The EU Ambient Air Quality Directive should take into account interactive health effects of air pollution and heat stress.

Press release from the EXHAUSTION project, 24 May 2023

Of relevance to the ongoing revision of the Ambient air quality and cleaner air for Europe directive (recast), the EU funded research project EXHAUSTION finds interactive effect of air pollution and heat that highlights the urgency in improving air quality across Europe.

In brief, the research shows that more people will die of heart and lung diseases in European cities when high temperatures co-occur with high levels of air pollution.

A comprehensive analysis for Europe, using a diverse set of health data, shows that the known health impacts of heat are significantly exacerbated by concurrent exposure to air pollution. Air pollution levels in Europe are still not safe, according to the European Environment Agency.

European Respiratory Society (ERS), Health Effects Institute (HEI) and International Society of Environmental Epidemiology (ISEE) Europe organise a stocktaking workshop on 24 May to discuss the proposed revision of the ambient air quality directive.

"It is important that the EU’s revised Ambient Air Quality Directive takes into account the consequences of more frequent heatwaves and generally higher temperatures due to climate change in Europe”, said EXHAUSTION Project Coordinator and Research Director Kristin Aunan at CICERO Center for International Climate Research.

In a study across 482 cities – including 156 European cities - the heat effect on cardiovascular and respiratory mortality was found to be significantly modified by air pollutants, (particulate matter (PM2.5 & 10), ozone and nitrogen dioxide).

“Reducing air pollution concentrations would not only reduce the health effects of bad air quality, but in addition reduce the health effects of heat as air pollution enhances the adverse effects of heat on health”, said Alexandra Schneider, Deputy Director of the Institute of Epidemiology at Helmholtz Munich.

Kristin aunan, project coordinator EXHAUSTION and Alexandra Schneider, Institute of Epidemiology at Helmholtz Munich. Photo credit: CICERO

In the study heat was associated with increased cardiorespiratory mortality. Moreover, the heat effects were modified by elevated levels of all air pollutants in most locations, with stronger effects for respiratory than cardiovascular mortality. This is the first-ever study to deeply investigate effect modifications by air pollutants such as PM2.5 and NO2 on a large-scale multi-country dataset. Link to study recently published in Environmental International (February 2023).

More material also available here: https://doi.org/10.5281/zenodo.7148318

The visualisation illustrates the health impact of simultaneous exposure to high temperatures and particulate air pollution matter (PM2.5). It shows the percentage increase in deaths from lung diseases when the temperature increases from moderate to high levels, given low, medium or high air pollution levels. Illustration by EXHAUSTION/Info Design Lab.