The U.S. Food and Drug Administration is under fire for setting what critics say are near-impossible standards for quick, at-home Covid-19 tests that could provide a breakthrough in stemming the spread of the virus.

Experts say that more than a decade of research — including two new studies out of California, and one on a Texas community — has made it clear that current setback distances, in states where they exist, are inadequate to protect public health. Now, political pressure to push oil and gas wells about half a mile from homes and other buildings is peaking across the country, over industry alarm that such measures could amount to a de facto ban on drilling.