Air pollution is not good for a person's health. It's a simple fact everyone acknowledges. However, the authors of a recently published research paper conclude it is not simply one's physical well-being that is threatened by smog and other airborne toxins, but also the ability to engage in high-level thinking.
The study, entitled The impact of exposure to air pollution on cognitive performance, was published August 27 by the National Academy of Sciences in the United States. Created by an interdisciplinary collaboration of scientists from Yale and several Chinese universities, the study utilized data collected from 20,000 participants from around China.
They found that cognitive levels drop severely over extended periods of time as air pollution levels intensify. Study co-author, Xi Chen, of the Yale School of Public Health, explained in The Guardian that the damage caused equates to losing time previously spent in school, saying:
Polluted air can cause everyone to reduce their level of education by one year, which is huge. But we know the effect is worse for the elderly, especially those over 64, and for men, and for those with low education [levels]. If we calculate [the loss] for them, it may be a few years of education.
Researchers working on the study utilized data collected between 2010 and 2014. Cognitive tests focusing on mathematical skills and language abilities were given to subjects on an annual basis over the four-year period and then compared with corresponding pollution levels wherever a given subjected lived and worked.
People living in places with high or rising levels of airborne nitrogen dioxide and sulphur dioxide — the main components of smog — were found to perform more poorly on the battery of tests over time. The findings point to a one-milligram increase per cubic meter in a given region's air pollution concentration over the course of three years causing an average cognitive regression equal to losing one month of schooling.
The damage, argue the authors, is cumulative and builds up over time. Upon release of their findings, the scientists from Yale stressed that their research points to a direct cause and effect relationship rather than a correlative one. And although the test subjects all live in China, the findings are applicable worldwide.
China specifically has been waging what Beijing refers to as a 'War on Pollution' since 2014. By some metrics, smog-causing pollutants in major cities have dropped by an average of 32 percent over that time, but remain three times higher than World Health Organization recommendations.