Exposure to some insecticidal chemicals, such as mosquito repellents, is associated with adverse health effects, according to an analysis of federal study data.
Among participants in the National Health and Nutrition Examination Survey (NHANES), higher levels of exposure to commonly used household pyrethroid pesticides were associated with a threefold increased risk of cardiovascular disease mortality (hazard ratio 3.00, 95% CI 1.02–8.80) Dr. Wei Bao and colleagues from the University of Iowa in Iowa City report.
People in the highest tertile of exposure to these pesticides also had a 56% increased risk of death from all causes compared with people in the lowest tertile of exposure to these pesticides (RR 1.56, 95% CI 1.08–2. 26).
However, the authors noted that pyrethroid insecticides were not associated with cancer mortality (RR 0.91, 95% CI 0.31–2.72).
Models were adjusted for race/ethnicity, sex, age, BMI, creatinine, diet, lifestyle, and sociodemographic factors.
Pyrethroid insecticides are approved for use by the U.S. Environmental Protection Agency and are most often used in mosquito repellents, head lice repellents, pet shampoos and sprays, and other indoor and outdoor pest control products and are considered relatively safe.
“Although more than 1,000 pyrethroids have been produced, there are only about a dozen pyrethroid pesticides on the U.S. market, such as permethrin, cypermethrin, deltamethrin and cyfluthrin,” Bao’s team explained, adding that the use of pyrethroids has “increased.” “In recent decades, the situation has worsened sharply due to the gradual abandonment of the use of organophosphates in residential premises. “
In an accompanying commentary, Stephen Stellman, Ph.D., M.P.H., and Jean Mager Stellman, Ph.D., of Columbia University in New York, note that pyrethroids “are the second most commonly used pesticide in the world, totaling thousands of kilograms and tens of hundred million US dollars.” US sales in US dollars. “
Moreover, “pyrethroid pesticides are ubiquitous and exposure is inevitable,” they write. It’s not just a problem for farmworkers: “Aerial mosquito spraying to control West Nile virus and other vector-borne diseases in New York and elsewhere relies heavily on pyrethroids,” Stelmans notes.
The study examined the results of more than 2,000 adult participants in the 1999–2000 NHANES project who underwent physical examinations, collected blood samples, and answered survey questions. Pyrethroid exposure was measured by urinary levels of 3-phenoxybenzoic acid, a pyrethroid metabolite, and participants were divided into tertiles of exposure.
During a mean follow-up of 14 years, 246 participants died: 52 from cancer and 41 from cardiovascular disease.
On average, non-Hispanic blacks were more exposed to pyrethroids than Hispanics and non-Hispanic whites. People with lower income, lower education levels, and poorer diet quality also tended to have the highest tertile of pyrethroid exposure.
Stellman and Stellman highlighted the “very short half-life” of pyrethroid biomarkers, averaging only 5.7 hours.
“The presence of detectable levels of rapidly eliminated pyrethroid metabolites in large, geographically diverse populations indicates long-term exposure and also makes it important to identify specific environmental sources,” they noted.
However, they also noted that because the study participants were relatively young in age (20 to 59 years), it is difficult to fully estimate the magnitude of the association with cardiovascular mortality.
However, the “unusually high hazard quotient” warrants more research into these chemicals and their potential public health risks, Stellman and Stellman said.
Another limitation of the study, according to the authors, is the use of field urine samples to measure pyrethroid metabolites, which may not reflect changes over time, leading to misclassification of routine exposure to pyrethroid pesticides.
Kristen Monaco is a senior writer specializing in endocrinology, psychiatry and nephrology news. She is based in the New York office and has been with the company since 2015.
The research was supported by the National Institutes of Health (NIH) through the University of Iowa Environmental Health Research Center.
Post time: Sep-26-2023