Chronic and acute toxicity of herbicides and pesticides

This chapter discusses case histories to illustrate chronic and acute toxicity of herbicides and pesticides. Popular perceptions of herbicide toxicity probably originate from two well-publicised toxic agents, paraquat and ‘Agent Orange’. The first effective inhibitors of AChE were the organophosphates (OPs). OPs are the cheapest and most ubiquitous AChE inhibitors and they vary enormously in potency. Their chronic impact on humans remains strongly disputed and this has cast a long shadow over cases of suspected OP chronic occupational injury. It is clear that all nervous systems have vulnerable points and pesticide designers and manufacturers have produced a vast array of agents aimed at attacking insect nervous systems. It is beyond question that most insecticides and several herbicides are extremely toxic if ingested in quantity by humans, which is not surprising due to the high amounts consumed in suicide bids, or during some accidental exposures.