At a glance
- Population-weighted particulate matter (PM2.5) levels in Germany were significantly lower in 2020 than in 2010.
- In 2020, the population-weighted particulate matter exposure was 8.6 micrograms per cubic meter on average for the year. This is 37 % less than in 2010.
- The decrease in exposure is due to declining emissions from stationary sources (e.g., power plants, industrial operations) and measures taken in the transportation sector.
For the assessment of health risks due to particulate matter, it is necessary to record the population's exposure in Germany and to evaluate it with regard to potential health consequences. Accordingly, the present indicator is a measure of the average population-weighted particulate matter exposure per year in Germany (measured in micrograms per cubic meter, µg/m³). It refers to particulate matter in outdoor air with a diameter smaller than 2.5 micrometers (PM2.5). With continuous recording of the indicator, trends over time can be derived for the average exposure of the total population for Germany.
Assessing the development
Over the period considered, we can see that the particulate matter exposure indicated by the indicator has shown a downward trend: in 2010, the indicator value was 13.7 micrograms per cubic meter (µg/m³); in 2020, however, the value was 8.6 µg/m³. This corresponds to a reduction of around 21 %. Since 2016, particulate matter exposure has stagnated at a level just below 11 µg/m³.
The emerging decrease in PM2.5 levels is mainly due to reduction measures for emissions from stationary sources (power plants, waste incineration plants and various industrial processes) as well as measures in the transport sector. Furthermore, variable weather conditions have a direct influence on air pollution with particulate matter. In isolated years, this can lead to a decrease or an increase in particulate matter pollution and thus superimpose temporal changes in emissions. This influence can be seen particularly well, for example, in the period from 2011 to 2013: while PM2.5 emissions fell continuously in this period, the particulate matter load in 2012 was significantly lower than would have been expected according to the emission levels due to weather conditions.
For the indicator's dataset, area-wide model data on PM10 concentrations from the REM-CALGRID chemical transport model are adjusted with the help of PM10 measurement data (annual mean values) from the Immission Measurement Networks of the federal states and the German Environment Agency. Subsequently, the PM10 concentrations are converted into PM2.5 concentrations using a constant conversion factor of 0.7. In a further step, these are combined with information on the spatial distribution of population density. Finally, the average exposure for the total population is calculated from the distribution of the population among the different PM2.5 concentration classes as an annual mean.
Here, only the monitoring stations in the rural and urban background are considered for the calculation of the indicator. Therefore, it can be assumed that the approach used here tends to underestimate the pollution situation.