Walter Olson has the story at Cato:
The Environmental Protection Agency is now backing off a whole series of deeply unpopular Obama-era initiatives. This time it’s the idea of tightening the federal standard for coarse airborne particulates — better known as “dust” — from the current 150 micrograms per cubic meter to a figure somewhere between 65 and 85, depending on what assumptions are used. That change could have dealt a tough economic blow to businesses, notably farms and ranches, that kick up quantities of dirt in the ordinary course of operation. Unfortunately, the EPA — unable to resist the urge to lash out against its critics — is being less than candid about its latest turnabout.
For background, read this piece of mine from February.