Pregnant mothers who are subjected to chemicals are at risk of delivering kids with poor cognition and behavioural problems. A new study in this regard has found that this exposure can harm and alter the infants' brain activity in the womb.

Published in the journal 'Proceedings of the National Academy of Sciences', researchers in this study used functional near-infrared imaging (fNIRS) to monitor blood flow in the brains of 95 teenagers born and raised in California's Salinas Valley, where agricultural spraying of pesticides is common. They found that these teenagers estimated to have higher levels of prenatal exposure to organophosphates (commonly used class of pesticides in the US) and showed altered brain activity while performing tasks that require executive control as compared to their peers.

"These results are compelling because they support what we have seen with our neuropsychological testing, which is that organophosphates impact the brain," said lead author Sharon Sagiv, associate adjunct professor of epidemiology at UC Berkeley.

Researchers used fNIRS to measure brain activation while teens were between the age of 15 to 17, engaged in a variety of tasks requiring executive function, attention, social cognition, and language comprehension.
fMRI uses infrared light to monitor blood flow in the outer regions, or cortex, of the brain.

They also found that teens with higher prenatal organophosphate exposure had less blood flow to the frontal cortex when engaged in tasks that test cognitive flexibility and visual working memory, and that they had more blood flow to the parietal and temporal lobes during tests of linguistic working memory.

"With fNIRS and other neuroimaging, we are seeing more directly the potential impact of organophosphate exposure on the brain, and it may be more sensitive to neurological deficit than cognitive testing," said senior author Brenda Eskenazi, Professor of the Graduate School at UC Berkeley.