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Human Health Screening Evaluation <br /> Former Vernalis Pump Station September 2,2010 <br /> 5.1 RESIDENTIAL CANCER RISKS <br /> SAIC-Benham calculated the oral and dermal cancer risks and inhalation cancer risks to potential <br /> on-site residential receptors for exposure to on-site soils using the following equations: <br /> Oral and Dermal Cancer Risks for Direct Contact with Soil (PEA Guidance Manual, Figure 2.3): <br /> Risksoii=(SFo x Cs x [1.57E-061) + (SFo x Cs x [1.87E-05] x ABS) <br /> Where: <br /> Risksoij =oral and dermal cancer risks from direct soil exposure <br /> SFo= oral cancer slope factor, (mg/kg-day)"1 <br /> Cs= concentration in soil, mg/kg <br /> ABS =dermal absorption fraction, dimensionless <br /> The oral and dermal cancer risk calculations for potential exposures to site soils are provided in <br /> Table 10. SAIC-Benham estimated the potential cancer risks for carcinogenic COPCs and then <br /> summed the risks among chemicals for oral and dermal exposures. <br /> Inhalation Cancer Risks for Air(PEA Guidance Manual, Figure 2.4): <br /> Riskair= SFi x Ca x 0.149 <br /> Where: <br /> Riskair inhalation cancer risk from indirect soil exposure <br /> SFi= inhalation cancer slope factor, (mg/kg-day)-1 <br /> Ca= concentration in air, mg/m3 <br /> Section 5.3 describes how SAIC-Benham estimated the value for Ca using equations presented in <br /> PEA Guidance Manual Figures 2.5, 2.6, and 2.7 for VOCs, and Figure 2.8 for non-VOCs. <br /> The inhalation cancer risk calculations for potential exposure to on-site soils are provided in <br /> Table 11. SAIC-Benham estimated the potential cancer risks for carcinogenic COPCs and then <br /> summed the risks among chemicals for inhalation exposures. <br /> SAIC-Benham then summed the cancer risks for oral and dermal exposures (Table 10) with the <br /> risks for inhalation exposures (Table 11)to estimate the cancer risks across exposure routes for <br /> on-site soil. The sum of oral, dermal, and inhalation cancer risks for on-site soil are provided in <br /> Table 12. <br /> 5.2 RESIDENTIAL NON-CANCER HEALTH HAZARDS <br /> SAIC-Benham calculated the calculation of oral and dermal health hazards, and inhalation <br /> hazards for exposure to on-site soils for potential on-site residential receptors using the following <br /> equations: <br /> The Benham Companies,LLC <br /> �rt j`® A Wholly Owned Subsidiary <br /> From S mxt fo Salanoss <br />