A new study has shown that reducing air pollution to levels recommended by the World Health Organization (WHO) would prevent more than 50,000 deaths a year across European cities.
The study, published in The Lancet Planetary Health, is the first to estimate the premature death burden due to fine particulate matter (PM2.5) and nitrogen dioxide (NO2) at a city level and ranks cities from the highest to the lowest mortality burden due to air pollution.
Experts are now calling for urgent policy action to reduce air pollution and achieve communities that are sustainable, liveable, and healthy for citizens.
Saving lives
Reducing air pollution levels to the WHO guidelines could prevent 51,213 premature deaths for PM2.5 exposure and 900 premature deaths for NO2 exposure a year, according to the study, which emphasises that reducing air pollution levels even further could prevent 124,729 premature deaths for PM2.5 exposure and 79,435 premature deaths for NO2 exposure a year.
Mark J Nieuwenhuijsen, of the Barcelona Institute for Global Health (ISGlobal), Spain, and co-author of the study, said: “These novel and city-specific estimates highlight the severe impact air pollution is having on city residents. We used air pollution exposure data at a fine resolution of 250m2 and city-specific mortality data, which allowed us 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. 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.”
Cities in the Po-Valley area of northern Italy, Poland, and the Czech Republic had the highest mortality burden rankings of PM2.5 mortality burden. The Italian cities of Brescia, Bergamo, and Vicenza were within the top five cities with the highest adverse health implications from PM2.5, alongside Karvina in the Czech Republic and Gornoslaski Zwiszek Metropolitalny in Poland.
In the ranking for NO2 mortality burden, Madrid (Spain), Antwerp (Belgium), Turin (Italy), Paris (France), and Milan (Italy) were the top five cities.
Urgent change is needed
The cities ranked as having the lowest mortality burden due to air pollution were in northern Europe, including Tromso in Norway, Umea in Sweden, and Oulu in Finland – which had the lowest mortality burden for both PM2.5 and NO2. Reykjavik in Iceland had the lowest mortality for PM2.5.
Sasha Khomenko, of ISGlobal 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. The Po-Valley in northern Italy is a densely urbanised area with high anthropogenic emissions, while areas in southern Poland and eastern Czech Republic are home to coal mining industries and domestic coal burning is frequent during the winter months.
“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 residents.
“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 authors note some limitations with the study, including that recently available air pollution data was from 2015, although sensitivity analyses conducted with 2018 data in some cities showed little difference in the mortality estimates. Additionally, three distinct models were used to estimate air pollution levels in the studied cities, and there was no mortality data available for different areas within each city, so the authors could not estimate which parts of the cities were affected the most.
