Air Pollution and Poverty : PM2.5 Exposure in 211 Countries and Territories

Air pollution is one of the leading causes of death worldwide, especially affecting poorerpeople who tend to be more exposed and vulnerable. This study contributes (i) updated global exposure estimates forthe World Health Organizations's 2021 revised fine particulate matter (PM2.5) thresholds, and (ii) estimates ofthe number of poor people exposed to unsafe PM2.5 concentrations. It shows that 7.28 billion people, or 94percent of the world population, are directly exposed to unsafe average annual PM2.5 concentrations. Low- andmiddle-income countries account for 80 percent of people exposed to unsafe PM2.5 levels. Moreover, 716 million poorpeople (living on less than $1.90 per day) live in areas with unsafe air pollution. Around half of them are locatedin just three countries: India, Nigeria, and the Democratic Republic of Congo. Air pollution levels are particularlyhigh in lower-middle-income countries, where economies tend to rely more heavily on polluting industries andtechnologies. The findings are based on high-resolution air pollution and population maps with global coverage, as wellas subnational poverty estimates based on harmonized household surveys.