US capital braces for 'very unhealthy' air as July 4 fireworks loom

Air quality across Washington DC and northern Virginia is expected to reach a "very unhealthy" level on Saturday as the region confronts sweltering temperatures and prepares for what the Trump administration hopes will be a record-breaking Fourth of July fireworks display. The US Air Quality Index also forecast deteriorating conditions in suburban Maryland, where pollution is expected to hit "unhealthy" levels throughout the day.

Health warnings

Maryland's Montgomery County Health Officer Dr. Kisha Davis told CNN that high temperatures will worsen air quality throughout the day, with fireworks adding to the pollution burden. "If you can be inside, be inside," Davis recommended.

"The air quality today is like running a marathon while smoking a cigarette," she said, noting that as of 9 am ET (1300 GMT), air quality in DC, northern Virginia, and suburban Maryland remained "moderate" but would deteriorate rapidly.

Record display

The fireworks display is expected to set a new Guinness World Record for the largest fireworks show, with nearly 850,000 shells scheduled to launch from 10 locations across the Lincoln Memorial Reflecting Pool, barges on the Potomac River, and West Potomac Park. The Washington Post reported earlier this week that internal National Park Service documents acknowledged the fireworks would significantly affect air quality, advising people to reduce exposure to pollution and recommending that anyone watching the display outdoors wear N95 masks.