In Germany, fine dust pollution is still relatively manageable compared to the rest of the world, but German cities still regularly exceed the limits recommended by the World Health Organisation (WHO). The WHO states that the air should not be polluted with more than five micrograms of particulate matter per cubic metre. In this country, this is usually not the case, as the latest world report on air quality by the Swiss technology company IQAir shows.

In 2022, Bonn had a fine dust pollution of 9.6 micrograms per cubic metre of air. This is shown on an interactive map on which cities all over the world can be zoomed in very closely. In a worldwide comparison, which includes the measured values of 7323 cities, Bonn is thus in 3441st place, i.e. in the better midfield. Compared to the previous year, the city has at least improved slightly; at that time, 11.3 micrograms of particulate matter per cubic metre were measured. This was not necessarily to be expected, since fine dust levels have risen again in many places as the pandemic has subsided.

There are also figures for nearby Bornheim. With 11.4 micrograms, the city is worse off than Bonn and exceeds the WHO maximum value by more than double. In terms of particulate matter, Bornheim is even more polluted than Cologne, a city with over a million inhabitants: here, the company IQAir speaks of 10.5 microgrammes per cubic metre. However, the figure has worsened by six percent compared to 2021.

In fact, only once has a value been measured in Germany that corresponds to the WHO recommendations: in the Bavarian town of Bad Hindelang in the southernmost tip of the country. With an average value of 11 micrograms per cubic metre, Germany ranks 25th out of 43 in the European comparison, with first place meaning the country with the worst pollution. Bosnia and Herzegovina holds this dubious rank with an annual fine dust pollution of 33.5 microgrammes per cubic metre.

However, the study's authors point out the major shortcoming of the evaluation: IQAir does not have the necessary data for some regions, simply because there are not enough air measuring devices there. Thus, the results of the report based on the values of 30,000 air quality measuring stations in 131 countries and regions are certainly meaningful. However, they could be much more comprehensive with more data. One example: the country of Montenegro reduced its pollution level by half last year to about 15 micrograms. This is probably mainly due to the fact that five additional cities have now been included in the calculation, which provide more data and allow new statements about air quality.

Missing data due to too few measuring stations

In Germany and Europe, there are relatively many measuring stations due to the high density of cities. Other countries, however, such as in Africa, are literally not on the study authors' radar. Only 19 of 54 African countries are included in the current report, making Africa the most underrepresented continent worldwide. And this despite the fact that the most polluted country in 2022 is located there: Chad with 89.7 micrograms of particulate matter per cubic metre - 17 times higher than the WHO guideline value.

The company IQAir therefore emphasises the importance of citizens' initiatives that collect data on their own and thus fill the gaps. For the current report, it says, more than half of all data was obtained through such initiatives. "When citizens get involved in monitoring air quality, we see a shift in awareness, and joint efforts to improve air quality become more intense," IQAir CEO Frank Hammes said in a company statement. Without such data, he says, there is a lack of urgency to do something about air pollution.

Only six countries comply with WHO guideline value

According to the study, a total of 90 percent of all observed countries and regions exceed the recommended guideline value. After Chad, the dirtiest air is found in Iraq, Pakistan, Bahrain and Bangladesh (their levels range between 80 and 65 micrograms per cubic metre in 2022). Central and South Asia are home to eight of the ten most polluted cities. China, with its high coal consumption, was able to further improve its values; 64 per cent of all cities examined in the country have reduced their particulate matter concentration. Nevertheless, the pollution level in the People's Republic is still six times higher than recommended by the WHO.

Only six countries meet the PM2.5 guideline: In Europe, these are Estonia, Finland and Iceland, and Australia, New Zealand and Grenada also fall under it. The Russian war of aggression has also led to a significant reduction in air pollution in Ukraine - since so many people had to leave the cities.

(Original text: Nina Bärschneider; Translation: Mareike Graepel)