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concentrations, excess cancer risk and non-cancer risk from traffic on these roadways. The <br /> estimated risk and hazard impacts were developed by BAAQMD to represent the average annual <br /> daily traffic (AADT) count, fleet mix and other modeling parameters specific to that segment of <br /> the highway. The estimated risk and hazard impacts were modeled by BAAQMD at two <br /> different heights, 6 feet and 20 feet. The 6-foot height estimates are used when receptors are <br /> located on the ground floor of a building and the 20-foot height estimates are used when <br /> receptors are located on the second floor or higher of a building. This tool was used to provide <br /> screening level predictions of community risk caused by El Camino Real traffic. <br /> The closest project residential setback from El Camino Real is estimated at 25 feet south from <br /> the edge of the nearest through traffic lane. The BAAQMD Google Earth results for the project <br /> are depicted in Figure 2 and shown in Table 2. Note that the BAAQMD cancer risks assume the <br /> use of age-sensitivity factors that assume the presence of a third trimester infant that would <br /> reside at the site almost continuously for 70 years. The proposed project is a senior assisted <br /> living facility, so continuous infant and child exposure would not occur. Therefore, the <br /> BAAQMD risk predictions are adjusted to eliminate the age sensitivity factor. The BAAQMD <br /> predicted cancer risk was divided by 1.7 to compute the corresponding lifetime exposure, <br /> assuming adult exposures. <br /> Table 2 Screenin Level Risk and Hazard Im acts from El Camino Real Traffic <br /> Cancer Risk PMz.s <br /> Ex osure er million Concentration Hazard Index <br /> El Camino Real at 25 feet 15.9 <br /> —6 feet above ground adjusted to 022 µg/m3 0.02 <br /> 9.4 for adults <br /> El Camino Real at 25 feet 103 <br /> —6 feet above ground adjusted to 0.15 µg/m3 0.02 <br /> 61 for adults <br /> Based on the screening analysis described above, the maximum lifetime cancer risk for adult <br /> exposures would be less than 10 in one million, PMz.s concentrations would be less than 03 <br /> µg/m3 and the Hazard Index that corresponds to non-cancer health effects would be less than 1.0. <br /> Therefore, exposure to El Camino Real traffic would not expose sensitive receptors to substantial <br /> air pollution, including substantial levels of TACs. This would be a less-than-significant impact. <br /> 7 <br />