Organophosphate insecticides exhibit a high level of pest control ability
combined with a low cost. Hence, they are used widely around the world in
agriculture and industry, which has led to a variety of negative effects in
nontarget species including humans. In Thailand, the insecticides have been
imported in high quantities. It was reported that more than 20 millions kilogram
(kg) of insecticides was imported in 2006, and costing more than 3 thousand
millions bath (Office of agricultural Regulation, 2006).