Pesticides harm non-target organisms through persistence and biological accumulation. Organochlorine and organometallic pesticides persist in the environment and, owing to their lipid solubility, remain present in the bodies of non-target organisms including human beings.

These agrochemicals enter plants and pass through different trophic levels via biomagnification, accumulating in tissues. Furthermore, organophosphates are acutely toxic as they inhibit cholinesterase, leading to the accumulation of the neurotransmitter acetylcholine. Residual forms of these pesticides may prove even more harmful than the original compounds in the long run.