No one would be surprised to learn that air pollution has a negative impact on our children’s breathing, but a Spanish study points to even more troubling associations.

It found that children who were exposed to air pollutants in the womb and over the first 8.5 years of their lives may suffer some serious damage to their brains. The greater the child’s exposure to certain contaminants before age five, the greater the damage to their brain in pre-adolescence.

Intense levels of pollution create a significant alteration to the brain’s white matter, the team found. That’s serious because our brain’s white matter is like an extension cord. It’s crucial to connecting different areas of the brain to each other. In fact, it’s so important that white matter is used as a marker of typical brain development.

The greater the child’s exposure to certain contaminants before age five, the greater the damage to their brain in pre-adolescence.

When the white matter’s microstructure is abnormal, it can lead to mental health complications such as depressive symptoms, anxiety and autism spectrum disorders.

Unfortunately, that’s not the only association the study found between early exposure to air pollution and damage to young brains. It also reported a link between exposure to fine particulate matter and the volume of a brain structure called putamen involved in motor function, learning processes and several other significant functions.

The study concluded that the greater the exposure to fine particulate matter, especially during the first two years of life, the greater will be the volume of putamen in preadolescence. A larger putamen has been associated with certain psychiatric disorders including schizophrenia, autism spectrum disorders and obsessive-compulsive spectrum disorders.

“The novel aspect of the present study is that it identified periods of susceptibility to air pollution,” Claire Binter, ISGlobal researcher and first author of the study, said in a press statement. “We measured exposure using a finer time scale by analyzing the data on a month-by-month basis, unlike previous studies in which data was analyzed for trimesters of pregnancy or childhood years. In this study, we analyzed the children’s exposure to air pollution from conception to 8.5 years of age on a monthly basis.”

Our brain’s white matter is like an extension cord. It’s crucial to connecting different areas of the brain to each other.

The research team’s findings were drawn from a group of over 3,500 children between the ages of 9 to 12 who were enrolled in the Generation R Study in the Netherlands. To figure out each participant’s exposure to air pollution during the study period, the researchers estimated the daily levels of nitrogen dioxide and particulate matter at their homes during the mother’s pregnancy until the children were 8.5 years old.

When the children were between 9- and 12-years-old, magnetic resonance images (MRI’s) of their brains were taken to enable researchers to look at the structural connectivity and the volumes of various brain areas at the time.

“One of the important conclusions of this study,” explained Binter, “is that the infant’s brain is particularly susceptible to the effects of air pollution not only during pregnancy, as has been shown in earlier studies, but also during childhood.”

If you’re worried about the effects of air pollution, talk to your health care provider. If you’re pregnant or have a young child and you’re living in an area exposed to high levels of pollution, the March of Dimes recommends that it will help if you:

  • Don’t smoke and keep secondhand smoke out of your home.
  • Use carbon monoxide alarms and test your home for asbestos, mold and radon.
  • Don’t paint or use cleaners with strong smells during pregnancy.
  • Follow air quality advice from local health officials; stay indoors as much as possible when air quality is bad.

The study is published in the journal, Environmental Pollution.