Environmental Engineering - Air Pollution Flashcards

Atmosphere

• The atmosphere, when scaled to the size of an apple, is no thicker than the skin on an apple.
• There is a surface but no "top" - the atmosphere gradually thins out with increasing altitude.

Layers of the Atmosphere

• Vertical temperature (T) profile
  • Troposphere - the higher the altitude, the lower the temperature. Convection occurs here, leading to weather patterns.
    • Weather patterns in the Philippines:
      • Northeast monsoon (Amihan)
      • Southwest monsoon (Habagat)
      • Intertropical convergence zone (where trade winds intersect)
  • Stratosphere - higher altitude, higher the temperature
    • Ozone layer is located here, which blocks harmful UV rays and heats the stratosphere.
  • Mesosphere - higher altitude, lower temperature (similar to troposphere)
    • No ozone layer in the mesosphere due to low air density.
  • Thermosphere - higher altitude, higher temperature
    • International Space Station (ISS) and space shuttles are located here.
    • Aurora occurs in this layer.
    • Extreme temperature, but low air density so no heat.
  • Exosphere
• Boundaries: Tropopause, Stratopause, Mesopause, Thermopause

Atmospheric Composition

• Key Components and Percent by Volume:
  • Nitrogen: 78.09 \approx 78
  • Oxygen: 20.94 \approx 21
  • Argon: 0.93 (outgassed from volcanoes)
  • Carbon dioxide: 0.0318 (continuously increasing)
  • Neon: 0.0018
  • Helium: 0.00052
  • Krypton: 0.0001
  • Xenon: 0.000008
  • Nitrous oxide: 0.000025
  • Hydrogen: 0.00005
  • Methane: 0.00015
  • Nitrogen dioxide: 0.0000001
  • Ozone: 0.000002
  • Sulfur dioxide: 0.00000002
  • Carbon monoxide: 0.00001
  • Ammonia: 0.000001

Convection Process

• Air molecules absorb heat from the earth, expand, and rise.
• At the top, they release heat and cool.
• Cooled air is pulled by gravity to the ground.
• This process only happens in the troposphere, driving weather patterns.

Air Pollution

• Definition (from RA 8749 - Philippine Clean Air Act):
  • Any alteration of the physical, chemical, and biological properties of the atmospheric air, or any discharge thereto of any liquid, gaseous or solid substances that will or is likely to create or to render the air resources of the country harmful, detrimental, or injurious to public health, safety or welfare or which will adversely affect their utilization for domestic, commercial, industrial, agricultural, recreational, or other legitimate purposes.

Sources of Air Pollution

• Man-Made
  • Motor Vehicles
  • Industry
  • Power Plants
  • Agricultural Sprays
  • Solid Waste Disposal
• Natural
  • Plant & Tree Pollens
  • Bacteria & Spores
  • Gases & Dusts from Forest & Grass Fires
  • Fogs
  • Ozone & Nitrogen dioxide from lightning
  • Volcanic ash & gases

Sources of Air Pollution (Continued)

• Stationary Sources (RA 8749):
  • Any building or immobile structure, facility or installation which emits or may emit any air pollutant.
    • Point Sources: Emissions from a specific location (e.g., stack pipes of industrial plants).
      • Mostly industrial plants, such as power plants, processing plants, manufacturing plants, etc.
    • Area Sources: Emissions from relatively large areas with specific activities.
      • Include busy roads and hubs, construction sites, aircraft operations, forest fires or the burning of wastes, and similar dispersed sources.
• Mobile Sources (RA 8749):
  • Any vehicle propelled by or through combustion of carbon-based or other fuel, constructed and operated principally for the conveyance of persons or the transportation of property goods.
• Biogenic sources: Plants and animals.

Air Pollutants

• Definition:
  • Any matter found in the atmosphere other than oxygen, nitrogen, water vapor, carbon dioxide, and the inert gases all in their natural or normal concentrations, that is detrimental to health or the environment, which includes smoke, dust, soot, cinder, fly ash, solid particles of any kind, gases, fumes, chemical mists, contaminated steam and radioactive substances

Types of Pollutants

• Primary Pollutant:
  • Found in the atmosphere in the same form as it exists when emitted from the source.
    • Examples: sulfur dioxide (SO2), nitrogen dioxide (NO2), and hydrocarbons.
• Secondary Pollutant:
  • Formed in the atmosphere as a result of chemical reactions (hydrolysis, oxidation, photochemistry).
    • Example: Photochemical smog (sunlight-driven mix of pollutants).

Major Air Pollutants

• Particulate Matter (PM)
  • Primary source is combustion.
  • Smaller particles are more dangerous.
    • TSP (Total Suspended Particulate): Concentration of particulate matter in sample.
  • Primary Particles:
    • Construction sites, Agricultural fields, Unpaved roads, Fires, Smokestacks.
  • Secondary Particles:
    • Power plants, Industry, Vehicles.
  • Types of Particulate Matter:
    • Dusts
      • Solid particles entrained by process gases directly from the material being handled or processed.
      • Direct offspring of a parent material undergoing a mechanical operation.
      • Entrained materials used in a mechanical operation.
    • Fumes
      • Solid particles formed by the condensation of vapors by sublimation, distillation, calcination, or chemical processes.
      • Frequently a metallic oxide.
      • Size: 0.03 to 0.3 micrometer.
    • Mists
      • Entrained liquid particle formed by the condensation of a vapor and by chemical reaction.
      • Size: 0.5 to 3.0 micrometer.
    • Smoke
      • Entrained solid particles formed as a result of incomplete combustion of carbonaceous materials.
      • Size: 0.05 to 1 micrometer.
    • Sprays
      • Liquid particle formed by the atomization of a parent liquid.
      • Settle under gravity.
      • Created by some mechanical disintegration process.
• Nitrogen Oxides (NO_x)
  • Important precursor to smog and acid rain, affects terrestrial and aquatic ecosystems.
  • Plays a major role, together with VOCs, in the atmospheric reactions that produce ozone.
  • Forms when fuel is burned at high temperatures.
    • Major emissions sources:
      • Transportation and stationary fuel combustion sources (electric utility and industrial boilers).
  • Nitrogen monoxide (NO)
    • Produced whenever air is heated to high temperature (automobile cylinders, high-temperature furnaces).
  • Nitrogen dioxide (NO_2)
    • Brownish, highly reactive gas present in all urban atmospheres.
    • Can irritate the lungs, cause bronchitis and pneumonia, and lower resistance to respiratory infections.
    • The major mechanism for the formation of NO_2 in the atmosphere is the oxidation of the primary air pollutant nitric oxide (NO).
• Sulfur Oxides (SO_x)
  • Sulfur dioxide (SO_2)
    • Colorless gas that is toxic and irritating to the respiratory system.
    • High concentrations affect breathing and may aggravate existing respiratory and cardiovascular disease.
      • Sensitive populations: Asthmatics, individuals with bronchitis or emphysema, children and the elderly.
    • A primary contributor to acid deposition, or acid rain, which causes acidification of lakes and streams and can damage trees, crops, historic buildings and statues.
    • Combines with water vapor in the air forming sulfuric acid & sulfates.
    • Sulfur compounds in the air contribute to visibility impairment.
    • Contributors: Industry Sector 90%, Transport 9%, Open Burning 1%
    • Usually emitted from the burning of coal and oil in electrical energy generation or heating or from internal combustion engines.
    • Released in the industrial production of sulfuric acid.
    • Ambient SO_2 results largely from stationary sources: coal and oil combustion, steel mills, refineries, pulp and paper mills and from nonferrous smelters.
• Carbon Oxides
  • Carbon monoxide (CO)
    • Colorless, odorless, and poisonous gas produced by incomplete burning of carbon in fuels (primarily by vehicles) and with the incomplete burning of fossil fuels.
    • When CO enters the bloodstream, it reduces the delivery of oxygen to the body's organs and tissues.
      • Health threats are most serious for those who suffer from cardiovascular disease, particularly those with angina or peripheral vascular disease.
    • Exposure to elevated CO levels can cause impairment of visual perception, manual dexterity, learning ability and performance of complex tasks.
    • Most CO emissions are from transportation sources.
  • Carbon dioxide (CO_2)
• Hydrocarbons
  • Diverse group of organic compounds that contain only hydrogen and carbon (ex: CH_4-methane).
  • Usually unburned fumes that evaporate from gas tanks & are emitted from exhausts of vehicles.
  • Some are related to photochemical smog and greenhouse gases
• Ozone (O_3)
  • Stratospheric Ozone
    • Essential component that screens out UV radiation in the upper atmosphere
    • Man-made pollutants (ex: CFCs) can destroy it
  • Ground Level (Tropospheric) Ozone
    • Man-made pollutant in the lower atmosphere
    • Secondary air pollutant
    • Component of photochemical smog
    • A photochemical oxidant and the major component of smog.
• Lead (Pb)
  • Exposure to lead (Pb) can occur through multiple pathways, including inhalation of air and ingestion of Pb in food, water, soil or dust.
  • Excessive Pb exposure can cause seizures, mental retardation and/or behavioral disorders.
  • Low doses of Pb can lead to central nervous system damage.
  • Recent studies have also shown that Pb may be a factor in high blood pressure and in subsequent heart disease in middle-aged males.
  • Lead gasoline additives, non-ferrous smelters, and battery plants are the most significant contributors to atmospheric Pb emissions.

Air Pollutant Composition

• Summary of Pollutants:
  • Particulate matter: Variable, Primary, Solid particles
  • Lead: Pb, Primary, Solid particles
  • Sulfuric acid: H2SO4, Secondary, Liquid droplets
  • Nitrogen dioxide: NO2, Primary, Reddish-brown gas
  • Sulfur dioxide: SO2, Primary, Colorless gas with strong odor
  • Carbon monoxide: CO, Primary, Colorless, odorless gas
  • Carbon dioxide: CO2, Primary, Colorless, odorless gas
  • Methane: CH4, Primary, Colorless, odorless gas
  • Benzene: C6H6, Primary, Liquid with sweet smell
  • Ozone: O3, Secondary, Pale blue gas with acrid odor
  • Chlorine: Cl2, Primary, Yellow-green gas

Criteria Air Pollutants

• National Ambient Air Quality Guidelines Values (RA 8749)
• Affects human health and environment
• EPA uses six "criteria pollutants" as indicators of air quality
• US EPA established a maximum concentration above which adverse effects on human health may occur.
  • Nitrogen Dioxide: NO_2
    • (Major Pollutant: Nitrogen Oxide)
    • brownish gas irritates the respiratory system originates from combustion (N2 in air is oxidized); NOx sum of NO, NO_2, other oxides of N
  • Ozone: ground level O_3
    • primary constituent of urban smog
    • reaction of VOC+ NO_x in presence of heat +sun light
  • Carbon monoxide: CO
    • reduces bloods ability to carry O_2
    • product of incomplete combustion
  • Lead: Pb
    • high Lead content in Chinese materials
    • cause learning disabilities in children, toxic to liver, kidney, blood forming organs
    • tetraethyl lead - anti knock agent in gasoline
    • leaded gasoline has been phased out
  • Particulate Matter: PM 10 (PM 2.5)
    • respiratory disorders
  • Sulfur Dioxide: SO_2 Acid Rain
    • formed when fuel (coal, oil) containing S is burned and metal smelting
    • precursor to acid rain along with NO_x

National Ambient Air Quality Guideline for Criteria Pollutants

• Criteria Pollutants - there are already a set of national ambient air quality guideline values or standards that need to be met to protect the environment.
  • Total Suspended Particulates (TSP) concentration of particulate to atmosphere
  • Carbon Monoxide (CO)
  • Sulfur Dioxide (SO2)
  • Lead (Pb)
  • Nitrogen Dioxide (NO2)
  • Ozone (O3)

Ambient Air Quality Guideline Values

• Concentration of air over specified periods classified as short-term and/or long-term which are intended to serve as goals or objectives for the protection of health and/or public welfare.
• In general, used as a basis for taking positive action in preventing, controlling, or abating health impacts from air pollution.
• National Ambient Air Quality Guideline Values
  • Basis for action (beyond permissible valves)
    • Maximum limits represented by ninety-eight percentile (98%) values not to exceed more than once a year.
    • Arithmetic mean
    • Attainment area- guidelines
      • Min 2 years complied in
    • Non attainment area
      • Reduce emission from cars
    • limits for Total Suspended Particulate Matter with mass median diameter less than 25-50 m
      • Annual Geometric Mean
    • Provisional limits for Suspended Particulate Matter with mass median diameter less than 10 mand below until sufficient monitoring data
      • Are gathered to base a proper guideline.
      • Evaluation of this guideline is carried out for 24-hour averaging time and averaged over three moving calendar months. The monitored average value for any three months shall not exceed the guideline value.
• Ambient Air Quality
  • The general amount of pollution present in a broad area; and refers to the atmosphere's average purity as distinguished from discharge measurements taken at the source of pollution
• Ambient Air Quality Monitoring
  • The measurement of a representative sample and is indicative of a portion of the atmosphere.
  • In theory, the pollutant concentrations measured in ambient air could be entirely different if the monitoring were located a short distance away.
  • The ambient network is designed to determine the concentrations expected to occur in the area covered by the network.
• Methods for Sampling and Measurement Based on USEPA 40 CFR
  • TSP High Volume-Gravimetric, USEPA 40 CFR, Part 50, Appendix B
  • PM-10-High Volume with 10 micron particle size inlet; Gravimetric, USEPA 40 CFR, Part 50, Appendix J
  • Sulfur Dioxide Gas Bubbler and Pararosaniline Method (West and Gaeke Method), or Flame Photometric Detector, USEPA 40CFR, Part 50, Appendix A
  • Nitrogen Dioxide Gas Bubbler Griess-Saltzman, or Chemiluminescence Method, USEPA 40 CFR, Part 50, Appendix F
  • Ozone-Neutral Buffer Potassium Iodide (NBKI), or Chemiluminescence Method. USEPA 40 CFR, Part 50, Appendix D
  • Carbon Monoxide-Non-dispersive Infra-red Spectrophotometry (NDIR). USEPA 40 CFR, Part 50, Appendix C
  • Lead High Volume and Atomic Absorption Spectrophotometry, USEPA 40 CFR, Part 50, Appendix G

Ambient Air Quality Monitoring Station Network

• Table 19 Philippine National Ambient Air Quality Guideline Values versus World Health Organization Guidelines
  • Criteria pollutants:
    • Particulate matter (PM10)
    • Sulfur dioxide
    • Carbon monoxide
    • nitrogen dioxide
    • Total Suspended Particulates
    • ozone
    • toluene
    • xylene.
    • lead
  • Non-criteria pollutants
    • carotenogenic substance
    • benzene
    • easy to evaporate (normal temp)
    • samples of VOCs volatile organic am pounds
• Measures meteorological data
  • wind direction
  • wind speed
  • vertical wind speed
  • Temperature
  • relative humidity
  • net radiation
  • barometric pressure
  • solar radiation (400-1100 nm)
  • UV radiation (295-385 nm).

Airshed

• Refers to areas with common weather or meteorological conditions and sources of air pollution which affect the interchange and diffusion of pollution in the surrounding atmosphere.
• start up air sheds
  • INTERIM AIRSHEDS
    • Metro Manila Airshed
      • NCR
      • Region 3 except Nueva Ecija
      • Region 4A except Quezon
    • Davao Airshed
    • Metro Cebu Airshed
    • Cagayan de Oro City, Geothermal Airshed
    • Naga City Airshed
    • BLIST Airshed (Baguio, La Trinidad, Itogon, Sablan, Tuba)
    • Agusan Del Norte Airshed
    • Zamboanga City Airshed

Air Quality Index (AQI)

• Index for reporting daily air quality.
  • It tells you how clean or polluted your air is, and what associated health effects might be a concern for you.
• The AQI focuses on health effects you may experience within a few hours or days after breathing polluted air.
  • suspended particulates
  • sulfur dioxide
  • photochemical oxidants or ozone
  • carbon monoxide
  • nitrogen dioxide

Six Levels of Health Concern (AQI)

• Index Ranges and Health Concerns:
  • 0 to 50: Good
    • Air quality is considered satisfactory, and air pollution poses little or no risk. Green
  • 51 to 100: Moderate
    • Air quality is acceptable.
    • For some pollutants there may be a moderate health concern for a very small number of people. Yellow
  • 101 to 150: Unhealthy for Sensitive Groups
    • People with lung disease, older adults and children are at a greater risk from exposure to ozone, whereas persons with heart and lung disease, older adults and children are at greater risk from the presence of particles in the air. Orange
  • 151 to 200: Unhealthy
    • Everyone may begin to experience some adverse health effects, and members of the sensitive groups may experience more serious effects. Red
  • 201 to 300: Very Unhealthy
    • A health alert signifying that everyone may experience more serious health effects. Purple
  • 301 to 500: Hazardous
    • A health warnings of emergency conditions. The entire population is more likely to be affected. Maroon

Smog

• Classical smog "london smog" - burning of coal or indivitial smoq
• Photochemical smog "Los Angeles smog" - cars and transpo emit nitrogen oxide

Photochemical Smog

• A mixture of pollutants that are formed when nitrogen oxides and volatile organic compounds (VOCs) react to sunlight, released by nitrogen oxide creating a brown haze above cities.
  • happens in morning
• Primary pollutants:
  • vehicles
    • Nitrogen oxides and VOCs, combine to change in sunlight in a series of chemical reactions to create what are known as secondary pollutants.
• Secondary pollutants
  • The secondary pollutant that causes the most concern is the ozone that forms at ground level.
  • Many other hazardous substances are also formed, such as peroxyacetyl nitrate (PAN).
    • evident if nakakaiyak yung hangin

Smog Formation

• Morning rush-hour traffic results in the production of large amounts of NO: N2 + O2 \rightarrow 2NO
• NO reacts with molecular oxygen (O2) from the atmosphere to form NO2: 2NO + O2 \rightarrow 2NO2
• Later in the morning. NO2 reacts with ultraviolet light to form atomic oxygen (O): NO2 \rightarrow NO + O
• Abundant O2 in the atmosphere reacts with atomic oxygen (O) to form ozone: O2 + O \rightarrow O_3
• Other components: PAN (peroxyacetyl nitrates), Formaldehyde

Thermal Inversion

• A condition when warm air becomes trapped between two layers of cold air and acts like a lid on the valley.
  • Cooler air is unable to mix with the warm air above and cannot escape because of the surrounding mountains. Cool
    air is trapped, sometimes for several days, and accumulates pollutants.
  • If thermal inversion continues, the levels of pollution can become dangerously high.

Global Warming

• Increase in temperature of earth due to greenhouse effect of gases
• Greenhouse effect
  • The warming thought to occur from the increase of greenhouse gases.
  • Called such because the effect is similar to what happens in a greenhouse where the glass allows light to enter but retards the loss of heat.
• heat is trapped to mainta the temperature

Climate Change

• Is the variation in the Earth's global climate or in regional climates over time.
• A change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods. - UNFCCC

Greenhouse Gases

• Those gases that can potentially or can reasonably be expected to induce global warming, which include carbon dioxide, oxides of nitrogen, chloroflourocarbons, and the like.
  • Philippine Clean Air Act (RA 8749)
    • Carbon dioxide (CO2)
      • Enters the atmosphere through burning fossil fuels (coal, natural gas and oil), solid waste, trees and wood products, and also as a result of certain chemical reactions (e.g., manufacture of cement).
    • Methane (CH4)
      • Emitted during the production and transport of coal, natural gas, and oil. Methane emissions also result from livestock and other agricultural practices and by the decay of organic waste in municipal solid waste landfills.
    • Nitrous oxide (N2O)
      • Emitted during agricultural and industrial activities, as well as during combustion of fossil fuels and solid waste.
    • Fluorinated gases
      • Synthetic, powerful greenhouse gases that are emitted from a variety of industrial processes.
        • Hydrofluorocarbons
        • Sulfur hexafluoride
        • Perfluorocarbons
        • Sometimes used as substitutes for stratospheric ODS (ozone depleting substances)
        • Nitrogen trifluoride
          • Typically emitted in smaller quantities, but because they are potent greenhouse gases, they are sometimes referred to as High Global Warming Potential gases ("High GWP gases").

Kyoto Protocol

• It is a protocol to the United Nations Framework Convention on Climate Change (UNFCCC) aimed at fighting global warming.
• The Protocol was initially adopted on December 11, 1997 in Kyoto, Japan, and entered into force on February 16, 2005.
• The first major international agreement towards GHGE reduction.
• Industrialized countries agreed to reduce emissions of six green house gases baskets to 5.2% below 1990 levels between 2008-2012.
• Greenhouse gases included:
  • Carbon dioxide (CO2)
  • Methane (CH4)
  • Nitrous Oxide (N2O)
  • Hydrofluorocarbons (HFCs)
  • Sulphur hexafluoride (SF6)
  • Perfluorocarbons (PFCs)
• Mechanisms to reduce the cost of meeting the above target.
  • International Emissions Trading (Article 17)
    • Allows the trading of assigned amounts within or among industrialized countries to meet quantified emission limitation or reduction commitments.
    • "Emissions Trading" or the selling of excess allowable emission of carbon dioxide of a country to another country that is still behind its target reduction of GHG emission.

Ozone Layer Depletion

• Ozone - a molecule that consists of three atoms of oxygen (O_3).
  • Occurs both in the Earth's upper atmosphere and at ground level.
• Ozone layer
  • Layer found in the stratosphere with high concentration of ozone molecules
    • Located 20-40 km from the earth's surface
    • Acts as a shield that envelops the entire earth and protects all life forms on earth from the harmful UV radiation
      emitted by the sun.
  • 1985 - Discovered a significant thinning of the ozone layer over the Antarctic occurred during the Southern Hemisphere spring.
    • Some regions of the ozone layer showed 95% depletion.
    • Antarctica - earth's southernmost continent, underlying the south pole
    • Has also been found to be occurring farther north than previously.
    • Measurements in arctic regions also suggest thinning of the ozone layer.
    • Arctic-region around the earth's north pole.
    • The presence of ozone in the atmosphere shields the earth from the harmful effects of UV light radiation.
      • O_2 absorbs UV light and is split into an oxygen molecule and an oxygen atom:
        • O_2 + O
      • Oxygen molecules are also split by UV light to form oxygen atoms:
        • O \rightarrow 2O
      • Recombination of oxygen molecules allows ozone to be formed again and to be available to absorb more UV light.
        • O + O + O_2

Ozone Depleting Substances

• Those substances that significantly deplete or otherwise modify the ozone layer in a manner that is likely to result in adverse effects of human health and the environment such as, but not limited to, chloroflourocarbons, halons and the like
  • RA 8749 (Philippine Clean Air Act)
    • Class I
      • green one gas and ozone depleting substances
      • Chlorofluorocarbons (CFCs)
        • Commonly known as "freon"
          • Contains chlorine, fluorine and carbon
          • Discovered by Thomas Midgley in 1928
          • Chlorine reacts with ozone in the following way to reduce the quantity of ozone present:
            • Cl + O3 \rightarrow ClO + O2
            • ClO + O \rightarrow Cl + O_2
              • These reactions both destroy ozone and reduce the likelihood that it will be formed because atomic oxygen (O) is removed as well.
                * Halons
      • Carbon tetrachloride
      • Methyl chloroform
      • Methyl bromide
    • Class II
      • Hydrochlorofluorocarbons (HCFCs)
• EFFECTS
  • Thinning of the ozone layer resulting to the loss of the blocking effect of the ozone layer against the UV radiation
• Recovery of ozone layer

Montreal Protocol

• Allows entry of greater concentrations of UV-B (which increases the risk of skin cancer, cataracts and
  suppressed immune system; can also damage terrestrial plant life, single-cell organisms and aquatic ecosystems.

Montreal Protocol on Substances that Deplete the Ozone Layer (Sept. 16, 1987)

• phale out ozone depleting globally
• satelite pictwa in 2000
• Landmark international environmental accord that was negotiated, entered into force, and amended in record
  time, in response to scientific information on the damage to the ozone layer by synthetic chemicals.
• Established a formula for determining calculated levels of consumption and production of controlled substances based on the ozone depleting potential of each substance.
  • Philippines September 14, 1988.
    • The DENR through the EMB-POD (Environmental Management Bureau- Philippine Ozone Desk)

Acid Deposition

• The accumulation of potential acid-forming
  particles on a surface.
• Natural causes:
  • Volcanoes, lightning, etc.
• Man-made causes/human activities:
  • Burning of fossil fuels (coal, oil)
  • Use of internal combustion engine
• Results when sulfur dioxide (SO2) and oxides of nitrogen (NOx) are converted to sulfuric and nitric acid, respectively, with the reaction of water and oxidizing agents, and
  return to the surface as either dry or wet
  deposition

Effects of Acid Deposition

*   Damage to ecosystem
    *   Declining Aquatic Animal Populations
    *   Thin-shelled eggs prevent bird reproduction because calcium is unavailable in acidic soil
    *   Forest decline (Ex: Black forest in Germany - 50% is destroyed)
*   Damage to properties
    *   Buildings and monuments made from materials containing limestone (calcium carbonate, CaCO_3).
        *   Sulfuric acid (H_2SO_4) reacts with (CaCO_3) to form gypsum (CaSO_4), which is more soluble and is eroded over years of contact with acid rain.
    *   Corrosion of metal surfaces

Acid Rain

• Unpolluted rainwater is slightly acidic because of the carbon dioxide from air dissolved in it.
  • CO2 + H2O => H2CO3
• Form of precipitation resulting from the acid-forming reactions.
  • Scotland-pH = 2.4 in 1974
  • Northeastern USA - pH = 4-4.5
• Contains high levels of sulfuric or nitric acids

Indoor Air Pollution

• main concern for indoor air pollution
  • Pollutants can be 2-5X greater than outdoors acc. USEPA, it is the most concern
• Radon
  • Emit alpha particles
  • Harmful when ingested/inhaled
  • Risk for lung cancer
• Cigarette smoke
• Hydrocarbons
• Carbon dioxide
• Carbon monoxide
  • reduces the ability to release oxygen
    in diving brain
• Particulate matter
• Radioactive materials
• Cyanide
• Carbon monoxide
• Nitrogen dioxide
• Formaldehyde
• Airborne pesticide residues
• Lead
• Asbestos
• Fungi and bacteria
• Many disease-causing microorganisms

Air Pollution Around the World

• Nine out of 10 people around the world breathe polluted air (WHO)
• An "alarming" 7 million people die each year from air pollution
• More than 90% of pollution-related deaths occur in low- and middle-income countries, mainly in
  Asia and Africa
• World's top 5 most polluted megacities (Based on the number of particles of pollution per cubic meter. Megacities are those with at least 14 million people.)
  • Delhi 292
  • Cairo 284
  • Dhaka 147
  • Mumbai 104
  • Beijing 92