New study finds correlation between ADHD and polluted air
Unborn children, who are exposed to air pollution in their mother’s womb, run a larger risk later on in life to develop mental illnesses like ADHD (Attention Deficit Hyperactivity Disorder) and a sensitivity to addictions.
Fine particles in the air can be harmful for the developing brain, even when the level is lower than the one which is esteemed safe, as is the conclusion of a large-scale study by scientists involved in the so-called Generation R project, analyzing growth, development and health of children in Rotterdam (Netherlands).
Researchers measured the air quality in the houses of pregnant women and later on took MRI scans of the brains of 783 children between 6 and 10 years old. In the results they saw differences in the thickness of the cerebral cortex that could be associated with the measured particles in the air.
“We have indicated a correlation between the exposure to particles before birth and a thinner cerebral cortex”, says co-author of the study, Hanan El Marroun, who is researcher at the Erasmus medical centre in Rotterdam. Researchers also discovered that exposure to particles during pregnancy is related to impulse control in children.
According to Marroun the differences in the brain could contribute to the ability to resist to temptations and the regulation of impulsive behaviour. This can lead to mental problems like addictions or ADHD, it can also have an influence on the ability to concentrate and focus, and could have consequences for school records.
The samples of air were almost all taken in regions where the level of pollution was under the European Union standard of 25 microgram, only 0,5% of pregnant women lived in a city zone where the 25 microgram standard was exceeded.
The World Health Organization (WHO), however, works with a stricter level: 10 microgram per cubic metre. According to the researchers the European limits for air pollution might not be low enough.
Neurologist/biologist Dick Swaab, who was not involved in the study, applauds the initiative. He also is convinced that the actual standard for particles should go down. He refers to an earlier American study that indicated a correlation between fine particles and the occurrence of autism.
“When air pollution could be an explanation for the increase of cases of autism, then it seems plausible to me that there is a correlation with ADHD or a development disorder with diminished inhibitions”, Swaab concludes.