Exposure to air pollution during pregnancy and childhood has lasting effects on the brain: study

Long-term exposure to air pollution is known to affect physical well-being, increasing the risk of respiratory diseases, cardiovascular diseases and cancer. Recent research has shown that exposure to air pollution early in life has lasting effects on the brain.

According to research by the Barcelona Institute for Global Health (ISGlobal), exposure to fine particles (PM2.5) and nitrogen oxides (NOx) during pregnancy and childhood can lead to significant changes in the microstructure of the white matter of the brain. Worryingly, these changes may persist into adolescence, raising concerns about the long-term effects of air pollution on brain development.

Previous studies have examined the effects of air pollution on the white matter of the brain, but most of them were confined to a single time point and did not follow participants throughout childhood.

Latest test published in Environmental Research involved 4,000 participants from Rotterdam, the Netherlands, who took part in the “Generation R” study and were followed from birth. Based on the participants’ locations, the team estimated their exposure to 14 different air pollutants during pregnancy and childhood.

To study changes in white matter microstructure, the researchers conducted brain scans on 1,314 children, once at about age 10 and then at about 14 years of age.

“Following participants throughout childhood and including two neuroimaging assessments for each child would shed novel lightweight on whether the effects of air pollution on white matter persist, attenuate or worsen,” said Mònica Guxens, an ISGlobal researcher in the study press release.

The results showed that higher exposure to PM2.5 during pregnancy, as well as increased levels of PM2.5, PM10, PM2.5-10 and NOx during childhood led to reduced fractional anisotropy, a measure of how water molecules dispersed in the brain . In more mature brains, water tends to flow more in one direction, resulting in higher values ​​of this marker. This association persisted into adolescence, indicating the long-term impact of air pollution on brain development.

“Each raise in air pollution exposure levels corresponded to a delay of more than 5 months in the development of fractional anisotropy,” the researchers wrote.

“We believe that the lower fractional anisotropy is likely the result of changes in myelin, the protective sheath that forms around nerves, rather than in the structure or packing of nerve fibers,” said first author Michelle Kusters.