Study Claims Air Pollution Can Ultimately Lead to Lower Intelligence: Report

The Chinese study uncovered a severe drop in language and arithmetic skills.

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A recent study performed in China finds that air pollution leads to a substantial drop in intelligence and that people living in areas with significant air pollution have seen reduced language and arithmetic test scores equivalent to losing a year of education, according to The Guardian.

Various sources claim that air pollution kills more than a million people in China each year, which has led to a government-backed embrace of electric and low emission vehicles. In fact, China as a whole bought nearly three times more electric vehicles than Americans did last year.  

The new air pollution study analyzed language and arithmetic tests on 32,000 people across China between 2010 and 2014, and compared the results to local records of nitrogen dioxide, sulfur dioxide, and particulate matter. All three contaminants are found in vehicle emissions. Because the study followed the same individuals for several years, causal factors such as genetic differences were negated. The scientists also accounted for age-related cognition changes.

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Pollution in China.

Vehicle emissions are the largest single source of air pollution in the United States. In China and other parts of the developing world, heavy use of coal is the main source of pollution, though vehicle emissions also play a big part. China has aggressively supported its electric vehicle manufacturers to combat the smog plaguing its large urban areas. Other nations, such as France, the UK, and Germany are also moving to limit vehicles seen as contributing to pollution and climate change.

“Polluted air can cause everyone to reduce their level of education by one year,” said Xi Chen, one of the study's three authors. "The effect is worse for the elderly, especially those over 64, and for men."

The research found that the longer people were exposed to polluted air, the bigger the drop in intelligence. "High air pollution can potentially be associated with oxidative stress, neuroinflammation, and neurodegeneration of humans,” Derrick Ho, a researcher at the Hong Kong Polytechnic University, told The Guardian.

The research was published by the Proceedings of the National Academy of Sciences of the United States of America.