The Pesticide Factor
The most common pesticide for residential use and increasingly used in agriculture may be encouraging expression of an ADHD phenotype.
Pyrethroid pesticide use may be encouraging expression of an ADHD phenotype, according to researchers from the Cincinnati Children’s Hospital in collaboration with researchers from Rutgers, University of Rochester, Brown University, and Simon Fraser University.1 [
These children were participants in the 2001-2002 National Health and Nutrition Examination Survey (
Exposure was assessed by measuring concurrent urinary levels of the pyrethroid metabolite 3phenoxybenzoic acid (3PBA). An ADHD diagnosis was defined as either meeting DSM-IV criteria via the
In all, 15% of the study population met criteria for an ADHD diagnosis. Urinary 3-PBA levels were detected in 79% of the study participants (mean, 1.14 μg/L), with the means for the 10th, 50th, and 90th percentiles being 0.07, 0.29, and 1.94 μg/L, respectively.
After adjusting for covariates, the researchers discovered that children with detectable urinary 3PBA were twice as likely to have ADHD as those in whom 3PBA was undetected. Higher 3-PBA levels also were associated with an increasing number of hyperactive/impulsive symptoms. In fact, hyperactive/impulsive symptom counts were 77 % higher in children with detectable 3-PBA levels than in children with nondetectable levels. Whereas effect on inattentiveness was insignificant, hyperactive/impulsive symptoms increased by 50 % for every 10-fold increase in 3PBA level measured. This effect was also sex-specific.
Boys most at risk
In correlation with animal studies,
Pyrethroid pesticides, such the insecticide permethrin, have been thought to be safer than organophosphates, which were banned for residential use by the US Environmental Protection Agency in 2000-2001. Pyrethroid pesticides are now the most commonly used pesticides for residential use and are increasingly being used in agriculture as well. Although additional investigation is warranted, given the findings of this study, residential and personal use of pyrethroid pesticides should be reconsidered. Clinicians serving the pediatric as well as obstetric care populations may want to inform patients and their caretakers of the health risks of pyrethroid-based pesticide/insecticide use in relation to ADHD symptomatology.
References:
1. Wagner-Schuman M , Richardson JR , Auinger P, et al. Association of pyrethroid pesticide exposure with attentiondeficit/hyperactivity disorder in a nationally representative sample of U.S. children. Environ Health. 2015;14(1):44.
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