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On losing your marbles

Several new studies suggest that air pollutants in general may be responsible for widespread cognitive decline in the human population.

william schlesinger
President Emeritus, Biogeochemist

In the past, I’ve written on how air pollution affects human health, focusing on how breathing fine particles—PM2.5 or particles less than 2.5 microns in diameter—can increase the risk of heart attack and stroke, as well as respiratory diseases such as asthma and emphysema.

Small particles cause an inflammation of lung tissues which has ancillary impacts on the interior of arteries throughout our body. Globally, more than 3 million premature deaths occur each year as a result of this air pollution. Unfortunately, newly proposed policies suggest that those responsible for air quality in the United States don’t understand the science, or don’t care to.

Several new studies suggest that air pollutants in general—gases as well as particles—may be responsible for widespread cognitive decline in the human population, particularly in males. The most recent study from China, published in the Proceedings of the National Academy of Sciences, found that the performance of students on standardized tests was lower in cities with polluted air. This study reports similar, but more significant, correlations between cognitive dysfunction and air pollution than found in an early study in Great Britain. In short, air pollution does more than irritate and inflame tissues; it can also cause neurological deterioration. Several studies also link Parkinson’s disease to fine particles in the atmosphere, although this correlation must certainly receive further study.

The medical costs of dementia are rising rapidly, yet few link the increased risk of dementia as a cost of dirty air. Rolling back the air pollution regulations of the Clean Power Plan will yield greater levels of air pollution, a greater risk for dementia-related illness, and greater future medical costs. We should not try to prop up the coal industry any more than we might have tried to prop up the business of mining lead for use in gasoline, paints, and water pipes after we discovered the neurological effects of lead in the human body. Lead poisoning and air pollution lead to a decline in mental function of the general populace.

With lead, we learned an important lesson in Flint, Michigan. We are about to do the same with the large swath of our citizens who will breathe polluted air under Trump’s Affordable Clean Energy (ACE) rule.


Burnett, R. and 53 others. 2018. Global estimates of mortality associated with long-term exposure to outdoor fine particulate matter. Proceedings of the National Academy of Sciences 115: 9592-9597.

Cullen, B and 8 others. 2018. Cross-sectional and longitudinal analyses of outdoor air pollution exposure and cognitive function in UK Biobank. Scientific Reports 8: doi: 10.1038/s41598-018-30568-6

Palacios, N. 2017. Air pollution and Parkinson’s disease—evidence and future directions. Reviews on Environmental Health 32: 303-313.

Palacios, N, and 6 others. 2017. Air Pollution and Risk of Parkinson’s Disease in a Large Prospective Study of men. Environmental Health Perspectives 125: doi: 10.1289/EHP259

Shi, L.H., A. Zanobetti and 5 others. 2016. Low-concentration PM2.5 and mortality: estimating acute and chronic effects in a population based study. Environmental Health Perspectives 124: 46-52.

Zhang, X., X. Chen, and X. Zhang. 2018. The impact of exposure to air pollution on cognitive performance. Proceedings of the National Academy of Sciences U.S. 115: 9193-9197


william schlesinger
President Emeritus, Biogeochemist

William Schlesinger is active in communicating science to policy makers and media. He has testified about environmental issues in Congress and in state houses, and has been featured in media including NOVA, the Weather Channel, Discover, National Geographic, and the New York Times.

He discusses a range of environmental issues in his weekly blog, Translational Ecology.

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