The Globeville, Elyria-Swansea and Commerce City communities in metro Denver are choked by air pollution from nearby highways, an oil refinery and a Superfund site^[1].

While these neighborhoods have long suffered from air pollution^[2], they’re not the only ones in Colorado^[3].

Now, Colorado is taking a major step to protect people from air pollutants that cause cancer or other major health problems, called “air toxics.” For...