Neonicotinoids Toxicity to Humans and Rodents

Humans are continuously exposed to insecticides through various routes, including dietary and drinking water intake or inhalation of pollen and dust. Chronic exposure to insecticides such as neonicotinoids has raised concerns about their potential toxic effects on non-target organisms. After ingestion, much of the neonicotinoids is excreted in the urine, but a portion of the parent compounds and their metabolites are distributed throughout the body where they may have potential adverse effects. Although neonicotinoids have a low affinity for human nicotinic acetylcholine receptors (nAChRs), compared to insect receptors, the high density and ubiquitous distribution of these receptors in the human nervous system makes them a potential target for toxic effects of neonicotinoids. Several in vivo and in vitro studies, especially with animals, have linked exposure to neonicotinoids with the development of toxic effects in mammals, including neurological symptoms, liver and kidney abnormalities, or metabolic changes, among others. This chapter will review human exposure to neonicotinoids and summarize the existing evidence on their potential impact on different systems of the human body. Due to the scarcity of studies on the toxic effects of neonicotinoids in humans, the information will be complemented by the available evidence on their effects in rodents.