Clean Air Act and acid rain improvement

 Acid rain is currently one of the most concerning environmental problems today, due to both its ecological effects and impacts on human health.  Although measures have been taken to reduce nitrogen oxide and sulfur dioxide emissions, years of power plants releasing these chemicals have left permanent damage to our forests and aquatic environments.  However, improvements have been measured in the US since the enactment of the 1990 Clean Air Act.  With the transient nature of acid precipitation, lets hope that this improvement will spread to other parts of the world.