The particulate matter is of varying sizes and varying composition, and from varying sources, and may contain a multitude of chemicals, both as primary and secondary air pollutants. Fugitive dust which may be caused by wind erosion, disturbance of soil or movement of various products, vehicles or equipment, trucks, etc., may cause major visibility problems, detrimental effects to agricultural products by coating them and/or health effects depending on quantities and weather conditions.
The liquids come from a variety of chemicals as well as water and may evaporate into the air in different sizes of droplets. These droplets can adhere to particulate matter and, depending on the size, be taken deeply into the lungs. They may also contribute to the production of acid rain and haze which reduces visibility.
Origins of Air Pollutants
Air pollution may be caused by anthropogenic (created by people) sources or natural sources. Air pollution may affect the health of people and the integrity of the environment. The various sources may interact and produce additional air pollutants. The pollutants are transported through the air from the source which may be a smokestack, etc., to the recipient which may be a person or the environment. The amount, nature, and direction of the wind have considerable bearing on the level of air pollution and the potential for damage. Also the presence of a temperature inversion (a weather-related event where the temperature of the atmosphere increases with altitude instead of normally decreasing, and cold air underlies the warmer air at higher altitudes thereby trapping contaminants coming into the air under what amounts to a lid of cold air) can enhance the effect of the pollutants.
This chapter will discuss the anthropogenic sources, including air toxics, and also the natural sources of air pollution which can be reduced to avoid disease, injury, and damage to the environment. It will also discuss primary air pollutants which are emitted from the anthropogenic and natural sources mentioned above. It will discuss secondary air pollutants that are formed by the reactions of the primary air pollutants and the atmosphere. Secondary air pollutants may include sulfuric acid, nitric acid, nitrogen dioxide, ozone, formaldehyde, peroxyacetyl nitrate, ammonium nitrate, and ammonium sulfate. It will discuss other pollutants including those that help cause climate change.