Seoul Air Quality Days: March 2017 vs 2018

The number of days in which the maximum air quality level reached certain health thresholds defined in the U.S. Environmental Protection Agency’s air quality index. The readings reflect concentrations of the pollutant PM2.5 that have been scaled to health categories in the index, or AQI.

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Notes

The daily cateories represent the maximum hourly reading of PM2.5 in central Seoul’s Jung District, scaled to the EPA Air Quality Index.

Source: Air Korea

Credit: Matt Stiles/The Daily Viz