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PUBLIC HEALTH ASSESSMENT

FAIRCHILD AIR FORCE BASE
SPOKANE, SPOKANE COUNTY, WASHINGTON


APPENDIX D: Exposure Dose Calculations

This section provides the calculated exposure doses and assumptions used for each completedexposure pathway. The dose estimates for each of these pathways are discussed under the PathwaysAnalysis/Public Health Implications section of the document. The reader should be aware thatmaximum concentrations are used to calculate these doses. This represents a worst-case scenario thatmay overestimate actual exposure.

Some pathways include an estimated TCE dose from skin absorption and inhalation of vapors resultingfrom showering, bathing and other indoor water uses. The assumption, as can be seen in the followingtables, is that the combined dose from these two routes of exposure is equivalent to that of ingestion. This assumption is supported by ATSDR guidance although some mathematical models indicate thatthe inhaled dose for VOCs that volatilize from drinking water can be several times higher than theingested dose 48,49,50. Therefore, a combined dose based on three different routes of exposure wasgenerated for comparison with an oral LOAEL and calculation of cancer risk using an oral slope factor.

The following exposure dose equations were used in conjunction with the exposure assumptions given in the tables below.

Ingested Dose - Drinking Water

    IDdw = Cdw x IRdw x CFdw x EF x ED / BW x AT

Ingested Dose - Soil

    IDs = Cs x IRs x CFs x EF x ED / BW x AT

Dermally Absorbed Dose - Soil

    DADs = DAevent x EF x ED x SA / BW x AT

    DAevent = C x AF x ABS x ADJ




Pathway 1 Craig Road Landfill Non-Cancer Dose Calculations

Receptor
Population
MediaContaminantMax
Conc.
(ppb)
Exposure
Route
Ingestion
Rate
(liters/ day)
ExposureFrequency
(days/year)
Exposure
Duration
(years)
Body
Weight
(kg)
Averaging
Time
(days)
InhalationEstimated
Dose
(mg/kg-day)
LOAELHazard
Index
Vietzke
Village
Pregnant
Women
Drinking
water
TCE79Ingestion23500.7560274Yes
x 2
5.0E-030.182.8E-02
Vietzke
Village
Infant
Drinking
water
Nitrate10,500Ingestion0.643500.54182No1.61.61
Airway
Heights
Pregnant
Women
Drinking
water
TCE3.2Ingestion23500.7560274Yes
x 2
2.0E-040.181.1E-03
Scafco
Pregnant
Women
Drinking
water
TCE2.0Ingestion23500.7560274No6.4E-050.183.6E-04


Cancer Dose Calculations

Receptor
Population
MediaContaminantMax
Conc.
(ppb)
Exposure
Route
Ingestion
Rate
(liters/ day)
Exposure
Frequency
(days/year)
Exposure
Duration
(years)
Body
Weight
(kg)
Averaging
Time
(days)
InhalationEstimated
Dose
(mg/kg-day)
Cancer
Potency
Factor
Cancer
Risk
Vietzke
Village
Child
Adult
Drinking
water
TCE79Ingestion135051725550Yes
x 2
2.1E-030.0112E-05
21040
26a70
Airway
Heights
Child
Adult
Drinking
water
TCE3.2Ingestion135051725550Yes
x 2
1.1E-040.0111E-06
21040
21570
Scafco
Worker
Drinking
water
TCE2.0Ingestion2250257025550No2.0E-050.0112E-07



Pathway 2

Wastewater Lagoons Non-Cancer Dose Calculations
Receptor
Population
MediaContaminantMax
Conc.
(ppb)
Exposure
Route
Ingestion
Rate
(liters/ day)
Exposure
Frequency
(days/year)
Exposure
Duration
(years)
Body
Weight
(kg)
Averaging
Time
(days)
InhalationEstimated
Dose
(mg/kg-day)
LOAELHazard
Index
West Thorpe
Road
Pregnant
Women
Drinking
water
TCE1.5Ingestion23500.7560274Yes
x 2
9.6E-050.185.3E-04



Cancer Dose Calculations

Receptor
Population
MediaContaminantMax
Conc.
(ppb)
Exposure
Route
Ingestion
Rate
(liters/ day)
Exposure
Frequency
(days/year)
Exposure
Duration
(years)>
Body
Weight
(kg)
Averaging
Time
(days)
InhalationEstimated
Dose
(mg/kg-day)
Cancer
Potency
Factor
CancerRisk
West Thorpe
Road
Child
Adult
Drinking
water
TCE1.5Ingestion135051725550Yes
x 2
5.0E-050.0116E-07
21040
21570



Pathway 3

No-Name Ditch Non-Cancer Dose Calculations
Receptor
Population
MediaContaminantMaximum
Concentration
(ppm)
Exposure
Route
Ingestion
Rate
(mg/day)
Exposure
Frequency
(days/year)
Exposure
Duration
(years)
Body
Weight
(kg)
Averaging
Time
(days)
Estimated
Dose
(mg/kg-day)
MRL/RfD
(mg/kg-day)
Hazard
Index
West Thorpe
Road
Older
Children
Soil/
Sediment
Arsenic42.9Ingestion100120104018259.8E-050.00030.3
Dermal
Contact
See
Below
West Thorpe
Road
Older
Children
Soil/
Sediment
TPH860Ingestion100120104018252.6E-030.03a0.1
Dermal
Contact
See
Below b
a = RfD for pyrene used as a surrogate value
b = Dermal Assumptions = SA=5,044, AF=1 mg/cm2, ABSarsenic=0.045, ABSTPH=0.1


Cancer Dose Calculations

Cancer Dose Calculations

Receptor
Population
MediaContaminantMax
Conc.
(ppm)
Exposure
Route
Ingestion
Rate
(mg/day)
Exposure
Frequency
(days/year)
Exposure
Duration
(years)
Body
Weight
(kg)
Averaging
Time
(days)
Estimated
Dose
(mg/kg-day)
Cancer
Potency
Factor
Cancer
Risk
EPA
Cancer
Group
West Thorpe
Road
Older Child
Adult
Soil/
Sediment
Arsenic42.9Ingestion1001201040255507.7E-061.71E-05A
Dermal
Contact
See
Below b
121570
b = Dermal Assumptions = SA=5,044, AF=1 mg/cm2, ABSarsenic=0.045

Pathway 4

Tordon Non-Cancer Dose Calculations
Receptor
Population
MediaContaminantMax
Conc.
Exposure
Route
Ingestion
Rate
Exposure
Frequency
(days/year)
Exposure
Duration
(years)
Body
Weight
(kg)
Averaging
Time
(days)
Estimated
Dose
(mg/kg-day)
RfD
(mg/kg-day)
Hazard
Index
West Thorpe
Road
Older
Children
Drinking
water
Tordon13.2
ppb
Ingestion2 l/day350104018251.3E-030.070.02
West Thorpe
Road
Older
Children
SoilTordon0.015
ppm
Ingestion100
mg/day
12010401825
Dermal
Contact
See
Below b
West Thorpe
Road
Older
Children
Surface
Water
Tordon0.16
ppb
Ingestion0.05 l/day12010401825
Dermal
Contact
See
Below b
b = Dermal Assumptions = SA=5,044, AF=1 mg/cm2, ABSTordon=0.1


Cancer Dose Calculations
No cancer slope factor is available for quantitative estimation of cancer risk from Tordon exposure.

Pathway 5.

On-Base Activities Non-cancer Dose Calculations
Receptor
Population
MediaContaminantMaximum
Concentration
(ppm)
LocationTotal Dose
(mg/kg-day)
MRL
(mg/kg-day)
RfD
(mg/kg-day)
Hazard
Index
Background b
On-Base
Workers
Soil/
Sediment
1,1,2,2-TCA2050Bldg. 24471.2E-030.3NA0.004NA
acetone7450Bldg. 24474.2E-0320.10.04NA
benzene300Bldg. 24471.7E-04NANANANA
butanone3100Bldg. 24471.7E-03NA0.60.003NA
methylene
chloride
1500Bldg. 24478.4E-040.060.060.01NA
TCE581PS-103.3E-040.002NA0.2NA
TPH36000PS-103.3E-02NA0.03 a0.7NA
INORGANIC SUBSTANCES
arsenic238AOC #81.0E-040.00030.00030.39.3
beryllium0.89WW-12.3E-07NA0.0050.000050.8
cadmium158SW-114.0E-050.00070.00050.080.72
cobalt38.1WW-19.7E-06NANANA11
manganese26000AOC #86.6E-03NA0.140.05663.5
lead1564FT-24.0E-04NANANA14.9
thallium43.1WW-11.1E-05NA0.000080.22.5 b
a = RfD for pyrene. Used as a surrogate.
b = 90th percentile background soil values for Spokane Basin taken (Ref. 29).
c = High normal background soil values derived from on-base samples (Ref. 4).
Assumptions: IRs =100 mg/kg, EF=52 days/year, ED=25 years, BW=70 kg, AT=9125 days, SA=5,044, AF=1 mg/cm2, ABSarsenic=0.045, ABSinorganics=0.01, ABSVOC=0.03, ABSTPH=0.1


Pathway 5

On-Base Activities (cont') Cancer Dose Calculations
Receptor
Population
MediaContaminantMaximum
Concentration
(ppm)
LocationDose
(mg/kg-day)
Cancer
Potency
Factor
Cancer
Risk
EPA
Cancer
Group
On-Base
Workers
Soil/
Sediment
1.1.2.2-TCA2050Bldg. 24474.1E-040.28E-05NA
arsenic238AOC #83.1E-051.56E-05A
beryllium0.89WW-18.4E-084.34E-07B2
benzene300Bldg. 24476.0E-050.0292E-06B2
methylene chloride1500Bldg. 24473.0E-040.00752E-06D
TCE581PS-101.2E-040.0111E-06B2
Assumptions: IRs =200 mg/kg, EF=52 days/year, ED=25 years, BW=70 kg, AT=25550 days, SA=5,044, AF=1 mg/cm2, ABSarsenic=0.045, ABSinorgaics=0.01, ABSVOC=0.03


APPENDIX E: Response to Public Comments

COMMENT 1: Atmospheric testing has not been done for this report. The reader isreferred to SCAPCA for further information. SCAPCA information, however, is notincluded in the report.

The Spokane County Air Pollution Control Authority (SCAPCA) currently evaluates emissionsdata from the Craig Road Landfill that Fairchild Air Force Base is required to collect. SCAPCAuses measurements of volatile organic compounds (VOCs)emitted from vents and air strippingtowers to determine whether these contaminants are at levels of concern in the ambient(outdoor) air at the perimeter of the landfill. As noted in completed exposure pathway 1b (page28), the Department of Ecology will take further action, if necessary, under the Controls for NewSources of Toxic Air Pollutants rule (WAC 173-460) as mandated by the Washington Clean Air Act (70.94 RCW).

For further information regarding air emission monitoring at the Craig Road Landfill, contact:

Kelle Vigeland
Spokane County Air Pollution Control Authority (SCAPCA)
1101 W. College Ave.
Spokane, WA 99201
509-456-4727 ext. 106

COMMENT 2: Warrior Park on Fairchild Air Force Base has tested high for leadcontaminants. The Health Assessment acknowledges the potential health risks to thechildren who play on that field and recommends further testing. We recommend that thebare dirt areas of the park should be fenced and made off limits to children until a healthrisk assessment can be completed.

The base completed extensive soil sampling for lead at Warrior Park in November 1997 inresponse to a recommendation made by DOH in the Draft for Public Comment release of thishealth assessment. The results of this sampling indicate that lead in surface soil at Warrior Parkposes no apparent public health hazard. The new data has been incorporated into this documentand is discussed under completed exposure pathway 5 (page 39).

COMMENT 3: We commend the Air Force for supplying Vietzke Village and Scafco Co. with water from Fairchild AFB.

Comment noted.

COMMENT 4: Pg 12 - I don't feel a true assessment of the health risk can be foundbecause not enough knowledge of quantity of how many different contaminants flowed inFairchild easement. It was my understanding the health department was going to dotesting on the easement soil. I feel the findings should not be "no apparent health risk" Itcannot be known without a doubt.

DOH considered the environmental sampling data from the Remedial Investigation for theFairchild Easement (No-Name Ditch) to be adequate. Additional sampling and analysis fortotal petroleum hydrocarbons (TPH) initiated after the RI was also considered. Using thesedata, exposure was estimated to be below a level of concern. DOH agrees that the risk fromexposure to soil and sediment in the Fairchild Easement (No-Name Ditch) can not be knownwith certainty. Effects from exposure to environmental contaminants are seldom, if ever,known with certainty. The conclusions made here are based on the best available science.

COMMENT 5: Pg 27 - We have lived here since 1966. Fairchild easement has never gone dry even in droughts.

This observation has been noted in the text under completed exposure pathway 3 (page 33).

COMMENT 6: Pg 30 - On cancer effects, after reading the first sentence, how can yousay at the end of statement there's no health hazard from drinking Tordon.

This section was revised for clarity. DOH considers the cancer risk for West Thorpe Road arearesidents exposed to Tordon in drinking water, soil and surface water to be slight or insignificant. The first sentence was intended to indicate that an estimate of cancer risk could not be calculatedbecause a cancer potency factor for picloram (active ingredient in Tordon) is not available. However, data from the National Toxicology Program of the National Institutes of Health showpicloram to be only a possible weak liver carcinogen in rats with no effect in mice. Such a weakresponse indicates that the cancer potency of picloram is not large. Therefore, the limitedexposure of West Thorpe Road residents is expected to result in only a slight or insignificantincrease in cancer risk.

COMMENT 7: Pg 43 - There is no mention of contamination in beef or birds eating grassor drinking water. What happens when humans eat this meat?

Animals at the bottom of the food chain can eat low levels of a contaminant in plants or waterand concentrate that contaminant in a specific body tissue (e.g., fat). This animal can then beeaten by another species higher in the food chain which will further concentrate the contaminantin its own body tissue. This process is called bioaccumulation. Stock or wild game in the WestThorpe Road area could have ingested contaminants from No-Name Ditch and area well water.None of these contaminants are expected to have bioaccumulated to any substantial extent. Therefore, exposure to meat ingested from stock or wild game in the West Thorpe Road arearepresents no apparent public health hazard.

COMMENT 8: Pg45 - Tordon - No mention of what happens when ingested with other contaminants.

No data are available to determine whether Tordon would have exerted an increased toxic effectwhen combined with exposure to other contaminants. Such increases in toxicity have beendemonstrated between chemicals at high doses and can exceed the sum of the independent effects(synergy). However, there is no evidence that this could occur at the very low levels found atthis site. The potential for the additive effects of multiple exposures to West Thorpe Road arearesidents was assessed and found not to be of concern (see page 38).

COMMENT 9: I have read this report hoping at last we'd have some answers to ourquestions but as usual there are only more questions. To me the report is only aneducated guess lacking facts. No more no less.

This report does not conclusively state that there is no public health hazard from the exposuresdiscussed. The uncertainty of health risk assessment concedes that if exposure is occurring orhas occurred, then risk is never zero. The conclusion category of "no apparent public healthhazard" indicates that while exposures did occur they were below a level of public healthconcern. The conclusion category "no public health hazard" is used only when exposure is absent.

It is important to understand that although risk from a specific hazardous waste site can be non-existent if people are not in contact with site-related contaminants, risk associated withenvironmental contamination, in general, is never zero. This unfortunate fact is due to thewidespread distribution of pollutants in our environment.

COMMENT 10: When I finally contacted the A.T.S.D.R. about our health problems, Iwas told that they had not been aware of any health problems at the site and as a result wewere on the bottom of the investigation list. And now that so much time had gone by andwe were the only remaining of the original residents, there were not enough "members"involved to justify moving the site up on the list. This response despite the fact that theA.T.S.D.R. was informed that I had documented clinical proof of brain damage,neurological impairment, immune system dysfunction, liver enlargement and impairment,cardiac dysfunction, and toxic acquired porphyria involving two children and an adult. Logic dictated that the many pregnant mothers who had come and gone at this site couldeasily be dealing with similar problems.

DOH has not received any clinical proof that residents exposed to contaminants related to theFairchild Air Force Base have suffered adverse health effects. This is not to say that such healtheffects are not present in the exposed community. The issue is whether site related exposurecould be responsible for these health effects. The Draft for Public Comment noted that childrenborn to pregnant women living at Vietzke Village prior to August 1989 could have been at lowrisk for heart defects. This assessment has now been expanded and discusses the potential forbirth defects in general. However, the available data are inconclusive and do not provide a directlink between birth defects and TCE in drinking water. What is also unclear is the amount ofTCE in drinking water and the duration of exposure required to elicit such adverse health effects.

The other health effects noted in this comment are not expected to result from exposure to site-related contaminants at levels found near the base.

COMMENT 11: After eight years of waiting for a health assessment, we receive a draftreport, which, again, totally ignores the "human" aspect of the problem and restricts itselfto the limited and incomplete residential water well tests done at the site. The first testdone while the wells were still in active use, and the second test done after the wells weresealed and no longer pumping.

The health assessment uses environmental data to determine past, present or future exposure tocontaminants and the likelihood that adverse health effects will result from this exposure. Theuse of sampling data is essential to the health assessment. Also important to the healthassessment process is the measurement of adverse health effects in exposed populations. Lack ofconsideration of disease occurrence in the exposed populations near the base appears to be thecriticism here. As is often the case at hazardous waste sites, exposed populations are not largeenough to detect increases in the incidence of disease. This is the situation with the exposedpopulations living near the base and thus, the assessment relied on environmental data toestimate the potential for adverse health effects to occur.

A crude analysis of cancer incidence in the 99022 zip code that was not included in the Draft forPublic Comment is included in this final release. No substantial increases in cancer were notedfor this zip code when compared with state rates. A slight increase in lung tumors was noted (21observed compared to 14.2 expected). The reason for this increase is not known but is unlikelyto be related to TCE exposure. The results and limitations of this analysis are discussed in theHealth Outcome Data section of this document (page 55).

COMMENT 13: Five rounds of testing on MW-85 between 1/90 and 4/91 consistentlyshowed TCE at dangerously high levels (890; 1,900; 2,300; 2,600 and 2,800 ppb). And yet,MW 79, 80 & 84 on the extreme northwest and northeast corners of Vietzke Villageshowed no detectable levels of TCE. The ground water flow was demonstrated to benorth-northeast.....so, the obvious question is, "Where did all that TCE go?" Theconclusion is obvious with the Vietzke Village wells located between those points.

There is no doubt that the Vietzke Village wells were contaminated with TCE. DOH expressedconcern that TCE in the Vietzke wells could have been higher prior to sampling. This concern isbased primarily on the variability of TCE levels detected in MW-85 which ranged from 360 to2,800 ppb with no established trend. Such a fluctuation could have occurred in the Vieztkewells. However, it is unlikely that levels ever reached those found in MW-85 due to differencesin location and design of the wells.

More information has been added to the discussion of this exposure pathway (see completedexposure pathway 1a, page 16). The discussion now cites studies that "suggest" the potentialfor other birth defects in addition to those related to heart development. These studies areinconclusive as to the amount and duration of TCE exposure required to elicit such effects but,considered together, suggest that this potential exists. It is important to note that these studiesare inadequate to determine whether the amount of TCE exposure at Vietzke Village wassufficient to cause birth defects. Therefore, this pathway remains an indeterminate public health hazard.

COMMENT 14: Another point of concern is that MW-84 on the extreme northwestcorner of Vietzke Village did test positive for 10,000 mg/l of Total PetroleumHydrocarbons. Unfortunately, inconsistent round testing does not allow for any pattern development.

This result comes from a sample taken from monitoring well MW-84 in August 1990. Previoussamples from this well were non-detect for Total Petroleum Hydrocarbons (TPH). A subsequentsample taken in February 1991 was also non-detect. The Remedial Investigation suggests thatthis unexpected result may have been caused by contamination introduced during the samplingprocedure. The fact that TPH was not detected in this well prior to or after this sample supportsthis possibility. TPH is not a contaminant associated with the Craig Road Landfill. TPHcontamination of drinking water wells is often the result of spilled gasoline or other types ofpetroleum products (e.g., heating oil, lubricants).

COMMENT 15: As part of the public health assessment, I took part in the interviews andmade available to the review committee written documentation of the serious healthconcerns involving my family. And yet, the report draft ignores both the proven healthproblems of this family and the obvious conclusion that the TCE levels were probablymuch higher than the limited residential well testing indicated. The interviews are onlyaddressed generally under the "Community Health Concerns" section and not treated as alegitimate part of the actual risk assessment.

The Community Health Concerns section is a legitimate part of the document. All healthconcerns gathered by DOH through personal interviews or by any other means are takenseriously. Many concerns are also addressed within the Pathways Analysis/Public HealthImplications section of the document. The purpose of the Community Health Concerns sectionis to ensure that these concerns are put in writing and addressed individually.

DOH does not dispute that real health problems exist in the exposed community. However, theassessment discusses only those health effects that might be related to the exposure in questionaccording to the available science. This assessment cannot provide an absolute answer as to thelikelihood that a health effect will or will not occur as a result of environmental exposure. Thepossibility that levels of TCE in the Vietzke Village prior to initial sampling could have beenhigher was noted in the discussion of this pathway (see page 21). However, no data are availablewith which to determine TCE levels in the Vietzke wells prior to July 1989.

COMMENT 16: The draft states, "If a pregnant woman drank that water, and it wascontaminated with higher levels of TCE, the child might have been at low risk for heartdefects. That risk would only be expected in about five births per thousand." How does thedraft justify it's risk statistics when I have two children who both developed cardiacdysfunction. One child's exposure began in utero, but the other child's exposure did notbegin until she was nine months old. Both children's environmental exposure was limitedtotally to this site.

This risk was derived from a single study and used in order to give the reader an idea of what a"low" risk might be. This final release has been revised to more accurately reflect the uncertaintyof the association between TCE in drinking water and birth defects. In addition, potentialassociations with birth defects other than cardiac are now discussed. The nature of the evidenceassociating TCE in drinking water with birth defects is not sufficient to determine whether theamount of TCE in the Vietzke wells was high enough to cause such effects.

The available data suggest that the developing fetus would be affected by TCE in drinking waterat lower concentrations than children or adults. The amount of TCE detected in the Vietzkewells is not anticipated to pose a public health hazard to adults or children. Levels of TCE priorto initial sampling of the Vietzke wells are not expected to have been high enough to pose apublic health hazard for children or adults.

COMMENT 17: The draft further states that "TCE is the only contaminant of concerndetected in the Vietzke wells." First, and most importantly, is the fact that the threeresidential wells (RW9-11) in Vietzke Village were never tested for anything but volatiles. Tests for heavy metals were never conducted as they were on the other monitoring wells. Furthermore, engineers over this site informed me that the Vietzke Village wells were notproperly constructed and could not be a part of the official testing process. That was partof the reason extra monitoring wells were installed. Monitoring wells which do notaccurately reflect previous groundwater movement now that the Vietzke Village wells are no longer pumping.

The Vietzke Village drinking water wells were tested for metals and nitrate in September 1982,July 1985, January 1986 and May 1986. Elevated nitrate levels were detected at a maximum of10.5 ppm in January 1986 while all metals were below detection. Analysis of monitoring wellsamples near the landfill indicate that the landfill is not a substantial source for metals or nitrate ingroundwater. The highest levels of nitrate in groundwater found in the area were in monitoringwells MW-78 and MW-80 both of which are apparently located near a septic drain field servingVietzke Village. Septic systems are common sources of nitrate contamination in groundwater. The presence of nitrate in the Vietzke Village wells is addressed under completed exposurepathway 1a (page 16).

The major health hazard associated with nitrates in drinking water is the development ofmethemoglobinemia in infants. This condition results in decreased oxygen delivered to bodytissue by the blood. This problem is directly linked to nitrite toxicity which is created from thereduction of nitrate in the body. A nitrate level of 10.5 ppm slightly exceeds EPA's MCL of 10ppm for nitrates in drinking water. The MCL for nitrite is set at 1 ppm. Existing evidence hasshown infants to be at risk for methemoglobinemia at levels above 20 ppm. More recentevidence has indicated that pregnant women are at risk for spontaneous abortions at levels above20 ppm. There is inconclusive evidence that nitrate in drinking water can cause birth defects atlevels near the MCL. The risk for these health effects at levels detected in the Vietzke wellscould be of concern depending on the amount of nitrate/nitrite in the diet.

Drinking water with nitrate or nitrite levels in excess of their respective MCLs should not beused for the preparation of infant feeding formulas. Pregnant women should not drink watercontaining nitrate levels above the MCL. In general, drinking water with nitrate levels above theMCL should be used for non-drinking purposes only.

COMMENT 18: Blood tests done on my daughter a full two years after cessation ofexposure still showed arsenic above background levels, and manganese levels in my sonwere above normal. Documented medical symptoms for all three family members areconsistent with arsenic, manganese, lead and TCE poisoning. Again, strong "human"indications that exposure at this site was much higher than indicated by the limited residential well tests.

There is no evidence to suggest increased exposure to metals for residents living at the VietzkeVillage. Elevated levels of arsenic in soil were detected in No-Name Ditch but this exposurepathway was estimated to pose no apparent public health hazard. Manganese was not detectedat elevated levels in off-base groundwater or soil. We all have some level of metals in our bodiesbecause they are naturally occurring elements and in some cases essential to our health. Themeasurement of metals in the body (e.g., blood, urine, feces, tissue, hair) is useful, therefore,only in comparison with established ranges of normalcy in the general population.

Arsenic levels in blood are considered an unreliable measure of environmental exposure sincearsenic is rapidly removed from the blood. This method can be effectively used in the workplaceto measure short-term (e.g., daily) arsenic exposure at the end of a workday. Typical bloodlevels in unexposed people are less than 1 ug/l. Arsenic in urine is a more reliable measure andcan remain elevated up to several days after exposure. Arsenic in urine below 30 ug/l isconsidered to be normal. However, contribution from the diet must be considered. Relativelynon-toxic forms of organic arsenic are excreted at high levels in urine after ingestion of fish. Therefore, distinguishing between organic arsenic and the potentially hazardous inorganic form isessential if an elevated result is obtained. Arsenic in hair has be used as an indicator of long-termexposure since levels can remain elevated for several months.

Manganese is an essential nutrient and is present in many foods. Normal ranges of manganese inbody tissues or fluid were not located, but workplace exposure has been shown to increase blood and urine levels.

COMMENT 19: Extensive neuro-psychological testing done on both children revealsdamage consistent with chemical exposure and damage. My son's neurological damage isso severe (due to his in utero exposure) that he is unable to manage his life withoutextensive pharmaceutical management. He has severe obsessive-compulsive disorder,attention-deficit disorder, hyperactivity and rage management problems. All three of ussuffer from varying neurological problems ranging from memory loss to Raynaud'sSyndrome.

The levels of TCE in Vietzke Village drinking water represent no apparent public health hazardto the general population. However, there is a concern that children born to women who drankVietzke Village water while pregnant prior to August 1989 could have been at some risk forbirth defects. Some of the birth defects that may be associated with TCE in drinking waterinvolve neural tube defects. Such a defect could result in abnormal nervous system development. As noted throughout this document, this association is not strong and requires further study. Although the medical conditions noted in this comment could be related to such a birth defect,the association of this defect with the TCE in your drinking water remains unclear.

COMMENT 20: All three of us have laboratory proof that we have acquired forms ofporphyria consistent with chemical poisoning. And there is no family history for any ofour many acquired health problems. Again -- so many strong indications that all of ourhealth problems are directly related to the "limited" exposure at this site.

This concern is addressed in the Community Health Concerns section of the document (page 58,#1). Porphyria is a difficult disease to diagnose and has been associated with various chemicalexposures. DOH could find no direct evidence, however, associating TCE, Tordon, or nitratewith this condition. Any diagnosis of porphyria should be made by a qualified physician. Please call Robert Duff at 1-888-5TOXICS (1-888-586-9427), if you would like a list of physicians in the Spokane area that specialize in environmental health.

COMMENT 21: I know all too well from my families many years of poor health andsuffering that there is no "if" involved in our exposure. And I also know that there weremany other pregnant mothers who came and went during the many years this site wasactively affected by those contaminated wells. I have patiently tried to work with andthrough the agencies entrusted with the protection of "human health." I was toldrepeatedly by the A.T.S.D.R. that if a "probable" risk was found at this site, thatinformation would be given to the general public for their protection.

This health assessment did find evidence of both current and past exposure to nearby residents. This exposure is discussed as five completed exposure pathways in the Pathways Analysis/PublicHealth Implications section of this document. The only exposure of potential concern to off-base residents involved pregnant women exposed to TCE and nitrate in drinking water prior toAugust 1989 at Vietzke Village The risk of adverse birth outcomes for pregnant womenexposed during this period is not clear. Further research may determine that the levels of TCEand nitrate in Vietzke Village drinking water may not have been a public health hazard. However, until more research is done this risk remains an indeterminate public health hazard. The available evidence indicates that the number of births during the exposure period would beinsufficient to detect any increase in birth defects or other adverse birth outcomes that may havebeen associated with TCE and nitrate in drinking water.

This final health assessment, the previously released Draft for Public Comment, and press releasealong with the upcoming public meeting represent DOH and ATSDR's effort to communicatethe findings of this health assessment.


APPENDIX F:

Table F1.

ATSDR Public Health Assessment Conclusion Categories
CategoryDefinitionCriteria
A. Urgent public health hazard This category is used for sites that pose an urgentpublic health hazard as the result of short-termexposures to hazardous substances.
  • evidence exists that exposures have occurred, are occurring, or are likely to occur in the future AND
  • estimated exposures are to a substance(s) at concentrations in the environment that, upon short-term exposures, can cause adverse health effects to any segment of the receptor population AND/OR
  • community-specific health outcome data indicate that the site has had an adverse impact on human health that requires rapid intervention AND/OR
  • physical hazards at the site pose an imminent risk of physical injury
  • B. Public health hazardThis category is used for sites that pose a publichealth hazard as the result of long-term exposuresto hazardous substances.
  • evidence exists that exposures have occurred, are occurring, or are likely to occur in the future AND
  • estimated exposures are to a substance(s) at concentrations in the environment that, upon long-term exposures, can cause adverse health effects to any segment of the receptor population AND/OR
  • community-specific health outcome data indicate that the site has had an adverse impact on human health that requires intervention
  • C. Indeterminate (potential) public health hazardThis category is used for sites with incompleteinformation.
  • limited available data do not indicate that humans are being or have been exposed to levels of contamination that would be expected to cause adverse health effects; data or information are not available for all environmental media to which humans may be exposed AND
  • there are insufficient or no community-specific health outcome data to indicate that the site has had an adverse impact on human health
  • D. No apparent public health hazardThis category is used for sites where humanexposure to contaminated media is occurring orhas occurred in the past, but the exposure isbelow a level of health hazard.
  • exposures do not exceed an ATSDR chronic MRL or other comparable value AND
  • data are available for all environmental media to which humans are being exposed AND
  • there are no community-specific health outcome data to indicate that the site has had an adverse impact on human health
  • E. No public health hazardThis category is used for sites that do not pose apublic health hazard.
  • no evidence of current or past human exposure to contaminated media AND
  • future exposures to contaminated media are not likely to occur AND
  • there are no community-specific health outcome data to indicate that the site has had an adverse impact on human health


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