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SAN LEANDRO SHORELINE DEVELOPMENT DRAFT EIR <br />CITY OF SAN LEANDRO <br />AIR QUALITY <br />radiation inversions¢ are more common during the winter. The highest air pollutant concentrations in the <br />Air Basin generally occur during inversions. <br />4.2.1.2 AIR POLLUTANTS OF CONCERN <br />A substance in the air that can cause harm to humans and the environment is known as an air pollutant. <br />Pollutants can be in the form of solid particles, liquid droplets, or gases. In addition, they may be natural <br />or man-made. Pollutants can be classified as primary or secondary. Usually, primary pollutants are directly <br />emitted from a process, such as ash from a volcanic eruption, carbon monoxide gas from a motor vehicle <br />exhaust, or sulfur dioxide released from factories. Secondary pollutants are not emitted directly. Rather, <br />they form in the air when primary pollutants react or interact. <br />Criteria Air Pollutants <br />The pollutants emitted into the ambient air by stationary and mobile sources are regulated by federal and <br />State law. Air pollutants are categorized as primary and/or secondary pollutants. Primary air pollutants are <br />emitted directly from sources. Carbon monoxide (CO), reactive organic gases (ROG), nitrogen oxides (NOx), <br />sulfur dioxide (SOA coarse inhalable particulate matter (PM10), fine inhalable particulate matter (PM2.5), <br />and lead (Pb) are primary air pollutants. Of these, CO, 502, NO2, PM10, and PM2.5 are "criteria air <br />pollutants," which means that ambient air quality standards (AAQS) have been established for them. ROG <br />and NOx are criteria pollutant precursors that form secondary criteria air pollutants through chemical and <br />photochemical reactions in the atmosphere. Ozone (03) and nitrogen dioxide (NO2) are the principal <br />secondary pollutants. Areas that meet AAQS are classified attainment areas, and areas that do not meet <br />these standards are classified nonattainment areas. <br />A description for each of the primary and secondary criteria air pollutants and their known health effects <br />is presented below. <br />■ Carbon Monoxide (CO) is a colorless, odorless, toxic gas produced by incomplete combustion of <br />carbon substances, such as gasoline or diesel fuel. CO is a primary criteria air pollutant. CO <br />concentrations tend to be the highest during winter mornings with little or no wind, when surface - <br />based inversions trap the pollutant at ground levels. Because CO is emitted directly from internal <br />combustion engines, motor vehicles operating at slow speeds are the primary source of CO in the Air <br />Basin. Emissions are highest during cold starts, hard acceleration, stop -and -go driving, and when a <br />vehicle is moving at low speeds. New findings indicate that CO emissions per mile are lowest at about <br />45 miles per hour (mph) for the average light-duty motor vehicle and begin to increase again at higher <br />speeds. When inhaled at high concentrations, CO combines with hemoglobin in the blood and <br />reduces its oxygen -carrying capacity. This results in reduced oxygen reaching the brain, heart, and <br />other body tissues. This condition is especially critical for people with cardiovascular diseases, chronic <br />lung disease, or anemia, as well as for fetuses. Even healthy people exposed to high CO <br />concentrations can experience headaches, dizziness, fatigue, unconsciousness, and even death.' The <br />' During the night, the ground cools off, radiating the heat to the sky. <br />s Bay Area Air Quality Management District (BAAQMD), 2010 (Revised 2011), Appendix C: Sample Air Quality Setting, in <br />California Environmental Quality Act Air Quality Guidelines. <br />4.2-4 DECEMBER 2014 <br />