Occasional exposure to pyrethroid insecticides is deemed harmless, in general. But since widespread exposure of pyrethroid insecticides is reported in large populations, it is crucial to investigate the effect of this exposure on long-term health outcomes. This study aims to assess the association between pyrethroid exposure and the risk of all-cause and cause-specific mortality.
This nationwide cohort included a total of 2,116 adults (1,145 women) aged 20 years or more who provided urine samples for pyrethroid metabolite measurements. The urinary levels of 3-phenoxybenzoic acid (a pyrethroid metabolite) were measured, and the primary outcome of the study was mortality (both all-cause and cause-specific).
During the median follow-up of 14.4 years, a total of 246 deaths occurred. Forty-one of these deaths were associated with cardiovascular disease (CVD) and 52 with cancer. The findings suggested that patients with higher urinary 3-phenoxybenzoic acid levels were at an elevated risk of death. The rate of mortality across increasing tertiles of urinary 3-phenoxybenzoic acid levels was 8.5%, 10.2%, and 11.9%, respectively. After multivariable adjustment, the hazard ratios for all-cause, cardiovascular, and cancer mortality among patients between the highest and lowest tertile of urinary 3-phenoxybenzoic acid levels were 1.56, 3.0, and 0.91, respectively.
The research concluded that widespread exposure to pyrethroid insecticides was associated with an increased risk of all-cause and cardiovascular mortality, but not cancer mortality.