PSI researchers Kaspar Dällenbach, Petros Vasilakos and Imad El Haddad (from left to right) have compiled measurement data on ground-level desert dust through a pan-European research network. The results of their analysis show: desert dust is a growing problem.
Photo Credit: © Paul Scherrer Institute PSI/Markus Fischer
Scientific Frontline: Extended "At a Glance" Summary: Desert Dust Accumulation in Europe
The Core Concept: Airborne particulate matter from North African deserts is reaching Europe in increasing concentrations, creating a rising source of air pollution that counteracts the continent's recent decline in anthropogenic emissions.
Key Distinction/Mechanism: Unlike particulate matter from urban construction (rich in calcium) or fossil fuel combustion (rich in carbon and soot), desert dust is identified by high concentrations of aluminum. This dust is driven into Europe by altered atmospheric circulation patterns that generate highly intense windstorms, transporting massive aerosol loads across the Mediterranean and Atlantic before settling at ground level.
Origin/History: Analysis of ice cores from the Colle Gnifetti glacier on the Swiss-Italian border reveals that desert dust concentrations have more than doubled over the past 150 years. Over the last decade alone, concentrations have increased by 10 to 25 percent across affected European regions.
Major Frameworks/Components:
- Chemical Speciation: The use of aluminum as an elemental tracer to precisely distinguish desert dust from human-made particulate matter.
- Pan-European Aerosol Tracking: The integration of long-term data from the ACTRIS research network, encompassing over one hundred continuous measuring stations.
- AI-Enhanced Spatial Modeling: The deployment of artificial intelligence to supplement physical meteorological models, allowing researchers to accurately map ground-level dust concentrations across regions lacking direct measurement infrastructure.
Branch of Science: Atmospheric Chemistry, Climatology, Environmental Science, and Epidemiology.
Future Application: The development of localized predictive warning systems for vulnerable individuals with respiratory conditions, and the creation of adaptive grid management protocols for energy providers to mitigate power generation losses from dust-coated solar panels.
Why It Matters: Elevated ground-level desert dust correlates with immediate spikes in mortality due to cardiovascular and respiratory events. As global warming accelerates the desiccation of the Sahara, this natural particulate pollution threatens to undermine European air quality improvements and complicate renewable energy stability.
Airborne particulate matter from the deserts of North Africa is reaching Europe in ever-increasing quantities. This has implications for health and for solar energy installations. A comprehensive study led by the Paul Scherrer Institute (PSI) and published in Nature shows that this type of pollution is on the rise—a trend that could be further exacerbated by climate change.
While particulate matter air pollution due to emissions from human activity in transportation, households, and industry is decreasing in Europe thanks to strict regulations, another source is developing in the opposite direction: desert dust.
To determine the level of desert dust pollution in different regions of the continent more accurately, researchers at the PSI, in cooperation with colleagues from across Europe, collected data acquired over the past 10 years from more than 100 measuring stations and combined it with artificial intelligence. The result: in southern Europe, the average concentration of desert dust is 5.3 micrograms per cubic meter of air—more than twice as high as in central and northern Europe, where an average of 2.1 micrograms was measured. Overall, the amount of dust has increased by about 0.5 micrograms per cubic meter during this period. “That corresponds to an increase in this dust pollution of 10 to 25 percent,” says project leader Kaspar Dällenbach from the PSI Center for Energy and Environmental Sciences. “This is not negligible, both in terms of the efficiency and cost-effectiveness of large solar installations and with regard to the health impacts of increased particulate matter pollution.”
Because relevant data collection at most measuring stations does not extend far enough into the past to enable scientists to make longer-term comparisons, the researchers also used ice core data from Colle Gnifetti on the Swiss-Italian border in the study. Dust particles trapped in the ice of the Alpine glacier over recent centuries reveal that the concentration of desert dust there has more than doubled over the course of industrialization—that is, over the last 150 years.
Desert Dust Is Easy to Distinguish from Other Particulate Matter
As a reliable indicator for desert dust, the researchers used the concentration of aluminum in airborne particulate matter. This element is characteristic of dust particles transported from deserts. Particulate matter from urban construction sites, for example, is very high in calcium, and particles from traffic and household emissions contain mainly soot or carbon from the combustion of petroleum. “Through chemical analyses, we can determine the origin of particulate matter found at ground level very accurately,” says Petros Vasilakos, another researcher at the PSI Center for Energy and Environmental Sciences and lead author of the study.
There are concerns that desert dust concentrations will continue to rise, partially undermining efforts to curb human-caused emissions of particulate matter. This study identifies the increasing desiccation of the Sahara Desert in North Africa as the cause. In addition, altered atmospheric circulation patterns are bringing increasingly strong winds from this region to Europe. “It is not yet definitively clear to what extent human-induced climate change has contributed to this development or whether it is further intensifying it,” says Dällenbach. “However, our current understanding suggests that the increase in desert dust is at least facilitated by human greenhouse gas emissions and the associated global warming. This leads to drier conditions in certain regions and the expansion of deserts.”
Desert Dust Can Put Stress on Human Health
With regard to the health consequences of elevated desert dust concentrations in Europe, the researchers evaluated the current state of epidemiological studies. Long-term effects from transported desert dust, such as pneumoconiosis, asthma, and chronic bronchitis, could only be proven definitively through extensive long-term studies. The immediate increase in mortality on days with elevated levels of airborne desert dust, however, is well documented: measurably more people die as a result of heart attacks and respiratory problems on days with dust pollution than on other days. “The number of storms carrying desert dust to us from the Sahara and the Arabian Desert has not actually increased,” says Vasilakos. “But they have become more intense over the 10 years studied, and as a result, they are now transporting more dust to Europe than they did before.”
Southern Europe is particularly affected—from Greece in the east through Italy to Spain and Portugal. The study also detected elevated dust levels in western France. “This is because,” explains co-author Imad El Haddad, who also conducts research at the PSI Center for Energy and Environmental Sciences, “air masses from the Sahara often flow out into the Atlantic and then turn north again toward western Europe.”
A Unique Combination of Physical Data and AI
First, this study is notable because it represents likely the most comprehensive data collection to date on desert dust in Europe. “We included virtually all available measurement series on this topic because we were able to recruit more than 50 colleagues across Europe to participate,” says El Haddad. The PSI researchers benefited from their membership in the pan-European research network ACTRIS, in which aerosol researchers join forces to coordinate their series of long-term measurements of aerosols, clouds, and trace gases internationally and to make them freely accessible.
Furthermore, the researchers used artificial intelligence to extend existing, purely physical models of particulate matter distribution. “While conventional models are good at predicting strong desert dust episodes, they rarely capture smaller dust events and have difficulty accurately determining the dust concentration at ground level,” says Dällenbach. “With our measurement data and the AI, which estimates concentrations for other regions of Europe based on measurements from more than 100 locations, we were able to supplement the model with this information and thus create a reliable, health-relevant particulate matter map of dust particles for all of Europe.” The data collected in this way can now also serve as a basis for future studies investigating long-term health consequences.
Unlike particulate matter directly attributable to human activity, such as exhaust fumes, chimney smoke, and abrasion processes, desert dust emissions cannot be reduced by any direct intervention. However, comprehensive climate protection measures to limit global warming could, in the long term, help to curb the desiccation of desert areas and thus the expansion of these dust sources. For now, though, Europe has to live with the increase in desert dust.
Establishing warning systems for high concentrations, similar to those used for urban particulate matter, is conceivable so that particularly sensitive individuals or those with lung conditions can take precautions on dusty days. The energy sector would also benefit: desert dust in the air shades solar panels and accumulates on them, reducing their electricity production. If energy providers could anticipate this, they could compensate by boosting production from other power plants, thus ensuring the stability of the grid.
Published in journal: Nature
Title: Rising dust pollution across Europe in a changing climate
Authors: Petros N. Vasilakos, Abhishek Upadhyay, Manousos I. Manousakas, Andrés Alastuey, James D. Allan, Célia A. Alves, Benjamin Bergmans, Benjamin T. Brem, Sonia Castillo, Theodoros Christoudias, Cristina Colombi, Sébastien Conil, Katja Dzepina, Anja Eichler, Konstantinos Eleftheriadis, Olivier Favez, Michael Flynn, Kristina Glojek, Stuart K. Grange, David C. Green, Christoph Hueglin, Jean-Luc Jaffrezo, Theo M. Jenk, Jianhui Jiang, Ekaterina Krymova, Franco Lucarelli, Petra Makorič, Dario Massabò, Nikolaos Mihalopoulos, Griša Močnik, Robin L. Modini, Claudia Mohr, Attilio Naccarato, Petra Pokorná, Paolo Prati, Nicole Probst-Hensch, André S. H. Prévôt, Xavier Querol, Cristina Reche, Jesús D. de la Rosa, Mark M. Scerri, Jean Sciare, Michael Sigl, Anja H. Tremper, Rita Traversi, Daniel Trejo Banos, Maria Tsagkaraki, Gaëlle Uzu, Roberta Vecchi, Marta Via, Kees de Hoogh, Imad El-Haddad, and Kaspar R. Daellenbach
Source/Credit: Paul Scherrer Institute | Jan Berndorff
Edited by: Scientific Frontline
Reference Number: as071526_01
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