Invisible and Ultrafine – How Do Air Pollutants Impact Health?

"In recent years, we have gained a better understanding of the effects of air pollutants on human health," says environmental physician Claudia Traidl-Hoffmann of Helmholtz Munich. However, new questions continue to arise for her and her colleagues. Traidl-Hoffmann views the interplay of space and time with air pollutants as the holy grail of research. She questions, "If a five-year-old child is continuously exposed to pollutants and develops diabetes at the age of 50, the question is, how are these two things connected, and what has happened in the body over all those years?"

Ella's case made headlines worldwide. The nine-year-old girl from London died of asthma in 2013. She was healthy for the first seven years of her life but developed asthma, and shortly after her ninth birthday, died of a sudden asthma attack. She became the first person in the world for whom air pollution was recorded as the cause of death. The World Health Organization has since classified clean air as a human right.

Prof. Annette Peters, who heads the Institute of Epidemiology at Helmholtz Munich is a leading expert on air pollutants and specializes in large, long-term population studies. In the NAKO Health Study, for example, where more than 200,000 participants are followed over many years, Peters played a pivotal role during the COVID-19 pandemic. One of the questions in such studies is, of course, "Who gets sick due to air pollutants?" Participants are interviewed and examined, and their place of residence is considered to  analyze the level of air pollutant exposure. This allows the study of their influence on human health over many years.

"The studies confirm the impact of air pollutants on health, and it became clear that the mixture of particles and gases in the air is complex, and the effects of particles of different sizes need to be differentiated in future risk assessments. Therefore, in 2021, the World Health Organization called for not only reducing limits for known air pollutants but also for obtaining more high-quality data on ultrafine particles or incorporating ultrafine particles into existing routine measurements, forming a crucial basis for the investigation of health effects."

Annette Peters, who was involved as a consulting expert in the decision-making process in 2021, recalls, "The newer scientific studies were taken very seriously by the WHO during the decision-making process. Very low fine dust concentrations were set. The limit for nitrogen dioxide was significantly reduced from 40 micrograms per cubic meter to only 10 micrograms. Another positive aspect is that peak concentration values were also reduced – previously, the guidelines for peak times were set independently of the annual average values." In plain language, this means that governments should now establish significantly lower limits for air pollutant emissions, and even though WHO guidelines are only recommendations, they emphasize the urgency to lawmakers. "This is particularly true for the European Union's limits. From a scientific perspective, the European Commission's current proposals are not ambitious enough and do not effectively protect public health, especially for children and patients with lung, cardiovascular diseases, or diabetes," says the epidemiologist. 

“Regarding air quality, we must think and collaborate on a global scale.”
_{Prof. Annette Peters}

One particularly positive aspect highlighted by experts is that these guidelines apply worldwide. Air pollution can be measured at the source of emissions, but it is not confined to the local environment, as particles can be transported by the wind over thousands of kilometers. "In Europe, we are fortunate to mainly receive air from the west, with the Atlantic Ocean in that direction. However, during east winds, we can see that pollutants from entirely different regions are transported to us," says Annette Peters, pointing out the Sahara dust that reaches Germany on hot summer days. Peters' conclusion is clear: "Regarding air quality, we must think and collaborate on a global scale. Therefore, we need an update of limits in Europe to effectively protect public health and the environment."

Latest update: November 2023.