Scenic vistas are diminished by haze that causes discoloration, loss of texture, and diminished visual range, and some of the pollutants that form haze have been linked to serious health effects and environmental damage. These reports summarize visibility in Class I areas that are protected and regulated by the Regional Haze Rule.

Elevated ozone concentrations adversely affect sensitive vegetation and ecosystems, including forests, parks, wildlife refuges, and wilderness areas. This graphical report summarizes ozone trends as measured by the EPA ozone monitoring network.

Deposition of sulfur and nitrogen compounds contributes to the acidification and eutrophication of sensitive terrestrial and aquatic ecosystems. This graphical report summarizes trends in wet deposition data from the NADP National Trends Network (NTN).

About half of the acidity in the atmosphere falls back to earth through dry deposition. This graphical report summarizes the sulfur and nitrogen composition of dry deposition data from the EPA's Clean Air Status and Trends Network (CASTNet).