Pyrethroid exposure: not so harmless after all

A recent report in JAMA Internal Medicine1 Bao W Liu B Simonsen DW Lehmler HJ Association between exposure to pyrethroid insecticides and risk of all-cause and cause-specific mortality in the general US adult population. JAMA Intern Med. 2019; (published online Dec 30.)DOI:10.1001/jamainternmed.2019.6019 Crossref Scopus (53) Google Scholar elicited great interest with clinicians, endocrinologists, and toxicologists. The authors' key finding was that 3-phenoxybenzoic acid, the main metabolite of numerous pyrethroid insecticides, increased risk of mortality from all causes and specifically, death from cardiovascular disease in the US adult population. 1 Bao W Liu B Simonsen DW Lehmler HJ Association between exposure to pyrethroid insecticides and risk of all-cause and cause-specific mortality in the general US adult population. JAMA Intern Med. 2019; (published online Dec 30.)DOI:10.1001/jamainternmed.2019.6019 Crossref Scopus (53) Google Scholar This finding was surprising because pyrethroids have low acute mammalian toxicity in comparison with the previous classes of pesticides, mainly organophosphates, which pyrethroids largely replaced in the 1980s.