ceptionally clean desert air has the seventh most polluted air in the country.
Pollution is introduced into the air by both natural and artificial contaminant particulates. Typical natural contaminants include salt particles from the oceans, and dust and gases from volcanoes. Typical artificial contaminants are wastes and gases that emanate from industrial, power generation, municipal, household, aircraft, rocket, and automotive combustion processes.
Many contaminant particulates introduced into the air rise to an altitude sufficient to permit their mixing with moisture in clouds. When such mixing occurs, the precipitation that falls from these clouds is polluted. When the contaminants create acid compounds, the precipitation is acidic in character, and, if the precipitation is rain, it is acid rain. This contaminated fallout from clouds may be hundreds of miles distant from the original sources of the air pollution. Thus, the a
...