BIO 3103 General Ecology: Air Pollution PDF

BIO 3103 GENERAL ECOLOGY | STUB CODE: 71 ENVIRONMENTAL ISSUES: AIR POLLUTION OUTLINE MAJOR POLLUTION PROBLEMS (OUTDOOR) VI Air Pollution A. Nature of the Atmosphere...

BIO 3103 GENERAL ECOLOGY | STUB CODE: 71 ENVIRONMENTAL ISSUES: AIR POLLUTION OUTLINE MAJOR POLLUTION PROBLEMS (OUTDOOR) VI Air Pollution A. Nature of the Atmosphere 1. Industrial smog - mostly from burning coal. B. Major Pollution Problems (Outdoor) 2. Photochemical smog - from motor vehicle and C. Most threatening indoor air pollutants industrial emissions. D. Air Pollution Comes from Natural and Human 3. Acid deposition - from coal burning and motor Sources vehicle exhaust. E. Two categories of Outdoor Pollutants F. Major Outdoor Air Pollutants G. Sources of SPM H. Burning Coal Produces Industrial Smog I. Sunlight + Cars = Photochemical Smog J. Acid Deposition/Acid Rain K. Harmful Effects of Acid Deposition L. Ways to Reduce Acid Deposition M. Ways to reduce outdoor air pollution/Solutions N. Motor Vehicle Air Pollution O. Indoor Air Pollution – Solutions P. Ways to Prevent Outdoor and Indoor Air Pollution Over the Next 30-40 Years NATURE OF THE ATMOSPHERE Two innermost layers of the atmosphere: MOST THREATENING INDOOR AIR POLLUTANTS Troposphere 1. Smoke and soot - from wood and coal fires(in Supports life developing countries) Where 70 – 80 % of the earth’s mass is found 2. Chemicals used in building materials and Atmosphere layer closest to the earth’s surface products 17 km above sea level at the equator 8 km over the poles AIR POLLUTION COMES FROM NATURAL AND 99 % of the volume of air we inhaled consists of two HUMAN SOURCES gases A. Nitrogen - 78 % B. Oxygen - 21% Air pollution - is the presence of chemicals in the atmosphere in concentrations high enough to harm organisms, ecosystems or human made materials or to alter climate. Natural Sources of Air Pollution Stratosphere 1. Dust blown by wind Contain the protective ozone layer 2. Pollutants from wildfires and volcanic eruptions 17-48 km above sea level 3. Volatile organic chemicals released by some 1/1000 that of troposhere – volume of water vapor plants Ozone concentration is much higher than troposphere Human Sources of Air Pollution Where small amount of ozone layer of the atmosphere is concentrated (ozone layer- 17-30 Where people, cars and factories are concentrated km above sea level) 1. Burning of fossil fuels in power and industrial Stratospheric ozone is formed when some oxygen plants molecules interact with UV radiation 2. Burning of fossil fuels in motor vehicles (mobile (3O2 + UV ↔ 2O3) sources) “Global sunscreen” of ozone in the stratosphere keeps about 95% of the sun’s harmful UV radiation from reaching the earth’s surface. KRYSTELLE JOANN P. DARROCA | BSBMIC-3  BIO 3103 GENERAL ECOLOGY | STUB CODE: 71 TWO CATEGORIES OF OUTDOOR POLLUTANTS Primary pollutants - are harmful chemicals emitted directly into the air from natural processes and human activities. Secondary pollutants - while in the atmosphere, some primary pollutants react with one another and with other components of air to form new harmful chemicals. MAJOR OUTDOOR AIR POLLUTANTS 1. Carbon oxides → Carbon Monoxide (CO) → Carbon Dioxide (CO2) 2. Nitrogen Oxides/Nitric Acid → Nitric Oxide (NO) → Nitrogen Dioxide (NO2) → Nitric Acid (HNO3) → Nitrous Oxide (N2O) 3. Sulfur dioxide/Sulfuric Acid → Sulfur Dioxide (SO2) → Sulfuric Acid (H2SO4) → Sulfate (SO4) Reduce visibility and aggravate breathing problems SO2 can be converted to Aerosols SO2 + H2 SO4 + SO4 4. Particulates - Suspended Particulate Matter (SPM) Components: SOURCES OF SPM Small and light to remain suspended in the air for long periods 1. Natural Sources (62%): A. Solid particles Small and light to remain B. Liquid droplets o Dust: Windblown dust from deserts and dry areas. Classification of Particles: o Wildfires: Emission of ash, soot, and A. Fine - (PM 10 – with diameters less than 10 µm) other particles. B. Ultrafine - (PM 2.5 – with diameters less than o Sea Salt: Evaporation of seawater 2.5 µm) releases salt particles into the atmosphere. DARROCA, KRYSTELLE JOANN P. | BSBMIC-3  BIO 3103 GENERAL ECOLOGY | STUB CODE: 71 2. Human Sources (38%): D. Liquids used as industrial solvents, dry o (a) Coal-burning power and industrial cleaning plants: Release large amounts of fine solvents and components of gasoline, particles. plastics and o (b) Motor vehicles: Emit particulate other products matter from exhaust fumes. o (c) Road construction: Activities BURNING COAL PRODUCES INDUSTRIAL SMOG generate dust and fine particles. o (d) Tobacco smoke: Adds fine From: Power plants and factories for heating homes particulate matter to the indoor and and often for cooking outdoor air. Components: Unhealthy mixture of: 3. Ozone (O3) A. Sulfur dioxide o Colorless, highly reactive gas. B. Suspended droplets of sulfuric acid o Major component/ingredient of C. Variety of suspended solid particles photochemical smog o Formed by the reaction of nitrogen Resulting smog is gray color known also as “gray-air oxides (NOx) and volatile organic smog” compounds (VOCs) in the presence of sunlight. TWO CATEGORIES OF OUTDOOR POLLUTANTS o Harmful to human health, especially the respiratory system, and can damage 1. Photochemical reaction - any chemical crops and materials like rubber and reaction activated by light. 2. Photochemical smog - mixture of primary and plastic. secondary pollutants formed under the influence of UV radiation from the sun. Health Effects 1. Coughing and breathing problems VOCs + NOx + Heat + Sunlight → ground level ozone (O3) 2. Aggravate lung and heart diseases + other photochemical oxidants 3. Reduce resistance to colds and pneumonia + aldehydes 4. Irritate the eyes, nose and throat + other secondary pollutants 5. Damages plants, rubber in tires, fabrics and plastics Formation of photochemical smog begins when exhaust from morning commuter traffic releases large amount of NO and VOCs into the air over a city. NO is converted to reddish-brown NO2 – why photochemical smog is sometimes called “brown-air smog” ACID DESPOSITION/ACID RAIN A regional air pollution problem. Primary pollutants (SO2 and NOx) emitted high into the atmosphere maybe transported as far as 1,000 km (600 miles) by prevailing winds. During their trip, they form secondary pollutants, such as droplets of sulfuric acid, nitric acid vapor, and particles of acid forming sulfate and nitrate salts They descend to the earth’s surface into two forms: i. Wet deposition - consisting of acid rain, snow, fog and cloud 4. Volatile Organic Compounds (VOCs) vapor ii. Dry deposition - consisting of o Organic compounds that exist as gases acidic particles in the atmosphere or that evaporate Resulting mixture called acid deposition or acid into the atmosphere. rain Examples: Harmful Effects of Acid Deposition A. Hydrocarbons emitted by the leaves 1. Damages statues and buildings of plants 2. Contribute to human respiratory disease B. Methane (CH4) – a greenhouse gas 3. Leach toxic metals (lead and mercury) from soils C. Benzene and rocks into lakes used as sources of drinking water. These toxic metals can accumulate in the DARROCA, KRYSTELLE JOANN P. | BSBMIC-3  BIO 3103 GENERAL ECOLOGY | STUB CODE: 71 tissues of fish eaten by people and other animals Indoor Air Pollution - Solutions 4. Harms aquatic ecosystems Prevention: 5. Can affect forests a. Leaching essential plant nutrients (Ca and 1. Clean ceiling tiles and line AC ducts to prevent Mg) release of mineral fibers b. Releasing ions of Al, Pb, Cd, Hg which are 2. Ban smoking or limit it to well-ventilated areas toxic to trees 3. Set stricter formaldehyde emissions standards for carpet, furniture, and building materials 4. Prevent radon infiltration Ways to Reduce Acid Deposition 5. Use office machines in well-ventilated areas Prevention: 6. Use less polluting substitutes for harmful cleaning 1. Reduce coal use agents, paints, and other products 2. Burn low-sulfur coal Clean up 3. Increase natural gas use 1. Use adjustable fresh air vents for work spaces 4. Increase use of renewable energy resources 2. Increase intake of outside air 5. Remove SO2 particulates and NOx from 3. Change air more frequently smokestacks gases 4. Circulate building’s air thru rooftop greenhouses 6. Remove NOx from motor vehicular exhaust 5. Use different venting systems for wood-burning 7. Tax emissions of SO2 stoves 8. Reduce air pollution by improving energy efficiency 6. Use exhaust hoods for stoves and appliances burning natural gas Clean up: 1. Add time to neutralize acidified lakes What We Can Do? 2. Add phosphate fertilizer to neutralized acidified A. Indoor Air Pollution lakes 1. Test for radon and formaldehyde inside your home and take corrective measures as needed. How should we deal with Air Pollution? 2. Do not buy furniture and other products containing 1. Legal, economic and technological tools can help formaldehyde. us to clean up air pollution. Laws and regulations can 3. Remove your shoes before entering your house to reduce air pollution reduce inputs of dust, lead, and pesticides 2. Prevention - the best solution 4. Test your house or workplace for asbestos fiber levels, and check for any crumbling asbestos Ways to reduce outdoor air pollution/Solutions materials if it was built before 1980. 5. Do not store gasoline, solvents, or other volatile A. Stationary source of air pollution hazardous chemicals inside a home or attached Prevention: garrage. 1. Burn low-sulfur coal 6. If you smoke, do it outside or in a closed room 2. Remove sulfur from coal vented to the outside 3. Convert coal to a liquid or gaseous fuel 7. Make sure that wood burning stoves, fireplaces, and 4. Shift to less polluting energy sources kerosene and gas- burning heaters are properly Dispersion or Clean up installed, vented and maintained. 1. Disperse emissions above thermal inversion layer 8. Install carbon monoxide detectors in all sleeping with tall smokestacks areas 2. Remove pollutants after combustion 3. Tax each unit of pollution produced Ways to Prevent Outdoor and Indoor Air Pollution Over the Next 30-40 Motor Vehicle Air Pollution Years Prevention: SOLUTIONS- Air Pollution 1. Use mass transit Outdoor: 2. Walk or bike 1. Improve energy efficiency to reduce fossil fuel use 3. Use fewer polluting fuels 2. Rely more on lower-polluting natural gas 4. Improve fuel efficiency 3. Rely more on renewable energy (especially solar 5. Get older, polluting cars off the road cells, wind, geothermal and solar- produced 6. Give large tax write-offs or rebates for buying low- hydrogen). polluting energy efficient vehicles 4. Transfer energy efficiency, renewable energy and Dispersion or Clean up pollution technologies to developing countries. 1. Require emission control devices Indoor: 2. Inspect car exhaust system twice a year 1. Reduce poverty. 3. Set strict emission standards 2. Distribute cheap and efficient cookstove or solar cookers to poor families in developing countries. 3. Reduce or ban indoor smoking. 4. Develop simple and cheap tests for indoor pollutants such as particulates, radon, and formaldehyde. DARROCA, KRYSTELLE JOANN P. | BSBMIC-3