600 counties violate proposed EPA ozone levels

摘要

The environmental laws passed in the 1970s have gone a long way toward cleaning up excesses spawned by the post-World War Ⅱ economic boom. We're a bit stumped over how best to finish the job vis-a-vis the nation's water, but not air pollution. Ozone levels fell 33% from 1980 to 2013, thanks to EPA's multipronged attack. Engine and equipment manufacturers are releasing products that meet Tier 4 vehicle emissions requirements, and the agency's crack down on coal-fired power plants and dust.