Air pollution jeopardizes brain function, study reveals

The world’s top 20 most polluted cities, according to the World Health Organization’s (WHO) database, are in developing countries. Almost all the cities in low- and middle-income countries with more than 1,00,000 residents fail to meet WHO air quality guidelines. A new study from China has said, long-term exposure to air pollution lowers brain function, which reflects in decreased verbal and mathematics scores, apart from causing heart disease and breathing problems.

The study retrospectively analysed data of nearly 32,000 people from two waves (2010 and 2014) of the China Family Panel Study, a nationally representative longitudinal survey that looks at topics like economic activities, education outcome, family dynamics, relationships, and health.

“We speculate that the pollutant damage is most likely accumulating in the white matter of the brain which is mainly associated with the language functioning. The negative impact of three-year accumulative exposure to air pollution for men’s verbal test scores is 49% higher than that for women,” Zhang, who is also a senior research fellow with the Washington-based International Food Policy Research Institute (IFPRI), said.

“This could be because men have a much smaller amount of white matter activated during intelligence tests so their cognitive performance is more affected. Of course, more research is needed to test this out,” Zhang added.

Though the research was conducted in China, the researchers suggest that the implications would be true for all developing countries, including India.

“The findings should be applicable to India. In fact, the impact probably is greater given that the air pollution is more severe in Delhi than in Beijing and other Chinese cities,” said Zhang.

According to WHO, 4.2 million deaths were recorded globally in 2016, whereas  in 2015 around 25 lakh people died in India due to air pollution. The situation is alarming for India as 14 cities in the country are among the world’s 20 most polluted cities.