Residents of the Delmarva Peninsula and community advocates say the poultry industry is thwarting their efforts to monitor harmful air pollution from chicken farms.

Twenty-four years ago, Sam Berley bought a little house on a quiet stretch of Backbone Road in rural Princess Anne, Maryland. Today, the house appears tiny, because it’s dwarfed by six massive metal barns that together house more than 250,000 chickens. The closest one is just 240 feet away.

Berley often stays inside with the windows closed to avoid the awful stench that comes and goes; his neighbor Lisa Inzerillo, who lives about a mile down the road—beside other concentrated animal feeding operations (CAFOs)—does the same. “At night, we turn on a flashlight … and it looks like it’s raining outside there are so many particles [in the air],” she said.

Inzerillo and Berley want to know what exactly those particles are and what breathing them in every day might mean for their health.