The Clean Air Act of 1970, the year the EPA was established, was even more robust, and subsequent amendments in 1977 and 1990 addressed ozone depletion and acid rain.

• 1970年，也是环保署成立之年，颁布的空气洁净法令更加强健，而随后在1977和1990年的修订中则把臭氧和酸雨问题也提了出来。