Sarah Werner

Clear(er) skies ahead

A new Helmholtz Climate Initiative factsheet spotlights the link between air pollutants and health. Meanwhile, the latest figures from the German Environment Agency offer hope: nitrogen levels in German cities decreased significantly last year.

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Pollutants such as nitrogen oxide and particulate matter affect the air we breathe. While they can occur naturally, for example during volcanic eruptions, they are also a result of human activity, especially in cities: emissions caused by traffic, industry, and generating power greatly impact our health and the climate. Our new “Air Quality and Pollutants” factsheet reveals precisely how.

Since air pollutants affect our health, the latest figures from the German Environment Agency on the development of nitrogen oxide and particulate matter in German cities in 2020 give us hope. Even though not all of the data has been analyzed yet, the Agency sees a clear trend: nitrogen dioxide levels in the air decreased significantly across Germany last year. In 2020, the annual mean limit of 40 micrograms of nitrogen oxide per cubic meter of air (µg/m³) was exceeded at around only 3 to 4 percent of the monitoring stations. In 2019, that figure still stood at 21 percent.

Fine particulate air pollution also plummeted in 2020. Last year, for example, saw the lowest pollution levels since measurements began in the late 1990s. But: Even though Germany stayed under the limits for PM10 and PM2.5, it clearly exceeded the current World Health Organization (WHO) recommendations, which stipulate an annual average of 20 µg/m3 for PM10. In 2020, some 4 percent (2019: 13 percent) of all monitoring stations across Germany were unable to adhere to this recommendation. For the even finer PM2.5 particles, the WHO’s guideline value for Europe is 25 µg/m³ as a daily mean; a value that 86 percent of all stations exceeded on more than three days.

What is fine dust?

Fine dust is a mixture of solid and liquid, tiny dust particles. Depending on their size, these particles are divided into different groups.

PM10 particles (PM=particulate matter) have a maximum diameter of 10 micrometres
PM2.5 particles have a diameter of less than 2.5 micrometres
Ultrafine particles have a diameter of less than 0.1 µm

Particulate matter is mainly produced by human activity, for example emissions from motor vehicles, stoves and heaters in homes or in metal and steel production. But there are also natural sources such as volcanic eruptions or soil erosion. Particulate matter has a significant impact on health: the European Environment Agency estimates that in 2018, around 711,000 life years were lost in Germany due to exposure to PM2.5.

(Source: UBA)