Exposure to traffic-related air pollution (TRAP) during early childhood is associated with structural changes in the brain at the age of 12, according to a study which warns that the pollutants may affect physical and mental development in kids.
According to the study, published in the journal PLOS ONE, children with higher levels of TRAP exposure at birth had reductions at age 12 in the brain's gray matter volume, and outer layer thickness compared to children with lower levels of exposure.
In the study, the researchers from the Cincinnati Children's Hospital Medical Center in the US used magnetic resonance imaging to obtain anatomical brain images from 147 children who were 12 years old.
The children were earlier part of the Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS), which recruited volunteers prior to the age of six months to examine early childhood exposure to TRAP and health outcomes, the scientists noted.
Using an air sampling network of 27 sites in the Cincinnati area, the scientists estimated the exposure of these children to TRAP at four or five sites over different seasons.
According to the researchers, the children and their caregivers also completed clinic visits at ages 1, 2, 3, 4, 7 and 12.
"The results of this study, though exploratory, suggest that where you live and the air you breathe can affect how your brain develops," said Travis Beckwith, lead author of the study from the Cincinnati Children's Hospital Medical Center.
"While the percentage of loss is far less than what might be seen in a degenerative disease state, this loss may be enough to influence the development of various physical and mental processes," Beckwith added.
The researchers explained that the brain's gray matter, which are regions with nerve cells wrapped by insulating glial cells, are involved in movement of body parts, as well as sensory perception, such as seeing and hearing.
They said the thickness of the brain's outer layer, the cortex, reflects the outer gray matter depth.
According to the study, specific regions in the brain's frontal and parietal lobes, and the cerebellum, which is responsible for voluntary movements like posture, balance, coordination, and speech, were affected with decreases on the order of 3 to 4 percent."If early life TRAP exposure irreversibly harms brain development, structural consequences could persist regardless of the time point for a subsequent examination," Beckwith said.