In its latest set of Clean Air Act rules, final regulations for levels of fine and coarse airborne particles, the Environmental Protection Agency has moved to tighten one standard, revoke another and leave two unchanged. EPA's actions, announced Sept. 21, drew criticism from industry groups, which say the agency was too strict. They also sparked blasts from environmental groups, which contend the agency wasn't tough enough.
In its new rules, EPA cut the daily standard for fine-particle pollution, or PM 2.5, to 35 micrograms per cubic meter, from 65 micrograms now. But EPA retained the current PM 2.5 standard of 15 micrograms.