Insecticide Exposure Linked to Increased Risk of Death

Insecticide exposure is associated with an increased risk of all-cause and cardiovascular disease mortality, according to the findings of a study published in JAMA Internal Medicine.

In this nationally representative cohort study, researchers assessed 2,116 adults (51.6% women) aged 20 years and older (mean age, 42) who participated in the US National Health and Nutrition Examination Survey, which took place from 1999 to 2002, and provided pyrethroid metabolite measurements. The researchers linked subjects in the study population to mortality data from the survey date through 2015. They used high-performance liquid chromatography in conjunction with electrospray chemical ionization to measure urinary levels of 3-phenoxybenzoic acid. The primary endpoint of this study was defined as all-cause mortality, as well as mortality from cardiovascular disease and cancer. The researchers analyzed the data from May to August 2019.

During a follow-up period of approximately 14.4 years the researchers observed 246 deaths occurred, including 41 associated with cardiovascular disease and 52 associated with cancer. They found that participants with higher urinary 3-phenoxybenzoic acid levels were at a higher risk of death during the follow-up period, with death occurring in 8.5% (unweighted, 75 of 709), 10.2% (unweighted, 81 of 701), and 11.9% (unweighted, 90 of 706) of participants across increasing tertiles of urinary 3-phenoxybenzoic acid levels. After adjustment for age, sex, race/ethnicity, socioeconomic status, dietary and lifestyle factors, body mass index, and urinary creatinine levels, the hazard ratios for all-cause mortality, cardiovascular disease mortality, and cancer mortality among participants with the highest tertile compared with those with the lowest tertile of urinary 3-phenoxybenzoic acid levels were 1.56 (95% CI, 1.08-2.26), 3.00 (95% CI, 1.02-8.80), and 0.91 (95% CI, 0.31-2.72), respectively.

The research authors wrote in their conclusion that: “In this nationally representative sample of US adults, environmental exposure to pyrethroid insecticides was associated with an increased risk of all-cause and cardiovascular disease mortality. Further studies are needed to replicate the findings and determine the underlying mechanisms.”