Pharma hub Basel ranked Switzerland’s most polluted city

Switzerland does poorly in terms of nitrous oxide levels linked to vehicle emissions. © Keystone / Gaetan Bally

An air pollution mortality ranking of more than 1,000 European cities shows that urban Switzerland can do better. 

The ranking – by the Barcelona Institute for Global Health in collaboration with researchers from the Swiss Tropical and Public Health Institute (Swiss TPH) and Utrecht University – is based on a study published in the journal The Lancet Planetary Health.  

Two types of pollutants were analysed: fine particulate matter (PM2.5) and nitrogen dioxide (NO₂). While NO₂ is a toxic gas linked mainly to vehicle emissions, PM2.5 is also released by other sources of combustion, including industry, household heating, and the burning of coal and wood. 

By the measure of fine particulate matter the Swiss cities with the highest mortality risk are Basel (rank 468), Winterthur (481), Geneva (rank 490) and Biel (497). The country fared worse when it came to NO₂ pollution, with two cities in the top 100: Basel (rank 91) and Zurich (rank 94). 

Across Europe, large cities in Spain, Belgium, Italy and France have the highest burden of deaths associated with NO₂, while the highest mortality attributable to fine particulate matter is found in Italy, Poland and the Czech Republic. The safest cities are in northern European countries like Iceland, Sweden, Finland and Norway.  

The World Health Organisation (WHO) recommends that the threshold for fine particulate matter should be 10 micrograms/m3 as an annual average. For nitrogen dioxide the limit should be 40 micrograms/m3 as an annual average. Respecting these WHO recommendations would potentially help avoid 52,000 premature deaths per year in Europe, according to the researchers.  

On average, 84% of the population in European cities is exposed to levels higher than those recommended by the WHO for PM2.5, and 9% for NO₂.