HealthDay News — Between 2000 and 2019, most of the world’s urban population lived in areas with unhealthy levels of fine particulate matter (PM2.5), according to a study published online Jan. 5 in The Lancet Planetary Health.
Veronica A. Southerland, M.P.H., from George Washington University in Washington, D.C., and colleagues estimated population-weighted PM2.5 concentrations and attributable cause-specific mortality in 13,160 urban centers between 2000 and 2019 using high-resolution annual average PM2.5 concentrations, epidemiologically derived concentration response functions, and country-level baseline disease rates.
The researchers found considerable heterogeneity in trends of PM2.5 concentrations between urban areas, although regional averages of urban PM2.5 concentrations decreased between 2000 and 2019. Of urban inhabitants, about 86 percent (2.5 billion inhabitants) lived in urban areas that exceeded the World Health Organization 2005 guideline annual average PM2.5, yielding more than 1.8 million deaths in 2019. In all regions except for Europe and the Americas, regional averages of PM2.5-attributable deaths increased, driven by changes in population numbers, age structures, and disease rates. PM2.5-attribuable mortality increased in some cities despite decreases in PM2.5 concentrations, resulting from shifting age distributions and rates of noncommunicable disease.
“The majority of the world’s urban population still live in areas with unhealthy levels of PM2.5,” Southerland said in a statement. “Avoiding the large public health burden caused by air pollution will require strategies that not only reduce emissions but also improve overall public health to reduce vulnerability.”