PRINCIPLES OF TOXICOLOGY - Biology East Borneo

470 RISK ASSESSMENTTABLE 18.4b Cancer Risks for Household Exposures to Pesticides (TEAM Studies)Pesticide Exposure (ng/m 3 ) Potency (mg/kg⋅day) –1 (× 10 –6 )Lifetime Cancer RiskBanned termiticidesHeptachlor71 4.5 90 (19)Chlordane 198 1.3 70 (15)Aldrin 13 17 60 (13)Dieldrin 3 16 14 (3)Heptachlor epoxide 0.4 9.1 1 (0.2)DDE 2.2 0.34 0.2 (0.4)DDT 0.7 0.34 0.1 (0.02)Other pesticidesDichlorvos 33 0.29 2.7g-BHC (lindane) 6.6 1.3 2.5a-BHC 0.5 6.3 1Propoxur 100 0.0079 0.2Hexachlorobenzene 0.3 1.67 0.1Dicofol 2.6 0.34 0.05o-Phenylphenol 58 0.0016 0.022,4-D 0.6 0.019 0.003Atrazine 0.05 0.22 0.003cis-Permethrin 0.4 0.022 0.003trans-Permethrin 0.1 0.022 0.001Source: Adapted from Wallace (1991).TABLE 18.5 The Therapeutic and Virtually Safe Dosages (VSD) of a Few MedicationsDrugCancer Slope Factor(mg/kg⋅day) –1VSD (mg/kg⋅day)Dose Ratio (dailydose/VSD)Incremental LifetimeCancer Risk perDaily Dose of Drug(10 –6 ) aRifampin 2.1 4.8 × 10 –7 18,000,000 704.5Isoniazid 4.9 × 10 –1 2.1 × 10 –6 2,400,000 93.9Clofibrate 5.4 × 10 –2 1.9 × 10 –5 1,500,000 58.7Disulfiram 3.6 × 10 –1 2.8 × 10 –6 1,300,000 50.9Phenobarbital 2.9 × 10 –1 3.5 × 10 –6 825,000 32.3Acetaminophen 1.3 × 10 –2 7.6 × 10 –5 747,000 29.2Metronidazole 4.4 × 10 –2 2.3 × 10 –5 467,000 18.3Sulfisoxazole 1.9 × 10 –3 5.3 × 10 –4 215,000 8.4Dapsone 1.7 × 10 –1 5.8 × 10 –6 123,000 4.8Methimazole 4.8 × 10 –1 2.1 × 10 –6 102,000 4.0Oxazepam 1.0 × 10 –1 9.8 × 10 –6 87,700 3.4Furosemide 6.0 × 10 –2 1.7 × 10 –5 68,723 2.7Source: Adapted from Waddell (1996).a Calculated by dividing Waddell’s dose ratio by the 25,550 days in a 70-year lifetime to get the incremental lifetime risk per dailydose of drug above the 10 –6 risk representing the VSD.