Laserfiche WebLink
' Human Health Risk Assessment <br /> Former Mobil Oil Bulk Plant 04-343 <br /> 500 East Grant Line Road <br /> Tracy, California <br /> 6.4 CALCULATION OF NONCARCINOGENIC HAZARD INDICES <br /> Risk characterization of noncarcinogenic health risks is accomplished by combining the <br />' quantitative exposure and dose-response estimates. The estimation of noncarcinogenic health <br /> risks is derived through the calculation of the Hazard Index. The Hazard Index is the ratio of <br />' the estimated air concentration to the chemical-specific reference concentration. The reference <br /> concentration represents the chemical concentration in air, to which a receptor may be exposed <br /> for an entire lifetime without experiencing adverse health effects. The estimated air <br /> concentration is divided by the reference concentration to derive the Hazard Index via the <br /> following equation. <br /> Hazzard Index = Estimated Air Concentration (mg/M) <br /> Reference Concentration (mg/m 3) <br /> Where the Hazard Index is less than unity (1.0) for any single chemical or combination of <br /> chemicals, no adverse health effects would be expected in the potentially exposed population. <br /> E <br /> The results of the Hazard Index calculations are presented in the following section. <br />' 6.4.1 Hazard Indices from Inhalation of Toluene, Ethylbenacne, <br /> and Xylenes Under Current Site Conditions <br /> 6.4.1.1 Airborne Concentration of Toluene, Ethylbenzene, and Xylenes in <br />' Nearby Commercial Building <br /> The calculated airborne concentrations of toluene, ethylbenzene, and xylenes in a nearby <br />' commercial building are approximately S 3.9 x 10' mg/m3, <_ 2.5 x 10-3 mg/m3, and <br /> 9.1 x 10' mg/m3, respectively. <br /> 1 <br /> 1 <br /> 30-0136-11 <br />' 6-4 <br />