PUBLIC HEALTH ASSESSMENT
ROCKY MOUNTAIN ARSENAL
ADAMS COUNTY, COLORADO
The contaminants released into the environment at RMA could be of public health concern andcould result in adverse health effects. However, for adverse health effects to occur, twoprinciple criteria must be met. The exposure pathway must be completed, and the exposure dosemust be sufficient to cause adverse health effects.
An environmental release does not always result in exposure. A person is exposed to acontaminant only if the person comes in contact with the contaminant by breathing, eating, ordrinking a substance containing the contaminant or by skin contact with a substance containingthe contaminant. Several factors determine the type and severity of health effects associatedwith such an exposure. Those factors include the concentration of the contaminant, thefrequency or duration of exposure or both, the route(s) or pathway(s) of exposure, and thepossibility of exposure to a combination of contaminants. Once exposure takes place,characteristics such as age, sex, nutritional status, genetics, lifestyle, and health status of theexposed individual influence how the individual absorbs, distributes, metabolizes, and excretesthe contaminant. The combination of those factors and characteristics determines the healtheffects that could result from exposure to a contaminant.
ATSDR considers the previously described physical and biologic characteristics whendeveloping health guidelines. Toxicological profiles and case studies in environmental medicineprepared by ATSDR summarize chemical-specific toxicologic and adverse health effectsinformation. Health guidelines, such as ATSDR's minimal risk level (MRL) and EPA'sreference dose (RfD) and cancer slope factor (CSF) are included in these ATSDR reports, aswell as in various databases. ATSDR public health professionals use those health guidelines todetermine an individual's potential for developing adverse non-cancerous health effects or cancer or both from exposure to a hazardous substance.
Health guidelines provide a basis for comparing estimated exposures with concentrations ofcontaminants in different environmental media (soil, air, water, and food) to which people mightbe exposed. An MRL is an estimate of the daily human exposure (including sensitivesubpopulations) to a contaminant that a person can experience without an appreciable risk ofadverse non-cancerous health effects over a specified duration of exposure (acute, <14 days;intermediate, 15-365 days; chronic > 365 days). Oral MRLs are expressed in units ofmg/kg/day. MRLs are not derived for dermal exposure. The method for deriving MRLs doesnot include information about cancer; therefore, an MRL does not imply anything about thepresence, absence, or level of cancer risk. An EPA RfD is an estimate of the daily exposure ofthe human population, including sensitive subpopulations, that is likely to be without appreciablerisk of adverse non-cancerous health effects during a lifetime (70 years). For cancer-causingsubstances, EPA has established the CSF as a health guideline. The CSF is used to determinethe number of excess cancers expected from exposure to a contaminant. Health guidelines aregenerally considered to have uncertainty (nature of calculation), and therefore, health guidelines should not be viewed as strict scientific definitions of what is toxic and what is nontoxic.
To link a site's human exposure potential with health effects that may occur under site-specificconditions, ATSDR estimates human exposure to site contaminants measured in differentenvironmental media (ATSDR, 1992c). The following relationship is used to determine theestimated exposure to the site contaminant:
- ED = (C x IR x EF) / BW
ED = exposure dose (mg/kg/day)
C = contaminant concentration (ppb)
IR = intake rate (L/day)
EF = exposure factor (hours, days, years)
BW= body weight (kg)
ATSDR uses standard intake rates for ingestion of water and soil. The intake rate for drinkingwater is 2 L/day for adults and 1 L/day for children. For incidental ingestion of soil, the intakerate is 100 mg/day for adults, 200 mg/day for children, and 5,000 mg/day for children with picabehavior (repeated ingestion of non-nutritive substances). Standard body weights for adults andchildren are 70 kg and 10 kg, respectively. The maximum contaminant concentration detectedin a specific medium at a site is generally used to determine the estimated exposure. This worst-case scenario enables ATSDR to determine the most severe health effects that might occur andassists us in determining whether more realistic scenarios should be evaluated. When unknown,the biological absorption from environmental media (soil, water, etc.) is assumed to be 100%.
Individuals have been exposed to multiple contaminants from incidental ingestion ofcontaminated soil at RMA. However, only very limited data on the health effects of exposure tomultiple contaminants are available. Effects of exposure to multiple contaminants can beadditive, synergistic (greater than the sum of the single contaminant exposures), or antagonistic(less than the sum of the single contaminant exposures). Also, simultaneous exposure tomultiple contaminants that are known or probable human carcinogens could increase the exposedperson's risk of developing cancer. Unless information is available to evaluate multipleexposures, ATSDR's evaluation of exposures in most public health assessments is limited toindividual contaminant exposures.
Only the completed exposure pathways, summarized in Table 15, are discussed in this section. Contaminants associated with the Irondale/Western Plume (Table 7 - Off-Post Alluvial AquiferGroundwater) will be briefly discussed prior to discussing Tables 13 and 14 that contain thecontaminants of public health concern in private wells. The potential exposure pathways, asdelineated in Table 18 (which includes irrigation well contaminants in Table 17), are notdiscussed here. Rather, the Conclusions and Recommendations sections of this Assessmentfocus on actions that are being taken or need to be taken to prevent or minimize those potential exposure pathways pointed out in this Assessment.
Evaluation of Table 7 - Off-Post Alluvial Aquifer Groundwater -
There are 8-10 residences (with ±3 persons per household, 30 people maximum) of concern in this area (see Table 3). Therefore, approximately 30 persons may be exposed to theIrondale/Western Plume contaminants listed in Table 7. Those contaminants -- 11DCLE,12DCE, TCLEE, and TRCLE -- have emanated from multiple off-site industrial sources, notfrom RMA. EPA collected the data from 1987 to 1989. Because the contaminants are in theAlluvial Aquifer groundwater and the data is not very recent, if these wells were to bereevaluated, additional information would be needed on the uses of these wells and the type andconcentration of contaminants present in the wells. Those wells are not part of the RMA NPLsite, but rather, they are in the EPA Study Area, west of RMA, which contain multiple NPL sitespreviously discussed in the Potential Pathways section. The Recommendations section and thePublic Health Action Plan contain specific recommendations concerned with minimizing or eliminating this pathway.
Evaluation of Tables 13 and 14 - Offpost Study Area Private Wells
The following sections evaluate the potential health effects of exposure to groundwatercontaminants in Offpost Study Area private wells; some of the contaminants are RMA-sourced,some are not. This discussion is organized according to aquifer, well number, and chemicalcompound, and, as a result, addresses single or multiple exposures along with well uses. Theuses of wells in the RMA Offpost Study Area were inventoried by the Tri-County HealthDepartment and incorporated in their database of Offpost wells. The symbols used in Tables 13and 14 are "D" for domestic use (cooking, washing, and bathing) and "DD" for drinking anddomestic use. Wells coded "D" are assumed to involve 5% ingestion from brushing teeth andincidental ingestion. Wells originally coded "DD" that currently receive bottled water are notcurrently used for drinking and are the equivalent of "D" wells at this time. This is furtherexplained in text below Tables 13 and 14 in this Assessment.
To be consistent with the well classification scheme designated by the TCHD in their database(and used by RMA), private wells labeled by their assigned well numbers are subsequentlyevaluated for health effects according to their use. Health effects are related to contaminantconcentration, exposure pathway, exposure frequency (including duration, if known), andpopulation exposed. The toxicologic evaluation of each contaminant addresses whether adversehealth effects are likely, given the above factors. Populations known or suspected to be sensitive to the contaminant are included in the evaluation.
Because the domestic use ("D") wells could be used as a drinking water ("DD") supply, theywere evaluated for health effects that could result from chronic ingestion of the well water, eventhough chronic ingestion of the levels of contaminants detected in those wells is not likelyoccurring, because bottled water is supplied to those residences. Because those wells could beused for a drinking water supply, a conservative public health approach was undertaken.
The chemicals detected in Offpost Study Area private wells are listed in Tables 13 and 14 andhave been evaluated for their public health significance. Only those chemicals deemed to be ofpublic health concern as of April 1994 are highlighted in Table 19, namely, lead andnitrate. Out of the 119 drinking and domestic wells currently in use and monitored regularly forRMA contaminants, a few wells have been identified that have produce water containing nitrateor lead at levels of public health concern. A progressive decline in the level of nitratecontamination in those wells has been observed and discussed previously in thisassessment. By August 1, 1996 the nitrate contamination in the drinking and domesticwells of the area had dropped below the 10,000 ppb MCL.
Local health officials have notified the users of contaminated wells of the possible health effectsthat might occur from continued use. Rocky Mountain Arsenal does not appear to be the sourceof those contaminants. The lead in the water could be from several sources such as naturallyoccurring lead in the groundwater or lead contamination in plumbing. The nitrate could betraced to many sources such as agricultural fertilizers, animal wastes, or private on-site sewagedisposal systems. There are also some wells in which RMA contaminants are detected (seeTables 13 and 14), but the levels of contamination are not of public health concern. Appendix Bcontains an evaluation of all chemicals detected in the Offpost Study Areas wells, listed inTables 13 and 14, as well as additional information for lead and nitrate. Private drinking waterwells to the north and northwest will continue to be monitored for both RMA and non-RMAsourced contaminants, and when a well is sampled, the results will be communicated to the wellusers.
The decision recorded in the Offpost ROD (HLA, 1995) to supply municipal water or analternative water source to the drinking water and domestic well users within the "DIMPfootprint area" (DIMP >0.392 ppb) will eliminate the continued use of all but two of wells listedin Table 19. Those wells that apparently do not qualify for replacement are 547A and 550A. Nitrate levels detected in well 547A have dropped below levels of health concern, leaving, as ofAugust 1996 only the elevated lead levels of well 550A of potential concern.
Well Number a
|Persons at Risk |
(Number of People Using Well)c
|331A||Nitrate - 23,000||Infants, Fetuses of Pregnant Women, and PregnantWomenc (3)||13|
|332B||Nitrate - 17,000||Infants, Fetuses of Pregnant Women, and PregnantWomen (2)||13|
|332D||Nitrate - 26,000||Infants, Fetuses of Pregnant Women, and PregnantWomen (2)||13|
|372A||Lead - 97.0||Children, Infants, Fetuses of Pregnant Women,Pregnant Women, and Other Adults (1)||13|
|456Aa||Nitrate - 13,000||Infants, Fetuses of Pregnant Women, and PregnantWomen (2)||13|
|540A||Lead - 92.6 |
Nitrate - 26,000
|- Children, Infants, Fetuses of Pregnant Women, |
Pregnant Women, and Other Adults (72)
- Infants, Fetuses of Pregnant Women, and Pregnant Women (72)
|541A||Nitrate - 12,000||Infants, Fetuses of Pregnant Women, and PregnantWomen (3)||13|
|547A / NQ? e||Nitrate - 16,000||Infants, Fetuses of Pregnant Women, and PregnantWomen (3)||13|
|550A / NQ? e||Lead - 65.5||Children, Infants, Fetuses of Pregnant Women,|
Pregnant Women, and Other Adults (16)
|551A||Lead - 100.0 |
Nitrate - 12,000
|- Children, Infants, Fetuses of Pregnant Women,Pregnant Women, and Other Adults (5) |
- Infants, Fetuses of Pregnant Women, and Pregnant Women (5)
|578A||Lead - 119.0 |
Nitrate - 14,000
|- Children, Infants, Fetuses of Pregnant Women,Pregnant Women, and Other Adults (5) |
- Infants, Fetuses of Pregnant Women, and Pregnant Women (5)
|579Aa||Lead - 98.8 |
Nitrate - 14,000
|- Children, Infants, Fetuses of Pregnant Women, |
Pregnant Women, and Other Adults (3)
- Infants, Fetuses of Pregnant Women, and Pregnant Women (3)
|602A||Lead - 77.1||Children, Infants, Fetuses of Pregnant Women,Pregnant Women, and Other Adults (1)||13|
|603A||Lead - 65.2||Children, Infants, Fetuses of Pregnant Women,Pregnant Women, and Other Adults (4)||13|
|613A||Nitrate - 11,000||Infants, Fetuses of Pregnant Women, and PregnantWomen (2)||13|
|616A||Nitrate - 16,000||Infants, Fetuses of Pregnant Women, and PregnantWomen (6)||13|
|739Aa||Nitrate - 13,000||Infants, Fetuses of Pregnant Women, and PregnantWomen (3)||13|
|931Aa||Lead - 18.6||Children and Fetuses of Pregnant Women (3)||14|
|969A||Nitrate - 11,000||Infants, Fetuses of Pregnant Women, and PregnantWomen (3)||13|
|973Aa||Nitrate - 10,000||Infants, Fetuses of Pregnant Women, and PregnantWomen (3)||13|
|981A||Nitrate - 12,000||Infants, Fetuses of Pregnant Women, and PregnantWomen (4)||13|
|1276Aa||Nitrate - 24,000||Infants, Fetuses of Pregnant Women, and PregnantWomen (6)||13|
|1305A||Nitrate - 12,000||Infants, Fetuses of Pregnant Women, and PregnantWomen (2)||13|
a = Well users are not on the bottled water program as of April 1994.
b = The MCL for nitrate is 10,000 ppb. The EPA Action Level for lead is 15 ppb.
c = Risk comes from using the water from the well for drinking (including infant formula made with this water) and/orcooking.
e = Denotes wells that may not qualify for replacement water supply.
There are numerous health studies specifically looking into whether past exposures to certainpesticides, DIMP, arsenic, and mercury (via the groundwater or air) were greater amongresidents of communities adjacent to RMA than among residents of comparison communitieslocated at least 10 miles from RMA, presumed to be unexposed. Studies have also beenconducted to investigate whether or not communities adjacent to RMA, with the greatestpotential for past exposure, have experienced higher occurrences of cancer than those with theleast potential.
Because studies are investigating whether past exposures may have adversely affected publichealth, past exposures will not be the main focus in this public health assessment. Rather,present and future pathways will be. Also, because various site-specific health investigationshave either been conducted or are proposed which go beyond or are more specific that county-level health outcome data, that county-level data will not be evaluated. County-level data oftenincludes many persons: those who were and were not potentially exposed. In contrast,community-specific health studies, by design, can specifically target those populations believedto have been potentially exposed.
The following is a summary and discussion of the activities or site-specific studies that have occurred or are in progress at, or adjacent to, RMA:
1.       Health Consultation on Rocky Mountain Arsenal (study completed).
In 1988, the Agency for Toxic Substances and Disease Registry (ATSDR) was requested byEPA to determine if proposed off-site groundwater remediation alternatives would be protectiveof public health. The consultation concluded that any of several water treatment methodsproposed by the South Adams County Water Supply District to treat VOC-contaminatedgroundwater would be protective of public health (ATSDR, 1988a).
2.      Preliminary Health Assessment for Rocky Mountain Arsenal (study completed).
In December 1988, ATSDR released a preliminary health assessment. It concluded that apotential public health concern existed due to documented on-site contamination and off-sitemigration. Numerous recommendations concerning preventative measures andcontaminant/pathway evaluation were suggested; most were subsequently enacted. Thisassessment occurred in the initial stages of the Remedial Investigation / Feasibility Study processand little quantitative information on contaminant characterization was available. Consequently,the primary finding was that a definitive statement on contaminant exposures and public healthwould be provided in a follow-up public health assessment (ATSDR, 1988b).
3.      Second Health Consultation on Rocky Mountain Arsenal (study completed).
In December of 1988, the EPA and U.S. Army requested ATSDR to do a health consultation onair contaminants released during the remediation of Basin F. Basin F was a 93 acre, lined,evaporation pond which was a documented source of groundwater contamination. Remediationof Basin F involved pumping liquids to temporary storage tanks and excavating the remainingsludges, the asphalt liner, and underlying contaminated soil. Shortly after remediation of BasinF began (summer of 1988), persons working or residing to the north and northwest of RMAbegan to complain of noxious odors, eye irritations, headaches, rashes, and nausea (TCDH,1989). Numerous chemicals, (pesticides, pesticide break-down products, inorganics, and metals)were detected as major constituents of the Basin F liquid, overburden, or underlying soil. Although a specific causal relationship was not determined, ATSDR recommended that airemissions from Basin F be prevented and additional environmental and health monitoringactivities be undertaken. In December of 1988, the U.S. Army ceased excavation activities atBasin F (ATSDR, 1989).
4.      Investigations Addressing Complaints from Residents Northwest of RMA (studycompleted).
Complaints from individuals residing northwest of RMA and about 1.25 miles from Basin Fwere received during the initial phases of remediation of Basin F. Those complaints of adversehealth effects, concern about potential cancer risks and other chronic health effects, and aircontamination from Basin F lead to two investigations. Tri-County Health Departmentconducted a medical survey of a limited number of Irondale Trailer Park residents complainingof adverse health effects (CDPHE, 1989; TCHD, 1989). There were no consistent findings orphysical examinations. Laboratory testing revealed a nonspecific pattern in the 13 individualsfor whom abnormalities were seen.
Concern over potential exposure to air-borne carcinogens caused the Colorado Department ofPublic Health & Environment (CDPHE) to evaluate the cancer risk from Basin F emissions. Cancer risk estimates were calculated by CDPHE using data from 24-hour air samples collectedon the Arsenal during July/August of 1988, one mile north of Basin F. According to the report,there were seven known or suspected carcinogens detected: methylene chloride, benzene,chloroform, trichlorethylene, tetrachloroethylene, aldrin, and dieldrin. A low increased risk ofdeveloping cancer was estimated for a six-month exposure to those seven carcinogens (ATSDR,1993a). In response to that information, the detection of chemicals in groundwater off site ofRMA, and the possibility of past exposure pathways to RMA hazardous substances throughdrinking water and inhaling wind-dispersed substances, a three-year exposure study wasconducted (ATSDR, 1993a) and cancer incidence for the northeast Denver Metro area wasexamined (CDPHE, 1993a). Those studies are discussed and evaluated in subsequentparagraphs.
5.      Cancer Incidence in the Northeast Denver Metro Area (study completed).
In 1988, the Colorado Department of Public Health & Environment (CDPHE) initiated adescriptive study of cancer incidence in response to concerns expressed by interested citizens. Itexamined data on cancer incidence by age, sex, and race in populations in the northeast DenverMetropolitan area over the 10-year period between 1979 through 1988. It compared the numberof diagnosed cancer cases in selected census tracts with the numbers expected to occur in thoseareas based on Denver metro area rates of cancer during the same time period (CDPHE, 1993a).
The study used data from the Colorado Central Cancer Registry of the CDPHE. Three areascomposed of selected census tracts in proximity to RMA were studied. The geographic areas(Area 1 and Area 2) studied were selected because people in those areas could conceivably havebeen potentially exposed to contaminants which may cause cancer. Area 1 was composed ofpersons residing north and northwest of RMA. Area 2 was composed of persons residing westof RMA. Area 3 was made up of persons south of RMA who were not presumed to have beenpotentially exposed to RMA contaminants via the soil, groundwater, or air (CDPHE, 1993a).
Statistically significant increases in cancer cases were not found for the geographical locationsstudied. However, in Area 2 (residents west of RMA), the lung cancer rate was elevated amongboth males and females over the 10-year study period. Males in that area also had a slightlyhigher, but not significantly higher, rate of cancer of the larynx. CDPHE concluded that thepattern of lung and laryngeal cancer has several possible causes: the most important amongthose is smoking, but also exposure to airborne environmental contaminants, exposures to radonand occupational dusts and fumes, diets low in vitamins A and C, and alcohol consumptioncould be responsible for the apparent increase. At this time, no further investigation is planned(CDPHE, 1993a).
For Area 1 (residents north and northwest of RMA), elevated incidences of bladder cancer werefound among males only for the period 1981-1985. Some residents of this area may have beenexposed to contaminants in groundwater, surface water, or air. An environmentally-causedincrease in bladder cancer would also be expected to occur among women; it did not. Occupational exposures are known to be important risk factors for bladder cancer among menand may explain the observed increase (CDPHE, 1993a). For those reasons, bladder cancerincidence has been selected for further investigation. ATSDR has funded Colorado StateUniversity to conduct a case-control investigation, which will compare characteristics of bladdercancer cases with those of persons not suffering from the disease. CSU also plans to evaluatewater supply and the distribution of groundwater contamination (CDPHE, 1993a;CSU, 1992). That study is further discussed below under item 8.
6.       Cancer Incidence in the Montbello Community (study completed).
As an update to the Cancer Incidence in the Northeast Denver Metro Area Study, CDPHEcompleted an analysis of observed and expected cancer incidence data for the Montbello area(along the southeast RMA border) of Denver, Colorado. Four years of data from 1985 through1989 were evaluated. The types of cancers they evaluated and the methods of analysis they usedwere consistent with those presented in the Cancer Incidence in Northeast Denver Metro reportsummarized above. The evaluation found no statistically significant increases in cancer amongmales or females (CDPHE, 1993b).
7.      The RMA Pilot Exposure Study (1989-1992): Parts I (completed) and II (Draft forPublic Comment; Final Pending).
In response to evidence of documented chemical concentrations in groundwater to the north,northwest, and west, the potential for exposure to contaminants via the air to the north,northwest, and west, and a substantial amount of subjective information from citizens to thenorth and northwest indicating that acute adverse health outcomes have taken place, an exposurestudy was initiated by CDPHE. The Division of Health Studies at ATSDR funded CDPHE toconduct the study, who contracted CSU to assist in conducting the study (Tsongas et al. 1991,ATSDR 1995). The target analytes chosen for this study were chosen because these were theprimary contaminants in the media at RMA, the health effects from exposure to them are fairlywell documented, and it seemed more likely that exposure would have occurred to them ratherthan other contaminants because they tend to degrade less quickly in the environment.
Part I: Analysis of Exposure to Arsenic and Mercury.
This report has been completed. This exposure study provided no evidence that the presence oramount of arsenic in urine (from 469 participants) was related to residence near RMA. Threestudy groups were identified. Area 1 contained residents to the north and northwest of RMA,including the Irondale Trailer Park and adjacent neighborhoods. Area 2 contained residentsdirectly west of RMA. Area 3 consisted of persons 12 to 15 miles north and northeast of RMAwith no documented residential exposure to RMA. Persons in Area 1 and 2 consisted of personswho were presumed to have been exposed to chemicals from RMA by residential exposurepathways via groundwater, surface water or air. In Area 2, persons who consumed well water orused well water on their gardens had an increased risk of having a quantifiable level of urinemercury compared to Areas 1 and 3; however, this difference was not found to be statisticallysignificant (ATSDR, 1993a). It should be noted that no health effects have been associated withthe levels of mercury found for those persons who had mercury detected in their urine. Subsequently, followup investigations did not reveal elevated groundwater mercuryconcentrations (CDPHE, 1994).
Part II: Analysis of Diisopropyl methylphosphonate (DIMP), Aldrin, Dieldrin, Endrin, Isodrin, and Chlorophenylmethylsulfone (CPMSO2).
This study was released for public comment and the comment period closed November 25, 1995. A final report will be issued sometime in 1996. The pilot exposure study was undertaken incommunities surrounding RMA in order to determine whether exposures to several chemicalswere greater among persons who resided there than among residents of a comparison area. Atotal of 472 people were interviewed and from that group urine samples were obtained from 469persons and serum samples from 444 persons. Urine samples were tested for DIMP andCPMSO2. The blood serum was screened for aldrin, dieldrin, endrin, and isodrin. The findingsfrom this study were released in September 1995. No confirmed evidence of aldrin, endrin, orisodrin in serum from study participants was found. Dieldrin was detected at levels below 3.40ppb in serum samples of six persons. There was no evidence found in this study that thepresence of dieldrin in serum was related to RMA. Researchers concluded that no acute healthaffects would be anticipated from a body burden of dieldrin at the levels found in this study.
Due to laboratory problems, analysis DIMP samples could not be completed. Initially CPMSOwas detected in 6 of 274 samples tested. One person had a quantifiable value of 20 ppb(detection limit of 10 ppb) and the others had detectable, but not quantifiable values of theanalyte in their urine. Re-analysis for CPMSO2 in six of the archived frozen samples wascompleted to confirm the initial detections of this compound. The confirmatory analyses found0.5 ppb in the sample of the one quantifiable detection and no CPMSO2 in the remainingsamples. No adverse health effects are likely from the level of CPMSO2 detected in the urinesample. The source of the reported CPMSO2 exposure is unknown, as is the prevalence ofresidues of CPMSO2 in the general population.
8.       Reproductive, Neurobehavioral, and Other Disorders in Communities Surroundingthe RMA (Draft for Public Comment; Final Pending).
ATSDR funded CSU to evaluate reproductive, neurobehavioral, and other disorders incommunities surrounding RMA. These studies were released for public comment in September1995. The final report of this study is expected sometime in 1996. The study of healthconditions was conducted between October 1991 and September 1994 in communities nearRMA. The study populations were grouped in the same manner as the Pilot Exposure Studiesreported above. Areas 1 and 2, north and west of RMA, were assumed potentially exposed. Area 3 was 12 to 15 miles north and northeast of RMA and served as the comparison area. Asummary of the key findings follows.
The study provides little indication that the prevalence of symptoms and disease was elevatedamong persons who resided near RMA. Only the prevalence of self-reported "low musclestrength" among men and women in Area 2 west of RMA was statistically significant. Thisreported prevalence of low muscle strength may be due to chance.
The prevalence of low muscle strength was significantly higher among persons who usedgroundwater for domestic purposes in Areas 1 and 2 when the groups were combined. It is notknown if the association between well water use and low water strength are directly related. Data collected in Area 1, north of RMA, do not support this association.
Statistical analyses of reproductive outcomes did not reveal significant associations withresidence near RMA. Both men and women living west of RMA did report an increase ininfertility, defined as difficulty in achieving conception when compared to the referencepopulation. A lower mean number of pregnancies and number of children born was alsoreported. The origin of the reported excess in infertility in Area 2 was not identified. No other indicators of reproductive health and outcome were detected.
No statistically significant differences in neurobehavioral performance was found among persons living near RMA compared with Area 3.
The incidence and association of bladder cancer near RMA was not statistically significant. Thecorrelation was stronger for persons who lived near RMA 20 or more years, but the associationwas still not statistically significant. A statistically significant association was observed betweenbladder cancer and the two risk factors "history of bladder infections" and smoking.
The researchers noted that the ability to identify statistically significant associations was limitedby the relatively small number of persons studied in each area (about 100 per group).
9.      Mortality Among Workers at Shell's Pesticide Manufacturing Plant at RMA(completed).
A retrospective follow-up study of the mortality experience of 2,384 workers at Shell's PesticideManufacturing Plant between 1952 and 1982 found an overall mortality rate similar to theColorado rate and that there was no apparent widespread or potent health threat at the plant(Amoateng-Adjepong, et al., 1995).
This study was conducted to evaluate the hepatobiliary cancer and pneumonia mortality rates in persons who had worked at this plant, to determine if these causes of death are related to specificwork areas within the plant, and to provide an updated assessment of other mortality patternsbased on previous studies in similar workers (Amoateng-Adjepong, et al., 1994).
This plant was in operation from 1947 to 1982 and produced pesticides, includingorganochlorines (e.g., aldrin, dieldrin, and endrin), organophosphates (e.g., azodrin, andvapona), planavin (nitralin), and dibromochloropropane (DBCP). Many chemicals, includingchlorine, bromine, benzene, vinyl chloride, and heavy metals, were used at this plant(Amoateng-Adjepong, et al., 1995).
A comparison of the plant cohort's mortality rates with those of the Colorado population foundthat observed and expected numbers of deaths were similar for all causes (465 observed/473expected) and for all cancers (113/106). Standardized mortality ratios (SMRs) were elevated forhepatobiliary cancer (5/2.0; SMR of 249; 95% confidence interval = 81-581), because of anexcess of biliary duct/gall bladder cancer, and for pneumonia (20/13; SMR of 150; 95%confidence interval = 92-232). These increases were not found to be statistically significant andwere limited to white men in hourly jobs but were not limited to any particular production unitand did not show duration-response trends. The causes of biliary tract cancer are unknown, butsuggested etiologic factors noted in other studies conducted elsewhere include chronic parasiticinfestations, non-parasitic infestations of the biliary tract, gall stones and possibly dinitrotolueneexposure. The chemicals manufactured at this plant have not been associated with biliarycancer. Therefore, the authors of this study concluded that it was unlikely that the excesses were due to occupational exposures at the plant (Amoateng-Adjepong, et al., 1995).
Health concerns that have been voiced to ATSDR are addressed below. Most of the concernswere voiced during Public Availability Sessions in communities adjacent to RMA. However,ATSDR Regional Representatives based in Denver, local officials, and representatives of theTCHD, CDPHE, Army, USFWS, EPA, Shell Oil Company, and other agencies also presentedconcerns from the public.
What are the possible off-post health effects from on-post soil cleanup activities?
Remediation personnel conducting on-post soil cleanup activities stand the greatest risk ofpotential exposure. However, previous remediation efforts and the planned final cleanupactivities conducted under the Offpost and Onpost RODs (HLA, 1995; Foster Wheeler, 1996)have been and will continue to be governed by comprehensive site safety plans. Those safetyplans and the activity coordination measures already in use are designed to ensure that allremediation activities are conducted so that the health and well being of workers, site-visitors, and residents of nearby communities is not jeopardized.
Environmental data for surface soils show that the highest chemical concentrations cluster in thecenter of the Arsenal and decrease in a gradient fashion to levels of insignificant healthconcentrations at the boundaries of RMA. Therefore, a future soil pathway is not expected toextend to off-site residents (EBASCO, 1992). Although it is feasible that during soil excavation,onpost transportation, and landfilling activities soil could be windblown engineering measureswill be taken to minimize that possibility and project supervision and environmental monitoringwill further assure that the accidental release of contaminants is minimized or eliminated.
The public health of the nearby neighborhoods will be further safeguarded by the activitiesundertaken under Component 18 of the Conceptual Agreement (Colorado, 1995). Thatcomponent, incorporated in the RODs, provides that a plan will be developed to monitor anyoff-post impacts on human health due to the remediation and to provide mechanisms forevaluation of human health on an individual and community basis, until such time as the soilremedy is complete.
At present, visitors to the refuge are denied access to areas containing soils that are contaminatedat levels that could result in adverse health effects (EPA, 1989a). Final site cleanup activitieswill remove the potential for exposure of refuge visitors to contaminants at levels that wouldcause adverse health effects. During the site cleanup activities there may be times that refugevisitation levels or available areas may be restricted because of activity coordination or safety reasons.
What are the possible off-post health effects from the Submerged Quench Incinerator(SQI) emissions?
Basin F liquid was destroyed on site where it was produced. The incinerator posed nosignificant risk to nearby residents. The incinerator startup began in March 1993 and allincineration activities were completed in 1995. The incinerator treated the liquid wastes moresafely and efficiently than predicted. Prior to full operation, the incinerator underwent testing toverify the system design. During testing, representatives of the Arsenal staff, the SQI operationsstaff, its transportation facilities, and the RMA Fire Department participated in a successfulemergency drill. A laboratory was established with equipment and staff for analyzing brinesamples and scrubber water from the incinerator's quench and air pollution control equipmentthroughout SQI operations. Performance testing of stack continuous emissions monitoring andair pollution control equipment began before the startup of SQI. Automatic emergencyshutdown controls tested under operating conditions functioned properly, operating systemsperformed as designed, and equipment was adjusted to meet operating standards.
The Final Human Health Risk Assessment was completed in March 1994. The multipathwayhuman health risk assessment, based on the SQI emission rates measured during the trial burn ofBasin F liquid, documented that the facility did not pose unacceptable carcinogenic risk or non-carcinogenic health effects to sensitive populations (Resident-A, Resident-B, Farmer, andWorker), as defined by EPA guidance (EPA, 1989b) and the Final Decision Document(Woodward-Clyde, 1990b). Refer to The Final Human Health Risk Assessment for detaileddescriptions of these populations. ATSDR reviewed the SQI emissions data and the results ofambient air monitoring and agreed that the operation of SQI was not of public health concern tooff-post residents or people who work or visit RMA (Weston, 1994, p. 11-10, 11-11).
Will RMA remediation activities result in adverse health effects from diminished airquality in the Montbello neighborhood, directly south of RMA?
Air monitoring at RMA is an ongoing function of the Comprehensive Monitoring Program(CMP). The CMP has the following objectives: 1) identify and evaluate potential air qualityhealth hazards; 2) monitor progress made in removing air contaminants from previous RMAactivities; 3) provide baseline data to evaluate the progress that will be made in future remedialactivities; and 4) develop real-time guidelines and standards with which to evaluate the effects of ongoing remedial actions.
To achieve those objectives, the air monitoring element of the CMP utilizes a combination ofabout 12 fixed-point RMA interior and perimeter air monitoring stations, strategically placedwith respect to possible contamination sources and prevailing wind directions, and about 24portable air monitoring stations. Those 24 portable monitoring stations detect and monitorpossible effects relating to ongoing remedial actions or other activities of special concern(Stollar, 1991a, p. 1).
In addition, the data and information compiled from the CMP provides a valuable historicalbaseline from which future activities can be planned, mitigation measures identified, andpotential future effects forecast and measured.
The Medical Monitoring Program established by the Conceptual Agreement (Colorado, 1995)and the RODs (HLA, 1995; Foster Wheeler, 1996) will evaluate the environmental monitoringneeds (including air monitoring) during the final site cleanup and will recommend the adoptionof an air monitoring plan designed to help ensure the protection of the public health of thenearby neighborhoods.
The data compiled thus far by the CMP indicate that the concentration of airborne contaminantsgenerated by previous RMA remediation activities declined rapidly with distance from thesource. At the RMA boundaries, the measured concentrations of total suspended particulate(TSP), metals, and volatile and semi-volatile organic compounds (VOCs, SVOCs) had declinedto levels below health concern (Stollar, 1991a, p. 11-14). Monitoring data further indicate thatthe air quality of the Arsenal and areas such as Montbello is affected by particulate, VOCs, andSVOCs resulting from the industrial activity and vehicle use within the Denver MetropolitanArea. From windrose data, it appears that the wind blows primarily from RMA to the north andnortheast, away from Montbello.
Evaluation of the human health risk associated with remediation activities, such as SQI, andfuture actions have been and will be completed before the actions are implemented. Actions thatmay potentially affect the Montbello Area and other off-post areas will be carefully monitored toassure that actual air contamination levels do not exceed the levels judged to be protective ofpublic health. The Conceptual Agreement (Colorado, 1995) specifically provides thattechnologies to control emissions and odors from material handling operations will bedetermined in the design of the remediation actions and implemented, as necessary, throughoutthe remediation phase.
Was SQI used for non-RMA hazardous wastes?
SQI was approved by EPA and the state of Colorado only for incineration of Basin F associatedwastes. Non-Basin F wastes were not approved for this incinerator. The SQI incinerated theorganics in the 10.5 million gallons of liquid that was stored in three steel tanks and a covered,double-lined pond filled with wastes formerly disposed of in Basin F (Weston, 1994). SQIsuccessfully completed it function in 1995 and was dismantled.
Specific Health Concerns:
In this portion of the assessment, specific health concerns are addressed in the context ofexposure pathways to RMA and non-RMA contaminants, known risk factors related to thedevelopment of specific health conditions or diseases, previous health studies and investigationsconducted in the communities adjacent to RMA, and additional information (such as, medicalhistory, occupation, and location of residence) gathered from discussions with residents whoattended the Public Availability Sessions and had health concerns.
The majority of concerns expressed by residents near RMA were for whether specific healthconditions or diseases, such as cancers, occur at excess rates in the communities adjacent toRMA. ATSDR attempted to gather as much information as possible from those who hadspecific health concerns and attended the Sessions, since a variety of health conditions ordiseases may share similar risk factors and certain risk factors may contribute more heavily tothe occurrence of a particular disease or condition. For instance, when residents near RMAexpressed specific health concerns, ATSDR inquired about such information as personal andfamily medical history, occupation, smoking status, place (s) and duration of residence, privatewell use and duration, and other exposure factors that might be related to the development ofcancer or other health conditions and diseases.
In addition to the information and responses appearing here, Appendix C has additionaldiscussion on the risk factors and a summary of important health information on each of thesespecific health conditions for people who may want to know more about these conditions orplaces to contact locally for more information. Also, if people reading this report suspect orhave a concern about cancer or some other type of health condition, they should contact theirpersonal physician or a local physician in their community.
Is there an excess of lupus in the Montbello community?
Unfortunately, there are no local or national databases that would allow us to determine whetheran excess of lupus exists in the Montbello community. However, the following informationspecific to the causes of lupus and actions taken to address this concern are provided below.
Mortality rates for lupus exist for the nation, state and counties of Colorado, but the informationis not collected such that Montbello is broken down separately from Denver County rates(Wonder, 1991). Furthermore, the mortality rates available only show the number of deathsattributed to lupus. Unlike incidence or prevalence rates, mortality rates do not have informationthat would allow us to address whether an excess exists for those who are currently diagnosedwith lupus. Incidence rates or prevalence rates are needed for the Montbello area or that general area in order for us to address this concern.
The Lupus Foundation of Colorado was consulted about whether a local database containingincidence rates for lupus existed for communities near Denver. They indicated that only nationalincidence rates are available for the U.S. Individual state information is not available (ATSDR, 1994e).
Local physicians were also contacted for their personal impressions as to whether they wereaware of concerns for an excess of lupus cases or personally had seen more cases of lupus thannormally observed. None of the doctors in the Montbello area had heard of or seen an usuallylarge number of cases of lupus (ATSDR, 1993c and 1993d).
In addition to contacting the local lupus chapter and physicians in the Montbello area, thepossibility for exposure to RMA contaminants and the causes of lupus were investigated. Windblown contaminants have been occasionally deposited on the surface soils of the southernportion of RMA near the Montbello community. However, the environmental data show that thesoil contamination on RMA decreases progressively from the location of the RMA sources to thesouthern boundary of RMA. The very low levels of surface soil contaminants that have beendetected in the southern part of RMA are not expected to harm people's health. Because thegroundwater contaminants have migrated to the north and northwest, residents in the Montbelloarea have not been exposed to those contaminants through drinking water. Because exposure toRMA contaminants at levels of public health concern has not occurred to Montbello residents, itis unlikely that cases of lupus in the Montbello community are related to RMA contaminants.
Lupus is more prevalent among blacks, especially black women. According to the demographicmakeup of Montbello, blacks comprise almost 60% of Montbello's population (see Table 3). Therefore, it is likely that more cases of lupus would be observed in the Montbello area ascompared to the surrounding communities near RMA, because the percentage of blacks inMontbello is considerably higher than in surrounding communities.
We do not know what causes lupus. Some evidence supports a genetic link; however, there is noproof that those with the genetic predisposition will develop lupus. Certain influences, includingviral infections, exposure to ultraviolet light, certain drugs (further discussed in Appendix C),chemicals, and other stressors seem to trigger the onset of a flareup of symptoms (LupusFoundation of America, Inc., 1992, p. 1).
There are two main types of lupus: systemic lupus erythematosus (SLE) and discoid lupuserythematosus (DLE). Patients may have one or both (Lupus Foundation of America, Inc.,1992, p. 1). In lupus, the immune system forms antibodies to the body's own tissue and attacksthe organs and body systems. Effects on joints, lymph glands, heart and lungs, kidneys,abdominal organs, and the brain are well documented (Aladjem, 1992, p. 1). Clinical signs andsymptoms can be characterized as general, non-specific illness (systemic symptoms includefatigue, malaise, fever, anorexia, weight loss, and nausea); non-life-threatening clinicalmanifestations (skin rashes, mouth ulcers, arthritis, and serositis); and potentially seriousinvolvement of major organs: heart, lungs, kidneys, or the brain (Aladjem, 1992, p. 2-3). Serositis is an inflammation of the membranes that line the lungs, heart, and abdomen.
Refer to Appendix C for more information on lupus.
Is there an excess of cancer in the Montbello neighborhood?
The Colorado Department of Public Health & Environment (CDPHE) used data from theColorado Cancer Registry to perform a review of cancer incidence rates for the Montbello areafrom 1985 to 1993 (CDPHE, 1993b). The types of cancers and the methods of analysis wereconsistent with those presented in the cancer incidence study for the Northeast Denver Metroarea that CDPHE also conducted and released in August 1993. No statistically significant ratesof cancer were observed for the Montbello area as compared to the 1986-1988 race-, sex-, andage-specific rates for the Denver Metropolitan Area.
Is it safe to eat vegetables grown in gardens irrigated by private well water in Commerce City or north of RMA?
Municipal water supply systems are subject to rigorous periodic testing requirements to ensurethe safety of the water of human consumption and uses such as irrigation of garden produce.
In order to assure the safety of the private well water for garden produce irrigation, the Armygathered new data in 1995 on DIMP concentrations in vegetables grown in the area. That datastrongly supports the findings of the previously completed Endangerment Assessment (HLA,1992b) and indicates that it is safe to eat vegetables irrigated with well water drawn from theAlluvial Aquifer north of RMA. The information that supports this conclusion is given below.
In 1990, a wide variety of vegetables and raw milk from farms and gardens offpost to the farnorth and northeast were collected by CDPHE and sampled for DIMP, which was not detected. Raw milk, cabbage, corn, onions, romaine lettuce, red leaf lettuce, green curly leaf lettuce,broccoli, turnips and greens, mustard greens, bok choy, and black-eyed peas were collected. Soil and groundwater sampling were not conducted in conjunction with this study. Therefore,even though DIMP was not detected in the vegetables, it was not certain that samples wereobtained from an area that contained enough DIMP in soils or groundwater to be expected to betaken up into the vegetables.
As reported in the Offpost RI Addendum in 1992, cattle, chicken, several different fish species,and milk were collected and analyzed for a broad range of target analytes (see Table 13). Nonewere detected at levels of public health concern (HLA, 1992a).
The Endangerment Assessment prepared for the Offpost Operable Unit (HLA, 1992b) evaluatedthe risk associated with the consumption of vegetables irrigated with Offpost groundwater andgrown in Offpost soils. That assessment concluded that consumption of those vegetables wouldnot result in any adverse health effects. Subsequent to the completion of the EndangermentAssessment data has been developed on DIMP contaminant levels in garden vegetables grown inthe area of potential concern. The Army asked Tri-County Health Department to obtain samplesof garden vegetables from Offpost sites to determine what concentrations of DIMP, if any, are in Offpost vegetables. The samples were collected from the garden of private residence north of RMA on October 12, 1995 and from two large vegetable farms on November 10, 1995. Theprivate garden was selected by the Army because it is irrigated only with water from well 1178Bwhich has higher concentrations of DIMP remaining than any other Offpost area well. Theconcentration of DIMP in that well have ranged from about 150 to 950 ppb. The commercialfarms were selected because they utilize a combination of groundwater (DIMP <20 ppb) andsurface water (uncontaminated by DIMP).
The vegetables were analyzed using a recently developed method to determine DIMPconcentrations in vegetables (detection limit, 20 ppb). The concentrations of DIMP detected inthe private garden cucumbers ranged from 340 to 920 ppb and the tomatoes from that gardencontained DIMP at an unquantifiable level below the detection limit. The vegetable samples(corn, onion, chile pepper) taken from the large vegetable farms contained no detectable DIMP.
Comparison of this 1995 garden vegetable data with the calculation of potential risk given in theOffpost Endangerment Assessment (HLA, 1992b) indicates that even under a "worst-case "exposure scenario, the consumption of vegetables irrigated with DIMP-contaminatedgroundwater is not expected to result in adverse health effects. This conclusion is basedupon the estimation of the potential DIMP concentration in lettuce. Lettuce was selected toevaluate the potential risk associated with consumption of Offpost-grown vegetables becausestudies have shown that plant leaves have the highest potential to accumulate DIMP.
Are there elevated levels of learning disabilities in the children residing in Commerce City, near the western boundary of RMA?
To address this concern, ATSDR contacted the Department of Education, Colorado Departmentof Health, to determine whether any local databases existed on rates of learning disabilities forcommunities surrounding RMA, particularly Commerce City (ATSDR, 1994a and 1994b). ATSDR learned that while they establish education guidelines for the state, they were unawareof any database that would contain the type of information requested. There are nine learningdisabilities that have been defined by the state, but no information exists on the rates of those disabilities.
As of June 11, 1992, the Colorado Department of Education issued the Rules for Administrationof the Exceptional Children's Educational Act to establish special education guidelines for thestate. There are nine learning disabilities defined according to state guidelines: dyslexia;hearing impaired; vision impaired; emotionally impaired; physically impaired; speech andlanguage impaired; emotionally disturbed; mentally impaired; and multiply impaired, a termused to describe a person with more than one of these disabilities.
Parents concerned about learning disabilities should contact their local school boards or the Colorado Department of Education for information about testing and what type of help existslocally for children with learning disabilities.
Has Diabetes been linked to the chemicals detected in private wells north, northwest, orwest of RMA? Could it be linked to prenatal exposure to those chemicals?
The individual who voiced this concern resided a little more than 2 miles north of thenorthwesternmost boundary of RMA. His family lived at this residence in Henderson from 1979until 1985, when they moved away. In their family, there are five children, and one child hasbeen diagnosed with insulin-dependent diabetes, or Type I diabetes mellitus. The family firstlived at this residence in Henderson in 1979; the son was born during January of 1983, and theybegan to suspect diabetes in 1985 when he was 2½ years old. This individual asked whetherdiabetes has ever been associated with prenatal exposure to DIMP in his private well. Hereported that a maximum level of 425 ppb DIMP had been previously detected in the water fromhis private well. This individual shared water sampling data with ATSDR and his address anddesignated well number such that the well could be investigated by ATSDR staff.
This individual's private well taps into the Arapahoe, one of the deeper aquifers. The drinkingwater well was used for drinking, bathing, showering, gardening, and other household uses. Atthe time of the November 1993 Public Availability Sessions when this concern was raised, thechildren were 12, 10, 8, 7, and 1½ years old; the three oldest are boys and the two youngest aregirls. The ten-year old was the child diagnosed with diabetes. The two oldest children werepotentially exposed to drinking water with multiple chemicals (e.g., Tables 5A and 5B) sincethey used their private well. The third oldest child born in 1985, may have been exposed toprenatal and minor environmental exposure before the family moved in May 1985. From ourconversations, it appears that the other siblings are in good health.
Recent sampling of this Arapahoe Aquifer well (494A) did not detect any contamination. Database queries to TCHD and the RMAED found that this residence and well are now ownedby another family. Well number 494A, an Arapahoe well, has been replaced with bottled water. In addition to this well, two other wells have been utilized. Well number 494B is an Alluvialwell used to water stock, and well number 494C is an Alluvial irrigation well used to watercrops. The 425 ppb of DIMP detected came from a 1985 sampling effort conducted by ESE,and this level is not expected to result in adverse health effects. Environmental data show thatthe DIMP value of 425 ppb was probably found in either the 494B or 494C well, not the 494Awell. Subsequent testing of 494A has never shown high DIMP values as high as 425 ppb(ATSDR, 1994f). A query of the RMAED disclosed that, in 1993, no reportable quantity ofDIMP was detected in well 494A and 16.5 ppb DIMP was found in irrigation well 494C(ATSDR, 1994g). All of these levels of DIMP detected at this location in both the Alluvial andArapahoe Aquifers are below the EPA LTHA of 600 ppb, therefore, adverse health effects arenot expected. Although the available data for the wells in question do not indicate the presenceof contaminants at levels of concern, such as those listed in Tables 13 or 14, even if thosechemicals were present, they have not been found to be associated with the risk of developingdiabetes.
Historically, the North Plume Group of the Alluvial Aquifer in the vicinity of these wells havebeen characterized by varying concentrations of the VOCs, SVOCs, and metals given in Table5A of this Assessment. However, the most recent sampling of the underlying Arapahoe Aquiferindicates only scattered detections of DIMP, arsenic, lead, and nitrates (see Tables 5B and 14). The known risk factors for developing diabetes do not include exposure to any of the chemicalsassociated with RMA.
Literature reviews were conducted (ATSDR 1994j) and various groups were contacted todetermine if exposure to environmental chemicals, such as the ones found at RMA, had beenassociated with the risk factors for developing diabetes. None of the chemicals typically foundat RMA has been associated with the risk factors for diabetes (ATSDR 1994c, 1994d, and1994i).
Refer to Appendix C for more information on diabetes.
Has Multiple Chemical Sensitivity (MCS) been associated with exposure to Arsenalchemicals?
The person who voiced this concern resided less than 3 miles southwest of RMA prior to beingdiagnosed with MCS and was using a private well for drinking water and other household uses. He is a landscape architect, spends a lot of his time outside at job sites, and, from ourdiscussions, appeared to be particularly aware of the ammonia odor associated with the printingworking with blueprints in his office.
If this person residing southwest of RMA was using water from his private well for drinkingwater and other domestic purposes, it is possible that this person may have been exposed togroundwater contaminants from the multiple industrial sources in that area. Sampling data onthe well water from his well was not provided to ATSDR, so it is unknown what he might havebeen exposed to through ingestion of water from his well.
The causes of MCS and the biochemical mechanisms involved with it are not well understood,and there are significant differences of opinion on it's causes: some physicians believe it iscaused by exposure to chemicals while others think it is a psychological phenomena. AlthoughMCS is poorly understood, it is unlikely that, in this case, MCS would be attributed to RMAchemicals, because groundwater flow direction is to the north and northwest and prevailingwinds blow predominantly to the north and northeast. It is unlikely that this particular individualwould have been exposed to RMA chemicals in the groundwater or air at levels of healthconcern. It seems more likely that there might be chemicals in his work environment, possiblyhis office or outdoor work sites, that he has become sensitive to.
ATSDR is aware that this individual is working with his personal physician to identify whichchemicals he is particularly sensitized to. This type of dialogue with his physician is appropriateto identify and possibly avoid the sensitizing agent or agents.
In 1992, ATSDR sponsored a conference on MCS to highlight the research currently being donein this area, especially research investigating symptoms and possible causes. Because MCS isnot well understood, ATSDR is working toward establishing an interagency working group, tostudy the issue of MCS possibly in 1995 (Environmental Health Perspectives, 1994).
Refer to Appendix C for more information on MCS.
Have respiratory conditions such as asthma, particularly in Montbello, been associatedwith exposure to Arsenal chemicals?
This concern has been voiced mainly by people residing in the Montbello area south of RMA. Wind rose data indicate that the predominant wind direction is from the south to the north andnortheast; groundwater flows to the north and northwest. Air monitoring performed on RMA,including data gathered from monitoring stations along the RMA boundary, has not foundcontaminants from RMA at levels of concern. The data does indicate that air pollution from theDenver metro area has affected air quality in areas offsite of RMA (Stollar, 1991).
Asthma is a common illness caused by a wide variety of irritants (see Appendix C for moreinformation). Because allergic hypersensitivity is the leading cause of asthma, most cases arerelated to a food or allergens frequently found in homes, which may include animal danders,house dust mites, and cigarette smoke.
Although remediation during the Basin F episode in 1988 might have temporarily increased oraggravated symptoms of an asthma patient, it's unlikely that it would have caused a chronic caseof asthma for people who resided north of RMA and were potentially exposed to airbornecontaminants. Asthma is caused by a wide variety of irritants, so it would be difficult topinpoint one exposure as the causal agent.
Refer to Appendix C for more information on asthma.
Has breast cancer been associated with Arsenal chemicals?
The persons expressing this concern resided about three miles northeast of RMA on a streetwhere several residents had recently been diagnosed with breast cancer. Because they livenortheast of RMA, it is unlikely that they were exposed RMA contaminants at levels of publichealth concern. Chemicals have migrated in the groundwater and air to the north and northwest;however, breast cancer is not caused by exposure to chemicals historically detected at RMA. The risk factors that are associated with the development of breast cancer are discussed further below.
A review of the literature was conducted to determine whether exposure to the types ofchemicals at RMA have been associated with the development of breast cancer. Epidemiological studies have been conducted to investigate the possibility that DDT or its majormetabolite, DDE are responsible for the development of breast cancer. One study, published in1993, found a positive relationship between breast cancer risk and serum levels of DDE (Wolffet al., 1993, p., 648). Another study, published in 1994 found no such relationship (Krieger N.et al., 1994, p. 589). Both studies found no association between polychlorinated biphenyls(PCBs) and risk of developing breast cancer. (These studies were not related to the CDPHEexposure studies that were conducted in the communities north and northwest of RMA.) Mostresearchers agree that more studies are required before an association between DDE (andsubsequently DDT) and breast cancer can be made. No significant exposure to these chemicalsis occurring from RMA. Low levels of DDT and DDE have been found in groundwater, surfacesoils, and biota at levels below health-based comparison values or FDA Action Levels.
The Colorado Department of Public Health & Environment recently conducted a study toinvestigate cancer incidence to the north, northwest, and west of RMA for the years 1978 to1989 and to the south for the years 1985 to 1989 (CDPHE, 1993a and CDPHE, 1993b). Thestudy found no statistically significant excess of breast cancer.
Refer to Appendix C for more information on breast cancer.
Has throat cancer been associated with Arsenal chemicals?
The persons expressing this concern resided a little less than 3 miles northeast of RMA. Becausethey lived northeast of RMA, it is unlikely that they were exposed to RMA contaminants atlevels of public health concern. Chemicals have migrated in the groundwater and air to the northand northwest; however, throat cancer is not caused by exposure to chemicals historicallydetected at RMA. The risk factors that are associated with the development of throat cancer arediscussed in Appendix C.
The Colorado Department of Public Health & Environment recently conducted a study toinvestigate cancer incidence to the north, northwest, and west of RMA for the years 1978 to1989 and to the south for the years 1985 to 1989 (CDPHE, 1993a and CDPHE, 1993b). Thestudy did not find a statistically significant excess of throat cancer. However, in Area 2 (west ofRMA), the lung cancer rate was elevated among both males and females during the 10-yearstudy period. Males in the area also had a slightly higher, but not significantly higher, rate ofcancer of the larynx. The lung and larynx are located further down the respiratory tract than thethroat. CDPHE concluded that the pattern of lung and laryngeal cancer has several possiblecauses. The most significant risk factor is smoking, and others include exposure to airborneenvironmental contaminants, exposure to radon and occupational dusts and fumes, diets low invitamins A and C, and alcohol consumption (CDPHE, 1993a).
Refer to Appendix C for more information on throat cancer.
Has stomach cancer been associated with chemicals that have been detected in wells north,northwest, or west of RMA?
The person who voiced this concern lives north of RMA in Henderson and worked as a furniturefinisher for 40 years. He put himself on bottled water in 1967; therefore, this person has notbeen exposed through ingestion of groundwater for nearly 30 years. Stomach cancer has notbeen associated with exposure to RMA-sourced contaminants found in Offpost Study Areaprivate wells or from any other RMA-sourced contaminants that people may have been exposedto via the air or groundwater. The Colorado Department of Public Health & Environmentconducted a study to investigate cancer incidence to the north, northwest, and west of RMA forthe years 1978 to 1989 and to the south for the years 1985 to 1989 (CDPHE, 1993a and CDPHE,1993b). The study did not find a statistically significant excess of stomach cancer. The riskfactors that are associated with the development of stomach cancer are discussed in Appendix C.
A relationship between the incidence of gastric cancer (stomach cancer) and concentration ofnitrate in drinking water has been shown in a few studies. Two epidemiological studies found an increased incidence of gastric cancer in populations drinking water with nitrate levels of 90,000 ppb and 110,000 ppb when compared with control populations not drinking those high levels(The National Research Council, 1988, p.422-423). Those levels are much higher than thelevels of nitrate typically detected in the Offpost Study Area private wells. In 1994 the level ofnitrate detected in Offpost Study Area private wells typically ranged from 10,000 ppb (theMCL) to 26,000 ppb. and have decreased since that time. It should also be noted that thesestudies, while suggestive, do not firmly establish an association between incidence of stomachcancer and high intake of nitrate. They do indicate a need for continued intensive study on themetabolism and effects of nitrate in humans, because the series of reactions whereby nitrate inwater may be converted to N-nitroso compounds (the direct carcinogenic agent) in humans is notwell understood (The National Research Council, 1988, p. 421-422).
Nitrate, a non-RMA sourced contaminant commonly found in rural farming areas, has beendetected in Offpost Study Area private wells (see Tables 5A, 5B, 13, 14, and 17), generallynorth of RMA. The most likely source of nitrates in those wells would be, not from RMA, butfrom the farms, stockyards, and septic sewer systems north of RMA (ATSDR, 1991, p. 2).
The earliest sampling for nitrates in the Offpost Study Area was in 1985 (ATSDR, 1994g). Thelevels of nitrates detected in the samples collected from 1985 into the early 1990's have beencomparable to the levels given in Tables 13, 14, and 17. We do know that nitrate levels havebeen declining during the 1990's but, we do not know how high the levels of nitrate might havebeen before 1985. If the elevated levels of nitrate found in the past in well water of some wellsin the Offpost Study Area were chronically ingested, non-cancerous health effects might resultfor certain groups of the population. Please refer to the Toxicological Evaluation section forfurther discussion on nitrates.
Refer to Appendix C for more information on stomach cancer.
Is there an excess of kidney cancer north, northwest, or west of RMA?
Reply: There was no excess incidence of kidney cancer found in studies conducted forthe off-post communities to the north, northwest, west, and south of RMA. Theknown risk factors for kidney cancer do not include RMA chemicals that havebeen measured in environmental media and to which people were exposed.
The Colorado Department of Public Health & Environment recently conducted a study toinvestigate cancer incidence to the north, northwest, and west of RMA for the years 1978 to1989 and to the south for the years 1985-1989 (CDPHE, 1993a and CDPHE, 1993b). Nostatistically significant excess of kidney cancer was found. However, the study concluded thatthere was an excess of bladder cancer cases, as compared to "expected state rates," in males 45 to 49 years old residing north of RMA. There was no excess incidence of bladder cancer found in women.
Since CDPHE investigators observed this excess only in males, they doubt that the findings arelinked to environmental exposure to RMA chemicals, because excess incidence would also beexpected in women if environmental exposure was the cause of bladder cancer. CSU iscompleting a study that follows up on CDPHE's findings. Cancer incidence data from theColorado Central Registry, maintained by CDPHE, will be used, and the study will also evaluatesuch factors as occupation, smoking status, and groundwater usage. That study is not yetcompleted.
The kidneys and bladder are part of the urinary tract, but they are separate organs. The kidneysremove waste products from the blood to produce urine. Urine then drains from the kidneythrough a long tube, the ureter, to the bladder where it is stored.