Poverty increases vulnerability to air pollution, cold and heat in Europe

Two recent studies led by the Barcelona Institute for Global Health (ISGlobal) show that poorer populations in Europe face a higher risk of mortality associated with air pollution and extreme temperatures. Both studies used data from the EARLY-ADAPT project, which analyses how environmental and socioeconomic factors jointly influence recent trends in public health. The indicators studied include human mortality, hospital admissions, workplace accidents, and maternal and child health.

Pollution does not affect everyone equally

The first study, published in Nature Medicine and led by ISGlobal in collaboration with the BSC-CNS, used machine learning techniques to build epidemiological models describing how mortality risk from air pollution varies between populations.

To do so, the team used data from the EARLY-ADAPT project covering 653 regions in 31 European countries between 2003 and 2019, analysing a total of 88,8 million deaths. These data were cross-referenced with regional socioeconomic indicators and daily levels of air pollution, specifically fine particulate matter (PM₂.₅ and PM₁₀), NO₂ and daily maximum eight-hour ozone levels.

“Quantifying the mortality risks attributable to air pollution in each region and period can help us identify the most vulnerable populations more accurately” Zhaoyue Chen, ISGlobal researcher and first author of the study.

The results show that areas with higher GDP, lower mortality rates and longer life expectancy have a lower risk of mortality associated with air pollution. The team also analysed how this risk changed over the study period and found that wealthier areas experienced a decrease in air pollution-related risk, while poorer regions or those with lower life expectancy showed little improvement or, in some cases, even a slight increase in risk.

The role of renewable energy

The research team also included renewable energy consumption in their analysis and found that, during the study period, the increased use of renewable energy was linked to lower air pollution levels and, consequently, to a reduction in associated mortality.

Specifically, greater use of renewable energy was associated with substantial reductions in several air pollutants and in the mortality attributed to them. The study estimates a 15% reduction in PM₂.₅ and a 12% reduction in associated mortality, as well as a 54% reduction in PM₁₀ and a 52% reduction in attributable mortality. In the case of NO₂, both pollution levels and associated mortality decreased by 20%.

However, the uptake of renewable energy has not been uniform across Europe. Southern and eastern regions still rely more heavily on fossil fuels, while northern countries, with greater resources, have been able to roll out renewable energy more rapidly. This makes countries that use less renewable energy more vulnerable to the risks associated with air pollution.

Moreover, the adoption of renewable energy not only helps reduce emissions, but is often part of broader transformations towards more sustainable urban environments: better public transport, more green spaces, more walkable cities, clean technologies and stricter environmental regulations. According to the study, these measures can reduce communities’ vulnerability to the health effects of air pollution.

Cold and heat: unequal vulnerability

A second study, published in Nature Health, developed several models to link socioeconomic factors in European regions with mortality associated with extreme temperatures, both heat and cold.

The researchers obtained daily mortality data from 654 regions in 32 European countries included in the EARLY-ADAPT database, allowing them to study more than 161 million deaths recorded between 2000 and 2019.

“As climate change does not affect all populations equally, our findings can help assess and strengthen the way socioeconomic factors are incorporated into adaptation policies” Joan Ballester, EARLY-ADAPT researcher and coordinator of the study.

To quantify the weight of inequalities, the team compared two hypothetical scenarios: one in which all regions had favourable socioeconomic conditions, and another in which all regions were at the least favourable end of the spectrum. The results show that factors such as economic inequality, material and social deprivation, and difficulty keeping homes warm can increase vulnerability to extreme temperatures.

However, this vulnerability does not take the same form everywhere. While the most unequal regions are particularly affected by cold, wealthier and more urbanised areas face a higher risk during heat episodes, probably due to the urban heat island effect.

Towards more equitable environmental policies

Together, these two studies show that the socioeconomic situation of European regions influences mortality associated with both air pollution and exposure to extreme temperatures. Although the data come from European countries, the findings point to a reality that is likely to be shared in other parts of the world.

Overall, both studies underline the need to incorporate an equity perspective into environmental and public health policies. “There is an urgent need to expand environmental and health monitoring to identify disparities, guide equitable strategies and ensure that resources reach those who need them most,” says Carlos Pérez García-Pando, ICREA and AXA Professor at the Barcelona Supercomputing Center (BSC).