Reducing vulnerability is key to reducing air pollution deaths
A major new global modelling study has found that improvements in population health and resilience, not just cleaner air, have played a crucial role in reducing deaths linked to air pollution over the past three decades.
Between 1990 and 2019, global air pollution mortality rates dropped by 45%. However, cleaner air alone did not drive this decline.
New research, led by scientists at the Stockholm Environment Institute at the University of York, has found that approximately 52% of the decrease was due to reductions in vulnerability. These factors include improved access to quality healthcare, falling poverty rates and better management of conditions such as hypertension, obesity and smoking.
Without these unintended shields, an estimated 1.7 million more people would have died from air pollution-related causes in 2019 alone.
While previous studies have largely focused on exposure levels, this analysis sought to isolate how changes in populations’ underlying susceptibility to harm, driven by factors such as healthcare and nutrition and overall disease burden, have affected outcomes.
The findings suggest that declining vulnerability has significantly reduced the global health burden of air pollution. The researchers estimate that a substantial portion of the drop in PM2.5-related mortality rates since 1990 cannot be explained by changes in pollution exposure alone, but instead reflects improvements in general health and living conditions.
To reach these conclusions, the team used a sophisticated demographic and health model combining global datasets on population, mortality and pollution exposure. They compared real-world trends with a hypothetical scenario in which only air pollution levels changed, allowing them to isolate the impact of vulnerability.
The research found that, after accounting for population aging, people in 2019 were significantly less likely to die from PM2.5-related heart disease, stroke, lung cancer, COPD and childhood respiratory infections than they were in 1990. 45% less likely.
The only exception was found to be type 2 diabetes, where virtually no change was seen.
A significant share of these reductions can be attributed to decreased vulnerability. In simple terms, populations today are generally less likely to die from the same level of pollution exposure than they were three decades ago.
The researchers also found that the sensitivity of pollution-related deaths to changes in vulnerability varies by disease. Cardiovascular conditions, for instance, showed a stronger link between improved underlying health and reduced pollution mortality than some other diseases.
Predictably, the study emphasises that reducing air pollution itself remains essential. While improved resilience has helped lower death rates, millions of deaths are still attributed to PM2.5 exposure each year.
Instead, the authors argue for a dual approach: tackling pollution sources while continuing to strengthen public health systems. Policies that reduce chronic disease, improve access to healthcare, and address social inequalities could significantly amplify the benefits of cleaner air.
Chris Malley, lead author of the study from SEI at the University of York said: ‘While cleaning our air remains a critical goal, our findings demonstrate that reducing emissions is only part of the solution.
‘To improve public health, we must also focus on the factors that make people susceptible to harm. Integrating healthcare improvements and poverty reduction into air quality strategies is an essential tool for protecting the world’s most vulnerable populations from the deadly effects of air pollution.’
The full research can be read here.
Photo: Frederic Köberl