Air pollution linked to brain alterations and cognitive impairment in children

March 8, 2018, Elsevier
Credit: CC0 Public Domain

A new study performed in the Netherlands has linked exposure to residential air pollution during fetal life with brain abnormalities that may contribute to impaired cognitive function in school-age children. The study, published in Biological Psychiatry, reports that the air pollution levels related to brain alterations were below those considered to be safe.

"We observed brain development effects in relationship to levels below the current EU limit," said lead author Mònica Guxens, MD, of Barcelona Institute for Global Health (ISGlobal), Spain, a center supported by the "la Caixa" Foundation, and Erasmus University Medical Center, the Netherlands. This finding adds to previous studies that have linked acceptable levels with other complications including cognitive decline and fetal growth development. "Therefore, we cannot warrant the safety of the current levels of air pollution in our cities," said Dr. Guxens.

Exposure to fine particles during fetal life was associated with a thinner outer layer of the brain, called the cortex, in several regions. The study showed that these contribute in part to difficulty with inhibitory control—the ability to regulate self-control over temptations and impulsive behavior—which is related to mental health problems such as addictive behavior and attention-deficit/hyperactivity disorder.

The study used a population-based cohort in the Netherlands, which enrolled pregnant women and followed the children from fetal life onward. Dr. Guxens and colleagues assessed at home during the fetal life of 783 children. The data were collected by air pollution monitoring campaigns, and included levels of nitrogen dioxide (a prominent air pollutant caused by traffic and cigarette smoking), coarse particles, and fine particles.

Brain imaging performed when the children were between 6 and 10 years old revealed abnormalities in the thickness of the brain cortex of the precuneus and rostral middle frontal region. Despite the relationship between these brain structure alterations and fine particle exposure, the average residential levels of fine in the study were well below the current acceptable limit set by the EU—only 0.5 percent of the pregnant women in the study were exposed to levels considered unsafe. The average residential levels of nitrogen dioxide were right at the safe limit.

"Air is so obviously bad for lungs, heart, and other organs that most of us have never considered its effects on the developing brain. But perhaps we should have learned from studies of maternal smoking that inhaling toxins may have lasting effects on cognitive development," said John Krystal, MD, Editor of Biological Psychiatry.

The fetal brain is particularly vulnerable during pregnancy—it hasn't yet developed the mechanisms to protect against or remove environmental toxins. The findings of the study suggest that exposure to levels even below those considered safe could cause permanent damage.

"Although specific individual clinical implications of these findings cannot be quantified, based on other studies, the observed cognitive delays at early ages could have significant long-term consequences such as increased risk of mental health disorders and low academic achievement, in particular due to the ubiquity of the exposure," said Dr. Guxens.

Explore further: Air pollutants linked to abnormal fetal growth

More information: Mònica Guxens et al. Air pollution exposure during fetal life, brain morphology, and cognitive function in school-age children, Biological Psychiatry (2018). DOI: 10.1016/j.biopsych.2018.01.016

Related Stories

Air pollutants linked to abnormal fetal growth

February 23, 2018
Chinese mothers who were exposed to a high level of certain air pollutants during pregnancy had a higher risk of abnormal fetal growth, according to a new Yale School of Public Health (YSPH) study.

Being raised in greener neighborhoods may have beneficial effects on brain development

February 23, 2018
Primary schoolchildren who have been raised in homes surrounded by more greenspace tend to present with larger volumes of white and grey matter in certain areas of the brain. Those anatomic differences are in turn associated ...

Mom's immune system shapes baby's brain

February 26, 2018
The state of a woman's immune system during pregnancy may shape the connectivity of her child's brain, suggests a study of teenage mothers published in JNeurosci. The research emphasizes the influence of maternal health on ...

Air pollution exposure in early pregnancy linked to miscarriage, study suggests

November 17, 2017
Exposure to common air pollutants, such as ozone and fine particles, may increase the risk of early pregnancy loss, according to a study conducted by the National Institutes of Health. The study appears in the journal Fertility ...

Air pollution exposure on home-to-school walking routes reduces the development of working memory in children

October 6, 2017
A study led by the Barcelona Institute for Global Health (ISGlobal) has demonstrated that exposure to air pollution on the way to school can have damaging effects on children's cognitive development. The study, published ...

Air pollution may contribute to white matter loss in the brain

June 15, 2015
In a new study, older women who lived in places with higher air pollution had significantly reduced white matter in the brain. For the study, a research team took brain MRIs of 1403 women who were 71 to 89 years old and used ...

Recommended for you

New brain research suggests that schizophrenia is an extreme version of a common personality type

September 18, 2018
Researchers have found that the signals in people's brains differ depending on a particular aspect of an individual's personality, termed Schizotypy, a discovery that could improve the way schizophrenia is characterised and ...

New era in virtual reality therapy for common phobias

September 18, 2018
Dick Tracey didn't have to visit a tall building to get over his fear of heights. He put on a virtual reality headset.

Do we trust people who speak with an accent?

September 18, 2018
You are in a strange neighbourhood, your cell phone's dead, and you desperately need to find the closest garage. A couple of people on the street chime in, each sending you in opposite directions. One person sounds like a ...

We are predisposed to forgive, new research suggests

September 17, 2018
When assessing the moral character of others, people cling to good impressions but readily adjust their opinions about those who have behaved badly, according to new research.

Being forgotten by acquaintances can affect self-esteem in the same way as being rejected

September 17, 2018
Psychologists at The University of Aberdeen looking into the experience of being forgotten have discovered that memory lapses can damage relationships.

Breakthrough in schizophrenia identifies importance of immune cells

September 14, 2018
Researchers from NeuRA and UNSW have made a major discovery in schizophrenia research that could open doors to new treatments, research and therapies.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.