Application for the Reassessment of a Hazardous Substance under ...

Children‘s total exposure was estimated as the sum of the dermal, hand-to-mouth andobject to mouth exposures, which was 1.2417 mg/kg b.w./day. This total exposurerepresents an RQ of 887 (in comparison to the AOEL of 0.0014 mg/kg b.w./day).Domestic Outdoor Surface ApplicationsScenarios (28 & 29): are also applications at 2.5 kg a.i./ha, but contaminated soilingestion (due to overspray or drift) is also possible.So, in addition to the estimated exposure of children above:4) Children‘s incidental ingestion of soil (US EPA, 2006b)The approach used to calculate doses that are attributable to soil ingestion is:Average Daily Oral Dose = (AR x DF) x F x IgR x SDF / BWADOD = (0.025 x 1) x 1.0 x 100 x (6.7 x 10 -4 ) x 1000 = 0.1117 μg/kg b.w.15Where:ADOD = oral dose on day of application (mg/kg b.w./day)AR = application rate (0.025 mg/cm 2 ); DF = 1;F = fraction of residue retained on uppermost 1 cm of soil (%) (note: this is anadjustment from surface area to volume);SDF = soil density factor -- volume of soil (cm 3 ) per microgram of soil;IgR = ingestion rate of soil (mg/day);BW = body weight (kg).Assumptions:F = fraction of residue retained on uppermost 1 cm of soil is 100 percent based onsoil incorporation into top 1 cm of soil after application (1.0/cm);SDF = soil density factor -- volume of soil (cm 3 ) per gram of soil; to weight 6.7 x10 -4 cm 3 /mg soil);IgR - ingestion rate of soil is 100 mg/day;BW - body weight of a toddler is 15 kg.5) Children‘s total exposure from applications at 2.5 kg a.i./ha:Children‘s total exposure was estimated as the sum of the dermal, hand-to-mouth,object to mouth exposures and soil ingestion, which was 1.2428 mg/kg b.w./day. Thistotal exposure represents an RQ of 888 (in comparison to the AOEL of 0.0014 mg/kgb.w./day).Dichlorvos reassessment – application Page 374 of 436