Particulate matter (PM) is a natural part of our air. Based on the size of the particles, this matter can be divided into different categories:
PM10: Particles with an aerodynamic diameter of < 10 µm
PM2.5: Particles with an aerodynamic diameter of < 2.5 µm
Ultra-fine particles (UFP): Particles with a diameter of < 0.1 µm or 100 nm
For comparison: a human hair has a diameter of 70 µm.
Accordingly, ultra-fine particles represent the smallest category of particulate matter.
For the larger categories, PM10 and PM2.5, the health risks are already scientifically proven. Both acute effects such as mortality after days with high particulate pollution or hospital admissions due to respiratory diseases as well as chronic effects such as cardiovascular diseases, diabetes mellitus or premature births are associated with increased particulate matter pollution. For this reason, limits for regulating these particles have already been prescribed by law.
The question of whether UFP represents an independent risk factor has not yet been conclusively determined. Although evidence could be found for pulmonary or systemic inflammatory reactions, accelerated arteriosclerotic processes or the influence of autonomous heart rhythm regulation, for example, these are not sufficient evidence of an independent health impact caused by UFP. Due to the very small size of the particles, suitable measurement methods have not yet been established. Therefore, there is no legally prescribed limit value for UFP to date.
In the BayUFP project association "Measurement, Characterisation and Evaluation of Ultra-Fine Particles", joint, networked research in five sub-projects and a coordination and communication project is intended to make a significant contribution to closing the existing research gaps and thus also to protecting and preserving the health of the Bavarian population.