Cutting Emissions Isn’t Enough? New Study Reveals More

Most air pollution mitigation efforts concentrate on what comes out of people’s mouths,  reducing the amount of nasty air that people breathe. But there’s an additional important dimension to consider: how vulnerable people are to that pollution. Vulnerability is a measure of how easily a person can be harmed by fine particulate matter in the air (PM2. 5). Contributing factors include pre-existing health conditions, income level, access to quality healthcare, race and smoking habits.

A new paper, lead by researchers at the Stockholm Environment Institute (SEI) at the University of York, has investigated whether changes in vulnerability are affecting mortality rates related to PM2. 5 between 1990 and 2019. The study challenges the international focus on air pollution. It suggests that reducing population vulnerability is as important as cutting emissions for saving lives. 

The study shows that reducing pollution is important, but it is only part of the solution. Advances in public health, better access to health care, reducing poverty over the last three decades, have also helped protect people from the deadly effects of dirty air.

The researchers used three main data sources: death rates from the Global Burden of Disease Study 2021, demographic data from UN Department of Economic and Social Affairs and PM2. 5 concentration data from State of Global Air. By analyzing these sources, they were able to track trends in deaths linked to PM2.5 between 1990 and 2019 among 193 countries while accounting for age and sex differences.

They built a model to estimate how death rates would have evolved if pollution levels were the only changing factor. Comparing those projections with actual data, they showed how other variables, like health status, poverty levels and smoking habit, molded vulnerability to PM2. 5 and influenced mortality trends.

Between 1990 and 2019, deaths attributable to fine particle pollution (PM2. 5) declined by about 45% worldwide, falling from 140 deaths per 100,000 people in 1990 to 78 deaths per 100,000 in 2019. Approximately half of this improvement was due to reduced PM2. half due to lower susceptibility and the other half double exposure.

Absence of these vulnerability reductions would have yielded an additional estimated 1.7 million deaths in 2019. The study concluded that when overall death rates (unrelated to pollution) declined by 1.8%, deaths attributed to PM2. 5 also declined by 1%.

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 proportion of people living in global poverty fell from 45% in 1990 to only 21% by 2019, giving us an unanticipated buffer against the harmful effects of air pollution. Meanwhile, public health efforts to combat obesity, smoking and uncontrolled hypertension have quietly saved millions of lives. However, such measures are rarely considered in air pollution plans, despite their major contribution to reducing mortality associated with air pollution.

The study demonstrates how efforts to reduce air pollution are best implemented alongside initiatives designed to improve health and resilience. Between 1990 and 2019, pollution levels in both North America and Europe were reduced by similar amounts. But Europe saw a decrease in deaths from pollution of almost double. The reason? There was more tangible progress in Europe towards improving health and social conditions, reducing risk.

The implication is clear: air quality strategies need to go beyond just reducing emissions. They also will need to integrate public health measures, from reducing poverty and improving access to healthcare, to lowering lifestyle risk,  to effectively protect people from the fatal effects of dirty air.