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Exposure Assumptions for Residential Individual Cancer Risk Breathing Age Exposure Fraction of Exposure Exposure Age Group Rate Sensitivity Duration Time at Frequency Time (L/kg-day)13 Factor" (years) Homely (days/year)16 (hours/day) 3rd Trimester 361 10 0.25 1 350 24 Infant (0 - 2) 1090 10 2 1 350 24 Child (2 - 16) 572 3 14 1 350 24 Adult (16 - 30) 261 1 14 0.73 350 24 For the inhalation pathway, the procedure requires the incorporation of several discrete variates to effectively quantify do se for each age group. Once determined, contaminant dose is multiplied by the cancer potency factor ("CPF") in units of inverse dose expressed in milligrams per kilogram per day (mg/kg/day 1) to derive the cancer risk estimate. Therefore, to assess exposures, we utilized the following dose algorithm: ITW-] BRDoseAIR,per age group = Cair X EF X X A X CF where: DoseA,R = dose by inhalation (mg/kg/day), per age group Cair = concentration of contaminant in air (µg/m3) EF = exposure frequency (number of days/365 days) BR/BW = daily breathing rate normalized to body weight (L/kg/day) A = inhalation absorption factor (default = 1) CIF = conversion factor (1x10-6, µg to mg, L to m3) To calculate the overall cancer risk, we used the following equation for each appropriate age group: ED Cancer RiskAIR = DoseAIR x CPF x ASF x FAH x AT is "Supplemental Guidelines for Preparing Risk Assessments for the Air Toxics `Hot Spots' Information and Assessment Act." SCAQMD, October 2020, available at: http://www,agmd.gov/does/default-source/planning/risl<- assessment/ab-2588-supplemental-Euidelines,pdf?sfvrsn=l9, p. 19; see also "Risk Assessment Guidelines Guidance Manual for Preparation of Health Risk Assessments." OEHHA, February 2015, available at: https://oehha.ca.gov/media/downloads/crnr/2015guidancemanual.pdf. 11 "Risk Assessment Guidelines Guidance Manual for Preparation of Health Risk Assessments." OEHHA, February 2015, available at: hops://oehha,ca,ov/media/downloads/crnr/2015uidancemanual,pdf, p. 8-5 Table 8.3. 15 "Risk Assessment Procedures." SCAQMD, August 2017, available at: http://www,agmd.gov/does/default- source/rule-bool</Proposed-Rules/1401/risl<assessmentprocedures 2017 080717,pdf, p. 7. 16 "Risk Assessment Guidelines Guidance Manual for Preparation of Health Risk Assessments." OEHHA, February 2015, available at: hops://oehha,ca,ov/media/downloads/crnr/2015uidancemanual,pdf, p. 5-24. 5