling, analysis, and instrument methods.

TABLE 3. INDOOR AIR PESTICIDE CONCENTRATIONS-1996 GREEN ACRES MILITARY FAMILY HOUSING

TABLE 4. INDOOR AIR PESTICIDE CONCENTRATIONS-1997, GREEN ACRES MILITARY FAMILY HOUSING

Pesticide	Highest Reported Detection Limit1 (g/m3)	Maximum Concentration Detected1 (g/m3)	Region 9 PRG's2 (g/m3)	ATSDR's Comparison Values-CREG3 (g/m3)
Aldrin	<0.005	<0.005	0.00039	0.01
alpha-BHC	<0.005	0.005	0.0011	0.0006
beta-BHC	<0.005	<0.005	0.0037	0.002
delta-BHC	<0.005	<0.005	--4	--
gamma-BHC (lindane)	<0.004	0.008	0.0052	--
alpha-Chlordane	<0.005	0.096	0.0052	0.003
gamma-Chlordane	<0.005	0.14	0.0052	0.003
4,4'-DDD	<0.005	0.97	0.028	--
4,4'-DDE	<0.008	0.18	0.02	--
4.4'-DDT	<0.008	0.022	0.02	0.01
Dieldrin	<0.008	0.21	0.00042	0.0002
Endosulfan I	<0.008	<0.005	22	--
Endosulfan II	<0.005	0.008	22	--
Endosulfan sulfate	<0.008	0.005		--
Endrin	<0.008	<0.008	1.1	--
Endrin aldehyde	<0.008	<0.008	--	--
Endrin ketone	<0.008	0.007	--	--
Heptachlor	<0.005	0.042	0.0015	0.0008
Heptachlor epoxide	<0.005	<.005	0.00074	0.0004
Methoxychlor	<0.005	0.004	18	--
Toxaphene	<0.2	<0.2	0.006	0.003

1. Armstrong Labs, 1997
2. U.S. EPA, 1996.
3. ATSDR, 1997.
4. A value is not available.

TABLE 5. 1994 SOIL SAMPLES AT DRIPLINE OF GREEN ACRES MILITARY FAMILY HOUSING AND MODELED BLOOD LEAD LEVELS IN CHILDREN

House Number	Address	Lead Concen-tration in Soil (mg/kg)1	Side of House	Prior Lead Paint Abatement2
124	124 Adams St.	935 1070 443 246	A B C D	P
333	333 U St.	443 314 330 475	A B C D	C
142	142 Gilley St.	608 2700 796 1530	A B C D	C
328	328 U St.	1010 224	A B	P
170	170 Baucom Blvd.	404 434 712	B C D	P
137	137 Baucom Blvd.	1600 647 616 700	A B C D	P
336	336 DeKay St.	841	B	C
	Averages	776

1. Composite samples were collected at facilities where (1) exterior lead-based paint was present, (2) the paint was in poor condition, and the soil was exposed for sampling. Each "side of house" composite was made up of five subsamples collected from bare soil areas to a depth of 1/2 inch or less. March AFB, 1995a.
2. C- Complete abatement, P - partial abatement, paint not removed behind bushes.

TABLE 6. NO APPARENT PUBLIC HEALTH HAZARD SITUATION: ON-BASE WATER SUPPLY

PATHWAY NAME	CONTAMINANTS	EXPOSURE PATHWAYS ELEMENTS					TIME	COMMENTS
		SOURCE	ENVIRON-MENTAL MEDIA	POINT OF EXPOSURE	ROUTE OF EXPOSURE	EXPOSED POPULATION
Water Supply On-Base	Volatile Organic Compounds and Boron	IRP Sites 2, 8, 12, 27, and 36	Ground water	Water Taps	Ingestion, inhalation, dermal contact	Base personnel and families living on base. Population varied per year but may have been as high as 10,000 at one time after World War II.	Past estimated from 1940s through 1983	Based on risk calculation no apparent public health hazards are expected.

TABLE 7. BASE PRODUCTION WELLS

Well	Years of Operation	Average Well Yield 1963-1978 (gpm)	Percentage of Well Total Based on Well Yield	Percentage of Total Water Supplied to the Base
BPW-1	1927-1983	395	15.2	6.7
BPW-2	unknown-1930s	unknown	--	--
BPW-3	1931-1978	202	7.8	3.4
BPW-4	1934-1978	195	7.5	3.3
BPW-5	1941-1988	890	34.2	15.0
BPW-6	1941-1988	921	35.4	15.6
Totals		2603	100	44.0

Source: Earth Technology Corp., 1989 and Hossain, 1984.

TABLE 8. CONCENTRATIONS OF VOLATILE ORGANIC COMPOUNDS AND BORON IN MARCH AFB'S WATER SYSTEM FROM 1978 to 1983¹

Chemical	Production Wells (g/L)	Water Treatment Plant (g/L)	Tap Water from Distribution System2 (g/L)	EPA's MCL3 (Date promulgated) (g/L)	ATSDR's CV4 (g/L)
Boron	ND5-4600	ND-2300	ND-900	--	100 Interim EMEG Child
Bromodichloro-methane	ND-5.6	ND-5.8	ND-21.9	See Note 6	0.6 CREG
Bromoform	ND	ND-18.9	ND-38.4	See Note 6	4 CREG
Carbon Tetrachloride	ND-9	ND-0.3	ND	5 (1987)	0.3 CREG
Chloroform	ND-10.6	3.5-13.0	ND-32.4	See Note 6	6 CREG
Dibromochloro-methane	ND	ND-9.8	ND-16.2	See Note 6	0.4 CREG
Methylene chloride	ND-0.4	ND	ND-0.5	5 (1992)	5 CREG
Tetrachloroethene	ND-1.5	ND	ND-0.4	5 (1991)	0.7 CREG
Trichloroethene	ND-33.6	ND	ND-2.6	5 (1987)	3 CREG

1 - These analytical results were taken from samples collected on various dates. Samples collected from the production wells were not necessarily taken on the same date as the water treatment plant or water distribution line. Appendix G lists the analytical data, the dates the samples were taken, and the references.
2- The distribution line sample was taken at the base hospital except on August 1979 for Boron (sample collected in building 24242 and was not-detected) and in August 1983 for TCE (sample collected in the dining hall and measured at 2.6 g/L and the barber shop measured at 1.9 g/L).
3- U.S. EPA's maximum contaminant level as specified in the National Primary Drinking Water Regulations
4- CV - Comparison values (see acronyms and abbreviations for further information).
    CREG - Cancer Risk Evaluation Guide for 1E-6 excess cancer risk.
    Interim (Intermediate) EMEG - Environmental media evaluation guide for noncarcinogens for duration exposure of 15 to 365 days.
5 - Chemical was analyzed for and not detected
6- These chemicals are components of trihalomethanes, a class of compounds with an MCL of 100 g/L. This MCL was promulgated in 1991.

TABLE 9. IRP SITES POSSIBLY CONTRIBUTING TO GROUND WATER VOC CONTAMINATION THAT IMPACTED THE BASE PRODUCTION WELLS

IRP Site Number	IRP Site Name	Dates of Operations	Description	March AFB Cleanup Activities
2	Waste Oil Pit/Solvent Tanks	1940s to 1950s	Above- and underground storage tanks, railroad unloading spur, and aviation gasoline fueling stations. Contaminants included solvents and petroleum products.	Abandoned USTs and contaminated soils removed in 1994. Ground water contamination will be addressed by EPA's Record of Decision for Operable Unit 2.
8	Flightline Shop Zone	1918 to present	Industrial operations including the maintenance and repair of jet engines and aircraft equipment including underground storage tanks. Wastes included fuels, waste oils, spent solvents, paints, and thinners.	Ground water pump and treat and soil vapor extraction proposed as part of the Record of Decision for Operable Unit 2.
12	Civil Engineering Storage Yard	1940 to 1993	Storage of drums, tanks, and transformers. Waste included waste oils and solvents.	Contaminated soil removed in 1994
27	Bldg. 422 Underground tanks	1941 to 1995.	Gas station, oil/water separator, and underground storage tanks used for products and wastes.	Building and tanks removed in January 1996. Ground water contamination will be addressed by EPA's Record of Decision for Operable Unit 2.
36	Bldg 458 Leach Pit	1929 to unknown. Leach pit removed in 1996.	Jet engine maintenance shop leach pit. Waste included solvents.	Contaminated soil removed in 1994. An additional soil cleanup action was planned in 1998. Ground water contamination will be addressed by EPA's Record of Decision for Operable Unit 2.

TABLE 10. RISK CALCULATIONS

Volatile Organic Compound	Concen-tration	Date of Sample	Well Number	Concen-tration in Well Water Supply (g/L)	Calculated Concentra-tion in Distribution System (g/L)	Cancer Risk		Noncancer Risk Hazard Quotient
						Child	Adult	Child	Adult
Bromodichlormethane	5.6	July 83	BPW-1	1.3	0.6	6.1e-07	8.7e-07	0.006	0.002
Bromoform	<0.2	July 83	BPW-1	0.0	0.0	--	--	--	--
Carbon Tetrachloride	9	Sept 82	BPW-1	2.1	0.9	1.9e-06	2.7e-06	0.250	0.070
Chloroform	15.7	July 83	BPW-1	3.6	1.6	1.6e-06	2.3e-07	0.030	0.009
Dibromochloromethane	<0.1	Sept 82	BPW-1	0.0	0.0	---	--	--	--
Methylene chloride	<0.2	July 83	BPW-1	0.0	0.0	--	--	--	--
Tetrachloroethene	1.5	Sept 82	BPW-1	0.3	0.2	1.7e-07	2.4e-07	0.004	0.001
Trichloroethene	66	June '83	BPW-1	15.2	6.7	1.2e-06	1.7e-06	0.210	0.060
Sums						5.5e-06	5.7e-06	0.500	0.142

TABLE 11. NO APPARENT PUBLIC HEALTH HAZARD SITUATION: OFF-BASE WATER SUPPLY

PATHWAY NAME	CONTAMINANTS	EXPOSURE PATHWAYS ELEMENTS					TIME	COMMENTS
		SOURCE	ENVIRONMENTAL MEDIA	POINT OF EXPOSURE	ROUTE OF EXPOSURE	POTENTIALLY EXPOSED POPULATION
Past Water Supply Off Base	Trichloroethene and Tetrachloroethene	IRP Sites 5,7,8,9,10,13,14,15, 16,23,29,31,and 34. IRP Site 31 as major source.	ground water	water supply taps, showers, cooking, washing, irrigation	ingestion, inhalation, dermal contact	Residents off base to the east with private wells, approximately 5 to 50 people	Past,, approximately 1970 to 1988	No apparent public health hazard for off-base residents based on concentrations and period of time water was used. To confirm the presence or absence of used private wells in the OU1 area, ATSDR recommends that AFBCA or AFRC send all parcel owners in the OU1 area letters asking about the presence of wells and their use. ATSDR recommends that AFBCA or AFRC sample previously unknown private wells if they are still in use. These wells should be sampled quarterly for one year. With the results of the first sample and each subsequent sample, AFBCA or AFRC should evaluate whether the sampled wells should be closed because of public health. AFBCA or AFRC should also provide information on the status of the investigated wells to State Department of Water Resources, Santa Ana Regional Water Quality Control Board, State Department of Health Services (Division of Drinking Water and Environmental Management), and the Riverside County Health Department. The AFBCA, AFRC, State, County, or private owners should close those wells that are no longer used or inadequately constructed within the plume or adjacent to the downgradient edge of the plume to prevent exposure and the spreading of contamination. The AFBCA or AFRC should confirm with the County of Riverside that well permits should not be issued in the OU1 area.

TABLE 12. CONCENTRATIONS OF PCE AND TCE IN OFF-BASE PRIVATE WELLS FROM 1986 TO 1990

Chemical	Range	EPA's MCL1	ATSDR's CREG2
TCE	ND3-17.0 g/L	5 g/L	3 g/L
PCE	ND-0.8 g/L	5 g/L	0.7 g/L

1 - The Maximum Contamination Level (MCL) for TCE and PCE was promulgated in 1987 and 1991, respectively.
2 - CREG - Cancer Risk Evaluation Guide (see acronyms, abbreviations, and glossary for further information)
3 - Not Detected

FIGURES

Figure 1. Site Map of March Air Force Base

Figure 2. March AFB Production Wells

Figure 3. Water Supply System at March AFB from 1960s to 1983¹

Figure 4. Location of Off-Base Private Wells and Ground Water Contamination

APPENDICES

APPENDIX A: POPULATION DATA AND CENSUS TRACT MAP

Appendix A. Population Data and Census Tract Map

APPENDIX B: SUMMARY OF SITE EVALUATIONS^1,2,3

CERCLA SITES

Site Location and Number	Status
IRP Sites 14, 22, 23, 32	These are sites with no evidence of contaminant release(s)
IRP Sites 5, 9, 13, 16, 22, 23, 30, 35, 38	These are sites where a Remedial Investigation was completed and the preliminary remediation goals were not exceeded or the calculated risks were below 1E-6 for carcinogens or the hazard index was at or below 1 for noncarcinogens.
IRP Sites 2, 7, 11, 19, 29, 37	These are sites where a clean up did not occur but the contamination requires that the land only be used for industrial purposes.
IRP Sites 4, 6a	Sites with completed clean up actions and no further action scheduled. | | | | | | V	These are sites with surface, sub-surface, or ground water contamination where the waste was kept in place and capped. Ground water is being monitored or addressed by a ground water treatment system.
IRP Sites 17		This Site consisted of a concrete swimming pool that was filled with soil, drums, paint containers and demolition debris. The pool contents were excavated in 1994. Confirmation samples found PCB contaminated soils below the excavation between 8.5 and 13.5 feet below ground surface at 0.8 to 4.4 mg/kg. One of these samples was spilt and analyzed by a separate laboratory. The PCB concentration was measured at 190 mg/kg. The ROD approves this site for use as residential. March AFB has placed restrictions on excavations at this site.
IRP Sites 20, 24, 26, 40		Suitable for residential.
IRP Site 1, 37, 44		These are sites where surface soil was remediated and the remaining contamination is only suitable for industrial use.
IRP Sites 15. 34	Site with completed clean-up actions and additional cleanup is required.	These are sites where surface soils are to be cleaned up.
IRP Sites 2, 3, 8, 27, 33, 34, 36		These are sites where subsurface soils and ground water are to be cleaned up. For Site 8, surface soil clean up only.
IRP Sites 12, 25		These are sites where the additional clean up consists of ground water monitoring
IRP Sites 10, 18, 31, 39	Sites with required cleanup.	Subsurface soils
IRP Sites 31		Ground water
IRP Sites 21, 41, 43	Sites that will be included in a Basewide Operable unit and Record of Decision. Sites 21 and 43 are proposed for ground water monitoring. Site 41 had an interim tank removal with proposed no further action.

Notes: IRP Site 28 consisted of a clustering of IRP Sites 5, 7, 9, 10, 13, and 15 to facilitate ground water monitoring and soil sampling activities. Another name for Site 28 that has been used is Zone Monitoring Number 1. March AFB is no longer using this cluster terminology. The reader is referred back to the individual IRP Sites.
Source: Tetra Tech, 1996, Satrom, 1998.

RCRA AND EBS SITES (continued)

Site Location and Number	Summary and Evaluation	Comments and Recommendations
RCRA Facility Assessment (RFA) Sites 105 Solid Waste Management Units (SWMUs) and 50 Areas of Concern (AOCs) were identified. These 155 units/areas were classified into three groups. The first group are those recommended for no further action and this consisted of 68 units/areas (59 SWMUs and 9 AOCs). The second group consists of those units/areas classified as requiring further action and this consisted of 57 units/areas (43 SWMUs and 14 AOCs). The third group is units/areas designated potential release locations consisting of 30 units/areas (3 SWMUs and 27 AOCs).2 The second group was determined to be no further action (Satrom, August 1988). The third group of 30 units/areas is listed below.		Work on the 57 SWMUs and AOCs requiring further action is pending. ATSDR will review additional data as it is provided.
A, B, E, F, H, J, K, M, N, O, Q, R, S, T, U, V, W, X, DD	Soil gas survey and/or geophysical survey conducted in 1995 did not find evidence of contaminant releases. No further action proposed (Tetra Tech 1996b)
C, D, G, I, L, P, Y, Z, AA	Sampling of these sites included one or more of the following: soil gas, soil boring, surface soil/hand auguring, and trenching (Tetra Tech 1996b). C - Soil gas levels below levels of concern. D - No current exposure. However, Tetra Tech recommends additional monitoring should be conducted during any invasive construction activities. G, I - Soil gas and surface samples are below levels of concern. P - Trench and surface soil samples below levels of concern. Z - Soil gas survey did not find evidence of contaminant release. Geophysical surveys did find evidence of debris. Ground water will be monitored as part of IRP Site 3 base wide ground water monitoring plan. AA - Soil samples below levels of concern.
L Y BB and CC	These are sites pending further work. Soil sampling to be conducted. Trenching and sampling to be conducted Soil sampling to be conducted.	ATSDRs comments on hold until additional information is provided.
Environmental Base Survey (EBS) Sites An Environmental Baseline Survey was conducted in 1994 of the entire March AFB. From this survey, 30 sites were identified with a potential for environmental concerns. Of these 30, 12 sites were recommended for no further action and two sites are being evaluated as part of Site 8 in Operable Unit 2. In addition, five more Areas of Concern were identified and investigated.
BB-1,7; Q-4,7; N-4,7; U-2,7; S-2,7; Q-7,7; Area Target Butt; A-28,1; Small Arms Drainage Ditch	These are areas that were visually inspected with a potential for containing contamination. However, in a subsequent visual inspection, these areas were regraded, soil removed was removed, or recent burnings of area occurred removing any visual clues of the contamination. In the case of area S-2,7, hazardous materials were not apparently used in the area and the absence of vegetation was due to the poor soil conditions.
A-28,1; N-3,7; and P-2,7 and three Sites at the Veterans Administration Property.	These are areas where oil was applied to unimproved area for dust and weed control from 1941 to 1945. These areas are referred to "oiled mats" or "oil-treated surface drill areas." Records indicate six oiled mats existed: two on West March (P-2,7 and N-3,7), one on the Main Base (A-28,1), and three on Veterans Administration (VA), Riverside National cemetery. EBS Site A-28,1 is now in an area now cover by the active flightline parking apron, P-2,7 is beneath the Arnold Heights military housing area, and N-3,7 is discussed below.	P-2,7 is beneath the Arnold Heights military housing area. Since PCBs were produced from 1929 to 1977 and were present in many oils, PCBs could be present in these oiled mat areas. Although, these oiled mats are more than 50 years old, degradation of PCBs is very slow in soils and an unknown past exposure may have occurred. The current status of these oil mats are unknown and would be very difficult to determine. Recommend sampling after demolition of P-2,7 if reuse involves children.
Area A (Buildings 2274 and 2305)	Sampling to be conducted	Additional sampling for Area A.
N-3,7; Q-2,7, Q-6,7; Q-8,7; 549; 5044 (Site T); U-5,7; U-4,7, Z-3,7; Z; STP; Building 355; Building 458; Building 479; A-2,7; Z-2,7; Z-3,7SR	N-3,7; Q-6,7; Q-8-7; 5044(T); U-5,7; Q-4,7; STP; 458 - Samples and laboratory results below levels of concern. Q-2,7 - Site being investigated as part of RFA Site P. Site P has concentrations below levels of concern. 549 - Soil removed from stained area. Samples and laboratory results below levels of concern. Z-3,7; PAH levels above screening levels. Extent of contamination is unknown. Z; Consists of three areas. Levels of PCBs in Area B is above screening levels. However, the location precludes possible significant exposure. 355 - Contaminated ground water is part of the OU-2 ground water plume. Soil gas will be further investigated as part of OU2 Site 8. Former Skeet Ranges A-2,7; Z-2,7; Z-3,7SR - Lead levels were not above levels of concern.	Q-4,7, Tetra Tech recommends excavation due to the potential for asbestos containing material. However, this area is in the former Weapons Storage Area and is secured by a fence and locked gate so no current exposures are unlikely. However, future use should consider this potential exposure. Z-3,7- Tetra Tech recommends additional investigation. However, because of location, current exposure is unlikely but could be a future issue.
5 Areas of Concern Buildings with Crawl Spaces Gregory Well Building Transformer Spill 15th Air Force Headquarter Cooling Tower JP-4 Pipeline Lt. General Archie Old, Jr. Golf Course-Pesticide Mixing Area	Buildings with crawl spaces include residential and office buildings. The residential buildings are addressed in Section II.A. The pesticide levels in the office buildings are not a public health concern. Gregory Well Building-Sampled for PCBs and not detected. 15th Air Force Headquarter Cooling Tower. Soils around the cooling tower were sampled for hexavalent chromium and none was detected. However, the samples should have been analyzed for trivalent chrome since the hexavalent chromium would probably be reduced in the environment. Regardless, no public health issues would result from this area because of its location and land use. Golf Course and JP-4 Pipelines - Levels not of concern
Other Sites
Building 373 (355) Building 426 Building 434 Building 453 Former Incinerator	Buildings 373, 434, and 453 are industrial shops and Building 426 is a former laundry. Soil gas was sampled at these buildings, soil was sampled at the former incinerator, and ground water and soils were sampled at Building 373.	Soil gas concentrations from buildings 426, 434, and 453 are below levels of concern. Soil samples from the former incinerator are below levels of concern. Ground water samples from Building 373 identify it as a source of VOC contamination. Since this area is within the Operable Unit 2 ground water plume it is not a concern. Furthermore, the soil gas concentrations are below levels of concern.

1. Tetra Tech 1996b.
2. Tetra Tech 1997a.
3. Tetra Tech 1995b.

APPENDIX C: PUBLIC HEALTH ASSESSMENT CONCLUSION CATEGORIES

CATEGORY A: URGENT PUBLIC HEALTH HAZARD

This category is used for sites where short-term exposures (< 1 yr) to hazardous substances or conditions could result in adverse health effects that require rapid intervention.

This determination represents a professional judgement based on critical data which ATSDR has judged sufficient to support a decision. This does not necessarily imply that the available data are complete; in some cases additional data may be required to confirm or further support the decision made.

Criteria:

Evaluation of available relevant information* indicates that site-specific conditions or likely exposures have had, are having, or are likely to have in the future, an adverse impact on human health that requires immediate action or intervention. Such site-specific conditions or exposures may include the presence of serious physical or safety hazards, such as open mine shafts, poorly stored or maintained flammable/explosive substances, or medical devices which, upon rupture, could release radioactive materials.

* Such as environmental and demographic data; health outcome data; exposure data; community health concerns information; toxicologic, medical, and epidemiologic data.

ATSDR Actions:

• biologic indicators of exposure study
• biomedical testing
• case study
• disease and symptom prevalence study
• community health investigations
• registries
• site-specific surveillance
• voluntary residents tracking system
• cluster investigation
• health statistics review
• health professional education
• community health education
• substance-specific applied research

CATEGORY B: PUBLIC HEALTH HAZARD

This category is used for sites that pose a public health hazard due to the existence of long-term exposures (> 1 yr) to hazardous substance or conditions that could result in adverse health effects.

This determination represents a professional judgement based on critical data which ATSDR has judged sufficient to support a decision. This does not necessarily imply that the available data are complete; in some cases additional data may be required to confirm or further support the decision made.

Criteria:

Evaluation of available relevant information* suggests that, under site-specific conditions of exposure, long-term exposures to site-specific contaminants (including radionuclides) have had, are having, or are likely to have in the future, an adverse impact on human health that requires one or more public health interventions. Such site-specific exposures may include the presence of serious physical hazards, such as open mine shafts, poorly stored or maintained flammable/ explosive substances, or medical devices which, upon rupture, could release radioactive materials.

*Such as environmental and demographic data; health outcome data; exposure data; community health concerns information; toxicologic, medical, and epidemiologic data.

ATSDR Actions:

• biologic indicators of exposure study
• biomedical testing
• case study
• disease and symptom prevalence study
• community health investigations
• registries
• site-specific surveillance
• voluntary residents tracking system
• cluster investigation
• health statistics review
• health professional education
• community health education
• substance-specific applied research

CATEGORY C: INDETERMINATE PUBLIC HEALTH HAZARD

This category is used for sites when a professional judgement on the level of health hazard cannot be made because information critical to such a decision is lacking.

Criteria:

This category is used for sites in which "critical" data are insufficient with regard to extent of exposure and/or toxicologic properties at estimated exposure levels. The health assessor must determine, using professional judgement, the "criticality" of such data and the likelihood that the data can be obtained and will be obtained in a timely manner. Where some data are available, even limited data, the health assessor is encouraged to the extent possible to select other hazard categories and to support their decision with clear narrative that explains the limits of the data and the rationale for the decision.

ATSDR Actions:

Public health actions recommended in this category will depend on the hazard potential of the site, specifically as it relates to the potential for human exposure of public health concern. Actions on the recommendations may have occurred before the actual completion of the public health assessment.

If the potential for exposure is high, initial health actions aimed at determining the population with the greatest risk of exposure can be recommended. Such health actions include:

• community health investigation
• health statistics review
• cluster investigation
• symptom and disease prevalence study

If the population of concern can be determined through these or other actions, any of the remaining follow-up health activities listed under categories A and B may be recommended.

In addition, if data become available suggesting that human exposure to hazardous substances at levels of public health concern is occurring or has occurred in the past, ATSDR will reevaluate the need for any followup.

CATEGORY D: NO APPARENT PUBLIC HEALTH HAZARD

This category is used for sites where human exposure to contaminated media may be occurring, may have occurred in the past, and/or may occur in the future, but the exposure is not expected to cause any adverse health effects.

This determination represents a professional judgement based on critical data which ATSDR considers sufficient to support a decision. This does not necessarily imply that the available data are complete, in some cases additional data may be required to confirm or further support the decision made.

Criteria:

Evaluation of available relevant information* indicates that, under site-specific conditions of exposure, exposures to site-specific contaminants in the past, present, or future are not likely to result in any adverse impact on human health.

*Such as environmental and demographic data; health outcome data; exposure data; community health concerns information; toxicologic, medical, and epidemiologic data; monitoring and management plans.

ATSDR Actions:

The following health actions, which may be reommended in this category, are based on information indicating that no human exposure is occurring or has occurred in the past to hazardous substances at levels of public health concern. One or more of the following health actions are recommended for sites in this category:

• community health education
• health professional education
• community health investigation
• voluntary residents tracking system

However, if data become available suggesting that human exposure to hazardous substances at levels of public health concern is occurring, or has occurred in the past, ATSDR will reevaluate the need for any followup.

CATEGORY E: NO PUBLIC HEALTH HAZARD

This category is used for sites that, because of the absence of exposure, do NOT pose a public health hazard.

Criteria:

Sufficient evidence indicates that no human exposures to contaminated media have occurred, none are now occurring, and none are likely to occur in the future.

ATSDR Actions:

APPENDIX D

CALCULATIONS OF RISK FOR EXPOSURE SITUATIONS ASSUMPTIONS AND FORMULAS

Note: Body weights, inhalation rates, and ingestation rates represent default values established by U.S. EPA (US EPA, 1989). In actuality, these values vary among individuals as documented in the Exposure Factors Handbook, Update to Exposure Factors Handbook (US EPA 1997a) EPA/600/8-89/043 - U.S. EPA May 1989. Nontheless, the default values established by EPA were used.

LIST OF INHALATION CANCER SLOPE FACTORS AND REFERENCE DOSES
(FROM IRIS UNLESS OTHERWISE INDICATED)

GREEN ACRES MILITARY FAMILY HOUSING
RISK ESTIMATES - CRAWL SPACE SOILS

OFF-BASE PRIVATE WELLS
RISK ESTIMATES - GROUND WATER USE

GREEN ACRES MILITARY HOUSING
RISK ESTIMATES -INHALATION TO INDOOR AIR PESTICIDES
SAMPLE RESULTS^*
HOUSE 205

* Chemicalsthat were not detected or detected infrequently were treated as follows for the dose calculations:

• Aldrin's non-detects were treated as zero because it was not detected in any of the houses.
• alpha-BHC non-detects were treated as one-half of the detection limit because of it was detected in one house.
• beta and delta-BHC non-detects were treated as zero because they were not detected in any of the houses even though they are isomers and a contaminant of gamma-BHC (lindane) and lindane was detected in one house.
• gamma-BHC (lindane) non-detects were treated as one-half of the detection limit because of one detection.
• Endosulfan I non-detects were treated as zero because it was not detected in any of the houses.
• Endosulfan II non-detects were treated as one-half of the detection limit because it was detected in one house..
• Endosulfan sulfate non-detects were treated as zero because they were not detected in any of the houses even though it is a degradation product of endosulfan I and II and endosulfan was detected in one house.
• Endrin and endrin aldehyde non-detects were treated as zero because they were not detected in any of the houses.
• Endrin ketone non-detects were treated as one-half the detection limit because it was detected in one house. Endrin ketone is an impurity and degradation product of endrin but the one detection was not considered significant to treat endrin and endrin aldehyde as non-zero.
• Heptachlor was detected in seven houses so the detection limit or actual reported concentrations were used.
• Heptachlor epoxide non-detects were treated as one-half of the detection limit because it is a breakdown product of heptachlor even though heptachlor epoxide was not detected in any of the houses. Heptachlor was detected in seven houses.
• Methoxychlor non-detects were treated as one-half the detection level because it was detected in one house.
• Toxaphene was not detected but the detection limit was the highest of the chemicals analyzed for at 0.0001 g/kg. Toxaphene is not necessarily used as a pesticide but may be mixed in with lindane and DDT. The detection limits were high compared to the other pesticides analyzed for. High detection levels may mask the presence of toxaphene. Because a reference dose is not available, toxaphene could not be calculated in the hazard quotients and was treated as zero..

APPENDIX E

AMOUNT OF WATER PRODUCED FROM THE WATER TREATMENT PLANT AND PRODUCTION WELLS
MARCH AIR FORCE BASE
1964-1984

APPENDIX F

LIST OF CONSTITUENTS ANALYZED FOR IN DRINKING WATER SOURCES AND TAP WATER
1978-1983

APPENDIX G

PAST CONCENTRATIONS OF VOLATILE ORGANIC COMPOUNDS AND BORON IN DRINKING WATER SOURCES
MARCH AIR FORCE BASE
1978-1983

APPENDIX H

CONCENTRATIONS OF TRICHLOROETHENE AND TETRACHLOROETHENE IN OFF-BASE PRIVATE WELLS AND BPW-6 FROM 1986 TO 1990
MARCH AIR FORCE BASE

Notes:
1. Villeneuve, 1995.
2.    ND Indicates a non-detect for PCE and TCE unless otherwise indicated.
       -- indicates that a sample was not taken
       When a concentration of TCE is presented and one for PCE is not, PCE was sampled for but not detected.
3. Fletcher 1986.
4. Bachand 1989.

APPENDIX I

DISCUSSION ON CANCER RISKS AND THE AIR FORCE'S RISK ASSESSMENT OF GREEN ACRES MILITARY FAMILY HOUSING

The Air Force completed a risk assessment (RA) for breathing the air inside the Green Acres Housing using indoor air data they collected in 1997. The results of the RA showed that three houses exceeded the 10^-4 (1 in 10,000) excess cancer risk. This risk level is above the level U.S. EPA generally finds acceptable [Code of Federal Regulations, Volume 40, Section 300.430(e)(2)(i)(A)(2)]. Excess cancer risk is the added excess risk of one additional cancer case in a population. A 10^-4 excess cancer risk means that there is a possibility of one additional cancer case in a population of 10,000 equally exposed people. This one cancer case would be in addition to those cancer cases that would normally occur in an unexposed population. This rate is approximately 1 in 4 or roughly 250,000 people in the population of one million.

The cancer risk assessment is a mathematical approach (also called a quantitative approach) in calculating the potential excess cancer cases in a population. The mathematical approach consists of two parts. The first part is a calculation of how much an individual is exposed to (exposure assessment) and the second part is the toxicity assessment.

The exposure assessment is a calculation of the amount a person is exposed to. This is also called the dose. The dose is the amount of a substance, measured in milligrams (mg) per body weight, measured in kilograms (kg), per day. If a person was taking 100 mg per day of a drug and weighted 100 kg, their dose would be 100mg/100kg per day or 1 mg/kg per day.

To determine dose, we use site-specific and generic data derived from a number of sources. The data includes how much a person weighs, how much he or she ingests in one day, and how much air he or she inhales per minute. This data is specific to each individual. However, we are dealing with many potential individuals when we do a risk assessment. As a result, we look at the population to obtain information on the range of this data. For instance, body weight may vary from a few ounces for a new born baby to 400 pounds for an adult. For an adult, the body weight may range for 90 pounds up to 400 pounds (these values are just examples, people can weigh more or less). Once we know the range, we identify how many people are similar. For instance, how many people weigh 90 pounds, how many people weigh 95 pounds, etc. This is called frequency. From the range and frequency, we can understand the population distribution; in this case body weight. The Air Force's risk assessment for March Air Force Base used 70 kg (154 lbs) which is approximately the population mean for adult weight.

The Air Force risk assessment also used site-specific data. This data included the length of time per year an individual would be in the house; 350 days per year for a full time resident to 11 2/3 days per year for reservists using the houses temporarily. The Air Force also considered people using these houses from 9 and 30 years. The Air Force assumed that the individual was in the house 24 hours per day.

The dose calculations conducted by the Air Force were conservative (i.e., protective of public health) in two ways. First, the actual time people spend in the house is rarely 24 hours per day. The average time is 16 to 18 hours per day. Second, the calculation assumes that the entire dose enters the body. In reality, the dose entering the body is lower. One example of this is the oxygen we breathe. The content of oxygen in the air we breathe is approximately 21% while the amount we exhale is 10 to 15 percent. Hence, only one-quarter to one-half of the oxygen is absorbed. Similarly, chemicals, whether they are inhaled or ingested are not absorbed into the body 100 percent. The risk assessment assumes 100 percent absorption and therefore errs on being protective of human health.

As discussed above, the toxicity assessment is the second part of the risk assessment. Toxicity assessment refers to the evaluation of the available evidence regarding the potential for particular contaminants to cause adverse effects. This evidence is taken from animal studies and epidemiology studies on humans. Most of the human studies come from workers exposed to chemicals while on the job. From these studies, the observed relationship between a lifetime daily dose and observed tumor incidence is fitted to a mathematical model to predict the incidence at low doses. The model used is called the linearized multistage no-threshold model to generate what is sometimes considered an upper bound on cancer risk. Although the actual cancer risk cannot be known, it is thought that it will not exceed the upper bound, might be lower, and could be zero. The result from this model is the cancer slope factor or also known as potency factor or unit risk factor. This value is the plausible upper bound on excess lifetime risk of cancer per unit of dose (National Research Council 1994).

Risk assessment is characterized by uncertainty. Although scientists have learned much about environmental contaminants, limited data and knowledge still require researchers to make assumptions throughout the risk assessment process. As a result, the risk assessment/quantitative approach is only one-half of the cancer evaluation. The other half is the qualitative assessment. Qualitative assessments evaluate the quality and assumptions of the data that go into the mathematical calculations and the factors that determine if a substance poses a carcinogenic risk. These factors include the following:

• Weight-of-evidence approach,
• Mechanistic inference and species concordance,
• Route specificity,
• Role of epidemiologic data,
• Susceptible populations,
• Structure-activity relationships, and
• Chemical interactions.

These factors are discussed in detail in ATSDR's Cancer Policy Framework available on the web at http://www.atsdr.cdc.gov/cancer.html or from ATSDR at 1-888-42-ATSDR (1-888-422-8737). In short, these factors include the quality of the toxicity studies (choice of appropriate control groups, sufficient number of animals, administration route, dose selection, tumor types), the relevance of animal data to humans, human studies (usually people exposed to chemicals at work at places like pesticide plants), long-term animal bioassays, short-term tests, and how the chemical moves through the body at the molecular and cell levels.

From a review of the qualitative and quantitative data for the pesticides at March AFB, we concluded that the cancer risk probably does not exceed the acceptable risks determined by EPA.

APPENDIX J

ADDITIONAL INFORMATION ON DDT (INCLUDING DDD AND DDE) AND DIELDRIN

DDT, DDD, AND DDE
Information on inhalation exposures comes from studies of workers occupationally exposed to DDT. The primary exposure routes were likely inhalation and dermal (skin contact). Absorption of DDT from the lungs may not have been significant, and ingestion of trapped particles of DDT in the lungs is more likely (ATSDR 1994b).

From studies in workers exposed to high levels of DDT, the central nervous system seems to be the primary target of DDT toxicity. Studies in animals support this finding, and also suggest that the liver and reproductive system may also be affected by exposure to DDT. These animal studies typically involve chronic oral exposure to high levels of DDT. Animal studies indicate that exposure to high levels of DDT may cause liver tumors, but studies in occupationally exposed workers do not indicate an association between DDT exposure and cancer (ATSDR 1994b). The concentrations of DDT in indoor air at Green Acres Housing would result in much lower exposure levels than those seen in human and animal studies.

The lowest dose observed in animal studies where no adverse health effects were seen was more than 500 times higher than the highest dose estimated from exposure to DDT in Green Acres indoor air. The animal study involved an oral route of exposure, while Green Acres estimated inhalation exposure. Animal experimental data show that DDT is poorly absorbed via the lungs (ATSDR 1994b). For this evaluation, we assumed that DDT is absorbed in the lungs to the same degree as the gastrointestinal tract. As a result, our exposure scenario overestimates the true exposure to DDT in Green Acres indoor air. Given our exposure scenario, health effects are unlikely from exposure to DDT, DDD, and DDE in the Green Acres Military Family Housing.

DIELDRIN
To address the lack of inhalation studies, levels of dieldrin in indoor air were estimated that would result in an equivalent dose of an oral MRL for noncancer effects. A study investigating absorption of aldrin, a compound similar in chemical structure to dieldrin, in isolated perfused rabbit lungs indicated that absorption via the lungs occurred (ATSDR 1993). This indicated that inhalation is an important exposure route. Studies on the oral route of exposure indicate that dieldrin is rapidly absorbed and detected in the blood, liver and body fat (ATSDR 1993). Although experimental data on the inhalation route is limited, we assumed that there were no significant differences in metabolism and subsequent distribution in body tissues when dieldrin is inhaled versus ingested. Although differences in metabolism and absorption between routes of exposure are likely, from a review of the toxicological data available for dieldrin, we believe that the differences are minimal. Since dieldrin has been detected in similar organ systems from oral and inhalation exposure, we assumed that relatively equivalent exposure levels by inhalation or ingestion would result in roughly equivalent internal doses. Therefore, ATSDR estimated air comparison values based upon the oral MRLs for inhalation exposures to adults, children and infants that would be unlikely to produce adverse health effects. This value was used in the evaluation in Section II.

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