logging in or signing up smog aSGuest8996 Download Post to : URL : Related Presentations : Let's Connect Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Copy embed code: Embed: Flash iPad Dynamic Copy Does not support media & animations Automatically changes to Flash or non-Flash embed WordPress Embed Customize Embed URL: Copy Thumbnail: Copy The presentation is successfully added In Your Favorites. Views: 3407 Category: Science & Tech.. License: All Rights Reserved Like it (0) Dislike it (0) Added: January 04, 2009 This Presentation is Public Favorites: 1 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript Slide 1: Look for efficient solutions Slide 2: CHEMISTRY PROJECT SMOG Slide 3: Smog, mixture of solid and liquid fog and smoke particles formed when humidity is high and the air so calm that smoke and fumes accumulate near their source. WHAT IS SMOG? Slide 4: Coinage of the term "smog" is generally attributed to Dr. Henry Antoine in his 1905 paper, “Fog and Smoke,” for a meeting of the Public Health Congress.. He said it required no science to see that there was something produced in great cities which was not found in the country, and that was smoky fog, or what was known as ‘smog.’” The following day the newspaper stated that “Dr. Henry did a public service in coining a new word for the London fog.” "Smog" also appears in a Jan. 19, 1893, Los Angeles Times article and is attributed to "a witty English writer." ORIGIN OF THE TERM Slide 5: Smog reduces natural visibility and often irritates the eyes and respiratory tract. In dense urban areas, the death rate usually goes up considerably during prolonged periods of smog, particularly when a process of heat inversion creates a smog-trapping ceiling over a city. Slide 6: HEAT INVERSION Slide 8: Smog prevention requires control of smoke from furnaces; reduction of fumes from metal-working and other industrial plants; and control of noxious emissions from automobiles, trucks, and incinerators. In the U.S. internal-combustion engines are regarded as the largest contributors to the smog problem, emitting large amounts of contaminants, including unburned hydrocarbons and oxides of nitrogen. SMOG PREVENTION Slide 9: The number of undesirable components in smog, however, is considerable, and the proportions highly variable. They include ozone, sulphur dioxide, hydrogen cyanide, and hydrocarbons and their products formed by partial oxidation. CONTENTS OF SMOG Slide 10: Chemistry is not everything Slide 11: Smog is a problem in a number of cities and continues to harm human health. Ground-level ozone, sulphur dioxide, nitrogen dioxide and carbon monoxide are especially harmful for senior citizens, children, and people with heart and lung conditions such as emphysema, bronchitis, and asthma. It can inflame breathing passages, decreasing the lungs' working capacity, and causing shortness of breath, pain when inhaling deeply, wheezing, and coughing. It can cause eye and nose irritation and it dries out the protective membranes of the nose and throat and interferes with the body's ability to fight infection, increasing susceptibility to illness. Hospital admissions and respiratory deaths often increase during periods when ozone levels are high . HEALTH EFFECTS Slide 12: The U.S. has developed an Air Quality index to help explain air pollution levels to the general public. 8 hour average ozone concentrations of 85 to 104 pp are described as "Unhealthy for Sensitive Groups", 105 ppb to 124 ppb as "unhealthy" and 125 ppb to 404 ppb as "very unhealthy" . The "very unhealthy" range for some other pollutants are: 355 µg m-3 - 424 µg m-3 for PM10; 15.5 ppm - 30.4ppm for CO and 0.65 ppm - 1.24 ppm for NO2 The Ontario Medical Association announced that smog is responsible for an estimated 9,500 premature deaths in the province each year. Slide 13: SMOG CYCLE Slide 14: Major incidents in the US 1948, October 30-31, Donora: 20 died, 600 hospitalized, thousands more stricken. Lawsuits were not settled until 1951. 1953, November, New York: Smog kills between 170 and 260 people. 1954, October, Los Angeles: heavy smog shuts down schools and industry for most of the month. 1963, New York: blamed for 200 deaths 1966, New York: blamed for 169 deaths Slide 15: A significant portion of industry and transportation burns fossil fuels, such as gasoline. When these fuels burn, chemicals and particulate matter are released into the atmosphere. Although a vast number of substances contribute to air pollution, the most common air pollutants contain carbon, sulphur, and nitrogen. These chemicals interact with one another and with ultraviolet radiation in sunlight in dangerous ways. Smog, usually found in urban areas with large numbers of automobiles, forms when nitrogen oxides react with hydrocarbons in the air to produce aldehydes and ketones. Smog can cause serious health problems. A NASA astronaut photograph of a smog layer over central New York Slide 16: Some of the cloud bands appear whitish, while others are orangey or brown. Scientists believe that the colors result from the presence of trace gases in Jupiter’s atmosphere. In the upper reaches of the atmosphere, the temperature drops below the freezing point of ammonia, one of the trace gases. In regions where warmer gases are carried up from below, the fresh ammonia freezes to form highly reflective white ice crystals. Jupiter’s Smog The ice crystals are swept horizontally by prevailing winds, causing the formation of bands that appear bright from reflected sunlight. Ultraviolet radiation from the Sun interacts with molecules of other trace gases in the upper atmosphere and generates yellow-brown smog. This smog settles down on the clouds causing those that are deeper in the atmosphere to appear darker brown. Within the darker bands, the atmosphere tends to sink and the ammonia ice crystals melt, exposing more brown smog particles and causing further darkening. Slide 17: Smog. Public attention was called to a new health menace when the deaths of 20 persons at Donora, Pa., from smog reached the headlines. Investigations following the tragedy indicate that the victims died of acute fluorine poisoning. Blood analyses of the diseased and hospitalized victims showed 12 to 25 times the normal quantity of fluorine. Corn crops, very sensitive to fluorine, were severely damaged and all of the vegetation north of the town was killed. Evidence found by the investigators indicated that hundreds of persons within the area showed primary symptoms of acute fluorine poisoning. As a result of the disaster, the U.S. Public Health Service will undertake a comprehensive investigation of contamination of the atmosphere by industrial wastes and make suggestions for correcting the situation in all industrial sections of the nation. Archive Essay Slide 18: Control of pollution is one area in which Los Angeles has achieved moderate improvement. The city’s notorious smog—produced mainly by exhaust emissions from millions of trucks, diesel buses, and automobiles, and trapped by the Santa Monica and San Gabriel mountains—is still among the worst in the United States. It is linked to a wide range of health problems, most noticeably to an alarming increase in asthma among children. It reached its worst levels in the 1970s, but strict vehicle emission standards imposed by the federal Environmental Protection Agency have had a marked effect. Federal and state officials are working to impose new measures, such as conversion of buses from diesel to natural gas and lower emission levels from automobile manufacturers. Smog In Los Angeles Slide 19: Mexico City Due to its location in a highland "bowl", cold air sinks down onto the urban area of Mexico City, trapping industrial and vehicle pollution underneath, and turning it into the most infamous smog-plagued city of Latin America. Within one generation, the city has changed from being known for some of the cleanest air of the world into one with some of the worst pollution, with pollutants like nitrogen dioxide being double or even triple international standards. Tehran In December 2005, schools and public offices had to close in Tehran, Iran and 1600 people were taken to hospital, in a severe smog blamed largely on unfiltered car exhaust. Slide 21: Griffith Observatory, Los Angeles High above the smog of central Los Angeles, Griffith Observatory has a much clearer view of the stars than the rest of the city. The world-famous observatory is perched high in the Hollywood Hills, in Griffith Park, a large park in the middle of the huge metropolis. Slide 23: The death of America rides in on the smog...Rush to the locks. Deliver us from our curse. For we must end on the road to that mystery where courage, death, and the dream of love give promise of sleep. Norman Mailer (1923 - ) Quotations The reason there's so much smog in L.A. is so God can't see what they're doing down there. Glen Campbell (1934 - ) Slide 24: THANK YOU THIS PROJECT IS PRESENTED TO YOU BY AAKASHDEEP MADHUSUDHAN SURAJ You do not have the permission to view this presentation. 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