Air pollution linked to increased mortality

Long-term exposure to air pollution is linked with increased mortality risk. 

Researchers from the Harvard School of Public Health predicted one million people’s exposure to air pollution by using satellite-based measurements and meteorological data. 

They found that each 1g/m3 increase in annual particulate matter (PM2.5) concentrations increased the absolute annual risk of death by 0.073%.

Each 1 ppb increase in annual nitrogen dioxide (NO2) concentrations increased the annual risk of death by 0.003%, and each 1 ppb increase in summer ozone (O3) concentrations increased the annual risk of death by 0.081%

These increases translated to approximately 11,540 deaths attributable to PM2.5, 1,176 deaths attributable to NO2, and 15,115 deaths attributable to O3 per year for each unit increase in pollution concentrations.

The researchers also found that men were at greater risk of death from PM2.5 and O3, and people who identified as Black had a higher risk of death caused by NO2 and O3.

The study also found an increased risk of death for people living in lower-income areas, pointing to disparities in the adverse effects of air pollution.

The authors have said that these results suggest that a 2020 Environment Protection Agency (EPA) decision not to tighten standards for ambient PM2.5 ‘was unjustified.’

The researchers listed interventions that could reduce air pollutants, such as stricter controls on industry and fossil-fuel electric-generating units, larger and more efficient catalysts on automobiles, city planning to promote active transport, and improved public transit.

Joel Schwartz, professor of environmental epidemiology and senior author of the study said: ‘Our finding that people living in lower-income areas are more susceptible to the harmful effects of air pollution means they are suffering a double whammy – more exposure, and greater risk from that exposure.

‘The Clean Air Act requires the EPA to protect sensitive populations with an adequate margin of safety. It is time for it to do so.’

Photo by Andreas Strandman