NGR302I Air Pollution. NGR302I Outdoor Air Pollution

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Air Pollution

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Outdoor Air Pollution

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Air Pollution Sources

Transportation Stationary sources Industrial

Issues Global warming Ozone depletion Acid rain Poisons

Remedies Prevention Removal Legislative Issues

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Air Pollution Index

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Major Air Pollutants

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Cars, Planes, Trains… Are the major source of NOx, CO, CO2, HC and

particulate. In US, car/person ratio approaches 1. During their lives, every American will drive and fly a

million miles, equal to forty trips around the globe. Worldwide, number of cars will exceed 1 billion in

2020; About one car for every seven man, woman, or child.

Efficiency is still low; 20% for ICE, 80% for the electricity (27% if electricity comes from fossil fuel); Hybrids can give 10-20% more gas mileage.

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Acid Rain

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pH

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Effect of pH on Fish Populations

Only a few marine species can survive when pH is smaller than 5.

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Global warming

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The Greenhouse Effect

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1995 UN Report International Panel on Climate

Change consisted of 2500 scientists reported:

“Unless there is a reduction in greenhouse emission, the Earth’s average temperature will increase by 2-6.5o F and the sea level will rise by 6 to 38 inches by the year 2100”

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Sources

Carbon dioxide (solid waste, fossil fuels)

Methane (organic wastes, livestock)

Nitrous oxide (agricultural and industrial activities, fossil fuels combustion)

Ozone Hydrofluorocarbons (HFCs),

and sulfur hexafluoride (SF6) (industrial processes)

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Effectiveness HFCs are the most heat-absorbent.

Methane traps over 20 times more heat per molecule than carbon dioxide, and nitrous oxide absorbs 200 times more heat per molecule than carbon dioxide.

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CO2 Production Rate of CO2

production is accelerating

Note the seasonal variations

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Vehicle Trend

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Top Ten Producers of Greenhouse Gases

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Effects of Global Warming No doubt that greenhouse gases are

warming the planet, scientists might only agree on its degree Sulfur from volcanic eruptions Particles from forest fires Warming effects are stronger than cooling effects

Doubling of CO2 emission will cause 4-9o F increase in the global temperature

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Worst Case Scenario Positive Feedback Mechanism

As temperature goes up, oceans dissolve less carbon dioxide

Less nutrient biomass (plankton) faster ozone depletion (more UV, less

plankton) More wetlands releasing methane Higher temperature

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What can you do… Purchase a more economy car Insulate your home Carpool Recycle Use more efficient appliances Plant trees Educate others

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Ozone Depletion

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The Problem

In 1990’s ozone concentration in the upper atmosphere has been decreased by 4-5% over the previous three decades

Satellite observations indicate a world-wide thinning of the protective ozone layer. The most noticeable losses occur over the North and South Poles because ozone depletion accelerates in extremely cold weather conditions.

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Ozone What is Ozone?

Molecules consist of 3 atoms of oxygen (O3)

It is a “secondary pollutant” It is not 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.

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Consequences

One chlorine or bromine molecule can destroy 100,000 ozone molecules, causing ozone to disappear much faster than nature can replace it.

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Good Ozone and Bad Ozone Good in Upper

Atmosphere (Blocks 99% of the Sun’ ultraviolet radiation)

Bad in Lower atmosphere (health hazard to human, environment, and crops)

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Sources Chlorofluorocarbons

(CFCs), halons, and other ozone depleting substances

Coolants Aerosols Foaming agents Fire extinguishers Solvents

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Ozone Destroying ChemicalsChemicals Uses Half Lives

(yr)Share of problem

US share of use

CFC-11 Coolant, aerosol, foam

60 28% 22%

CFC-12 Coolant, aerosol, foam

13 47% 30%

CFC-113 Solvent 90 5% 45%

CCl4 Solvent 50 15% 27%

Methyl Chloroform

Solvent 7 2% 50%

Halon-1211 Coolant, foam

25 1% 25%

Halon-1301 Fire extinguisher

110 2% 50%

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History 1930 – CFC First utilized 1974 - US production increased to 800,000 tons per year 1978 - US banned use of CFC 1982 – Volcanic ash from eruption of El Chichon in

Mexico depleted ozone concentration in mid latitude 1985 - A team of British scientist discovered the ozone

hole over Antarctica and Arctic 1995 – Crutzen, Molina, Rowland shared the Nobel Prize

in Chemistry for understanding how ozone is formed and decomposed in the atmosphere

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Formation

Kineticsa. Cl + O3 Cl-O

+O2

b) Cl-O + O3 Cl + 2O2

c) Repeat step a. Net reaction

2O3 3O2

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Consequence Increase UV exposure

UV-B causes aging of the skin, cancer and cataracts Estimated additional 12 million skin cancers within the next 50 years in the

US alone Impairs human immune systems Damages UV sensitive crops (soybeans)

Food Shortage Decreases the photoplankton (a plant that grows in the ocean) Because plants "breathe in" carbon dioxide and "breathe out" oxygen,

carbon dioxide levels in the air could also increase. Floods and Drought

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Myths Since CFCs are heavier than air,

CFC will sink back to lower atmosphere.

It is because of the volcanoes (HCl) and ocean (NaCl) that ozone are depleted.

Depletion is only over Antarctica (and to a lower extent over Arctic)

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Internet Resources State of Environments in Different Countries (

http://www.unep.org/unep/soe.htm)

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Indoor Air Pollution Average person stays 90% of his time indoors Energy conservancy projects have exacerbated this problem Common sources of indoor air pollution are:

Cigarette and tobacco smoke Paints, lead and other construction material Stoves, refrigerators and other appliances cleaners and chemicals Pesticides Soil Drinking Water

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Sources of Indoor Air Pollution

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Sick Building Syndrome SBS is usually referred to office or residential buildings

in which occupants experience a large increase of dizziness, nausea, headaches, sore throat, etc.

EPA estimates that 20 to 30% of all US buildings are sick.

Appliances, carpeting, building materials are mostly responsible

Problem more severe after 1970 Arab oil embargo Building codes require sufficient ventilation for large

buildings. Similar codes do not exist for smaller commercial buildings and homes.

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Radon (Rn-222) Chemically inert Naturally occurring, radioactive material

dispersed through rocks and soil In homes mostly through basements, faucet showerhead, and walls

Mostly from radioactive decay of U-238, U-235, and Th-232 Emits gamma rays, and alpha particles with eventual decay to stable lead

Once inside quickly decays (T1/2=3.8 days) to lead, bismuth and deposits on solid surfaces within the home

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Safety Limit EPA – 0.3 pCi/l (pico curie per liter)

Compare with .2 pCi/l for average outdoor levels and 1 pCi/l for average indoor levels

Immediate action if above 200 range Action within years if between 4-20 range

Could be considerably higher if there is a Radon problem

Radon releases alpha particle ( some will be deposited in the lung as we breathe)

20,000 cases of lung cancer per year attributed to radon in US Very high correlation among smokers

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Smoking 2 million die of smoking related illnesses

(cancer, emphysema, bronchitis, heart ailment) worldwide 325,000 annual death toll in the US 5000 die from second hand smoking Increased health and insurance cost of 40-100

million dollars Fine particles, odor, and other

carcinogenic materials are the main cause

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Asbestos Naturally occurring minerals that

can be separated into small-diameter fibers

It is chemically stable, and excellent thermal and electrical insulator

3,000-12,000 persons die (in US) every year from mesothelomia (a form of lung cancer)

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Asbestos safety 1986 – Asbestos Hazard and Emergency

Act Mandated the removal of asbestos-

containing materials from schools There are still in some old buildings in form

of asbestos-filled vinyl floor tile, insulation on pipes and boilers, asphalt roofing shingles

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Chemicals and Solvents Chlorinated Compounds

Tetrachloroethylene – in dry cleaners, damage to liver and kidney

1,1,1 Trichloroethane – aerosol spray cans and propellant, nerve disorder and asthma

Methylene chloride – Paint removers, softners, nerve disorder and diabetes

Chloroforms – Hot shower water (from chlorine added to water), carcinogenic

Benzene Ring-containing Compounds Styrene and vinyl chloride – plastics and carpets, kidney and

liver damage Benzo-a-pyrene – Wood and tobacco smoke, carcinogenic

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Chemicals (Continued) Formaldehydes

Plastics, adhesive resins, ENT irritant, nausea and dizziness

Microorganisms VOC - Molds, bacterias

CO, NOx, and O3 (Usually associated with outdoor air pollutions

CO and NOx - Kerosene heaters, stoves Ozone – Copy machines

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Control1. Ventilation2. Exclusion and removal3. Product Selection4. Maintenance

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ControlPollutant Ventilatio

nExclusion

& Removal

Product Selection

Maintenance

Radon Cigarette Smoke

Asbestos Toxic Chemicals

Inorganic Bases

Micro-organisms

Reference: Dubeck et al, “A world View of environmental Issues”, Saunders College Publishing, 2nd Ed. , 1998

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Regulations Practically nonexistent

Except for radon, asbestos, CFC, and tobacco smokes (state level)

1993: Indoor Air Quality Act (passed by senate but not acted by the House)

Voluntary Standards (industry specific)

EPA (Outdoor only) TSCA (Chemical Substances) OSHA (Significant Risk in the Workplace) CPSA (Consumer products)

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Remedy Most common is litigation under

Common Law Out of court settlements

State Workman Compensation

NEED FEDERAL LEGISLATION

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Internet Resources EPA (

http://www.epa.gov/iaq/pubs/targetng.html)

OSHA (www.osha.gov) World Health Organization (WHO) (

www.who.ch) State of Environments in Different

Countries (http://www.unep.org/unep/soe.htm)