Table 3.
Job category |
Worker ID |
Worker mean daily dose (ug/kg)1 |
Category mean daily dose (ug/kg)2 |
Margin of exposure (target MOE >100)3 |
---|---|---|---|---|
Engineer | 1 | 1.69 | 1.0 | 150 |
3 | 0.74 | |||
4 | 0.59 | |||
Technician | 1 | 61.3 | 29.7 | 5 |
2 | 14.3 | |||
3 | 13.6 | |||
Applicator | 3 | 118.3 | 141.4 | 1 |
4 | 134.6 | |||
5 | 171.4 |
Worker mean daily dose based on two measurements for each worker; dose was calculated by the following equation: dose (ug/kg) = TCPy (ug/g creatinine) * 1.7 g creatinine/day * 1/0.7 * 1.766)/body weight (kg); creatinine clearance = 1.7 gram/day (ICRP Report of the Task Group on Reference Man, 1994); incomplete excretion factor = 0.7 (human oral dosing study by Nolan et al. 1984); chlorpyrifos molecular weight = 350.6, TCPy molecular weight = 198.5, chlorpyrifos equivalent factor = 1.766; body weights ranged from 65 to 88 kg, with weight for one worker imputed from weights of workers in the same job category.
Category mean dose is the mean of the three worker mean daily doses in each worker category
For comparison with biologically-based dose estimates, a dermal NOAEL of 5.0 mg/kgday * 0.03 dermal absorption factor was used (32, Table 8), resulting in a NOAEL = 150 ug/kg-day; Margin of Exposure (MOE) = NOAEL/dose; Target MOE > 100.