A commonly used household pesticide has been linked to attention deficit hyperactivity disorder (ADHD) in children and young teens.
Pyrethroids, a type of pesticide, were introduced as a supposedly safer alternative to organophosphates.
Organophosphates were banned for residential use in the US 15 years ago.
But the research may question the safety of their replacement.
Dr Tanya Froehlich, a developmental paediatrician who led the study, said:
“Given the growing use of pyrethroid pesticides and the perception that they may represent a safe alternative, our findings may be of considerable public health importance.”
The results come from 687 children who were followed as part of the 2000-2001 National Health and Nutrition Examination Survey.
This collected information about hyperactivity and impulsivity as well as biomarkers of pyrethoid exposure.
The results showed that children with the biomarker were twice as likely to have ADHD as those without.
The connection was much stronger in boys than girls.
Dr. Froehlich said:
“Our study assessed pyrethroid exposure using 3-PBA concentrations in a single urine sample.
Given that pyrethroids are non-persistent and rapidly metabolized, measurements over time would provide a more accurate assessment of typical exposure and are recommended in future studies before we can say definitively whether our results have public health ramifications.”
The study was published in the journal Environmental Health (Wagner-Schuman et al., 2015).