New Delhi, Oct 10 : Maternal exposure to air pollution particles such as PM2.5 during pregnancy can affect brain development in newborn babies, according to a new study.

Researchers at Hospital del Mar, the Barcelona Institute for Global Health (ISGlobal), and the CIBER area of Epidemiology and Public Health (CIBERESP) in Spain analysed extremely small particles -- about thirty times thinner than a human hair. It was composed of harmful elements from combustion processes and toxic organic compounds, but also of essential elements for brain development, such as iron, copper, and zinc.

The results, published in the journal Environment International, showed that newborns of mothers exposed to higher levels of fine airborne particles during pregnancy show slower myelination at this very early stage of life.

Myelination is a key process in brain maturation, in which myelin coats neuronal connections, making them more efficient for transmitting information.

Both a slowdown and an excessive acceleration of brain maturation can be harmful for the child. The researchers said it remains to be determined whether the effect observed in this study will have negative consequences for children's later abilities.

"Our study shows that the myelination process -- a progressive indicator of brain maturation -- occurs at a slower rate in newborns most exposed to PM2.5 during pregnancy," Gerard Martínez-Vilavella, researcher at the MRI Unit of the Radiology Department at Hospital del Mar.

For the study, the team monitored levels of air pollutants to which women were exposed during pregnancy, and after delivery, 132 newborns were selected. These infants underwent MRI scans before their first month of life to assess the degree of brain maturation through their levels of myelination.

"In the early stages of life, brain changes are large and complex. Both excessive slowdown and acceleration of brain maturation can be harmful to the child. However, it remains to be determined whether the observed effect is necessarily detrimental,' said Dr. Jesús Pujol, head of the MRI Unit of the Radiology Department at Hospital del Mar.

"This study opens an exciting new field of research aimed at determining the optimal speed of brain maturation during pregnancy and understanding how the mother and placenta may act as effective filters to protect and optimise this process," Pujol added.

The team called for further research to understand how each of the pollutants affects the development of the newborn brain.

/IANS