Reducing air pollution to World Health Organisation recommended levels would prevent more than 50,000 deaths a year across European cities, according to a new study published in The Lancet Planetary Health journal.
In the first such study of its kind, the paper, released on Wednesday (20 January), estimated the number of premature deaths due to fine particulate matter (PM) and nitrogen dioxide (NO2) in over 1000 cities across Europe, ranking cities from the highest to the lowest mortality burden due to air pollution.
It concluded that reducing air pollution to below WHO recommended levels could prevent 51,213 premature deaths per year, while upping the ambition and reducing beyond recommended levels could prevent the deaths of more than twice that figure.
Air pollution is a major environmental cause of illness and death around the world, with city areas being hotspots for pollution and disease.
Previous research has assessed the adverse health impacts associated with air pollution at a country-wide level. However, unlike previous research, the study used air pollution exposure data at a fine resolution of 250m2 as opposed to 10 km2 used in previous studies, as well as city-specific mortality data.
The study also ranked the cities using a mortality burden score based on mortality rates, the percentage of preventable mortality and the years of life lost due to each air pollutant.
Madrid was found to have the highest NO2 mortality burden, with an estimated 206 deaths found to be preventable under WHO levels and 2,380 preventable deaths under the lowest levels, representing 0.6% and 7% of annual deaths respectively.
The bigger and capital cities in Western and Southern Europe ranked highest for NO2 mortality burden, including Antwerp in Belgium, Turin in Italy, and Paris, France.
Brescia, in northern Italy, had the highest PM mortality burden score with 232 preventable deaths under WHO levels and 309 under lowest levels, accounting for 11% and 15% of annual deaths respectively.
The Italian cities of Bergamo and Vicenza were also in the top five cities with the highest adverse health implications from PM, alongside Karvina in the Czech Republic and Gornoslaski Zwiszek Metropolitalny in Poland.
On the other hand, cities in Scandinavian countries had the lowest mortality due to air pollution for both PM and NO2, with Tromso in Norway reporting the lowest mortality burden associated with NO2, while Reykjavik in Iceland recorded the lowest mortality burden associated with PM.
Mark J Nieuwenhuijsen, of the Barcelona Institute for Global Health (ISGlobal), and co-author of the study, said that these novel and city-specific estimates highlight the “severe impact air pollution is having on city residents”.
“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 said, adding 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% and 9% of the population across all cities were exposed to PM and NO2 levels above the WHO guidelines, respectively.
“Identifying local differences is important as they are not always accounted for by national level estimates,” Sasha Khomenko, of ISGlobal and co-author of the study, added.
“For example, past country-level estimates for Italy did not rank it as having the highest mortality burden due to PM exposure, but in our study, we saw the highest mortality in cities in Northern Italy.”
She added that she hoped that local authorities use this novel data to inform and implement new policies that positively impact on the health of their local residents.
The researchers now say that further research is needed to account for different health impacts based on region, age, sex and economic status to give a deeper understanding on the issue and allow for more targeted policy actions.
[Edited by Benjamin Fox]