Dust can be found everywhere. Not just around us, but also in the public debate, especially in the form of the much-quoted particulate matter. Particulate matter is not only produced during combustion processes in motor vehicles, it also comes from many other sources: whether it’s power stations and district heating plants, stoves, heating systems, metal and steel production, during the handling of bulk goods or in brake and tire wear. It can also form naturally through soil erosion, forest fires and volcanic eruptions or even agriculture. Here, chemical processes produce secondary particulate matter from gaseous precursors such as ammonia.
Particulate matter can be differentiated according to particle size. Ultimately, however, all types of particulate matter – coarse (2.5 to 10 microns diameter), fine or ultra-fine – have one thing in common: they are potentially harmful to human health. Depending on their size they can settle in the nasal cavities, bronchi or lungs and even enter the bloodstream. Among other effects, they have a negative impact on the cardiovascular system and can cause lung cancer. They also damage the environment, by acidifying lakes and streams, damaging sensitive forests or threatening the diversity of ecosystems.