The atmosphere is a vector for a variety of materials that may impact source water quality. These materials can be divided into two groups: man-made impacts and naturally-occurring impacts. Man-made impacts can include chemicals released as a result of industry and agriculture, radioactive fallout, and even the use of a variety of warfare agents. Natural hazards can include pathogenic microbes, toxic metals, and nutrients. These airborne materials, regardless of their origin, may impact source waters during short or long range atmospheric transport. Short range atmospheric inputs are arbitrarily defined here as those traveling less than 10 kilometers from their source. Long range atmospheric threats, are transported much further by winds, storm systems, or aerosolized soil dust. This paper focuses on the authors' work on African desert dust, which is a type of windblown contaminated soil that has long range effects. Includes 20 references.