Heatwaves and air pollution combined: Europe’s silent killer
Air pollution has become a pressing environmental challenge, leading to elevated mortality rates across Europe. This problem is further exacerbated by the rising occurrence of heatwaves due to climate change, which results in increased levels of ozone and particulate matter. The influence of wildland fires and smoke further compounds the impact on European populations, increasing premature death and hospitalisation due to lung and heart diseases. Understanding the primary vulnerability factors within different communities and regions is crucial for shaping effective climate change policies.
Assessing the health impacts due to extreme heat and air pollution
The EU-funded EXHAUSTION project sought to quantify shifts in cardiopulmonary disease (CPD) mortality and morbidity due to extreme heat and air pollution. Researchers considered various climate scenarios and identified strategies for mitigating adverse effects. Utilising epidemiological methods, the study established the relationship between temperature and daily number of deaths across Europe and estimated the health burden. Moreover, it examined the impact of concurrent air pollutants such as particulate matter and ozone, on the heat-health relationship. “We observed air pollution to be a significant modifier for the impact of heat on health, with a higher increase in deaths from respiratory diseases when air pollution levels were high,” highlights project coordinator Kristin Aunan. EXHAUSTION also assessed a range of vulnerability factors across European cities, both community level characteristics and individual parameters. Key project findings reveal an elevated risk of up to 60 % of CPD mortality and morbidity during heat exposure, with a stronger heat effect observed for respiratory mortality/morbidity compared to cardiovascular causes. The elderly and females were more vulnerable to heat, with temperature effects demonstrating geographical and seasonal variations, including more pronounced heat effects in southern Europe. Moreover, urban environment-related factors affected the risk of heat-related mortality, especially from respiratory diseases. Thus, people living in urban areas with dense populations, high air pollution levels and low coverage of green spaces demonstrated greater vulnerability to heat.
Heat and air pollution projections: the role of wildfires
EXHAUSTION projected health-relevant heat stress indicators for rising heatwave duration and intensity, and associated changes in air pollution levels. Although air pollution surface concentrations are projected to decrease, the contribution from wildfire emissions is increasing, making it more difficult to reach air quality targets. Wildfires are emerging as a key source of particulate matter pollution, especially in eastern Europe.
Implications for climate change policies and public health
In the future, even with lower emissions, more people may die from heat than will be saved from cold-related deaths, leading to an overall increase in temperature-related fatalities. In conclusion, the EXHAUSTION project’s work underscores the critical importance of revamping urban environments and enhancing living conditions across European cities to combat the compounding effects of air pollution and rising temperatures. “It is becoming more and more evident that air quality and climate change are intertwined challenges and must be tackled together,” emphasises Aunan. Alignment of the EU air pollution mitigation measures with the new WHO Air quality guidelines is expected to bring clear health benefits, alongside resilience and sustainable development. To succeed, these measures must prioritise the protection of the most vulnerable population groups. The findings from EXHAUSTION shape forthcoming studies, including the new PLANET4HEALTH project that will investigate the combined heat stress and air pollution in the African continent. Together, these efforts aim to create a safer and healthier future for Europe and beyond.
Keywords
EXHAUSTION, air pollution, mortality, climate change, heatwave, particulate matter, ozone, wildland fires, cardiopulmonary disease