In 2024, the Biden administration enacted wide-ranging regulations to protect communities near petrochemical plants from air toxics. The Trump administration has since granted exemptions to scores of polluting facilities and is working to rewrite the long-awaited rule.

In April 2024, Tish Taylor and her father, Robert, stood behind President Joe Biden’s Environmental Protection Agency chief, Michael Regan, as he signed a regulation designed to dramatically reduce toxic pollution from petrochemical plants like those that cluster near the Taylors’ homes along the lower Mississippi River, in Louisiana.

Taylor struggled not to cry through the signing ceremony, which followed years of demands from communities like hers — in the 85-mile corridor between New Orleans and Baton Rouge that has become known as Cancer Alley — for tighter limits on plants’ emissions. The new regulation, known as the HON rule, was “a wonderful gift to generations ahead of us,” Taylor said.…