Air Pollution Causes, Effects, and Solutions Terms to be familiar with… CAA – Clean Air Act CO – carbon monoxide NOx – nitrogen dioxide and nitrogen oxides PM – Particulate Matter SOx – Sulfur dioxide and sulfur oxides VOC’s – Volatile Organic Compounds Our Atmospheric Composition Composition of dry atmosphere, by volume ppmv: parts per million by volume Gas Volume Nitrogen (N2) 78.084% (780,840 ppmv) Oxygen (O2) 20.946% (209,460 ppmv) Argon (Ar) 0.9340% (9,340 ppmv) Carbon dioxide (CO2) 375 ppmv Neon (Ne) 18.18 ppmv Helium (He) 5.24 ppmv Methane (CH4) 1.745 ppmv Krypton (Kr) 1.14 ppmv Hydrogen (H2) 0.55 ppmv Not included in above dry atmosphere: Water vapor (highly variable) typically 1% Chemical and Transport Processes Related to Atmospheric Composition. These processes link the atmosphere with other components of the Earth system, including the oceans, land, and terrestrial and marine plants and animals. Credit: CCSP Strategic Plan (illustrated by P. Rekacewicz). Air Pollution Air Pollution Control Act of 1955 1st federal air pollution law 1960s - Clean Air Act of 1963 – (Emissions standards set for stationary sources such as power plants and steel mills) 1970 – The Clean Air Act (CAA) of 1970 – EPA was formed to enforce air pollution laws (change in national policy from advisor to enforcer) – Six major air pollutant types 1990 – The Clean Air Act of 1990 – Clean Air Act of 1970 is re-written and new titles established Six Common Air Pollutants Particulate Matter Carbon monoxide Nitrogen dioxide Lower Troposphere OZONE producing activities Sulfur dioxide Lead The EPA asked to Obama Administration to consider Carbon dioxide as a new common air pollutant. Source: U.S. Environmental Protection Agency- March 2008 Particulate Matter (PM) It is known as “Particle Pollution” and can range in sizes and effects on humans Particle sizes of 10 um (diameter) or smaller poses a greater health risk “Course particles” found near roadways and in mining and concrete industries are from 2.5 – 10 um “Fine particles” found in smoke and haze can have diameters smaller than 2.5 um Carbon monoxide (CO) CO is a colorless-odorless gas produced by the incomplete combustion of fossil fuels. Motor vehicle exhaust contributes to 56% of the CO produced in the U.S. Over 20% comes from other engines, boats and equipment not on-road. Could be worse in the colder months due to more dense air masses. CO Pollution EPA : 1999 Data Numbers of cases of carbon monoxide poisoning by age group. ........ Data for 1996 and 1997 from the Annual Report of the Am. Assoc. of Poison Control Centers, Toxic Exposure Surveillance System (published in the American J. Emergency Medicine). Statistics reported to 67 reporting centers for the two years. The total number of poisonings in 1996 were 22,154, and in 1997, 20,930. For children less than age 6 the numbers were 3,029 and 3,116; for children age 6-19 the numbers were 3,814 and 3,530; and for adults (>19 years), the numbers were 12,220 and 11,869. Nitrogen dioxide (NOx) Generic term for multiple combinations of nitrogen and oxygen Like CO, colorless and odorless NO2 can be seen as a brown-red gas Is mostly produced after combustion of fossil fuels at high temperatures Sources include motor vehicles, electric utilities, industry, and commercial and residential fossil fuel usages. “Well We’re Living Here in Allentown…” NOx is Alarming Contributes to the formation of acid rain Can contribute to nutrient load that affects water quality Reacts to form toxic chemicals Contributes to Global Warming (traps long wave radiation on Earth) which becomes Thermal Radiation. Los Angeles California: the smog is the brown layer in the picture Source: http://www.city-data.com/picfilesv/picv8898.php New York city picture: This 1963 photo shows a massive smog episode in New York City. (Photo: AP/Wide World Photo, EPA Journal Jan/Feb 1990. OZONE It is not usually emitted directly into the air, but at ground level is created by a chemical reaction between oxides of nitrogen (NOx) and volatile organic compounds (VOC) in the presence of sunlight. Sunlight and hot weather cause ground- level ozone to form in harmful concentrations in the air. Good Good Ozone is “Bad” Here Ozone There are two forms of Ozone. The Ozone that limits UV rays from reaching the Earth is in the Stratosphere (10 – 30 miles above the Earth’s surface. The “Bad” Ozone is in the lower Troposphere. Ozone Ground-level Ozone can be measured using remote monitoring devices Crops affected by ground-level ozone Source: Forsyth County Environmental Affairs Department, 537 N. Spruce Street, Winston-Salem, NC 27101-1362. Sulfur dioxide (SOx) Common in raw materials like coal, ore, and crude oil. Processing and burning of raw materials emits SOx. Over 65% of SO2 released to the air, or more than 13 million tons per year, comes from electric utilities, especially those that burn coal. SOx emission Source: http://www.epa.gov/air/urbanair/so2/what1.html Trends in Sulfur Dioxide Emissions Following Implementation of Phase I of the Acid Rain Program: Total State-level Utility SO2 (1980, 1990, 1999) EPA Source:http://www.epa.gov/airmarkets/cmap/mapgallery/mg_so2_before_and_aft.html A steel factory in Homestead, Pennsylvania, 1907, pictured on a stereopticon card. Library of Congress, Prints and Photographs Division, Detroit Publishing Company Collection. Normal Lung Aveoli (Left) versus Emphysema (Right) SOx Environmental Impacts Acid Rain SO2 and nitrogen oxides react with other substances in the air to form acids, which fall to earth as rain, fog, snow, or dry particles. Plant and Water Damage Acid rain damages forests and crops, changes the makeup of soil, and makes lakes and streams acidic and unsuitable for fish. Exposure over a long time changes the natural variety of plants and animals in an ecosystem. Aesthetic Damage SO2 accelerates the decay of building materials and paints, including irreplaceable monuments, statues, and sculptures. Acadia, ME Big Bend, TX Bryce Canyon, UT Lead The major sources of lead emissions have historically been motor vehicles (such as cars and trucks) and industrial sources. These emissions have been phased out in the U.S., but NOT globally. The major sources TODAY are smelters, waste incinerators, utilities and lead-acid battery manufacturers. Notice the change in lead emission sources since the banning of lead fuel use in the early 1980’s in the U.S. Source: http://www.epa.gov/air/urbanair/lead/what.h tml Lead Concerns Particularly affects young children and infants Is still found at high levels in urban and industrial areas Deposits on soil and water and harms animals and fish In 1999, ten areas of the country did not meet the national health-based air quality standards for lead. Solutions to Industrial Emissions Wet Scrubbers Baghouse (Venturi) Filters Electrostatic Precipitators Cyclone Separators Wet Scrubbers The purge stream, which contains the particulate and sulfur oxides removed from the flue gas, may either be treated in the refinery's existing wastewater treatment system or may be treated in a dedicated PTU (Purge Treatment Unit). Cyclone Separators Cyclone dust collectors have been used as a pre-filter before a cartridge or baghouse collector, to weed out the larger, more abrasive dust particles that can easily damage standard media filters. Baghouse filter "Baghouse" is an example of surface filtration "Filter" is a membrane (sheet steel, cloth, wine mesh, or filter paper) with holes smaller than the dimension of the particles to be retained. It is not the cloth/fabric that does the filtering, it is usually the cake on the filter that stops particles from flowing through Electrostatic Precipitators Electrostatic precipitators have collection efficiency of 99%, but do not work well for flyash with a high electrical resistivity (as commonly results from combustion of low-sulfur coal). Flyash is a common emission from the burning of fossil fuels Indoor Pollutants VOC’s (emitted from dishwashers) Solvents (common) from paints, etc Over-insulated homes can cause pollutants to be held indoors Poorly maintained heating systems PM Health Effects Particle pollution - especially fine particles - contains microscopic solids or liquid droplets that are so small that they can get deep into the lungs and cause serious health problems. Numerous scientific studies have linked particle pollution exposure to a variety of problems, including: increased respiratory symptoms, such as irritation of the airways, coughing, or difficulty breathing, for example; decreased lung function; aggravated asthma; development of chronic bronchitis; irregular heartbeat; nonfatal heart attacks; and premature death in people with heart or lung disease. CO Health Effects Cardiovascular Effects – People with heart disease can feel effects from exposure to CO (chest pains and trouble breathing) Central Nervous System – People who are exposed to high levels of CO can experience poor vision, reduced dexterity, and tiredness. High levels of CO are fatal NOx Health Effects NOx and VOC’s reacted with sunlight (UV) to form ground level Ozone Acid rain lowers pH on terrestrial and water bodies and affects many species Reacts with ammonia to form nitric acid which can cause respiratory distress and damage to lung tissue Can react with Ozone to produce mutagenic compounds. Examples of these chemicals include the nitrate radical, nitroarenes, and nitrosamines OZONE Health Effects Can irritate respiratory passageways Can cause wheezing, coughing, and breathing difficulties Permanent exposure can cause lung damage Chronic exposure can also cause asthma, reduces lung capacity, and bronchitis Plants too can become more susceptible to diseases Can reduce crop forest yields SOx Concerns SO2 and the pollutants formed from SO2, such as sulfate particles, can be transported over long distances and deposited far from the point of origin. This means that problems with SO2 are not confined to areas where it is emitted. SO2contributes to the formation of acid rain, which: -damages trees, crops, historic buildings, and monuments; and -makes soils, lakes, and streams acidic. SOx Health Effects Respiratory Effects from Gaseous SO2 Peak levels of SO2 in the air can cause temporary breathing difficulty for people with asthma who are active outdoors. Longer-term exposures to high levels of SO2 gas and particles cause respiratory illness and aggravate existing heart disease. Respiratory Effects from Sulfate Particles SO2 reacts with other chemicals in the air to form tiny sulfate particles. When these are breathed, they gather in the lungs and are associated with increased respiratory symptoms and disease, difficulty in breathing, and premature death. Lead Health Effects Damages organs - Lead causes damage to the kidneys, liver, brain and nerves, and other organs. Exposure to lead may also lead to osteoporosis (brittle bone disease) and reproductive disorders. Affects the brain and nerves - Excessive exposure to lead causes seizures, mental retardation, behavioral disorders, memory problems, and mood changes. Low levels of lead damage the brain and nerves in fetuses and young children, resulting in learning deficits and lowered IQ Lead Environmental Effects Affects animals and plants - Wild and domestic animals can ingest lead while grazing. They experience the same kind of effects as people who are exposed to lead. Low concentrations of lead can slow down vegetation growth near industrial facilities. Affects fish - Lead can enter water systems through runoff and from sewage and industrial waste streams. Elevated levels of lead in the water can cause reproductive damage in some aquatic life and cause blood and neurological changes in fish and other animals that live there.
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