Use of permethrin and other pyrethroids and mortality in the Agricultural Health Study.

Abstract

Pyrethroid insecticides have been linked with multiple health outcomes. One study reported an association with increased all-cause and cardiovascular mortality. Given the widespread use of pyrethroids, these findings warrant confirmation. We explored associations of permethrin/pyrethroid use with overall and cause-specific mortality among 50 665 licensed pesticide applicators in the Agricultural Health Study. At enrolment (1993-1997), participants self-reported information on permethrin/pyrethroid use. Information on causes of death came from linkage with death registries through 2016. We used Cox proportional hazards models to estimate HRs and 95% CIs with adjustment for potential confounders. Over an average 21 years of follow-up, 19.6% (9,955) of the cohort died. We found no clear evidence that ever-use of permethrin/pyrethroid was associated with elevated overall mortality or with mortality from most causes examined. There was suggestive evidence, based on a small number of deaths among those exposed, for elevated pyrethroid-associated mortality from some neurological, respiratory and genitourinary diseases in the overall sample and from lung cancer among never-smokers. Although based on mortality, which is also affected by survival, rather than incidence, these findings are biologically plausible, and future investigations in other populations may be warranted.