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-I~. _ <br /> 5.8 Air Quality <br /> 5.8.1 Environmental Setting <br /> Air quality is dependent upon the source location, the amount <br /> and type of pollutants emitted, and on the subsequent atmospheric <br /> dispersion of the pollutants. Schematically, air quality may be <br /> described as follows: <br />L <br /> DISPERSION <br />15 <br />V Emissions + Meteorology + Air Chemistry -~~-Air Quality <br /> / <br /> SOURCES RECEPTORS <br /> There are several distinctions made in the identification of <br /> air pollutants. One distinction made is between primary and secondary <br />it air pollutants. Primary pollutants are those pollutants that are <br /> emitted directly from sources. Carbon monoxide, hydrocarbons (organic <br /> gases), oxides of nitrogen, sulfur dioxide, and particulate matters are <br /> primary pollutants. Secondary pollutants are those pollutants formed by <br /> chemical and photochemical reactions in the atmosphere. Photochemical <br /> oxidants and nitrogen dioxide (NO 2) are principal secondary pollutants. <br /> x <br />Li; <br /> Primary and secondary pollutants are transported and dispersed <br /> by meteorological processes. Meteorological factors important to the <br /> transport of air pollution within the South Coast Air Basin, in which <br /> the proposed project site is located are wind speed and direction, and <br /> the presence of atmospheric temperature inversions. With very light <br /> wind speeds (average of 5.7 miles per hour) the basin atmosphere has a <br /> limited capability to disperse air pollutants horizontally. As shown in <br /> Figure 29, the dominate daily wind pattern is a northeasterly daytime <br /> sea breeze and southwesterly nighttime land breeze. <br /> 124