ARCHIVED REPORTS_XR0008402 - Laserfiche WebLink

Home Browse Search

i pathways Surface water is not present at the site and groundwater is not utilized as a drinking water source. In addition, because of the low mobility of these pesticides in the environment and the clayey soil , groundwater was not investigated. Therefore, this HHA does not consider ingestion of groundwater as a significant exposure pathway. The chemicals listed in the health-based criteria presented in Tables 8-5 through 8-10 of the RCRA Guidance document are a subset of the hazardous constituents listed in Appendix VIII of 40 CFR Part 261 The concentrations for each constituent listed in the above-mentioned tables are derived from EPA-established chronic and/or acute toxicity criteria for ingestion or inhalation exposure routes and were calculated using the following set of intake assumption: Surficial Soils (Ingestion) • 0.1 g/day for 70 Kg person/70-year exposure period for carcin- ogens • 0.2 g/day for a 16 Kg child/5-year exposure period for systemic toxicants (corresponds to a period of 1 to 6 years of age) Air (Inhalation) • 20 m3 air/day for 70 Kg adult/70-year exposure period For the initial HHA, exposure to surface soil (0 to 6 inches deep) was considered. The range and average concentrations of pesticides detected in the surface soil are provided in Table B-2. Averages were calculated using one-half the detection limit when the chemical was not detected in a sample. This is considered a conservative approach because the detection limits were frequently elevated due to laboratory dilution of the extracts. TOXICITY ASSESSMENT For carcinogens, the RCRA health-based criteria for specified routes of exposure were derived from risk-specific doses (RSDS) in accordance with EPA Guidelines for Carcinogen Risk Assessment (EPA, 1986) . The RSD is an upper bound estimate of the average daily dose of a carcinogenic substance that corresponds to a specified excess lifetime cancer risk. The RCRA RSDS given in the EPA Guidelines (EPA, 1986) correspond to an excess lifetime cancer risk level of 10-6 for Class A and B carcinogens or 10-5 for Class C carcinogens The EPA uses the 10,4 to 10"6 range of excess lifetime cancer risk as the site remediation goal for Superfund sites (EPA, 1989) . For systemic toxicant the health-based criteria for specified routes of exposure were calculated using Reference Doses (RfDs) and are an estimate of the daily exposure that an individual (including sensitive individuals) can experience without appreciable health effects during a WPI13 B-2 882526 01