What is Atmospheric Deposition?

Atmospheric deposition is the process, long recognized by scientists, whereby precipitation (rain, snow, fog), particles, aerosols, and gases move from the atmosphere to the earth's surface. Materials reaching the earth in precipitation or as dry deposition originate from a variety of air pollution sources and can be harmful to the environment and public health. Acidic deposition is the most widely acknowledged form of atmospheric deposition, with well-known effects on lakes, streams, and forests. More recently, atmospheric contributions of nutrients have received increasing attention, particularly as a source of excessive nitrogen entering the Chesapeake Bay. In addition, atmospheric deposition may be a significant source of environmental contaminants such as trace metals and toxic organic compounds.