Sulfur dioxide is an atmospheric pollutant that poses threats to both human health and the environment. High concentrations of sulfur dioxide irritate the eyes, nose, and lungs, and can result in temporary breathing impairment. It is also a precursor to sulfuric acid, a major constituent of acid rain.
This visualization, created using data from the Ozone Monitoring Instrument (OMI) onboard NASA’s Aura satellite, shows annual, average changes in sulfur dioxide concentrations from 2005 to 2017. Sulfur dioxide concentrations from volcanic (i.e., natural) sources have been removed.
Sulfur dioxide is produced by the combustion of coal, fuel oil, and gasoline (since these fuels contain sulfur), and in the oxidation of naturally occurring sulfur gases, such as in volcanic eruptions. The largest source of sulfur dioxide in the atmosphere is the burning of fossil fuels by power plants and other industrial facilities. National and regional rules to reduce emissions of sulfur dioxide can improve air quality.