Dermal Exposures Sample Clauses

Dermal Exposures. 5-5 5.1.2 NON-OCCUPATIONAL EXPOSURES .......................... 5-6 5.2 CARCINOGENIC HEALTH RISK ................................... 5-8 5.3 INTERPRETATION OF CANCER RISK ESTIMATES .................... 5-15 5.3.1 REGULATORY HISTORY .................................. 5-15 5.3.2 RELATIVE SITE RISKS ................................. 5-18 5.4 POTENTIAL AQUATIC IMPACTS .................................. 5-19 5.5 CONCLUSIONS ................................................ 5-25 5.6 RECOMMENDATIONS ............................................ 5-26 6.0 REFERENCES ...................................................... 6-1 7.0 GLOSSARY ........................................................ 7-1 APPENDICES APPENDIX A LANDFILL GAS CONTROL DESIGN MEASURES APPENDIX B SAMPLING LOCATION FIGURES APPENDIX C EMISSION, EXPOSURE, AND DOSE CALCULATIONS SPREADSHEETS APPENDIX D ISC COMPUTER OUTPUT 171 LIST OF FIGURES FIGURE PAGE 1-1 Westport Site Vicinity Map ........................................ 1-2 1-2 Westport Site Topography .......................................... 1-3 1-3 Proposed Westport Development Site Plan ........................... 1-5 1-4 Proposed Westport Development in Relation to Existing Topography ............................................... 1-6 1-5 Approved All-Commercial Plan: Westport Office Park ................ 1-7 172 LIST OF TABLES TABLE PAGE 3-1 Occupational Exposure Limits and EPA Reference Doses and Carcinogenic Potency Factors for Soil Vapor Compounds .................. 3-9 4-1 Soil Vapor Emission Estimates .......................................... 4-18 4-2 Box Model On-Site Exposure Point Air Concentrations .................... 4-21 4-3 ISC Model Exposure Point Air Concentrations ............................ 4-23

Dermal Exposures. Potential non-carcinogenic health effects associated with dermal exposures can be evaluated by comparing the calculated dose per episode to the EPA Reference Dose (RfD) for chronic exposure identified in Table 3-1. The RfD, as identified and discussed in Section 3.1 represents the daily dose of a chemical to which a person may be exposed for a lifetime without appreciable adverse (non-carcinogenic) effect. Although these RfDs were not specifically developed for the dermal routs of uptake, the oral RfD will be used to evaluate the potential adverse health impacts associated with dermal exposure. The RfDs cited are for chronic exposure. Much less stringent limits would normally be applied for intermittent, short-term or subchronic exposures. Therefore, use of this approach will greatly over-state any actual health impacts. The RfDs, predicted doses (from Section 4.5.1.1) and MOS are as follows: RfD Dose (mk/kg-day) (mg/kg - episode) MOS ----------- ----------------- --- Benzene 0.0007 1.2 x 10(-6) 5.8 x 10(2) Ethylbenzene 0.1 8.7 x 10(-5) 1.1 x 10(3) The predicted exposures associated with the dermal contact scenario with contaminated groundwater are well below the chronic Rfd, having margins of safety of over one hundred. These two compounds were selected to be representative of the potential health hazards for a number of compounds in the groundwater. Therefore, based on this very simplistic and highly conservative approach an individual could be exposed to at least one hundred times more, or one hundred other compounds at similar concentrations and toxicity without experiencing adverse non-carcinogenic health effects. No adverse non-carcinogenic health effects are therefore expected to be associated with incidental contact with groundwater from the site. 294