Exposure to polluted air in the womb and during the first eight and a half years of a child’s life can alter the brain, according to a new study.
he research, published in the Environmental pollution magazine, has shown a link between air pollution and the microstructure of white matter.
Traces of cerebral white matter provide connectivity between different brain regions. This connectivity can be measured by observing the microstructure of this white matter as a marker of typical brain development.
Experts at the Barcelona Institute for Global Health who led the study say the findings are significant because the abnormal structure of the white matter has been linked to mental illnesses such as depression and anxiety.
The study found that the greater a child’s exposure to pollution before age five, the more brain structure was altered.
Researchers found that exposure to particulate matter in the first two years of life — dust particles, dirt, soot, smoke or contaminating fluids — the greater the volume of the putamen.
This is a brain structure involved in motor functions and learning processes, but with less specialized functions than the cortical structures.
“Greater putamen has been linked to certain psychiatric disorders (schizophrenia, autism spectrum disorders, and obsessive-compulsive spectrum disorders),” said ISGlobal researcher Anne-Claire Binter, who co-authored the study.
“One of the important conclusions of this study is that babies’ brains are particularly sensitive to the effects of air pollution, not only during pregnancy, as shown in previous studies, but also during childhood.”
The study analyzed the effects of air pollution on 3,515 children each month until they turned eight years and six months.
To determine the level of exposure, experts estimate the daily levels of nitrogen dioxide and particulate matter in the children’s homes during the mother’s pregnancy and in their early life.
After their ninth birthday, the children underwent imaging to examine the structural connectivity in their brains and volumes of different brain structures.
According to Public Health England (PHE), air pollution is the biggest environmental threat to health in the UK. PHE estimates that between 28,000 and 36,000 deaths can be attributed to long-term exposure to polluted air each year.