Mark Schiefelbein / AP
Researchers studying the effects of air pollution conducted mathematical and verbal tests on more than 25,000 people in 162 Chinese counties over the course of several years. They covered these results at the time of each environmental test and found sobering results.
In a study published in Proceedings of the National Academy of Sciences on Monday, scientists found that environmental pollution is associated with a marked decline in perception. The effect increases with age.
The findings underscore the need for China to clean up, says study co-author Xi Chen, professor of health policy and economics at the Yale School of Public Health.
"If air pollution from China improves to the US standard EPA level, it means that everyone could improve their education by about a year," Chen said, referring to an annual EPA standard measurement for particulate matter was used until 2006.
The researchers tested the same subjects in 2010 and 2014, and the mathematical and verbal tests should show "different dimensions that are representative of the brain's functioning," said Chen, who allowed the researchers to study the implications Comparing environmental pollution across ages, from children to the elderly.
"We can say that the greater impact on older adults is true"
The Scientists found both short-term and cumulative effects of air pollution on cognitive performance.The impact of environmental pollution on verbal performance deteriorated with age, especially among men and those with less education.
People with lower levels of education are likely to suffer more harm says Chen, because they work more often outdoors and are exposed to higher levels of stress
He says pollution from the environment could make older people less effective in making financial and medical decisions.
Could the connection between cognitive decline and environmental pollution be caused by another factor? Chen says the study is trying to overcome this problem by testing the same people over time.
It's not exactly how pollution influences cognitive decline, though Chen suggests that pollution could have a negative effect on the brain matter that could vary between men and women. As NPR reports, "the white matter of the brain coordinates communication between brain regions."
James Hendrix, director of the Alzheimer's Association's Global Science Initiatives, was skeptical of the claim that pollution affects white matter. "I think that's speculation, I think we have no direct cause and effect that can be proven," he said.
He says that it's a challenge to establish a causal link between pollution and cognitive decline: "I would say that this is probably yours Risk increases – how difficult is it to say. " He says that there should be other factors that people should be aware of – such as nutrition, exercise, cognitive stimulation and social interaction – and may change.
"All these things play a role in an overall risk for Alzheimer's," says Hendrix
China has a major pollution problem that has led to red warnings in dozens of cities, and the government is actively trying to address the problem.
Tens of thousands of factories were shut down last year, allowing inspection crews to identify who violated environmental regulations. Rob Schmitz, NPR staff member, said, "China's government could finally seriously engage in enforcing its environmental laws."