Hiroko Tabuchi

Marathon runners consistently finished slower in cities with higher levels of dangerous particles in the air, researchers found.

The Environmental Protection Agency has hired numerous former lobbyists and industry insiders who now work on chemical regulation, emission limits and other rules.

A bipartisan group of lawmakers has asked the military to explain why cleanup of PFAS chemicals at bases nationwide has been pushed back.

Kyle Kunkler fought for a restricted weed killer that can harm plants and wildlife when it drifts to nearby land. He’s now at the E.P.A., which wants to allow its use.

The state leads the country in “repair cafes,” which bring neighbors together while keeping all manner of items out of the trash.

Mr. Newsom said he was concerned that the measure restricting PFAS chemicals would make pots and pans more expensive for Californians.

The new timeline could slow cleanup in some communities by nearly a decade. The chemicals, widely used in the military, are linked to cancers and other health risks.

The decision came despite an effort by a former industry lawyer who is now at the E.P.A. to reverse the regulation.

Rachael Ray and other food celebrities are speaking up in defense of nonstick pans. The actor Mark Ruffalo, who starred in a movie about the risky chemicals, is criticizing them.

Cue the Sun: This Lab Recreates Hot, Sweaty Days to Test Humans