What Are the Sources of Air Pollution?
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Air Quality Lesson 3 Subject/Target Grade Science and Social Studies/ Middle School (7-9) What Are the Duration Two 45-50 minute periods – Classroom setting Sources of Materials per class • Clear 2-L pop bottle with pollutants from Lesson 1 Air Pollution? • pan of water Only • Air Quality Unit Poster • Air Pollution Sources (transparency master) • Name That Source (answer key) Lesson Overview • Percentage of Air Emissions in Michigan This lesson looks at the sources of air pollutants. Students by Source Type (transparency master) examine the sources of air pollutants (point, mobile, area, • What Causes the Most Pollution? (answer key) and natural) using charts of actual data for Michigan. The • Michigan Air Toxics (transparency master) concept of an airshed and its importance for understanding • Estimate of Mercury Air Emissions in air pollution is developed. Michigan (transparency master) • Great Lakes Airshed (transparency master) An enhancement activity on the MEECS Air Quality per student CD has students attending “smoke school” so they can • Looking for Air Pollution (student activity) • Name That Source (student resource) see how air quality regulators do their work. An extension • Name That Source (student activity) using online mapping capabilities for emissions and their • What Causes the Most Pollution? sources is presented. (student activity) Students answer two essential questions: What are the sources of air pollutants? What are the relative Previewamounts of pollutants from these sources? Michigan Grade Level Content Expectations Objectives Grade 6-7 Science: Students will be able to: • Analyze information from data tables 1. Categorize pollution sources as point, mobile on-road, and graphs to answer scientific questions. S.IA.06.11 mobile off-road, area, or natural. • Describe the origins of pollution in the at- 2. Demonstrate an understanding of the relative mosphere, geosphere, and hydrosphere and contributions of each type of pollution source. how pollution impacts habitats, climatic For 3. Define the term “airshed” and relate it to air pollution change, threatens or endangers species. E.ES.07.42 in Michigan. (continued on next page) Michigan Environmental Education Curriculum Support Lesson 3 Air Quality 59 Lesson 3 What Are the Sources of Air Pollution? Advance Preparation 1. Prepare either a set of student handouts or Michigan Grade Level Content transparencies of Air Pollution Sources, Expectations (continued) Percentage of Emissions in Michigan by Source, Estimates of Mercury Emissions in Michigan, Grade 6-8 Social Studies: and The Great Lakes Airshed. The charts are • Describe the environmental effects of human action on the atmosphere, biosphere, lithosphere also available as a PowerPoint on the MEECS and hydrosphere. 6 - G5.1.1, 7 - G5.1.1 Air Quality CD. HS Social Studies: • Read and interpret data in tables and graphs. 2. Set up and test the demonstration of the effect P2.2 of adding air pollutants to a body of water. Use the clear 2-L pop bottle with pollutants from Lesson 1 and a panOnly of water. Background Information Sources of air pollution can be local, regional, from biological sources such as trees, bacteria, or global. An airshed is the area that contributes algae, and animals. Biological particles include to a region’s air and the contaminants found in pollen, spores, bacteria, and viruses. Livestock air. Its area is vast and it does not recognize any produce significant quantities of methane, ammonia political boundaries. Another definition of an gas, and carbon dioxide. airshed from the U.S. EPA’s Office of Water is “the geographic area responsible for emitting Clearing land (which produces particles) and 75% of the air pollution reaching a body of burning wood (which produces gases and particles) water.” While watersheds are actual physical are ways early humans caused air pollution. Today, features of the landscape, airsheds are determined burning of fossil fuels contributes significantly to using mathematical models of atmospheric air pollution with the release of soot (black carbon), deposition. Airsheds are very useful in explaining sulfate, metals, fly ash, carbon dioxide, carbon the transportation of pollutants and can help to monoxide, toxic organic compounds, and nitrogen effectively manage ambient air and a body of water. oxides. Evaporative emissions such as gasoline spills and solvents in certain paints also contribute Many types of sources contribute to air pollution in to air pollution. an airshed, both natural and anthropogenicPreview (human- produced). Volcanoes, desert dust, sea spray, Anthropogenic (human-produced) air emission meteorites, decay of radon, and fires produce natural sources in an airshed can be classified as stationary air pollution. Volcanic ash can travel hundreds to or mobile. Stationary sources include point thousands of miles downwind from a volcano. Fresh sources such as a factory or power plant with volcanic ash is gritty, abrasive, sometimes corrosive, significant emissions and area sources such as and always unpleasant. Although ash is not highly painting operations, dry cleaners, service stations, toxic, it can trouble infants, the elderly, and those landfills, light industry, and agricultural burning. with respiratory ailments.For Besides particles, Mobile sources are classified ason-road including volcanoes produce gases such as carbon dioxide, automobiles and trucks and non-road or off-road sulfur dioxide, carbon monoxide, and hydrochloric including gasoline or diesel-powered lawn and acid. Lightning contributes to the formation of garden, construction, and agricultural equipment; ozone. Gaseous (biogenic) emissions are produced airplanes; trains; ships; and recreational vehicles. 60 Air Quality Lesson 3 Michigan Environmental Education Curriculum Support What Are the Sources of Air Pollution? Lesson 3 National and state emission inventories that vehicles, at power plants, and in other industrial categorize human-produced emission sources are processes. In 2002, the majority of the nation’s done periodically. These inventories help to track particle pollution (64% for PM2.5 and 86% for PM10) changes in emissions and aid in planning emission was from fugitive dust from roads and construction, reductions. Ozone is not included in the inventories agriculture/forestry operations, and fires. since it is not usually emitted directly from a source. Special inventories of air toxics and greenhouse Volatile organic compounds (VOCs), which are gases are being developed. In 2000, it was estimated important in the formation of ozone and which may that the United States contributed 22.6% of world be toxic, are included in emission inventories. Of carbon dioxide emissions. There has been an effort the 16.5 million tons reported nationwide in 2002, to quantify natural emissions, which will assist 45% of the VOCs were from industrial processes, regulators in understanding the natural background 27% were from highway vehicles, and 16% were contributions to air pollution. from off-road vehicles. A study indicated that 30% of all the VOCs emitted in urban areas in eastern About 67% of sulfur dioxide (SO ) released into Texas were of biogenic origin including oak, pine, 2 Only the air in the United States in 2002, or more than 13 sycamore, poplar, and eucalyptus trees. million tons, came from electric utilities, especially those that burn coal. Other sources of SO2 are Carbon monoxide is a component of motor vehicle industrial facilities that derive their products from exhaust, which contributes about 56% of all CO raw materials such as metallic ore, coal, and crude emissions nationwide. Other non-road engines and oil, or that burn coal or oil to produce heat. Examples vehicles (such as construction equipment and boats) of such industrial facilities are petroleum refineries, contribute about 22% of the CO emissions. Higher cement manufacturing, and metal processing levels of CO generally occur in areas with heavy facilities. Also, locomotives, large ships, and some traffic congestion. In cities, 85% to 95% of all CO non-road diesel equipment currently burn high sulfur emissions can come from motor vehicle exhaust. fuel and release SO2 emissions into the air. Other sources of CO emissions include industrial processes (such as metals processing and chemical Nitrogen oxides form when fuel is burned at manufacturing), residential wood burning, and high temperatures, as in a combustion process. natural sources such as forest fires. Woodstoves, Nationwide, the primary human-produced sources gas stoves, cigarette smoke, and unvented gas and of NOX are motor vehicles (55%), electric utilities kerosene space heaters are sources of CO indoors. (22%), and other industrial, commercial, and The highest levels of CO in the outside air typically residential sources that burn fuels (22%). NO can occur during the colder months of the year when PreviewX also be formed naturally. inversion conditions are more frequent and the air pollution becomes trapped near the ground beneath Almost 7 million tons of fine particles (PM2.5) and a layer of warm air. 22 tons of coarse particles (PM10) were released nationwide according to the 2002 inventory. Some The major sources of lead emissions have particles are directly emitted into the air. They come historically been motor vehicles and industrial from a variety of sources such as cars, trucks, buses, sources. Due to the phase out of leaded gasoline, factories, construction sites, tilled fields, unpaved as of 1997 metals processing