Air quality in Washington, D.C., remained at unhealthy levels for more than 10 hours after the 40-minute fireworks show over the National Mall, according to data from AirNow, a website maintained by the Environmental Protection Agency reporting air quality measurements from physical sensors.
Jason Hill, an environmental scientist at the University of Minnesota who reviewed a decade of AirNow D.C. sensor readings at The Washington Post’s request, said the amount of fine particulate matter (PM2.5) in the air reached levels seen in past Independence Day celebrations. But they stayed high through Sunday morning, compared to more rapid drops in previous years.
PM2.5 refers to particles so small that when breathed in, they enter the bloodstreams and lungs.
A sensor in the southern Navy Yard neighborhood recorded a peak at 3 a.m. of 212.8 micrograms per cubic meter, reaching the “Very Unhealthy” level of the EPA’s air quality index. The data showed that the smoke and other pollutants were still low to the ground hours later and had shifted to other areas, instead of dissipating.
An interactive AirNow map captured “unhealthy” and “very unhealthy” air engulfing the District and its surrounding areas during and after the fireworks. The darker the color, the worse the quality of the air. According to the map, air over parts of D.C. was deemed “unhealthy” until around 11 a.m., and “unhealthy for sensitive group” until around 1 p.m.
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The post See how bad the air quality in D.C. really got after the Freedom 250 fireworks appeared first on Washington Post.
