Published: Wednesday, December 23, 2020 Smog in Washington, D.C. Photo credit: Gary Todd/Flickr Smog hovering over Washington. Gary Todd/Flickr As the mother of five asthmatic children, Charday Urey knows the drill. When an EPA air quality index tips into the "unhealthy" zone, she closes the windows, turns on the air conditioner and keeps her kids indoors. "In the summertime, I don't even have a life," said Urey, a lifelong Washington, D.C., resident who ties some of her family's health problems to dirty air. "I need to make sure that nobody's asthma's acting up." EPA's air quality index is grounded in part in the national standard for ground-level ozone. But whether the agency's 70-parts-per-billion threshold is truly tough enough to protect children with asthma is embroiled in a long-festering debate that will not be settled by EPA chief Andrew Wheeler's expected decision to leave it in place through 2025.