Exposed: how toxic air reduces intelligence

Poison: Children in China’s Shandong province wear masks to keep safe from the smog. © Getty

How can we solve the air pollution crisis? Humans are losing almost three years of life on average because of outdoor air pollution – as well as huge reductions in cognitive ability.

Right now, up to 90% of the world’s population is breathing air with unsafe levels of pollution. The consequences on health have been widely documented but, now, scientists have made an alarming new discovery.

Humans are missing out on almost three years of life expectancy on average because of outdoor air pollution, researchers have found.

“The loss of life expectancy from air pollution is much higher than many other risk factors, and even higher than smoking,” said co-author, Prof Jos Lelieveld of the Max Planck Institute for Chemistry. “That was quite unexpected, I must say.”

This comes on top of a previous study proving that chronic exposure to air pollution may cause a “steep reduction” in maths and language abilities. In extreme cases, this was the same as the loss of a year’s worth of education.

The consequences are most serious for men and those aged over 64.

British charity Medact called the findings “extremely worrying”, and the study adds to a growing catalogue of research which demonstrates the dangerous effects of air pollution.

Unicef has reported that around 4.5 million British children are exposed to dangerous levels of air pollution – which can impact brain and lung development. And the World Health Organisation estimates that toxic air causes millions of premature deaths per year.

The poorest in society suffer the most, with figures showing that 90% of these fatalities occur in middle or low-income countries. But there are also over 40 UK towns and cities with unsafe levels of pollution.

The impact on public health may be immense, but there are some radical ideas for solutions.

Architect Stefano Boer wants to cover buildings with trees and greenery, creating entire “forest cities” which would absorb carbon dioxide and harmful particulates.

Elsewhere, aeronautical engineer Moshe Alamaro plans to use a jet engine to blast Delhi’s air pollution high up into the atmosphere, away from the human population – effectively creating a giant “virtual chimney”. However, the scheme is yet to get off the ground.

Others prefer more subtle economic and political methods. Some have proposed a “smog allowance”, which would force some companies to pay higher salaries to workers exposed to dirty air, incentivising businesses to clean up their acts. Meanwhile, cities like Oslo and Paris have experimented with simply banning cars from their city centres on certain days.

How can we solve Earth’s air pollution crisis?

Air emergency

Scientific innovation is the way to do it, some argue. Tinkering around with regulations is time-consuming, and schemes which penalise businesses or crack down on cars are unpopular and difficult to enforce. Only big thinking and investment in engineering can bring about the radical change we need.

Not so fast, others respond. Relying on scientists to devise a way out of this mess does not address the root cause the problem: our addiction to burning fossil fuels. We all have a duty to encourage our leaders to invest in green energy, as well as to live in more sustainable ways from day to day.

You Decide

  1. How worried are you about air pollution?
  2. Can the problem be solved by politicians alone?


  1. In pairs or small groups, write a list of all the things that you think produce air pollution. Which of these do you think is the most polluting? Would it be possible to live without all of these things. Why or why not?
  2. Read the last two links in Become an Expert. The articles suggest several potential solutions to fix the air pollution crisis. Which single solution do you think would be the most effective? Why? Which do you think would be the least effective?

Some People Say...

“The environment will continue to deteriorate until pollution practices are abandoned.”

BF Skinner (1904-1990), US psychologist, author, inventor, and philosopher

What do you think?

Q & A

What do we know?
The study was based on measurements of sulphur dioxide, nitrogen dioxide, and small particulates where the participants lived. However, it is unclear which of these three pollutants is most to blame. Researchers tested people aged 10 and over between 2010 and 2014, with 24 maths questions and 34 language questions.
What do we not know?
If the levels of air pollution in the UK have any impact on the cognitive ability of Britons. Despite having some badly polluted urban areas, Britain is far less polluted than many other countries. Of the world’s 15 most-polluted cities, 14 are found in India.

Word Watch

According to the World Health Organisation (WHO).
Widely documented
According to the WHO, air pollution is linked to health conditions, including heart disease, strokes, chronic obstructive pulmonary disease, lung cancer, and acute respiratory infections.
Published in the Proceedings of the National Academy of Sciences.
Recurring repeatedly over a long period of time.
Unsafe levels
According to guidelines set by the WHO.
Forest cities
Follow the Independent newspaper link to find out more.
Microscopic particles of solid or liquid matter in the air.
Smog allowance
Follow the Guardian link for more information.
In one scheme, Norway’s Oslo banned diesel cars from the city centre every day from 6am until 10pm. In Paris, a short-lived scheme restricted the days on which certain cars could enter the city centre based on whether their number plates ended with an odd or even number.

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