Acid rain causes acidification of lakes and streams and contributes to the damage of trees at high elevations and many sensitive forest soils. In addition, acid rain accelerates the decay of building materials and paints, including irreplaceable buildings, statues, and sculptures that are part of our nation's cultural heritage. Prior to falling to the earth, sulfur dioxide ( and nitrogen oxide gases and their particulate matter derivatives—sulfates and nitrates—contribute to visibility degradation and harm public health.