Crumby, a 67-year-old Joppa native, uses the small devices to spray medicine directly into her lungs to keep her heart from failing. She has emphysema, a lung condition that causes shortness of breath. She huffs, puffs and struggles to catch her breath on a sunny day in March as she attempts to say a few words between inhales and exhales.

Crumby blames her illness on her surroundings. Joppa, less than 10 miles south of downtown Dallas, has been cited by some researchers as among the most air-polluted neighborhoods in the city.

The historic freedman’s town has been seen as a dumping ground for “toxic shit,” Crumby said, pointing toward a corridor of industrial facilities a few miles away. Joppa, like so many Black communities across the country, sits right next to industry — a rail yard, a roofing company that produces asphalt shingles and concrete batch plants.

In the air Crumby breathes there are microscopic particles that can penetrate deep into the lungs and enter the bloodstream, often referred to as soot. The technical name is particulate matter 2.5, or PM 2.5. These particles, which are 30 times smaller than a single strand of hair, cause air pollution. And this air pollution can lead to health complications. Some scientists call it the deadliest form of air pollution.