PUBLIC HEALTH ASSESSMENT
SIDNEY LANDFILL
SIDNEY, DELAWARE COUNTY, NEW YORK
DISCUSSION - ADULT AND CHILDREN'S HEALTH ISSUES
To evaluate the potential health risks from contaminants of concern associated with the Sidney Landfill site, the NYS DOH has assessed the risks for cancer and noncancer health effects. The health effects are related to contaminant concentration, exposure pathway, exposure frequency and duration. For additional information on how the NYS DOH determined and qualified health risks applicable to this Public Health Assessment, see Appendix C.
Workers at the Sidney Landfill were likely exposed to contaminants in on-site surface soils. Also, trespassers may have come in contact with contaminated soils. Major on-site soil contaminants are polychlorinated biphenyls (PCBs), arsenic, and lead. PCBs cause cancer in laboratory animals exposed to high levels over their lifetimes (ATSDR, 1995a). Based on the results of animal studies, the NYS DOH estimates that long-term chronic exposure of workers and trespassers to the highest levels (158 mg/kg) of PCBs found in on-site surface soils at the Sidney Landfill site could pose a low increased cancer risk. The site is currently posted and there is little evidence of use; however, it is not fenced. Remedial measures under way, which include consolidating and covering wastes, will eliminate this potential exposure pathway in the future.
PCBs also cause noncarcinogenic toxic effects. Effects reported in humans after occupational exposures to PCBs include skin, eye and respiratory tract irritation, and less frequently, effects on the liver and the nervous and digestive systems (ATSDR, 1995a). There may be a link between a mother's increased exposure to PCBs and effects on her child's birthweight and behavior (ATSDR, 1995a; Rogan and Gladen, 1991, 1992). PCBs have also caused skin, liver, nervous system, immune system and reproductive effects in animals (ATSDR, 1995a). Although the risks of noncarcinogenic effects from exposure to on-site soils contaminated with PCBs are not completely understood, the existing data suggest that they could be low.
Arsenic is a known human carcinogen (ATSDR, 1993a). Ingesting inorganic arsenic increases the risk of skin cancer and tumors of the bladder, kidney, liver and lungs. Studies of people exposed to high levels of arsenic in drinking water in foreign countries provide evidence of an association between arsenic ingestion and skin cancer. To date, however, studies in the United States have not shown such an association. The existing data suggest that chronic exposure of workers or trespassers to the highest levels (376 mg/kg) of arsenic detected in soil at the Sidney Landfill site could pose a low increased cancer risk. Chronic exposure to lead is predominantly associated with neurological and hematological effects and the developing fetus and young children are particularly sensitive to lead-induced neurological effects (ATSDR, 1993b). Chronic exposure to lead at the highest levels (53,800 mg/kg) found in on-site surface soils could pose a high risk of adverse health effects.
Individuals could have and may still be exposed to PCB-contaminated sediments at the South Pond. The PCB mixture Aroclor 1248 was detected in sediment at levels as high as 44 mg/kg. The toxicological properties of the PCBs have already been discussed. Based on the results of animal studies, chronic exposure to PCBs in off-site sediments could pose a low increased cancer risk. The risks of noncarcinogenic effects from potential exposure to PCB-contaminated sediments could be low. People who use South Pond for recreational purposes also may be exposed to the PCB mixture Aroclor 1248 in surface water (Appendix B, Table 4). Chronic exposure to PCBs at the highest level (1.19 mcg/L) found in surface water could pose a low increased cancer risk. The risks of noncarcinogenic effects from potential exposure to PCB-contaminated surface water would be minimal.
Chronic exposure to chemicals in drinking water is possible by ingestion, dermal contact and inhalation from water uses such as showering, bathing, and cooking. Although exposure varies depending on an individual's lifestyle, each of these exposure routes contributes to the overall daily uptake of contaminants and thus increases the potential for chronic health effects.
Three seasonally used private residential water supplies adjacent to the Sidney Landfill site and one seasonally used spring from which water was carried (also adjacent to the site) to a resident's home, are contaminated with chlorinated solvents at levels that exceed New York State drinking water standards. Residents using these spring water supplies were exposed to these contaminants in their drinking water for an undetermined period of time, possibly up to about 26 years from some time after the Sidney Landfill began operating in 1968 to 1994 when whole house carbon filter units were installed on the two water supplies containing the highest levels of chlorinated solvent contaminants. Levels of contamination prior to 1985/1986 are not known. Although residents began using bottled water for drinking in 1985/1986, exposure to these contaminants by dermal contact and inhalation from water uses such as showering, bathing and washing dishes was still possible. In addition, the resident who used a spring from which water was carried was advised of its contamination and no longer uses the spring for potable purposes.
Trichloroethene was detected in drinking water at levels as high as 1,025 mcg/L. The highest levels of tetrachloroethene, total 1,2-dichloroethene and 1,1,1-trichloroethane were 14, 29, and 66 mcg/L, respectively. Trichloroethene and tetrachloroethene cause cancer in laboratory animals exposed to high levels over their lifetimes (ATSDR, 1995,b,d). Chemicals that cause cancer in laboratory animals may also increase the risk of cancer in humans who are exposed to lower levels over long periods of time. Based on the limited sampling data and results of animal studies, past exposure to trichloroethene and tetrachloroethene contaminated drinking water could pose a low to moderate increased cancer risk. Toxicological data are inadequate to assess the carcinogenic potential of 1,1,1-trichloroethane and total 1,2-dichloroethene detected in some of these private water supplies.
Trichloroethene, tetrachloroethene, 1,1,1-trichloroethane and total 1,2-dichloroethene can also cause noncarcinogenic toxic effects primarily to the liver, kidneys and central nervous system (ATSDR, 1995b,c,d; 1996). Chemicals that cause effects in humans and/or animals at high levels of exposure may also pose a risk to humans who are exposed to lower levels over long periods of time. Although the risks of noncarcinogenic effects from exposure to these contaminants in drinking water are not completely understood, the existing data suggest that they could have been moderate for exposure to trichloroethene at a level of 1,025 mcg/L.
In June 1997, another private water supply well was found to be contaminated with chlorinated solvents at levels exceeding drinking water standards. Vinyl chloride was detected at 11 mcg/L, 1,2-dichloroethene at 21 mcg/L and trichloroethene at 9.4 mcg/L. Previous sampling in 1986 and 1990 did not detect contamination at levels above standards; however, we do not know when contaminant levels increased. Water from the well was used seasonally from 1990 to 1996, when the house was destroyed by fire.
Residents using this water supply were exposed on a seasonal basis to elevated levels of these contaminants for an undetermined period of time, possibly up to six years. Vinyl chloride is a known human carcinogen (ATSDR 1997). It has been associated with an increased risk of cancer in workers who breathed relatively high levels in workplace air over many years. Some workers who breathed vinyl chloride for several years have also shown noncarcinogenic effects, primarily on the liver, nervous system and immune system. Based on the limited sampling data, past exposure to vinyl chloride contaminated drinking water could pose a low increased cancer risk. The increased cancer risk from exposure to trichloroethene would be very low. The risks of noncarcinogenic effects would be low for vinyl chloride and minimal for 1,2-dichloroethene and trichloroethene.
When the property was purchased by the current resident in June 1997, until a new well was drilled in 1998, the resident used bottled water for drinking and contaminated water for other household uses. The new well was tested after installation and is not contaminated. Although the level of exposure to these chemicals via inhalation and skin contact is not known, NYS DOH estimates that the increased risk of cancer from household uses of the water for one year would be very low to low for vinyl chloride, and very low for trichloroethene. The increased risk of noncancer effects from household uses of the contaminated water for less than one year are estimated to be minimal.
Workers and trespassers could have come in contact with contaminated leachate seeps on the site. The contaminants selected for further evaluation are vinyl chloride and the PCB mixture Aroclor 1248 (Appendix B, Table 5). Chronic exposure to leachate contaminated with vinyl chloride at the highest level (16 mcg/L) detected could pose a low increased cancer risk. The toxicological properties of PCBs have already been discussed. Chronic exposure to PCBs at the highest level (3.6 mcg/L) found in on-site leachate seeps could pose a low increased cancer risk to workers. However, the site is currently posted and there is little evidence of use; although it is not fenced. Remedial measures, which are underway, and include consolidating and covering wastes, will eliminate this potential exposure pathway in the future.
The ATSDR Child Health Initiative emphasizes examining child health issues in all of the agency activities, including evaluating child-focused concerns through its mandated public health assessment activities. The ATSDR and the NYS DOH consider children when evaluating exposure pathways and potential health effects from environmental contaminants. We recognize that children are of special concern because of their greater potential for exposure from play and other behavior patterns. Children sometimes differ from adults in their susceptibility to the effects of hazardous chemicals, but whether there is a difference depends on the chemical. Children may be more or less susceptible than adults to health effects from a chemical and the relationship may change with developmental age.
The potential for trichloroethene and PCBs (two of the primary contaminants detected at the Sidney Landfill Site) to cause adverse effects in the offspring of humans and/or laboratory animals has been assessed in several studies. Studies of children born to women who were exposed to trichloroethene in drinking water during pregnancy provide limited evidence that an association may exist between oral trichloroethene exposure and adverse developmental effects (e.g., neural tube and oral cleft defects, low birth weight) as well as childhood leukemia (ATSDR, 1995d). In each of these studies, the mothers were exposed to other chemicals other than trichloroethene, and the overall data are not strong enough to conclude that the effects are caused by trichloroethene and not by some other factor or factors. When pregnant animals are exposed by ingestion and/or inhalation to large amounts of trichloroethene, adverse effects on the normal development of the offspring are observed (ATSDR, 1995d). In most, but not all of these studies, the high amounts of trichloroethene also caused adverse health effects on the parent animal. Some studies of pregnant women exposed to PCBs suggest a link between a mother's increased PCB exposure from eating contaminated fish or from other environmental sources and slight effects on her child's birthweight, short-term memory, and learning (ATSDR, 1995a). However, the women in these studies were also exposed to other chemicals and the effects of these chemicals on them and their children are not understood. PCBs given orally to laboratory animals during pregnancy cause adverse effects on the animals' offspring (ATSDR, 1995a). In some of these studies, the high amounts of PCBs also caused health effects on the parent animal. The estimated levels of exposure to trichloroethene and PCBs in environmental media at and near the Sidney Landfill Site were compared to the exposure levels in the animal studies in which adverse health effects were observed, and were found to be lower. Thus, the possibility that children may have increased sensitivity to trichloroethene and PCBs was taken into account when evaluating the potential health risks associated with the site.
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