Air Pollution Chapter 20

Facts about Air ____% is Nitrogen (N 2 ) ____% is Nitrogen (N 2 ) ____% is Oxygen (O 2 ) ____% is Oxygen (O 2 ) ____% is Argon (Ar) ____% is Argon (Ar) ____% is Carbon Dioxide (CO 2 ) ____% is Carbon Dioxide (CO 2 )

What services does the atmosphere provide for the earth?

Definition of Air Pollution Gases, liquids and solids present in the atmosphere in high enough levels to harm organisms or materials Gases, liquids and solids present in the atmosphere in high enough levels to harm organisms or materials Primary air pollutants – Primary air pollutants – Secondary air pollutants – Secondary air pollutants –

Major Classes of Pollutants 1. Particulate matter – solid and liquid particles that are suspended in the atmosphere. Solid particulate matter = Solid particulate matter = Liquid particulate matter = Liquid particulate matter = Effects – Effects –

Major classes of Air Pollutants (cont.) 2. Nitrogen Oxides – gases produced by chemical interactions between nitrogen & oxygen when a source of energy produces high temperatures. - Group called NO x & consists of nitric oxide (NO), nitrogen dioxide (NO 2 ) and nitrous oxide (N 2 0) -Effects inhibits plant growth inhibits plant growth aggravates health problems aggravates health problems photochemical smog & acid deposition photochemical smog & acid deposition corrodes metals corrodes metals depletes stratosphere of ozone. depletes stratosphere of ozone.

Major classes of Air Pollutants (cont.) 3. Sulfur oxides – produced by the chemical interactions between sulfur and oxygen - Sulfur dioxide (SO 2 ) is an emitted air pollutant and a primary pollutant - Sulfur trioxide (SO 3 ) is a secondary air pollutant that forms when sulfur dioxide reacts with O 2 in the air - Reacts with H 2 0 to form sulfuric acid - Effects - Corrosion (acid deposition) - Irritate respiratory tracts

Major classes of Air Pollutants (cont.) 4. Carbon Oxides – including carbon monoxide and carbon dioxide - Carbon monoxide is the largest quantity of pollutant except C02 - Effects bloods ability to carry oxygen. - Carbon dioxide is a greenhouse gas.

Major classes of Air Pollutants (cont.) 5. Hydrocarbons - Compounds containing only hydrogen & carbon - Simplest form is methane (CH 4 ) - Smaller hydrocarbons are gases at room temperature. - Medium hydrocarbons are liquid at room temperature and many are volatile - Largest hydrocarbons are solids at room temperature. - Effects - Part of photochemical smog - Methane is a greenhouse gas

Major classes of Air Pollutants (cont.) 6. Ozone – (O3) - In the stratosphere – ozone present is good as it blocks the UV radiation emitted from sun. - In the troposphere – ozone reacts with sunlight, NOx, and hydrocarbons to form photochemical smog - Reduces visibility - Stresses plants - Causes health problems.

Major classes of Air Pollutants (cont.) 7. Air toxics or pollutants - Lots of other chemicals

What are the main sources of primary air pollutants? Transportation – mobile sources Transportation – mobile sources Industries - stationary sources, top 3 are chemical, metal and paper industries. Industries - stationary sources, top 3 are chemical, metal and paper industries. Mobile sources – Stationary sources –

What is hydrocarbon isoprene? It is hydrocarbons emitted from trees at high temperatures It is hydrocarbons emitted from trees at high temperatures It is a natural pollutant It is a natural pollutant

Effects of Pollution Damages organisms Damages organisms Reduces visibility Reduces visibility Corrosion Corrosion Reduce crop plants productivity Reduce crop plants productivity Harm respiratory tracts Harm respiratory tracts Acid deposition Acid deposition Global temperature change Global temperature change Stratospheric ozone depletion Stratospheric ozone depletion

Human effects of Air Pollution Eye irritation Eye irritation Respiratory tract inflammation Respiratory tract inflammation Suppress immune system Suppress immune system Respiratory illness such as asthma emphysema, & chronic bronchitis Respiratory illness such as asthma emphysema, & chronic bronchitis

What is smog? Smog is air pollution that reduces visibility. Smog is air pollution that reduces visibility. Industrial smog – Industrial smog – Photochemical smog – Photochemical smog –

What are the ingredients of smog? Photochemical smog comes from : Photochemical smog comes from :

Thermal Inversion/Temperature Inversion Air near ground is colder than air at higher levels Air near ground is colder than air at higher levels Traps polluting gases and particulates matter down near ground Traps polluting gases and particulates matter down near ground Occurs often in valleys, near coasts, or leeward side of mountains. Occurs often in valleys, near coasts, or leeward side of mountains. Animation Animation Animation

Urban Heat Island Localized heat buildup Localized heat buildup Increases number of thunderstorms Increases number of thunderstorms Contribute to buildup of pollutants especially particulate matter (dust domes) Contribute to buildup of pollutants especially particulate matter (dust domes)

Health Effects of Air Pollution Particulate Matter Particulate Matter Carbon Monoxide Carbon Monoxide Ozone Ozone Children and air pollution Children and air pollution

How can we control air pollution? Fit smokestacks with electrostatic precipitators, fabric filters, scrubbers to remove particulates. Fit smokestacks with electrostatic precipitators, fabric filters, scrubbers to remove particulates. Careful land excavating to keep dust down. Careful land excavating to keep dust down. Temperature reduction in autos & industry to reduce NO x formation Temperature reduction in autos & industry to reduce NO x formation Use low sulfur fuels and alternative energy sources. Use low sulfur fuels and alternative energy sources. Use no tillage practices & less nitrogen-based fertilizers used. Use no tillage practices & less nitrogen-based fertilizers used. Catalytic afterburners to oxidize unburned gasses. Catalytic afterburners to oxidize unburned gasses.

Air Pollution Regulations Clean Air Act Clean Air Act Authorizes the EPA to set limit on amount of specific air pollutants permitted. Authorizes the EPA to set limit on amount of specific air pollutants permitted. Focuses on lead, particulate matter, sulfur dioxide, carbon monoxide, NO x, ozone with maximum allowed concentration. Focuses on lead, particulate matter, sulfur dioxide, carbon monoxide, NO x, ozone with maximum allowed concentration. Sets levels for “attainment” and ranks non- attainment areas as marginal to extreme. Sets levels for “attainment” and ranks non- attainment areas as marginal to extreme.

Air Pollution Regulations (cont.) In California, air quality managed by Air In California, air quality managed by Air Quality Management Districts. Ours is Bay Area Quality Management District (BAAQMD) Ours is Bay Area Quality Management District (BAAQMD)

What is Ozone Depletion? Stratospheric ozone – block UV radiation. Stratospheric ozone – block UV radiation. UV – A ( nm) not blocked by ozone UV – A ( nm) not blocked by ozone UV – B ( nm) partially blocked by ozone UV – B ( nm) partially blocked by ozone UV – C ( nm) fully blocked by ozone. UV – C ( nm) fully blocked by ozone. Thinning of ozone in September over Antarctica results in ozone hole Thinning of ozone in September over Antarctica results in ozone hole

What are the causes of ozone depletion? Chlorine & bromine containing substance catalyze ozone destruction Chlorine & bromine containing substance catalyze ozone destruction Primary substances Primary substances CFC (used in coolants, insulators) CFC (used in coolants, insulators) Methyl bromide (pesticides) Methyl bromide (pesticides) Carbon Tetrachloride (solvents) Carbon Tetrachloride (solvents) Methyl chloroform (solvents) Methyl chloroform (solvents)

Effects of Ozone Depletion Excessive exposure to UV radiation Excessive exposure to UV radiation Causes health problems such as eye cataracts, skin cancer, and weakened immunity Causes health problems such as eye cataracts, skin cancer, and weakened immunity Crops/forests damaged Crops/forests damaged Montreal Protocol Montreal Protocol Stipulated 50% reduction in CFC by 1998 Stipulated 50% reduction in CFC by 1998

Acid Deposition Wet deposition – sulfuric and nitric acid in precipitation. Wet deposition – sulfuric and nitric acid in precipitation. Dry deposition – dry sulfuric acid and nitric acid-containing particles Dry deposition – dry sulfuric acid and nitric acid-containing particles Acid Precipitation – rain, sleet, snow and fog Acid Precipitation – rain, sleet, snow and fog Sulfur dioxide and NO x reacts with water to produce dilute solutions of sulfuric acid (H 2 SO 4 ), nitric acid (HNO 3 ) & Nitrous Acid (HNO 2 ) Sulfur dioxide and NO x reacts with water to produce dilute solutions of sulfuric acid (H 2 SO 4 ), nitric acid (HNO 3 ) & Nitrous Acid (HNO 2 ) Acid Rain animation Acid Rain animation Acid Rain animation Acid Rain animation

What are the effects of Acid Deposition? Corrosion Corrosion Makes toxic metals more soluble (aluminum) Makes toxic metals more soluble (aluminum) Weakens eggshells as calcium become unavailable due to increased acidity Weakens eggshells as calcium become unavailable due to increased acidity Plants/forest decline Plants/forest decline Alters chemistry of soil which effects root development & mineral dissolution & uptake. Alters chemistry of soil which effects root development & mineral dissolution & uptake.

Remediation of Acid Deposition Reduce sulfur dioxide and NOx emissions by installing scubbers Reduce sulfur dioxide and NOx emissions by installing scubbers Use cleaner fuels/alternative fuels Use cleaner fuels/alternative fuels Reduction in auto emissions. Reduction in auto emissions.

Where is pollution the worst? 5 worst Cities for air pollution? 5 worst Cities for air pollution? Mexico City, Mexico Mexico City, Mexico Beijing, China Beijing, China Shanghai, China Shanghai, China Tehran, Iran Tehran, Iran Calcutta, India Calcutta, India

Air Pollution in Bay Area Pollutants do not stay in the Bay Area. Pollutants do not stay in the Bay Area. Pollutants go to Central Valley, Sierras, and can even head south. Pollutants go to Central Valley, Sierras, and can even head south. Air Quality Index Air Quality Index Air Quality Index Air Quality Index

What compounds stay in the environment? Persistent compounds – these that do not readily breakdown and accumulate in the environment. Persistent compounds – these that do not readily breakdown and accumulate in the environment. Example – PCB, Dioxins, DDT, Pesticides, Example – PCB, Dioxins, DDT, Pesticides, Global Distillation effect – volatile chemicals evaporate for land, are moved by winds to higher latitudes where they condense and fall to the ground. Global Distillation effect – volatile chemicals evaporate for land, are moved by winds to higher latitudes where they condense and fall to the ground.

Indoor Air Quality Common contaminants include: Common contaminants include: Radon Radon Cigarette smoke Cigarette smoke Carbon monoxide Carbon monoxide Formaldehyde Formaldehyde Household pesticides & solvents Household pesticides & solvents Ozone Ozone Asbestos Asbestos Particulates Particulates Viruses, bacteria, fungi Viruses, bacteria, fungi Dust mites Dust mites Pollen Pollen

What is sick building syndrome? The presence of air pollution inside a building causing health effects such as eye irritation, nausea, headaches, fatigue, depression, colds. The presence of air pollution inside a building causing health effects such as eye irritation, nausea, headaches, fatigue, depression, colds.

Radon Colorless, tasteless, naturally-occurring radioactive gas resulting from radioactive decay of uranium in earth. Colorless, tasteless, naturally-occurring radioactive gas resulting from radioactive decay of uranium in earth. Emits alpha particles, a form of ionizing radiation that is very damaging to tissue but doesn’t penetrate very far Emits alpha particles, a form of ionizing radiation that is very damaging to tissue but doesn’t penetrate very far Can cause cancer, mostly due to inhalation Can cause cancer, mostly due to inhalation