Mayfield is from Chester, a city of 34,000 just 15 miles southwest of Philadelphia, which is widely known as an environmental justice community — one where residents, predominantly low-income people of color, have faced disproportionate exposure to environmental hazards. It’s home to a paper plant, a waste incinerator, a sewage treatment facility and neighbors a natural gas processing hub, which choke the air with nitrogen oxides and particulate matter. The community has twice the asthma rate of the rest of the state, and the highest rate of infant mortality in Pennsylvania.