People's unequal exposure to air pollution : evidence for the world's coal-fired power plants

The world's over 3,800 coal-fired power plants are sources of substantial emissions of toxic air pollutants. This study explores people's unequal exposure to air pollution from these coal plants. It simulates the wind dispersion of pollutants originating from each coal power plant using the Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT) with Gaussian dispersion. The study generates three-dimensional pollution trajectories and provide a global map of nitrogen oxide (NOx), sulfur dioxide (SO2), and particle pollution from coal plants and their contributions to overall pollution levels. The study estimates that 2.3 billion people globally are exposed to SO2 and particle pollution from coal plants; 247.5 million of them are exposed to transboundary pollution from foreign coal plants. The findings show that pollution increases with income levels, though at a diminishing rate at high income levels. In the proximity of coal power plants, downwind areas are associated with higher pollution and lower income levels compared to areas upwind. These findings are consistent with strategic location choices that cause or reinforce environmental injustices associated with air pollution.