The research attempted to minimize the impact of other variables besides environmental pollution. For example, test takers who migrated via counties between 2010 and 2014 and others who worked in mining, smelting, wood processing and other "polluted professions" were excluded.
Dr. He said, however, that the long-term effects of pollution can be difficult, in part because individual exposure depends on so many factors – including whether a person uses air filters at home.
In another review, Rajasekhar Balasubramanian, an expert on air quality at Singapore, noted that while the authors of the study speculated that continued exposure to environmental pollution could alter brain chemistry, they did not provide clinical evidence. (The authors agreed that the hypothesis should be further explored.)
"The result of such studies would provide a solid scientific basis for tightening air quality standards to reduce air pollution and protect public health in developing and developed countries." Balasubramanian (19659002) As public outrage in China has increased over smog and associated respiratory diseases, officials have closed hundreds of coal plants in recent years, cut the limits on driving and coal burning in residential areas, and sent police teams to inspect factories.
But China's carbon dioxide emissions rose last year, and even though the country is on track to reach its major climate goals In the cities, there is still a dangerously high level of outdoor air pollution.
In a sign of the problems, a study published in April revealed that about 142 million people or just Ove. Half of the population polled in 155 Chinese cities was exposed to the average annual "multiple concentrations" in 2014 above the limits set by the World Health Organization. According to the study, eastern China and megacities are hardest hit.