Chapter 37 - Organophosphate and carbamate pesticides

Abstract

This chapter discusses organophosphate (OP) and carbamate (CM) pesticides. OP and CM are used worldwide as pesticides in agriculture and public health protection, and in veterinary and human medicine. There is mounting evidence suggesting that these pesticides produce reproductive and developmental toxicity. OPs and CMs are used for a variety of purposes, such as insecticides to protect crops, gardens, homes and offices, agents of warfare, threat and terror, and therapeutic agents in human and veterinary medicine. For both types of pesticides, the brain is the primary target organ, especially during prenatal and neonatal periods, Toxicokinetic studies revealed that it is rapidly absorbed, distributed and metabolized in both animals and humans. Inhibition of AChE by OPs and CMs leads to excessive ACh accumulation at the synapses and NMJs, which results in overstimulation of muscarinic and nicotinic ACh receptors. Many OPs and CMs are developmental neurotoxicants, and therefore it is of great interest to focus on the effects of anti-ChEs on the developing central nervous system (CNS). It has been reported that multiple neurotransmitter systems are modulated by these pesticides. Mechanisms in reproductive and developmental toxicity, including oxidative stress in developmental neurotoxicity and endocrine disruption, are described in this chapter. Reproductive toxicity is expressed as alterations in sexual behavior and performance, infertility and/or loss of the fetus during pregnancy. The effects of toxicity in males and females are described in this chapter. The risk assessment process involves four steps: hazard identification, dose–response assessment, exposure assessment, and risk characterization.