Investigations of the Starr Property began in 1989 following complaints to CT DEP about odors. Soils, waste, soil gas, ground water, domestic wells, surface water, sediments and air have been sampled during these investigations.
The following discussion and data tables present the contaminants identified for further evaluation.
Contaminants are presented by the media in which they were found. The contamination is also broken into on-site and off-site. The listed contaminant does not mean that it will cause adverse health effects from exposures. The list indicates which contaminants will be discussed further in the public health assessment. These contaminants were selected based upon the following factors:
We evaluate these contaminants in the subsequent sections of the public health assessment and determine whether exposure to them has public health significance.
Tables in Appendix E include the comparison values that were used to identify contaminants for further evaluation.
Soil
In August of 1989, CT DEP collected surface soil (0-2 inch depth) and waste samples in five locations within the areas of obvious contamination. All five samples were tested for semivolatile organic compounds, four of the five samples were tested for metals and one of the five samples was tested for volatile organic compounds and cyanide. (See Appendix D, Sampling locations)
During the Remedial Investigation, soil and waste samples were collected at twenty locations. Samples were taken at varied depths including borings. These samples were analyzed for metals, semivolatile organic compounds, volatile organic compounds and cyanide. (See Appendix D, Sampling locations)
Tables 1 and 2 list the contaminants identified for further evaluation. Table 1 represents sampling of surface soil, 0-2 inches, and Table 2 represents sampling of soil and waste deeper than 2 inches.
Table 1
Concentrations of Contaminants
Identified for Further Evaluation
Surface Soil 0-2 inch depths
On-Site
| CONTAMINANT | CONCENTRATION RANGE PPM* |
| naphthalene | ND-2700 |
| 2-methylnaphthalene | ND-90 |
| acenaphthene | ND-72 |
| dibenzofuran | ND-130 |
| fluorene | ND-21 |
| phenanthrene | ND-450 |
| anthracene | ND-140 |
| pyrene | ND-270 |
| benzo(a)anthracene | ND-84 |
| chrysene | ND-74 |
| benzo(a)pyrene | ND-53 |
| lead | 37-1200 |
| arsenic | 0.8-3.5 |
| cyanide (total) | 180-640 |
Table 2
Concentrations of Contaminants
Identified for Further Evaluation
Subsurface Soil Deeper than 2 inches
On-Site
| CONTAMINANT | CONCENTRATION RANGE PPM* |
| arsenic | 0.8-86 |
| lead | 3.2-483 |
| cyanide (total) | ND-582 |
| cyanide (amenable) | ND-502 |
Because the use of dirt bikes and all terrain vehicles has disrupted soils in areas of obvious contamination, we looked at subsurface soil contamination as part of our exposure assessment. Polycyclic aromatic hydrocarbons, such as acenaphthene, fluorene, phenanthrene and benzo(a)pyrene, were detected at higher concentrations in surface soils as was lead and total cyanide. Arsenic was detected at higher concentrations in subsurface soil. There was no amenable cyanide detected in surface soil but it was detected in subsurface soil. Amenable cyanide is cyanide that is available for reaction within the human body if exposure were to occur.
Soil Gas Survey
A soil gas survey was done on-site to screen for the presence of volatile organic compounds in the subsurface soils and to determine whether coal gasification waste or other volatile organic compounds were in soil and groundwater. On May 29, 1992, Malcolm Pirnie, Inc. surveyed a 200 square foot area where obvious waste was present. Twenty-five samples were taken.
Volatile organic compounds were detected at very low levels in the southeastern corner of the survey area. These readings correlated with observable surface waste and did not indicate that substantial amounts of buried organic wastes were present.
Ground Water Monitoring Wells
Eleven ground water monitoring wells were sampled during the Remedial Investigation. (See
Appendix D, Well locations) Eight shallow overburden wells and three deep wells were sampled
in two rounds. During these two sampling rounds, ground water was sampled for volatile organic
compounds, semivolatile compounds, metals and cyanide. Table 3 lists the contaminants identified
for further evaluation.
Table 3
Concentrations of Contaminants
Identified for Further Evaluation
Ground Water Monitoring Wells
On-Site
| CONTAMINANT | CONCENTRATION RANGE PPB* |
| arsenic | ND-31 |
| lead | ND-50 |
| cadmium | ND-40 |
| mercury | ND-7 |
| cyanide (total) | ND-230 |
| cyanide (amenable) | ND-90 |
Carbon disulfide was detected in one shallow well during the first round of sampling but was not detected in that same well during the second round of sampling. Xylene and toluene were detected in one shallow well during the second round of sampling. These contaminants were found at levels well below comparison values. The results of the deep groundwater samples indicate that waste disposal has not adversely affected deep groundwater quality.
Leachate
Leachate was sampled during the Remedial Investigation at three locations. (See Appendix D,
Sampling locations) These samples were analyzed for volatile organic compounds, semivolatile organic compounds, cyanide and metals. Table 4 lists the contaminants identified for further evaluation.
Table 4
Concentrations of Contaminants
Identified for Further Evaluation
Leachate
On-Site
| CONTAMINANT | CONCENTRATION RANGE PPB* |
| benzene | ND-43 |
| naphthalene | ND-70 |
| cyanide (total) | 40-500 |
| cyanide (amenable) | ND-500 |
Toluene, xylene and carbon disulfide were also detected in leachate at concentrations below levels of health concern.
Sediment and Surface Water
In May 1990, CT DEP collected seven surface water samples and nine sediment samples on-site.
(See Appendix D, Sampling locations) These samples were analyzed for volatile organic
compounds, semivolatile organic compounds, cyanide and metals. Table 5 and 6 list the
contaminants identified for further evaluation.
Table 5
Concentration of Contaminants
Identified for Further Evaluation
Sediment
On-Site
| CONTAMINANT | CONCENTRATION RANGE PPM* |
| cyanide (total) | 0.04-270 |
| cyanide (amenable) | ND-240 |
Table 6
Concentration of Contaminants
Identified for Further Evaluation
Surface Water
On-Site
| CONTAMINANT | CONCENTRATION RANGE PPM* |
| naphthalene | ND-0.057 |
| cyanide (total) | ND-1.4 |
| cyanide (amenable) | ND-1.1 |
No volatile or semivolatile organic compounds were detected in surface water except for naphthalene. Concentrations of volatile and semivolatile compounds were very low in sediments. The gullies and pond drain into a wetland area that feeds the Scantic River. Migration of contaminants from on-site surface water to off-site areas is possible.
Ambient Air
In October, 1990, CT DEP conducted one day of on-site air sampling at one upwind, two downwind, and two on-site locations with obvious soil contamination. (See Appendix D, Sampling locations) Sorbent tube samples were used during sampling events of thirty minutes each. The sampling included volatile organic compounds, cyanide, and petroleum distillates.
In December, 1991, CT DEP conducted one day of air screening tests in areas where odors were strong versus areas where odors were not evident. Nine test sites were sampled for phenol and hydrogen cyanide using detector tubes. There was only one positive sample of hydrogen cyanide however the detector tube had expired so the hydrogen cyanide concentration of 0.25 ppm was approximated. Hydrogen cyanide was not detected during any of the more thorough air sampling events therefore the result of 0.25 ppm is considered only qualitatively.
On February 22 and 23, 1992, two days of air sampling was performed. Volatile organic compounds, semivolatile organic compounds and hydrogen cyanide were sampled for. Three on-site locations were sampled for seven hour periods. (See Appendix D, Sampling locations) The three on-site sampling locations included areas of obvious soil contamination and a leachate outbreak area. Toluene and styrene were the only two contaminants detected at concentrations well below health comparison values.
In August, 1992, additional air sampling was conducted for one twenty-four hour period. High temperatures and low winds increased the likelihood of capturing a "worst case scenario" with respect to pollutant off-gassing from the soil. Samples were tested for forty-three volatile organic compounds and twenty polycyclic aromatic hydrocarbons. One on-site sample was taken in an area of obvious soil contamination. Seven VOC's and five PAH's were detected at concentrations similar to background and well below levels of public health concern.
The characteristic almond-like odor of cyanide has been identified at the site, however air sampling has not quantified cyanide either on-site or off-site.
Table 7 lists the contaminants identified for further evaluation detected in ambient air. The table
includes contaminants detected during all of the ambient air sampling events. The sampling date
indicates the date that the highest concentrations was detected.
Table 7
Concentration of Contaminants
Identified for Further Evaluation
Ambient Air
On-Site
| CONTAMINANT | CONCENTRATION RANGE PPB* | SAMPLING DATE* |
| benzene | ND-7 | 10/1990 |
| trichloroethylene | ND-68 | 10/1990 |
Soil Gas Survey
Two phases of soil gas surveys were done in the residential areas northwest of the site in September of 1992 by Malcolm Pirnie, Inc. Phase one screened for the presence of volatile organic compounds and phase two was done to determine whether any volatile organic compounds detected were from buried waste.
Results of the soil gas survey indicate that while low levels of non-methane volatile organic compounds were detected in the residential soil gas survey, they are not related to coal gasification wastes and are likely due to background.
Sediment and Surface Water
Off-site surface water and sediment samples were taken in the Scantic River in September 1989 by
the CT DEP and during the Remedial Investigation. CT DEP sampling in 1989 included three
sampling locations, one upstream, one downstream and one adjacent to the site. (See Appendix D,
Sampling locations) Sampling during the Remedial Investigation included ten locations. (See
Appendix D, Sampling locations) Tables 8 and 9 list the contaminants identified for further evaluation.
Table 8
Concentration of Contaminants
Identified for Further Evaluation
Sediment Off-Site
| CONTAMINANT | CONCENTRATION RANGE PPM* |
| arsenic | 1.4-6.8 |
| cyanide (total) | ND-10 |
| cyanide (amenable) | ND-7.7 |
Table 9
Concentration of Contaminants
Identified for Further Evaluation
Surface Water Off-Site
| CONTAMINANT | CONCENTRATION RANGE PPM |
| cyanide (total) | ND-.21 |
| cyanide (amenable) | ND-0.03 |
The highest concentrations of contaminants were found in samples adjacent to or down stream from the site indicating that migration of contaminants through surface water is occurring.
Ambient Air
During the February 22 and 23, 1992, air sampling event, four off-site sampling locations were located in the residential area. (See Appendix D, Sampling locations) Odors were present during these sampling events. Toluene and styrene were detected at two of the four homes. The highest concentrations of toluene and styrene, were well below levels of health concern.
Four off-site sampling locations were monitored during the August 1992 sampling event which
occurred over one twenty-four hour period. Ten volatile organic compounds and five polycyclic
aromatic hydrocarbons were detected in the residential areas. Four of the volatile organic
compounds detected in the residential areas were not detected in the on-site sample. Driveway
sealing was occurring in the residential neighborhood during the testing. This could explain the
levels of PAHs found in residential areas and not on-site. Table 10 lists the contaminants identified
for further evaluation in the off-site ambient air sampling.
Table 10
Concentration of Contaminants
Identified for Further Evaluation
Ambient Air Off-Site
| CONTAMINANT | CONCENTRATION RANGE PPB* |
| benzene | ND-0.5 |
| tetrachloroethylene | ND-5.5 |
Private Wells
Private wells approximately 2,000 feet south of the site in East Windsor were sampled on several occasions in 1989 and 1990 by CT DEP.
In August of 1989 five homes on Melrose Place were sampled for physical parameters, hydrocarbons, organohalides, heavy metals and cyanide. During this sampling, no organics or hydrocarbons were detected in any of the five wells. Low concentrations of cyanide were detected in three of the wells, the highest concentration was 0.03 ppm. The Action Level for cyanide in water is 0.20 ppm.
In September of 1989, four homes on Yosky Road were sampled for physical parameters, hydrocarbons, organohalides, semivolatile organics, heavy metals and cyanide. During this sampling, trace concentrations of 1,1,1-trichloroethane (<1ppb) were detected in all four wells. Two wells also had trace levels of silver (0.008 ppm).
In October of 1989, three homes on Melrose, previously sampled during the August 1989 sampling and one home on Yosky, previously sampled in September of 1989 were again sampled. No cyanide or volatile organic compounds were detected in confirmatory sampling. All other parameters were well within acceptable water quality parameters.
In October of 1990 a deep and shallow well on Yosky were sampled. The resident complained about a sheen on water drawn from the shallow well. Acetone (220 ppb), toluene (370 ppb) and methyl ethyl ketone (470 ppb) were detected in the shallow well. Nothing was found above health comparison values in the deep well.
In November of 1990, two additional homes on Yosky were sampled. These homes were on either side of the property with the shallow and deep wells. Nothing was found above health comparison values in either of the wells.
C. QUALITY ASSURANCE AND QUALITY CONTROL
Environmental data was collected at the Starr property by CT DEP and Malcolm Pirnie, Inc.. The QA/QC procedures outlined as part of the Remedial Investigation Work Plan were reviewed and appeared to be satisfactory. QA/QC procedures for a variety of sampling activities conducted by CT DEP were not reviewed. Some data from these sampling events is questionable. Air sampling conducted by CT DEP in December of 1991 utilized sorbent tubes for hydrogen cyanide with expired dates. These results were approximated. In addition, one private well sample was high in acetone and methyl ethyl ketone suggesting laboratory contamination.
No physical hazards were identified.
In this section we evaluate whether residents were, are, or could be exposed to contamination on the site or migrating from the site. In order for an exposure to be complete five elements must be present: a source of contamination, transport through an environmental medium, a point of exposure, a route of human exposure and an exposed population. A potential exposure pathway exists if one of the five elements is missing but could exist. An exposure pathway can be eliminated if at least one of the elements is missing and will never be present.
Soil Pathway
Soil contamination has resulted from historic waste disposal practices. Past, present and future exposures are possible from contamination of surface and subsurface soils on-site. People who trespass on the site maybe exposed to contamination in the soil through incidental ingestion, inhalation of soil particles, and dermal contact. Individuals who ride dirt bikes and all-terrain vehicles are at greatest risk due to the disruption of the soil during these activities. The exposed, unvegetated areas on site are the most likely exposure points and also represent the areas where the most significant soil contamination was found. Surface and subsurface soils have been contaminated with naphthalene, polycyclic aromatic hydrocarbons and some metals including lead, arsenic and cyanide.
Ambient Air Pathway
Past, present and future exposures are possible from contamination of the ambient air. Inhalation of contaminants in the air may occur on-site and in nearby residential areas. Volatile organic compounds have been detected in the air both on-site and in the residential neighborhoods. Odors have also been evident in these areas. On-site activities including dirt bike riding in areas of obvious soil contamination, may cause soil contaminants to become airborne and dispersed into residential areas.
Ground Water Pathway -Private Wells
Past, present and future exposures to contaminated water are possible for residents drinking water from private wells on the Enfield, East Windsor line, south of the Starr property. Low concentrations of cyanide have been found in several private wells. In addition, acetone, toluene, and methyl ethyl ketone were detected in one shallow well. These results are questionable, however, due to possible laboratory contamination.
Surface Water and Sediment
Past, present and future exposure to contaminated sediment and surface water may occur for individuals who trespass on the site or recreate in the down stream areas of the Scantic River. Trespassers on the site may come in direct contact with leachate, surface water and sediment while engaging in recreational activities including dirt bike riding. Dermal contact with site contaminants is possible. Leachate, surface water and sediments have been contaminated with cyanide, benzene, naphthalene and arsenic.
The most significant contamination of sediments and surface water was found on-site, however,
cyanide and arsenic were detected in off-site samples. This is likely the result of contaminant
transport in surface water from the site to the Scantic River.
In this section, we discuss the adverse health effects that could occur in people exposed to site contaminants. To understand the health effects that might be caused by a specific chemical, it is helpful to review factors related to how the human body processes such a chemical. Those factors include the exposure concentration (how much), the duration of exposure (how long), the route of exposure (breathing, eating and drinking, or skin contact), and the multiplicity of exposure (environmental media, routes of exposure, and combinations of contaminants). Once exposure occurs, a person's individual characteristics such as age, sex, diet, general health, lifestyle, and genetics, influence how the body absorbs, distributes, metabolizes, and excretes the chemical. Together those factors determine health effects that exposed people might have.
To evaluate health effects, ATSDR has developed Minimal Risk Levels (MRLs) for contaminants commonly found at hazardous waste sites. The MRL is an estimate of daily human exposure to a contaminant below which non-cancer, adverse health effects are unlikely. MRLs are developed for oral and inhalation exposure routes, and for duration of exposure (acute: 14 days or fewer; intermediate: 15-364 days; chronic: 365 days or more).
Minimal Risk Levels are compared to human exposure doses. Exposure doses are calculated by making certain assumptions about contaminant concentration, duration of exposure and route of exposure based on site characteristics and human activities at the site. It is not always possible to calculate an exposure dose due to lack of information. Where possible, exposure doses have been calculated and reported in the following discussion of specific contaminants.
ATSDR publishes MRLs in its series of chemical-specific documents called Toxicological Profiles -- documents that describe health effects, environmental transport, human exposure, and regulatory status of a chemical. Preparers of this public health assessment have reviewed those profiles for the contaminants of concern at this site.
Arsenic
Arsenic was detected in soil (86 ppm), sediments (6.8 ppm) and ground water monitoring wells (31 ppb).
People may be exposed to arsenic in soil and sediment through dermal contact, inhalation of soil that may become airborne during site activities and incidental ingestion.
Dermal exposure to inorganic and organic arsenicals have not been studied extensively. No quantitative data on dermal exposure to organic arsenicals were located. Some studies of workers exposed to arsenic dust report that inorganic arsenic can cause contact dermatitis. Studies suggest that direct contact is of concern at high exposure doses but do not suggest a problem at lower exposure doses. It is not likely that dermal exposure to the arsenic at concentration found at the site would cause contact dermatitis. No studies were found regarding neurological, developmental, reproductive, genotoxic, or cancer effects following dermal exposure to arsenic.
Workers who inhaled inorganic arsenic dusts in air experienced irritation of the nose and throat. These minor effects were absent at exposure levels around 0.1 - 1 mg/m3. No studies of respiratory effects following exposure to organic arsenic were found in humans. Other occupational studies of workers exposed to arsenic dusts indicate that arsenic dust can cause nausea, vomiting, and diarrhea at high concentrations.
Inhalation exposure to inorganic arsenic dust increases the risk of lung cancer. We do not know the concentrations that dirt bike riders may be exposed to, however, we do not feel that this type of incidental exposure is likely to significantly increase the risk of lung cancer in these individuals.
No adverse health effects would be expected from incidental ingestion of arsenic at the concentrations found at the site. Exposure doses of .000017 mg/kg/day for adults and .00049 mg/kg/day for children were calculated using conservative assumptions about exposure. The Minimal Risk Level established by ATSDR for ingestion is .0003 mg/kg/day.
Benzene
Benzene has been detected in leachate and ambient air both on-site and off-site.
Benzene was detected in on-site leachate at 43 ppb. Dermal exposure to leachate may occur to trespassers on-site. Benzene is slightly irritating to the skin and acts by defatting the keratin layer of the skin. Skin irritation is unlikely to occur in persons who may come in contact with the benzene in leachate at 43 ppb. Absorption of benzene through the skin is minimal.
Benzene was detected in ambient air samples. The highest concentration detected on-site was 7 ppb and the highest concentration detected off-site was 0.5 ppb. People are exposed to benzene on a daily basis primarily from benzene in the air. Background levels of benzene in the air range from 2.89-20 ppb. Chronic inhalation exposures to benzene have been studied in humans whose occupations include benzene exposure. Workers exposed to less than 1 ppm or 1,000 ppb for one to twenty-one years showed no changes in erythrocytes, leukocytes, thrombocytes, hemoglobin, or hematocrit. Benzene does cause leukemia. Studies documenting an increased risk of leukemia from benzene exposure involve benzene concentrations in the parts per million range, significantly higher than was found at the Starr property.
Cyanide
Amenable cyanide has been detected in subsurface soil (502 ppm), ground water monitoring wells (90 ppb), private wells (.03ppm), leachate (500 ppb), sediment (240 ppm) and surface water (1.1 ppm). Amenable cyanide is the more appropriate measure of cyanide toxicity.
People who trespass on the site may be exposed to cyanide through dermal contact with soil, sediment and surface water containing cyanide. Dermal exposure may also occur for people who are involved in recreation activities in and near the Scantic River. Incidental ingestion and inhalation exposure to cyanide may occur for people involved in dirt bike riding on-site. Private well users are exposed to cyanide through ingestion of water containing cyanide.
No studies were found regarding hematological, musculoskeletal or hepatic effects in humans or animals following dermal exposure to cyanide. Some cyanide compounds such as potassium cyanide have a corrosive effect on the skin which allows them to penetrate the skin rapidly. Sodium cyanide dust is reported to be irritating to the eyes. Skin irritation may also occur from contact with cyanide dust. Information regarding dermal exposure in the occupational setting identified significant neurological effects at concentrations much higher than was found at the site.
We cannot evaluate the exposure that may result from inhalation of soil dust generated during dirt bike riding. Respiratory changes are common in humans exposed to cyanide. Nasal irritation has been reported in humans exposed to 16 ppm cyanide for 6-8 minutes. No effects were reported after exposure to 8 ppm. Cardiovascular effects have been observed in persons accidentally poisoned with cyanide. Abdominal spasms have been reported after acute poisonings as well.
Exposure doses for adults and children were calculated assuming 0.03 ppm cyanide in water, an ingestion rate of 2 liter per day for adults and 1 liter per day for children. These exposure doses are well below the EPA Reference Dose of 0.02 mg/kg/day. No adverse health effects would be expected from drinking water containing cyanide at 0.03 ppm.
Lead
Lead was detected in surface soil and ground water monitoring wells above screening values. The concentration of lead in soil was 1200 ppm and the highest concentration in ground water was 50 ppb.
People who trespass at the site may be exposed to lead in soil through dermal contact, incidental ingestion and inhalation of soil dust.
Lead is not easily absorbed through the skin. No studies were found regarding adverse health effects following dermal exposure.
Ingestion and inhalation exposure to low levels of lead for long periods of time can cause lowered I.Q. and brain damage in children. It is unlikely that the concentrations of lead at the site would significantly change blood lead levels of people exposed. This assumes that both inhalation exposures and ingestion exposures are intermittent and incidental, like exposures that would occur during dirt biking activities.
Naphthalene
Naphthalene was detected on-site in soil (2,700 ppm), leachate (70 ppb) and surface water (57 ppb).
People who trespass on-site may be exposed to naphthalene through dermal contact and through inhalation of soil dust containing naphthalene.
There are very few studies describing dermal effects in humans or animals caused by exposures to naphthalene. No studies were found regarding respiratory, cardiovascular, gastrointestinal, or musculoskeletal effects in humans following dermal exposure. Jaundice was observed in infants exposed to naphthalene treated diapers. Naphthalene is a mild dermal irritant when directly applied to shaven skin of rabbits at 500 ppm for four hour duration. These effects were reversible within seven days after exposure. No studies were located regarding dermal effects in humans after exposure to naphthalene. It is not known whether the concentrations of naphthalene found at the site would cause skin irritation to people exposed to it.
Little information is available on the effects of breathing naphthalene on human health. Exposure to naphthalene in the home, primarily due to mothballs has been associated with headache, nausea, vomiting, abdominal pain, malaise, confusion, anemia, jaundice, and renal disease. Naphthalene was not detected during the air sampling events, however, naphthalene could become airborne during on-site activities including dirt biking. We do not know what concentrations people may be exposed to in air during these activities.
No adverse health effects would be expected from incidental ingestion of naphthalene at the concentrations found at the site. Exposure doses were calculated for adults, .000055 mg/kg/day, and children, .015 mg/kg/day using conservative assumptions about soil ingestion.
Polycyclic Aromatic Hydrocarbons
Polycyclic aromatic hydrocarbons (PAH's) were detected in on-site soils and waste. Benzo(a)pyrene, the most toxic of the PAH's was detected at concentrations as high as 53 ppm. Persons who trespass on-site, particularly those who engage in dirt-biking, may be exposed to PAH's through dermal contact and inhalation and incidental ingestion of soil particles.
Dermal exposure to a group of PAH's can cause skin disorders. Humans who received 120 dermal applications of 10,000 ppm benzo(a)pyrene over four months experienced reversible and apparently benign skin reactions. Adverse skin reactions in persons exposed to the PAH's in soil at the site are not likely.
Inhalation exposure to PAH's at the site may be possible due to activities at the site that could stir up and allow these contaminants to become airborne. No PAH's in air were detected during on-site or off-site sampling however, these sampling events did not occur when dirt bike riding on-site was occurring. No studies have been located regarding inhalation exposure to PAH's and systemic, immunological, neurological, developmental, reproductive or genotoxic effects due to inhalation exposure to PAH's.
Epidemiological studies have shown increased death due to lung cancer in humans exposed to coke-oven emissions, roofing tar emissions, and cigarette smoke which all contain PAH's. Exposure from these activities are significantly higher and the duration longer than would occur at the site.
No adverse health effects would be expected from incidental ingestion of benzo (a) pyrene at the concentrations found at the site. Exposure doses were calculated for adults, .000011 mg/kg/day, and children, .00031 mg/kg/day using conservative assumptions about soil ingestion. The MRL for ingestion of benzo (a) pyrene is .01 mg/kg/day.
Tetrachloroethylene
Tetrachloroethylene was detected in ambient air in an off-site sample at 5.5 ppb. Intermittent exposure to tetrachloroethylene through inhalation may be occurring for residents in the nearby neighborhoods and trespassers on-site. At 5.5 ppb, the highest concentration detected at the site, no adverse health effects would be expected. ATSDR has set an Environmental Media Evaluation Guide of 9 ppb for inhalation of tetrachloroethylene for exposures lasting longer than 14 days but less than one year.
Tumor incidence data was evaluated in an effort to address citizen concerns about cancer in the neighborhood around the Starr property. While this type of analysis may generate clues regarding the association between environmental exposures and disease outcomes, it must be stressed that such an association is not sufficient to establish a causal link. Many other factors may also contribute to the onset of disease, including diet, tobacco use, family history, age, race, occupation and socioeconomic factors.
Information on the total number of cancer cases in Connecticut and in Enfield was obtained from the CT DHS Tumor Registry. Since 1935 it has been required by law that all tumors diagnosed in Connecticut residents be reported to the Tumor Registry. Age specific cancer incidence rates were generated for Connecticut and Enfield for 1979-1988 by dividing the number of cases identified during the period in an age group by the population in that age group according to 1985 population statistics. We looked specifically at brain cancer and leukemia, the cancers of concern to citizens.
The standard incidence ratio (SIR) is an overall summary measure of the cancer risk. The SIR is calculated by multiplying the Connecticut cancer incidence rates by the population of the town to estimate an "expected" number of cancers in each age group. The actual (or observed) number of cases identified by the Tumor Registry are divided by the expected number to obtain the SIR. When the SIR is less than one the risk of cancer is less than expected. This method allows for the inclusion of age as a risk factor in the analysis. Age is important to consider because generally speaking the risk of cancer varies with age.
Table 11 presents the standard incidence ratios for brain cancer and leukemia for Enfield.
Table 11
Standard Incidence Ratio of Selected Tumor Sites
Enfield, CT 1979-1988
1985 Population, 41,700
| TUMOR SITE | OBSERVED = SIR EXPECTED |
95% CONFIDENCE INTERVAL |
| BRAIN | 46 = 1.056 43.55 |
(0.75,1.36) |
| LEUKEMIA | 30 = 0.77 38.56 |
(0.49,1.05) |
* Confidence Interval: the range of values within which one can be 95% confident that the SIR is the true valued and has not occurred by chance.
The results of this analysis indicate that there was no overall increase of brain cancer or leukemia occurring in Enfield during the time period. We were only able to look at town statistics and could not look specifically at the area around the site. In addition, this type of study does not identify cause effect relationships between exposure and outcome. These issues limit the value of a negative study. We do believe that there is little biological plausibility of these cancers being caused by the site because exposure to carcinogens at levels and durations likely to cause cancer have not been documented at this site.
C. COMMUNITY HEALTH CONCERNS EVALUATION
We have addressed each of the community health concern as follows:
The odors at the site have been described in two different ways, almond-like and coal tar-like. Cyanide has a characteristic almond-like odor. Polycyclic aromatic hydrocarbons may cause coal tar-like odors. Sampling events both on-site and off-site during periods when odors were strong have not identified cyanide or PAHs at levels of health concern. Hydrogen cyanide has an odor threshold of 0.58 ppm in air. (4) It is possible that these compounds can be smelled at levels lower than would cause an adverse health effect. People near the site have complained about headaches when odors from the site are present. Based on the information about site contaminants and the concentrations of these contaminants in ambient air, we cannot explain why headaches are occurring from a toxicological standpoint. Investigations at similar sites with coal tar wastes have also identified strong odors however, aggressive air monitoring has not been successful in identifying or quantifying the causative agent(s).
Ambient air sampling in the residential areas have not identified contaminants at concentrations likely to cause adverse health effects in residents, children, or pregnant women. Therefore, we do not feel pregnant women are at risk. Odors from the site have raised a number of concerns and may be contributing to headaches. Sampling data has not quantified levels of contamination likely to cause these headaches.
After hearing concerns about brain cancer and leukemia in the neighborhoods surrounding the Starr property, we looked at cancer occurrence in Enfield. We did not find that brain cancer or leukemia were occurring at a greater rate than we would expect. The analysis used to look at cancer do have limitations. These studies do not identify cause effect relationships between exposure and outcomes. In addition, we were only able to look at town statistics and could not break that down to areas specifically surrounding the site. We do believe however that these tumors were not likely caused by exposure to the site. There is little known exposure occurring to carcinogens and the latency period for many tumors are longer than the potential exposure from site contamination. (The residential areas were developed in 1987.)
Environmental sampling as well as historical information regarding past disposal practices at the site suggest that contamination is localized. The northern and southern gullies that border the site appear to have prohibited the dumping of waste in areas that later were developed into residential areas. In addition, soil gas sampling in residential areas did not reveal the presence of waste. Migration of site contaminants seems to be restricted to surface water and air emissions.
Ambient air sampling on-site and off-site have not been conducted during periods of dirt bike riding or invasive site activities. It is possible that dust generated during these activities could reach the nearest residential areas. We do not have enough information to assess the levels of contamination that might become airborne during these activities. We have considered the risk to dirt bike riders in a qualitative manner in the Toxicological Implication Section and feel the risk to people in the residential areas would be significantly lower. However, we strongly recommend that dirt bike riding and other on-site activities be prohibited.
Ambient air sampling both on-site and in the residential neighborhoods have not identified contamination in the air at concentrations likely to cause adverse health effects. Some of the contaminants found at the site have very low odor thresholds which means you can smell them at concentrations lower than the levels in which harmful health effects might occur. It is possible that exposure to coal tar products may play a role in citizen complaints of headache through an odor-mediated mechanism.
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