The federal government’s latest annual report on air quality trends, “Our Nation’s Air – EPA Celebrates 50 Years!,” documents pollution reduction progress from 1970-2019, emphasizing gains during the last few years. The combined emissions of Environmental Protection Agency-designated criteria pollutants and their precursors dropped 7 percent from 2017 to 2019. That metric reflects three-year declines in the emissions levels of nitrogen oxides, -10 percent; particulate matter 2.5, -1 percent; sulfur dioxide, -16 percent; carbon monoxide, -6 percent; and, volatile organic compounds, -3 percent.
Over the 2017-2019 window, the number of days EPA listed as unhealthy for sensitive groups in the Air Quality Index dropped by 34 percent as criteria pollutant volume swooned: Carbon monoxide, 8-hour, -10 percent; lead, three-month average, -28 percent; nitrogen dioxide, annual, -4 percent and 1-hour, -2 percent; ozone, eight-hour, -4 percent; particulate matter/10 microns, 24-hour, -22 percent, 2.5 microns, annual and 24-hour, -7 percent and -12 percent; and, sulfur dioxide, 1-hour, -10 percent.
Between 1970 and 2019, the combined emissions of criteria and precursor pollutants dropped by 77 percent, while the U.S. economy grew 285 percent. From 1990 to 2019, emissions of air pollutants continued to decline: NOx, -65 percent; PM 2.5, -36 percent; PM 10, including lead, -30 percent; sulfur dioxide, -91 percent; carbon monoxide, -69 percent; and, volatile organic compounds, -47 percent.
“Americans are breathing the cleanest air ever recorded,” says EPA Administrator Andrew Wheeler. “The Trump administration has shown that improvements in both public health and economic growth can take place at the same time.”
NATIONAL EMISSIONS BY SOURCE CATEGORY
The Environmental Protection Agency has refined air pollutant definitions and tracking since its chartering in 1970. The “Our Nation’s Air” report models, from left, concentrations of carbon monoxide, ammonia, nitrogen dioxide, 2.5- and 10-micron particulate matter, sulfur dioxide and volatile organic compounds.