Researchers from the International Food Policy Research Institute (IFPRI) examined data from the national longitudinal study of China Family Panel Studies, which evaluated the cognitive test outcomes of just under 32,000 people between 2010 and 2014 against short- and long-term air pollution.
Researchers found that both verbal and mathematical scores "decrease with increasing cumulative exposure to air pollution," with a pronounced decline in verbal scores among older, less educated men.
"The damage air pollution has on aging brains is likely to cause significant health and economic costs, bearing in mind that cognitive functions are important for the elderly both in their daily errands and in economic decisions," so author Xiaobo Zhang from Peking University said.
Cognitive decline or impairment, which according to the study could be caused by air pollution, are also potential risk factors for the development of Alzheimer's or other forms of dementia.
Most severely hit
While the study adds to the already numerous health concerns about air pollution, it is being used by developing countries of particular interest whose smoggy cities could hamper national economic development.
"Air pollution cognitive impairment is also likely to hinder the development of human capital, so a close focus on adverse health effects could underestimate the overall cost of air pollution," Zhang said. "Our findings about the damaging effect of air pollution on cognition imply that the indirect effect of pollution on social welfare could be much greater than previously thought."
In Beijing, the rich make their homes and equipment to filter out pollutants in the air and water, while poorer residents put in unfiltered smog that affects not only their health, but also, according to the new study, their cognitive abilities.