A new study has linked a commonly used pesticide to attention deficit hyperactive disorder (ADHD) in children and teens— specifically males.

Pyrethoid pesticides became popular in the early 2000s after the Environmental Protection Agency (EPA) banned two other pesticides containing phosphorus. They are often considered a safe choice for residential pest control and public health purposes because they are not acutely toxic, Science Daily reported.

But in animals, exposure to pyrethroid suggested an increased vulnerability to impulsivity and hyperactivity. Pyrethroid was also found to make male mice vulnerable to abnormalities in dopamine, the neurochemical thought to regulate many activities in the brain, Science Daily reported. For this study, researchers at Cincinnati Children’s Hospital Medical Center focused on data of 687 children between ages 8 and 15.

The data was collected from the 2000-2001 National Health and Nutrition Examination Survey (NHANES), which included a diagnostic interview of ADHD symptoms and pyrethroid pesticide biomarkers. Pesticide exposure measurements were collected through random urine samples, according to Science Daily.

Researchers found that boys with detectable urinary 3-PBA, a biomarker of exposure to pyrethroids, were three times as likely to have ADHD as those without a biomarker. Hyperactivity and impulsivity increased by 50 percent for every 10-fold increase in 3-PBA levels found in boys, Science Daily reported. However, in girls, biomarkers were not associated with increased odds.

“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,” study co-author Dr. Tanya Froehlich, a developmental pediatrician at Cincinnati Children’s, said in a news release.

“Our study assessed pyrethroid exposure using 3-PBA concentrations in a single urine sample,” Froehlich said. “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,” she said.

The results were published online in the journal Environmental Health.