Breathing in polluted air can reduce your intelligence as well as knocking years off your life.

New research shows that air pollution causes a ‘huge’ reduction in brain power, the equivalent of losing a year in education.

The shock figures come as 90% of the world’s urban population is now breathing in unsafe levels of air pollution.

Air pollution is known to be a big problem in China (Picture: Visual China Group)

Researchers in China discovered that high pollution levels led to significant drops in language and maths test scores.


The negative impact increased with age and less-educated males were the worst affected group.

Xi Chen at Yale School of Public Health in the US, a member of the research team said: ‘Polluted air can cause everyone to reduce their level of education by one year, which is huge.



‘But we know the effect is worse for the elderly, especially those over 64, and for men, and for those with low education.

‘If we calculate [the loss] for those, it may be a few years of education.’

Air pollution is known as the ‘invisible killer’ and the World Health Organisation says it is behind an estimated seven million premature deaths each year across the world by contributing to heart attacks and strokes.

However little was known about its impact on our mental abilities.

A Chinese woman wears a mask as she waits for a bus on a polluted day in Beijing, China. (Picture: Getty)

The latest research saw experts study the maths and verbal skills of 20,000 people in China over four years.

They then compared the test results with records of nitrogen dioxide and sulphur dioxide pollution. Levels of carbon monoxide did not form part of the study.

Scientists found that the longer people were exposed to dirty air, the larger the damage to intelligence.

Language ability was hit more than maths and men suffered more harm than women.

Scientists said this may be because of the differences in male and female brains.

The study followed the same individuals aged as young as 10.

They were given 24 standardised maths questions and 34 word-recognition questions.

Because they were followed for several years, genetic differences and gradual decline in cognition because of age could be accounted for.

Breathing in polluted air affects our language and maths abilities (Picture: Getty)

Air pollution was seen to have both a short and long-term impact on intelligence.

Dr Chen said the fact that there was also a short-term impact could have important consequences for example students who had to take important exams on highly polluted days.

One of the reasons older men with less education are the worst effected could be because they often work outdoors in manual jobs, with more exposure to toxic air.

The study also suggested that pollution could increase the risk of degenerative diseases such as Alzheimer’s and other forms of dementia.

Experts said the fact that older people were badly hit by this pollution was worrying because many people need to make important financial decisions late in life.

The study was published in the journal Proceedings of the National Academy of Sciences.

The research establishes a link between pollution and lower test scores but does not yet prove cause and effect.



However experts believe that pollutants directly change our brain chemistry. Previous studies have shown that high air pollution can potentially be associated with oxidative stress, neuroinflammation, and neurodegeneration of humans.

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