A new study shows that air pollution can cause a “huge” reduction in our intelligence. The study was a project involving researchers at Peking University in China and Yale University in the United States. The researchers reported that long-term exposure to air pollution can affect a person’s mental abilities in two areas: language and mathematics. The researchers studied about 25,000 people from across China. Between 2010 and 2014, these Chinese men, women and children were given language and math tests. Then researchers compared the test results with measurements of pollution in the air, namely nitrogen dioxide and sulfur dioxide. Xi Chen of the Yale School of Public Health led the study. He and his team found that breathing polluted air can reduce a person’s education level by about one year. Chen said that the effect generally is worse for those over 64 years of age, for men and for those with little or no education.