Every day, you need to make sure to get 4,200 mg of potassium for digestion, to maintain healthy blood pressure, to carry out muscle contractions, and also for proper nerve, kidney, and heart functions.
Over the next decade, the legislation was once again amended to extend these deadlines and to mandate states to revise their implementation plans. Congress did not amend the Clean Air Act during the decade of the 1980s, in part because President Reagan's administration placed economic goals ahead of environmental goals.
Although air quality has improved significantly since 1970, the Clean Air Act Amendments passed by the U.S. Congress in 1990 required Virginia's Department of Environmental Quality to enhance the vehicle emissions inspection program -- to keep improving air quality and to reduce emissions further.