Cutting pollution to WHO limits could prevent 50,000 deaths a year across Europe

Reducing air pollution in cities to the maximum levels recommended by the World Health Organisation could prevent more than 50,000 deaths a year across Europe, new research suggests.

Across the EU around one in eight deaths has been linked to air pollution, with around 400,000 dying every year, and worldwide, it is the fifth greatest risk factor for global mortality. But despite these headline figures, the exact extent of the wider health effects of air pollution at the city level remains largely unknown.

A new study has ranked 1,000 European cities on various air pollution measures, including for pm2.5 (fine particulate matter) and nitrogen dioxide (NO2). It also estimated numbers of preventable deaths if cities reduced air pollution to below WHO recommended levels, and preventable deaths if each city reduced pollution even further - to the lowest levels recorded in the study.

“Compliance with WHO air pollution guidelines could prevent 51,213 deaths per year for pm2.5 exposure and 900 deaths per year for NO2 exposure,” the study states.

If cities were able to cut their pollution to the lowest levels recorded in the study - which were seen in countries including Iceland and Norway, then even more lives could be saved.

Almost 125,000 premature deaths could be avoided through pm2.5 exposure and almost 80,000 through NO2 exposure, each year.

Madrid had the highest “NO2 mortality burden”, the research found, with 206 preventable deaths if pollution was reduced to WHO recommended levels. If the Spanish capital reduced pollution even further, to the lowest recorded pollution levels, 2,380 deaths could be prevented.

Brescia in northern Italy was found to have the highest “pm2.5 mortality burden”, with 232 preventable deaths at WHO recommended levels, and 309 under lowest levels.

At the other end of the scale, Scandinavian cities were found to have the best air quality.

Tromso in Norway had the lowest mortality burden associated with NO2, while Reykjavik in Iceland had the lowest mortality burden associated with pm2.5. In both cities there were no preventable deaths due to air pollution under either reduction scenario.

No city in the UK fell into the top 500 worst ranked cities across Europe for pm2.5.

The worst ranked town in Britain was Eastbourne on the south coast, which came in overall with a mortality ranking of 648 out of the 1,000 urban areas used in the study. There were 10 preventable deaths at recommended WHO levels of pollution, and 63 preventable deaths if pollution was lower.

Brighton came in after Eastbourne, and London was ranked at 732 with 107 preventable deaths if pollution levels for pm2.5 were reduced to WHO recommended levels and 2,088 if pollution was cut to the lowest levels.

On the NO2 rankings, London fared worse, placed at 186 worst for the toxic fumes across Europe, with 2,398 avoidable deaths if pollution was cut to the lowest levels, though only five avoidable deaths if the NO2 pollution was cut in line with WHO recommendations.

In Germany, Berlin was ranked 254th worst for pm2.5, with 851 preventable deaths at WHO recommendation level, while for NO2, it was not among the 1,000 worst urban areas.

Mark Nieuwenhuijsen, of the Barcelona Institute for Global Health, and co-author of the study, said: “These novel and city-specific estimates highlight the severe impact air pollution is having on city residents.”

He said the air pollution data and city mortality figures allowed the scientists “to identify local differences not accounted for by previous studies conducted at national level”.

“The study proves that many cities are still not doing enough to tackle air pollution, and levels above WHO guidelines are leading to unnecessary deaths.”

He added: “In addition, we contribute to previous evidence that even under the WHO guidelines there is a large mortality burden as there is no safe exposure threshold below which air pollution is harmless and local government health policy should reflect this.”

In the study, 84 per cent and 9 per cent of the population across all cities were exposed to pm2.5 and NO2 levels above the WHO guidelines, respectively.

On average, reducing pm2.5 to WHO recommended levels could prevent 2 per cent of annual mortality across the studied cities, while lowering pm2.5 to the lowest measured levels could prevent 6 per cent of annual deaths.

For NO2, reductions to WHO recommendations could prevent 0.04 per cent of annual deaths across the studied cities. However, the scientists said reducing NO2 levels to the lowest measured levels could prevent a much higher average of 4 per cent of annual mortality.

Sasha Khomenko, also of the Barcelona Institute for Global Health and co-author of the study, said: “We saw varied results between the cities within the study potentially because of the different sources of air pollution affecting each region.

“Metropolitan areas like Madrid experience high rates of mortality due to NO2, a toxic gas associated with high volumes of traffic in densely populated urban areas.

“Traffic, fuel burning, and industrial activities are the main contributors to pm2.5.

“Identifying local differences is important as they are not always accounted for by national level estimates. For example, past country-level estimates for Italy did not rank it as having the highest mortality burden due to pm2.5 exposure, but in our study, we saw the highest mortality in cities in Northern Italy. We hope that local authorities use this novel data to inform and implement new policies that positively impact on the health of their local residents.”

He added: “We need an urgent change from private motorised traffic to public and active transportation; a reduction of emissions from industry, airports and ports; a ban on domestic wood and coal burning and planting of more trees in cities, which will make cities not only healthier, but also more liveable and sustainable.”

The research is published in the journal The Lancet Planetary Health.