Washington: A new study has found that a common insecticide used in homes is associated with delayed mental development of young children.
Pyrethroid insecticides are commonly used in many homes but its safety remained unclear, as they had never been evaluated for long-term neurotoxic effects after low-level exposure.
Now, scientists at the Columbia University``s Mailman School of Public Health have found a significant association between piperonyl butoxide (PBO), a common additive in pyrethroid formulations, measured in personal air collected during the third trimester of pregnancy, and delayed mental development at 36 months.
The study was conducted with a subset of 725 pregnant women participating in a prospective longitudinal study of black and Dominican women living in upper Manhattan and the South Bronx underway at the Columbia Center for Children``s Environmental Health (CCCEH).
The insecticide permethrin was selected for the evaluation because it is one of the most common pyrethroid insecticides used in US homes, as well as the most commonly sold pesticide, according to a nationally representative sample.
PBO, a chemical that is added to insecticides to increase efficacy was also selected for evaluation. Any detection of PBO in air is a marker of a pyrethroid insecticide application.
In all, 342 women were studied for permethrin exposure in personal air during pregnancy; 272 for permethrin in maternal and umbilical cord plasma; and 230 were evaluated for exposure to PBO.
To collect the air samples, mothers from the CCCEH Mothers and Newborns cohort wore a small backpack holding a personal ambient air monitor for 48 hours during the third trimester of pregnancy.
The children of these mothers were evaluated for cognitive and motor development at age three.
PBO was detected in the majority of personal air samples. The results demonstrate that children who were more highly exposed to PBO in personal air samples scored 3.9 points lower on the Mental Developmental Index than those with lower exposures.
The findings of the study appeared online in the journal, Pediatrics.