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5.9 PUBLIC HEALTH The results of the screening modeling analysis (see Section 5.1,Air Quality) were used to determine the maximum impact operating conditions in modeling the annual and 1-hour averaging periods, and these modeling results were used in determining cancer risk and chronic HHI,and acute HHI,respectively. The total weighted risk"rate' for each equipment unit,as described in the previous section,was used in place of emission rates in the modeling analysis. The weighted risk"rates" used for the HRA modeling are summarized in Appendix Table 5.1D-6. The value then calculated by the AERMOD model was the total risk at each receptor. Health risks potentially associated with the estimated concentrations of pollutants in air were characterized in terms of potential lifetime cancer risk (for carcinogenic substances),or comparison with RELs for non-cancer health effects (for non-carcinogenic substances). Health risks were evaluated for a hypothetical maximum exposed individual (MEI) located at the Point of Maximum Impact (PMI). Human health risks associated with emissions from the project are unlikely to be higher at any other location than at the PMI. If there is no significant impact associated with concentrations in air at the PMI location,it is assumed to be unlikely that there would be significant impacts in any other location. The Maximally Exposed Individual Resident (MEIR) is an individual assumed to be located at the MEIR point (i.e.,a residential receptor) where the highest concentrations of air pollutants associated with facility emissions are predicted to occur,based on air dispersion modeling. Health risks potentially associated with concentrations of carcinogenic pollutants in air were calculated as estimated excess lifetime cancer risks. The total carcinogenic risk at any specific location is found by summing the contributions from each carcinogen. Potential non-cancer health effects from exposure to short-term and long-term concentrations in air were evaluated by comparing modeled concentrations in air with the RELs. An REL is a concentration in air at or below which no adverse health effects are anticipated. RELs are based on the most sensitive adverse effects reported in the medical and toxicological literature. Potential non-cancer effects were evaluated by calculating a ratio of the modeled concentration in air and the REL. This ratio is referred to as a hazard quotient. The inhalation cancer potency factors and RELs used to characterize health risks associated with modeled concentrations in air are taken from the Consolidated Table of OEHHA/CARB Approved Risk Assessment Health Values (GARB,May 22,2008) and are presented in Table 5.9-5. 5.9-16 SAC/371322/082340007(LEC_5.9_PUBLIC_HEALTH.DOC)