Hundreds of thousands of children from age one to 14 years old are believed to have been made ill each year by breathing in pollutants, researchers estimate.
The study, led by the Barcelona Institute for Global Health, looked at cases of asthma in 63,442,419 children across 18 European countries, including the UK.
They compared asthma rates with estimations of levels of exposure to pollutants in more than 1.5 million square km areas. And, they estimated how rates could be affected if levels were reduced.
Overall, researchers estimated 11.4% of the total cases of asthma could be prevented each year if countries adhered to the maximum air pollution levels recommended by the World Health Organisation (WHO) for the tiny particles known as PM2.5.
This equates to more than 10,000 cases in the UK being prevented annually.
Around 1.1m children are believed to suffer from asthma in the UK. It is thought that pollution from traffic can damage airways, leading to inflammation and the development of asthma in children who are genetically predisposed to the condition.
In the study, researchers estimated 0.4% (2,434 cases) could be prevented with the reduction of another pollutant, nitrogen dioxide (NO2), which is a better marker of traffic sources.
If countries went further, tens of thousands more cases of childhood asthma could be avoided, the researchers predict.
In the UK, 44,895 cases (29% of the UK total) could be avoided if the country reduced air pollution to the lowest levels recorded in 41 previous studies. And 191,883 cases (33%) could be avoided each year across the 18 European countries in the study.
The study, published in the European Respiratory Journal, concluded: “Our estimates are larger than previous documentation and underline the urgent need to reduce children’s air pollution exposure across Europe.”
“In the UK, 44,895 cases (29% of the UK total) could be avoided if the country reduced air pollution to the lowest levels.”
Haneen Khreis, lead author of the study and a researcher at the Texas A&M Transportation Institute in America, said: “Only in the past two years, several analyses on air pollution and onset of childhood asthma have emerged, strengthening the case from different research teams that air pollution is contributing substantially to the burden of paediatric asthma.”
Dr Samantha Walker, director of policy and research at Asthma UK, said it’s “outrageous” that children across the UK are potentially breathing in toxic air that is causing them to develop asthma.
“This research is yet another reminder that the government needs to tackle air pollution as an urgent priority and commit to meeting air-quality standards from the World Health Organisation in its upcoming environment bill,” she said.
“No child should face the risk of getting asthma or having a life-threatening asthma attack because of filthy air.”