Every day we breathe in a large number of tiny plastic particles, but the micro- and nanoplastics in the air and their health consequences are still poorly understood. A research team in Leipzig has now taken a closer look at how heavily the breathing air is contaminated with such particles in a major German city and what health risks could be associated with it.
Plastic particles are now everywhere: they have even been found in deserted regions such as polar regions or high mountains. The smallest of these plastic particles are particularly problematic. Nanoplastics are particles smaller than one micrometer, and microplastics are those between one micrometer and one millimeter. Nanoplastics in particular can reach particularly deep into the lungs and trigger oxidative stress or inflammatory reactions.
However, knowledge about plastic particles in the air is still patchy. Accordingly, there are currently no limit values or recommendations from either the World Health Organization (WHO) or the European Union. While plastic pollution in the oceans is already part of the negotiations for a UN plastic agreement, airborne plastic particles have so far played little political role.
Particle measurements at the traffic hotspot
Now a research team led by Ankush Kaushik from the Leibniz Institute for Tropospheric Research has, for the first time, examined in more detail how widespread micro- and nanoplastics are in the air we breathe in a major German city. For their study, the researchers took fine dust samples from the air on a busy street in Leipzig. The particles were then analyzed in the laboratory using the chemical analysis method of pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) to identify the type of plastic and determine its quantity. Using epidemiological models, the research team then estimated what risks might be associated with exposure to plastic particles in the air.
“This gave us a focused and detailed overview of the composition of micro-nano-plastics under heavy traffic influences. This setup offered the advantage of being able to record the peak values of urban exposure with a fine size resolution of particulate matter and generate high-quality baseline data for assessing health risks,” explains Kaushik.
Most of the plastic in the air comes from car tires
The results show: The majority of plastic particles in the city air apparently come from tire abrasion – around 65 percent of the plastics detected were due to this. This was followed by particles made from polyvinyl chloride (PVC), polyethylene (PE) and polyethylene terephthalate (PET), among others. The team explains that the fact that these plastics often occur together with carbon-containing aerosols suggests that they come from similar sources and enter the air together.
Through their extrapolation, the researchers found that Leipzig residents who spend time on busy Torgauer Straße around the clock would inhale approximately 2.1 micrograms of plastic particulate matter per day, which corresponds to 0.7 milligrams per year. Based on international studies and assessments, Kaushik and his colleagues then determined what these concentrations could mean for health. This resulted in a potentially increased risk of death of five to nine percent for cardiovascular diseases (relative risk 1.08) and of eight to 13 percent for lung cancer (relative risk 1.12). The relative risk describes how much higher the probability of illness or death is in a more exposed group compared to a less exposed group.
More regulation and long-term studies needed
In view of these results, the researchers advocate that plastic particles in the air be taken more into account in air quality monitoring and regulation. “The fact that the majority of microplastics consist of tire abrasion shows that there is a need for action and that the fine dust problem cannot be solved simply by switching to electromobility,” says Kaushik’s colleague Hartmut Herrmann. “To protect health, it would be important to also take tire wear into account when regulating air quality and to set limits for microplastics in the air.”
Further long-term studies are needed to confirm the toxicity of individual types of plastic, establish safe limits and develop regulatory standards, said Kaushik and his colleagues. However, in their opinion, the results from Leipzig underline how important it is to monitor micro- and nanoplastic particles in the air as new pollutants and to further refine the methods for assessing health risks.
Source: Leibniz Institute for Tropospheric Research; Specialist article: Communications Earth & Environment, doi: 10.1038/s43247-025-02980-0