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PESTICIDES. Alexander V. Lyubimov, M.D., Ph.D. Director Toxicology Research Laboratory Department of Pharmacology University of Illinois at Chicago. Pesticide is a substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest (US EPA).
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PESTICIDES Alexander V. Lyubimov, M.D., Ph.D. Director Toxicology Research Laboratory Department of Pharmacology University of Illinois at Chicago
Pesticide is a substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest (US EPA). Pest includes harmful, destructive, or troublesome animals, plants, or microorganisms.
APPLICATORS ONLY? Are there ANY other populations (besides occupationally exposed) who can be poisoned by PESTICIDES?
HOW WE CAN SURVIVE IT? NO-EFFECT-LEVEL (NOEL) in animals is used to determine: Residue Tolerance Limits maximum safe levels of pesticide in food
PESTICIDES CLASSIFICATION 1.Insecticides 1.1 Organophosphates (most are actually thiophosphates) 1.2 Carbamates 1.3 Organochlorines 1.4 Botanical compounds 2.Herbicides 2.1 Chlorophenoxy compounds 2.2 Bipyridyl compounds 2.3 Miscellaneous compounds 3. Rodenticides * Continued
* Continued 4. Fungicides 4.1 HCB 4.2 Organomercurials 4.3 PCP 4.4 Phthalimides 4.5 Dithiocarbamates (EBDC) * Continued
* Continued 5. Fumigants 5.1 Phosphine 5.2 Ethylene Dibromide / Dibromochloropropane (DBCP)
BIPYRIDYL DERIVATIVEParaquat LD50 ≈ 22 – 262 mg/kg, moderately toxic Target Organ : Lung in all species Mechanism of action : Free Radical superoxide anion, O2- Lipid peroxidation Treatment : Gastric lavage mineral adsorbents hemoperfusion No hyperbaric oxygen!
FUNGICIDES Low acute toxicity LD50 ~ 800 – 10,000 mg/kg. Cytotoxic Mutagenic (mechanism of action to fungus) Teratogenic Carcinogenic ~ 90% in animal models.
HCB Immunosuppression Hepatic and thyroid tumors (animals) Teratogen (transplacental and milk acquisition)
DITHIOCARBAMATES (EBDC) Low toxicity (Biotransformation Ethylene Thyourea (ETU) in animals is well known to produce: Mutagenicity, Carcinogenicity Teratogenicity, Embryotoxicity
FUMIGANTS Phosphine (ALP PH3) Ethylene Dibromide / Dibromochloropropane (DBCP) produce: gastric carcinomas DBCP – sterility in humans