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Laws to Prevent and Reduce Air Pollution. Unit 4. Human Input of Pollutants into Troposphere. Nitrogen and Sulfur compounds released by burning fossil fuels CO 2 & other greenhouse gases from burning fossil fuels & clearing forests. Urban Air Pollution. Photochemical Smog in every City.
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Human Input of Pollutants into Troposphere • Nitrogen and Sulfur compounds released by burning fossil fuels • CO2& other greenhouse gases from burning fossil fuels & clearing forests
Photochemical Smog in every City Chemical reactions triggered by light. Over 100 chemical substances i.e. O3 The hotter the day the more O3 Acid rain
Industrial Smog • consists mostly of sulfur dioxide (SO2), sulfuricacid (H2SO4) suspended in droplets, & particulates (soot) • sulfurcompounds in coal & oil react with oxygen to form sulfur dioxide: S + O2 –> SO2 Acid rain • Industrial smog is less common in “developed countries”, but a major problem in countries like China, India, & Russia where oil & coal are burned without sufficient pollution control.
Acid Deposition • Acid deposition, which consists of rain, snow or gas with a pH lower than 5.6 is commonly called acid rain. Soils and lakes vary in their ability to buffer or remove excess acidity.
Effects of acid rain on Aquatic Life • high acidity (low pH) leaches harmful minerals such as aluminum into the environment; • killsfish & other organisms; inhibits reproduction; disrupts food chains; & decreases productivity. • Massive plant, invertebrate, fish & bird extinctions • Norway and Sweden over 16,000 lakes are dead • Canada 14,000 lakes are affected • US over 9,000 lakes are affected
Effects air pollution on Health • carbon monoxide (CO): reacts with hemoglobin in red blood cells & reduces ability of blood to carry oxygen; • particulates: long–term exposure contributes to lung disease & cancer, aggravates bronchitis & asthma; • sulfur dioxide (SO2): causes constriction of airways & can cause bronchitis;
Effects air pollution on Health • nitrogen oxides (especially NO2): irritate lungs, cause conditions similar to bronchitis & emphysema; • volatile organics (& toxic particulates): cause mutations, reproductive problems, & cancer; • ozone: causes coughing, chest pain, shortness of breath, & eye, nose, & throat irritation.
Clean Air Acts of 1970, 1977, & 1990 • require Environmental Protection Agency (EPA) to establish national ambient air quality standards (NAAQS); • NAAQS apply to seven pollutants: suspended particulate matter, sulfur oxides, carbon monoxide, nitrogen oxides, ozone, volatile organic compounds, & lead;
Clean Air Acts of 1970, 1977, & 1990 • prevention of significant deteriorization • national emission standards for toxic air pollutants require the EPA to regulate many toxic air pollutants.
Success of Clean Air Act • decrease of six of seven major pollutants; • nitrogen dioxide levels increased slightly, primarily from automobiles; • 1996 study by EPA shows that benefits greatly exceed costs: 1970–90 $436 billion spent, health benefits of $2.7 to $14.6 trillion; • EPA estimates that 107 million Americans live in areas that exceed at least one outdoor air pollution standard.
National Emissions Standards for Hazardous Air Pollutants • Identified and targeted 8 toxic pollutants • Arsenic - Coke oven emissions • Asbestos - Mercury • Benzene - Radionuclides • Beryllium - Vinyl chlorides Clean Air Act (CAA) 1990 expanded to 188 toxic Air Pollutants
Solutions to prevent & reduce indoor air pollution.