Air Pollution and Mortality
Global Study Reveals Persistent Health Risks Despite Declining Pollutant Levels
For their investigation, the researchers utilized data from the Multi-Country Multi-City (MCC) Collaborative Research Network, an international collaboration of various research teams. Their goal is to better understand the relationships between environmental stressors—factors that can be harmful to living organisms—climate, and health. “The enormous amount of data available through the network has enabled us to analyze the health impacts of air pollution on a global scale over an extended period and to track trends,” says Maximilian Schwarz, a scientist at the Institute of Epidemiology at Helmholtz Munich and the lead author of the study.
Many Factors Could Be the Cause
According to the study, the risk of mortality has not significantly changed during the period under review—despite lower pollutant concentrations. Schwarz attributes this finding to various factors: "These include the aging population in many regions, the fact that older people tend to be more health-compromised than younger individuals, and that the sources and composition of air pollutants may have changed." Furthermore, the study reveals differences in the impacts depending on geographic region and when analyzing the simultaneous influence of various pollutants on mortality.
The study focuses on pollutants that are regulated by legal limits, such as particulate matter in the PM10 and PM2.5 size classes, as well as NO2. “Due to the data available, we were unable to investigate the impact of other potentially relevant pollutants,” says Schwarz. These include, for example, ultrafine particles, which are suspected to have a greater impact on human health than larger particles (see infobox). “Our study underscores the global need for more comprehensive and expanded monitoring. Additionally, existing data must be made available for scientific use,” Schwarz continues. This is necessary to investigate new research questions more precisely.
Health Policy Relevance
The director of the Institute of Epidemiology, Prof. Dr. Annette Peters, emphasizes that national and international efforts to improve air quality must align more closely with the stricter recommendations of the World Health Organization (WHO): “The 2021 updated WHO air quality guidelines are further validated by the current study. The planned revision of air quality limits at the European level is an essential step to better manage the health risks posed by air pollution,” says Peters.
Original publication
Maximilian Schwarz, Annette Peters, Massimo Stafoggia, Francesca de'Donato, Francesco Sera, Michelle L Bell, Yuming Guo, Yasushi Honda, Veronika Huber, ... Martina S Ragettli, Yue Leon Guo, Shih-Chun Pan, Shanshan Li, Antonella Zanobetti; "Temporal variations in the short-term effects of ambient air pollution on cardiovascular and respiratory mortality: a pooled analysis of 380 urban areas over a 22-year period"; The Lancet Planetary Health, Volume 8