Neurotoxicity of Pesticides - The University of North ：北大学的农药的神经毒性.ppt

Definition of a Pesticide Any substance intended for preventing, destroying, repelling, or mitigating any pest Insecticides Herbicides Fungicides Pesticides are Not New Fumigants Sulfur (1000 BC) Bordeaux mixture (CuSO4, lime (Ca(OH)2, H2O)- 1882) Insecticides Arsenic (16th Century) Tobacco leaves (Nicotiana tabacum - 1690) Rotenone (Derris eliptica – 1800s) Pyrethrum (Chrysanthemum cinerriafolum- 1800s) Paris Green (copper arsenite 1800s) Rodenticides Nux vomica (Strychnos nux-vomica) There is No Such Thing as a Completely SAFE Pesticide But Pesticides can be USED safely. All Pesticides have some type of biological activity The trick is to balance efficacy and safety. Pesticide Regulations Wiley or Sherman Act (1906) Federal Food, Drug, and Cosmetic Act (1938) Pesticide tolerances set in 1954 and 1958 1958: Delaney Act No additive is deemed safe if found to cause cancer Pesticides were one type of additive Federal Insecticide, Fungicide, and Rodenticide Act 1947 (initially administered by USDA) 1972 (switch to EPA) Defines registration and labeling requirements Can cancel registration Set tolerances FDA monitors residue levels Food Quality Protection Act 1996 Special considerations for children Higher susceptibility Consider child consumption patterns Development of a New Pesticide is a Lengthy and Costly Process FIFRA Product and residue chemistry Environmental fate Toxicology Acute toxicity Oral, dermal, inhalation, irritation, ocular, delayed neurotox, dermal sensitization Subchronic Rat, mouse, dog (dermal, inhalation, neurotox) Chronic Rodent, dog, carcinogenicity Reproductive Fertility, teratology, in vitro mutagenicity Biotransformation Occupational exposure Spray drift Environmental impact on non-target species Efficacy The Majority of Insecticides are Neurotoxic Toxicological Syndromes Associated with Insecticides Acute syndromes Cholinesterase inhibitors Arsenic Pyrethrins and pyrethroids Chronic toxicosis Delayed neuropathy (OPIDN) Residues Organoch