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Long-Term Study Reveals Decrease in Air Pollution in Eastern Europe
The atmospheric pollution from fine particulate matter, specifically those measuring less than 1 micrometer, has experienced a notable decline in rural Saxony, averaging a decrease of 5% per year. Particularly significant reductions were evident in air masses originating from Eastern Europe, where PM1 levels dropped by up to 28% annually.
In contrast, the organic content within these particles saw only a modest decline, around 2% per year. While the levels associated with mineral oil and coal combustion remained stable, there was a slight increase of 0.5% per year in organic particles from biomass combustion, suggesting a rise in wood usage for heating or an increase in forest fires.
This assessment stems from a decade-long analysis conducted by scientists from the Leibniz Institute for Tropospheric Research (TROPOS), alongside colleagues from the University of Modena and MeteoSwiss. The study utilized measurements from the TROPOS rural background station Melpitz, located near Leipzig, to provide a comprehensive chemical profile of air quality from 2012 to 2022.
The advancements in online measurement techniques have allowed for more detailed evaluations of air pollution, affirming the critical role long-term monitoring plays in air quality management. As documented in the journal Atmospheric Environment, such insights underline the ongoing need for observing how the sources of particulate matter are evolving and how these changes impact the chemical makeup of particulate matter within Central Europe.
Health Implications of Aerosol Particles
Aerosol particles, which can significantly affect both climate and public health, are a concern. The European Environment Agency (EEA) estimated that approximately 293,000 fatalities across Europe in 2021 were attributable to air pollution. Despite extensive air quality monitoring over the years, there remains a significant gap in understanding how sources of fine particulate matter shift and what implications these shifts have on their chemical composition.
Utilizing cutting-edge aerosol mass spectrometers, such as the Aerosol Chemical Speciation Monitor (ACSM) employed in this analysis, has enabled precise identification of organic aerosol sources. This enhances our understanding of trends and sources, providing clarity on wind direction influences over shorter periods, a crucial aspect since wind patterns can change rapidly.
Currently, Germany employs only two of these sophisticated ACSM devices, with the one at the TROPOS facility in Melpitz representing a vital resource for ongoing research.
Regulatory Challenges and Future Directions
The Melpitz station plays a pivotal role within the ACTRIS EU research network as well as the EMEP European air monitoring framework. Positioned in Saxony’s lowlands, it serves as a representative site for analyzing rural air quality in Eastern Germany, uniquely situated between Atlantic and continental climatic zones.
The EU Air Quality Directive established an annual average limit of 40 micrograms per cubic meter for particulate matter PM10, effective since 2008. Future regulations aim to significantly reduce this to 20 micrograms per cubic meter by 2030, while the PM2.5 threshold is set to decrease from 25 to 10 micrograms per cubic meter. The World Health Organization recommends an even stricter limit of 5 micrograms per cubic meter. However, no established limit currently exists for the smaller PM1 particles. Despite this, scientists regard PM1 as a crucial health indicator, as these fine particles penetrate deep into the lungs, potentially causing inflammatory responses through the bloodstream.
From the data collected between 2012 and 2022, Melpitz registered an average PM1 concentration of just below 10 micrograms per cubic meter, exhibiting significant seasonal variations, peaking at nearly 16 micrograms per cubic meter during the winter of 2016-2017.
Organic components comprised nearly 50% of the total particle concentration, followed by nitrate, sulfate, ammonium, and equivalent black carbon (eBC). The noticeable reduction in total organic component mass, approximately 5% annually, primarily resulted from decreasing levels of nitrate and eBC, both of which declined by around 1% each year.
“These reductions highlight the effectiveness of air quality initiatives across Europe, particularly those targeting emissions from transportation,” explains Samira Atabakhsh from TROPOS. She notes that while air quality has typically been worse in Eastern Europe compared to the West, this disparity is narrowing, indicating overall enhancements in air quality.
Identifying Sources of Organic Aerosols
The study revealed five primary sources of organic aerosols, three of which were tied to human activity: mineral oil combustion (identified as HOA for Hydrocarbon-like Organic Aerosol), biomass burning (termed BBOA), and coal burning (labeled CCOA). The other two categories (LO-OOA and MO-OOA) were not specifically linked to either anthropogenic or biogenic sources.
The contributions of these sources to organic aerosol levels were approximately 7% for HOA, 10% for BBOA, 12% for CCOA, and 31% and 40% for LO-OOA and MO-OOA, respectively.
HOA concentrations remained relatively stable, though easterly winds showed a slight decline, hinting at consistent local emissions. In contrast, BBOA exhibited heightened levels during winter months, representing an increase in biomass used for residential heating. Unexpectedly, CCOA levels increased with westerly winds, potentially reflecting a rise in coal utilization within Western European energy production.
Future Research and Implications
Further research is essential to understand the evolving trends of air pollution and its sources. This will be facilitated by leveraging various European observatories that are part of the EU ACTRIS research infrastructure. Such collaborative efforts will provide a comprehensive framework for tracking changes in air quality and pinpointing causes more effectively.
Dr. Laurent Poulain from TROPOS emphasizes the significance of these long-term measurements, stating, “They exemplify how European and national air quality regulations not only influence urban environments but also extend to rural areas through long-range transportation of pollutants.”
“The findings underscore the necessity of monitoring shifts in mass concentration and the distribution of sources contributing to particulate matter levels,” he adds. This research not only aids in identifying the sources of particulate matter but also in predicting changes in aerosol properties, including their hygroscopicity and light interaction, which can enhance climate modeling efforts.
More information:
Samira Atabakhsh et al, Trends of PM1 aerosol chemical composition, carbonaceous aerosol, and source over the last 10 years at Melpitz (Germany), Atmospheric Environment (2025). DOI: 10.1016/j.atmosenv.2025.121075
Source
phys.org