Excessive use of pesticides can be very dangerous. Among pesticides, organophosphates appear to be the most toxic one. Many organophosphates are potent neurotoxins, functioning by inhibiting the
action of acetylcholinesterase (AChE) in nerve cells. They are one of the most common causes of poisoning worldwide, and are frequently intentionally used in suicides in agricultural areas. Their
toxicity is not limited to the acute phase, however, and chronic effects have long been noted. Neurotransmitters such as acetylcholine (which is affected by organophosphate pesticides) are
profoundly important in the brain's development, and many OPs have neurotoxic effects on developing organisms even from low levels of exposure.