Presentation on theme: "Laws to Prevent and Reduce Air Pollution Unit 4. Human Input of Pollutants into Troposphere Nitrogen and Sulfur compounds released by burning fossil fuels."— Presentation transcript:
Photochemical Smog in every City Chemical reactions triggered by light. Over 100 chemical substances i.e. O 3 Acid rain The hotter the day the more O 3
Industrial Smog consists mostly of sulfur dioxide (SO 2 ), sulfuric acid (H 2 SO 4 ) suspended in droplets, & particulates (soot) sulfur compounds in coal & oil react with oxygen to form sulfur dioxide: S + O 2 –> SO 2 Acid rain 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; kills fish & 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 (SO 2 ): causes constriction of airways & can cause bronchitis;
Effects air pollution on Health nitrogen oxides (especially NO 2 ): 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 national emission standards for toxic air pollutants require the EPA to regulate many toxic air pollutants. prevention of significant deteriorization
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