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<br /> ED = Exposure duration (years) <br /> AT = Averaging time for lifetime cancer risk (years) <br /> FAH = Fraction of time spent at home (unitless) <br /> <br />Inhalation Dose = Cair x DBR x A x (EF/365) x 10-6 <br />Where: <br />Cair = concentration in air (μg/m3) <br />DBR = daily breathing rate (L/kg body weight-day) <br />A = Inhalation absorption factor <br />EF = Exposure frequency (days/year) <br />10-6 = Conversion factor <br /> <br />The health risk parameters used in this evaluation are summarized as follows: <br /> <br /> Exposure Type  Infant Child Adult <br />Parameter Age Range  3rd Trimester 0<2 2 < 16 16 - 30 <br />DPM Cancer Potency Factor (mg/kg-day)-1 1.10E+00 1.10E+00 1.10E+00 1.10E+00 <br />Daily Breathing Rate (L/kg-day)* 361 1,090 572 261 <br />Inhalation Absorption Factor 1 1 1 1 <br />Averaging Time (years) 70 70 70 70 <br />Exposure Duration (years) 0.25 2 14 14 <br />Exposure Frequency (days/year) 350 350 350 350 <br />Age Sensitivity Factor 10 10 3 1 <br />Fraction of Time at Home 0.85 0.72 0.72 0.73 <br />* 95th percentile breathing rates for 3rd trimester and infants and 80th percentile for children and adults <br /> <br />Non-Cancer Hazards <br /> <br />Potential non-cancer health hazards from TAC exposure are expressed in terms of a hazard index (HI), which is the <br />ratio of the TAC concentration to a reference exposure level (REL). OEHHA has defined acceptable concentration <br />levels for contaminants that pose non-cancer health hazards. TAC concentrations below the REL are not expected <br />to cause adverse health impacts, even for sensitive individuals. The total HI is calculated as the sum of the HIs for <br />each TAC evaluated and the total HI is compared to the BAAQMD significance thresholds to determine whether a <br />significant non-cancer health impact from a project would occur. Typically, for residential projects located near <br />roadways with substantial TAC emissions, the primary TAC of concern with non-cancer health effects is DPM. For <br />DPM, the chronic inhalation REL is 5 micrograms per cubic meter (μg/m3). <br /> <br />Annual PM2.5 Concentrations <br /> <br />While not a TAC, PM2.5 has been identified by the BAAQMD as a pollutant with potential non-cancer health effects <br />that should be included when evaluating potential community health impacts under CEQA. The thresholds of <br />significance for PM2.5 (project level and cumulative) are in terms of an increase in the annual average concentration. <br />When considering PM2.5 impacts, the contribution from all sources of PM2.5 emissions should be included. For <br />projects with potential impacts from nearby local roadways, the PM2.5 impacts should include those from vehicle <br />exhaust emissions, PM2.5 generated from vehicle tire and brake wear, and fugitive emissions from re-suspended dust <br />on the roads. <br /> <br /> <br />8.A. - Page 97