Background 2 Organophosphorus (OP) pesticides are the most commonly used insecticides for agriculture. OPs are neurotoxins that are associated with neurobehavioral deficits, cancer,and infertility. ▣Farmworkers are also exposed to other insecticides (e.g., pyrethriods,carbamates), and to herbicides.Background 2 † Organophosphorus (OP) pesticides are the most commonly used insecticides for agriculture. † OPs are neurotoxins that are associated with neurobehavioral deficits, cancer, and infertility. † Farmworkers are also exposed to other insecticides (e.g., pyrethriods, carbamates), and to herbicides