CE 326 Principles of Environmental Engineering Prof. Tim Ellis

Transcription

1 AIR POLLUTION CE 326 Principles of Environmental Engineering Prof. Tim Ellis January 25, 2008

2 Seven Major Pollutants of Concern 1. P 2. S Oxides (SO X ) 3. O 4. N Oxides (NO X ) 5. Carbon M (CO and other hyrdrocarbons) 6. Volatile O Compounds (VOCs) 7. L (& others: mercury, other inorganic metals, radon, HCl) CE 326 Principles of Environmental Engineering, Copyright 2008 Tim Ellis, Iowa State University

3 Particulates released d into the air largely a result of s sources a nearly u urban pollutant. Although particulate levels in North America and Western Europe rarely exceed 50 micrograms of particulate matter per cubic meter (µg/m 3 ) of air, levels in many Central and Eastern European cities and in many developing nations are much higher, often exceeding 100 μg/m 3 ( en.epochtimes.com/news_images/ airpollution.jpg

4 Global distribution of urban PM 10 concentrations Sweden France Canada United States Venezuela Greece South Africa Kenya Argentina Egypt Italy Ecuador Brazil Nicaragua Colombia Costa Rica Panama Mexico Ghana Honduras Guatemala Chile Nepal Thailand Iran, Islamic Rep China India Indonesia Nigeria Pakistan Adapted from Reference Cumulative percentage of urban population 0 % 20 % 40 % 60 % 80 % 100 % Urban population Annual concentration Population-weight PM 10 concentrations μg/m 3

5 Size of Particulates PM : 2.5 to 100 μ in diameter, usually comprise s and d from industrial processes, agriculture, c and road traffic, p, and other natural sources. PM 2.5 : particles less than 2.5 μ in diameter generally come from combustion of f fuels. vehicle exhaust s, which is often coated with various chemical contaminants fine sulfate and nitrate t a that t form when SO 2 and nitrogen oxides condense in the atmosphere. largest source of fine particles is c -fired power plants, but auto and diesel e are also prime contributors, especially along busy transportation corridors. CE 326 Principles of Environmental Engineering, Copyright 2008 Tim Ellis, Iowa State University

6 Health Effects S particulates most damaging (PM 2.5 ) PM 2.5 aggravate existing h and lung diseases changes the body's defenses against i materials, and damages l tissue. E, children and those with chronic lung or heart disease are most sensitive lung impairment can persist for 2-3 weeks after e to high levels of PM 2.5 C carried by particulates can also be toxic

7 Science 307: , News Focus, March 2005

8 Sulfur Oxides Sulfur Oxides (SO X, mainly SO 2 ) emitted largely from burning c, high-sulfur o, and d fuel. usually found in association with p SO 2 is the p for fine sulfate particles (separating the health effects of these two pollutants is difficult) SO 2 and particulates make up a major portion of the pollutant l in many cities, acting both separately and in c to damage health. concentrations are higher by a factor of in a number of cities in Eastern Europe, Asia, and South America, where residential or industrial coal use is still prevalent and diesel traffic is heavy major component of a r

9 Health Effects SO 2 affects people q, usually within the first few minutes of e SO 2 exposure can lead to the kind of a health effects typical of particulate pollution. Exposure is linked to an increase in h and deaths from respiratory and cardiovascular causes, especially among a and those with preexisting respiratory diseases severity of these effects increases with rising SO 2 levels, and e enhances the severity by increasing the volume of SO 2 inhaled and allowing SO 2 to penetrate deeper into the respiratory tract Asthmatics may experience w and other symptoms at much lower SO 2 levels than those without asthma. When o is also present, asthmatics become even more sensitive to SO 2 indicating the potential ti for synergistic effects among pollutants

10 Ozone major component of p smog formed when from fuel combustion react with VOCs S and heat stimulate ozone formation, peak levels occur in the s. W in cities in Europe, North America, and Japan as auto and industrial emissions have increased. Many cities in developing countries also suffer from high ozone levels, although few monitoring data exist powerful o, can react with nearly any biological tissue.

11 Ozone concentrations of ppm can irritate the respiratory tract and impair l function, causing coughing, shortness of breath, and c pain. Exercise increases these effects, and heavy exercise can bring on symptoms even at low ozone levels ( ppm). ozone exposure l the body's defenses, increasing susceptibility to respiratory infections As ozone levels rise, hospital a and emergency room visits for respiratory illnesses such as asthma also increase. hospital admissions rise roughly 7 to 10 percent for a 0.05 ppm increase in ozone levels. in 13 cities where ozone levels e U.S. air standards, the American Lung Association estimated that high ozone levels were responsible for approximately 10,000 to 15,000 extra hospital admissions and 30, to 50, additional emergency room v during the ozone season

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13 Preventable health effects due to a 10% reduction of environmental levels of PM 10 and ozone between een 2000 and 2020 cases 10,000,000 1,000,000 Mexico City Sao Paulo Santiago New York 100,000 10,000 1, All ages Child Chronic Asthma Children: mortality bronchitis attacks Acute bronchitis Source: Cifuentes et al, 2001 Mortality Chronic morbidity Morbidity

14 Nitrogen Oxides principal i p component of photochemical smog component of a rain (NO X is oxidized to NO - 3 in the atmosphere, NO - 3 reacts with moisture to form nitric acid H 2 NO 4 ) formed i due to high temperature of combustion of atmospheric nitrogen CE 326 Principles of Environmental Engineering, Copyright 2007 Tim Ellis, Iowa State University

15 Carbon Monoxide H has an affinity for CO that is 200 to 250 times its affinity for oxygen this reduces its affinity for oxygen, disrupts release of oxygen. Blood level of 0.4% is maintained by CO produced by b. Blood is cleared of 50% of CO in 3-4 hours after e. Global emissions of CO are 350 million tons per year, 20% from mobile sources. CO concentration in c smoke is ~400 ppm. 24% of emergency room patients complaining of f -like symptoms in one study showed carbon monoxide poisoning CE 326 Principles of Environmental Engineering, Copyright 2008 Tim Ellis, Iowa State University

16 Carbon Monoxide health effects CO blocks the oxygen transport in your blood. CO is 100x better at binding in the oxygen site. CO poisoning is like suffocating.

17 Volatile Organic Compounds (VOCs) contribute tib t to o generation many are subject to NESHAPS (benzene from gasoline vapors) significant i emissions (e.g., perchloroethylene from dry cleaners) many are c or suspected carcinogens CE 326 Principles of Environmental Engineering, Copyright 2008 Tim Ellis, Iowa State University

18 Other Air Pollutants Lead Mercury other inorganic metals Indoor air pollution Second hand smoke Radon CE 326 Principles of Environmental Engineering, Copyright 2007 Tim Ellis, Iowa State University

19 Pyramid of Effects Death Hospital Admissions $ Doctor visits it Asthma attacks, medication use, symptoms $ lung function changes, immune cell responses, heart rate or heart rate variability responses 19

20 CE 326 Principles of Environmental Engineering, Copyright 2008 Tim Ellis, Iowa State University