Underscoring how important this month’s event are is a new study from China that concludes exposure to Particulate Matter air pollution erodes a person’s IQ, especially in older people.
“Polluted air can cause everyone to reduce their level of education by one year, which is huge,” said Xi Chen at Yale School of Public Health in the US, a member of the research team. “But we know the effect is worse for the elderly, especially those over 64, and for men, and for those with low education. If we calculate [the loss] for those, it may be a few years of education.”
In some ways this latest research, published in Proceedings of the National Academy of Sciences (PNAS), only confirms earlier studies associating PM pollution with Dementia and other developmental diseases like Autism and ADHD. But it was the largest study yet to look at the impact PM has on cognitive abilities and it looked at people of all ages, not just students. 20,000 men and women were followed for four years and many other variables besides exposure to air pollution were ruled out as causes of the decline, including the inevitable decline of mental dexterity with age.
The more a person was exposed to dirty air, the more their intelligence suffered, with language skills suffering more than mathematical or analytical, and men more than women.
At the same time even short term exposure to air pollution was seen to have an effect on intelligence, a result with consequences for students taking tests or workers attempting to passing certification exams.
Derrick Ho from Hong Kong Polytechnic University was quoted in a Guardian article stating his own research group had similar preliminary findings in their work. “It’s because high air pollution can potentially be associated with oxidative stress, neuroinflammation, and neurodegeneration of humans.”
Specifically, exposures to pollutants such as carbon monoxide (CO) and particulate matter prevent proper blood flow and could affect the flow of oxygen to the brain, which in time, affect cognition. Long-term exposure of these pollutants can lead to lesions in the brain’s white matter, which is dangerous for cognitive skills.
The study has worrying implications for neighborhoods like Joppa and West Dallas that are crowded next to PM polluting industries and freeways. Residents from those communities often start out with material or social disadvantages that limit their opportunities. Constant exposure to a toxin that robs them of IQ points makes things even worse. It’s one more thing that can trap them in downward spiral.