The impact of air pollution on verbal tests, researchers found, became more pronounced as people got older.
Above all, air pollution reduces liveablity of different cities, including the capital already ranked among the world's worst liveable cities for different reasons by different worldwide agencies.
"Air pollution reduces the level of intelligence for a year, said si Chen of the Yale school of public health, USA".
The study estimated that reducing fine particulate matter concentrations to the US Environmental Protection Agency (EPA) standard of 50 microgrammes per cubic metre would increase verbal and math scores. Not only can the effect of air quality on this older population undermine their ability to function, making them less productive in many cases, but China may have to provide special care to many of them, an additional cost to the government.
In paper published Monday in Proceedings of the National Academy of Sciences, scientists found that pollution is linked to a significant decline in cognition, and that the impact increases with age.
The study suggests that while the research findings are specific to China, it can shed light on other developing countries with severe air pollution.
In a country struggling with pollution and with nearly non-existent laws or implementation of laws promoting environmental protection, the study carried out in China is most relevant to safeguard the safety of the future generation.
Zhang elaborated, "The damage on cognitive ability by air pollution also likely impedes the development of human capital". The study also showed that individuals with little education were more affected by pollution, possibly because they typically work outdoors.
A good number of India's most polluted cities are not too keen to clean up their act, according to a list maintained by the Central Pollution Control Board (CPCB). Differences between male and female brains may also account for this difference, the study said.
"Indian government has been denying the global studies, even by prominent bodies like World Health Organization, which quantified the number of deaths caused by air pollution in the past and are advocating for Indian studies on the same", Greenpeace India campaigner Sunil Dahiya said.
According to who, the 20 most polluted cities in the world are in countries that are developing.
China came out as the most polluted country in a separate study by research group Eco Experts last month, with three cities in the top 10 - Beijing, Guangzhou and Shanghai.