1. Water Pollution
Notes 3

2. Outdoor Air Pollution
Subtitle

3. Sources
Ambient air pollution is air borne waste from everyday activities
Can be natural or man made
Natural Sources
Volcanic eruptions release particles as well as sulfur dioxide and other gas
Fires from burning vegetation
Winds can kick up dust in dry regions
Man Made Sources
Can be mobile or stationary and point source or non-point source
Coal plant would be point source and stationary
Cars would be a mobile non-point source
Pollutants can either be harmful directly or cause chemical reactions that cause harmful compounds
Primary pollutants include soot and carbon monoxide and can react to form harmful substances
Secondary pollutants are made from reactions from primary pollution such as tropospheric ozone or sulfuric acid

4. Sources Residence time is how long a substance remains in the air
Depends on how they react with air and how quickly they settle to the ground
Brief residence times exert localized impacts
Long residence times exert impacts regionally or globally – drive global climate change because they deplete ozone

5. Types of Pollution and Issues Posed
Toxic air pollutants are known to cause cancer, reproductive defects, neurological developmental, immune system, or respiratory problems
Monitor 188 different toxic air pollutants
300 monitoring sites that map the toxins and help with risk assessment for different diseases
Smog is our most common air quality problem
Industrial smog from coal or oil burning by-products such as soot and the chemicals found in coal and oil
Photochemical smog formed when sunlight drives chemical reactions between primary pollutants and normal atmospheric compounds – Found predominantly in urban areas
Synthetic chemical deplete stratospheric ozone
Halocarbons – Hydrocarbons that halogens have replaced the hydrogens
CFCs: chlorofluorocarbons which has been severely limited in use due to the extremely detrimental effects

6. Types of Pollution and Issues Posed
Rural areas see air pollution as well
Drift from cities
Pesticides that enter the air
A lot of rural pollution comes from feedlots
Acid Deposition
Also known as acid rain, when acid reaches the Earth’s surface from the atmosphere by some means whether through precipitation or particulates settling
Acid deposition has many impacts
Cumulative effects on the environment
Leeches nutrients from the soil
Mobilizes toxic metal ions such as zinc, mercury, and copper by making them soluble
Acidifies bodies of water

7. Clean Air Act
Subtitle

8.
Legislation
Starting in the 50s, the US began looking at improving air quality through research and laws
Clean Air Act of 1970 created stricter standards, imposed emissions limits for new stationary and mobile sources of pollution
1995 Businesses were only allowed certain amounts of emissions and were able to sell and trade those allowances
Saw a decrease in sulfur dioxide emissions
Spawned similar cap-and-trade programs for other pollutants like greenhouse gasses
EPA has national standards but its up to the states to monitor

9. EPA sets standards for “Criteria Pollutants”
Criteria pollutants are pollutants judged to pose a threat to human health
Carbon Monoxide
Colorless, odorless gas produced by vehicles and engines – 78%
Factories and burning materials release this gas as well
Binds in an irreversible manner to hemoglobin blocking oxygen
Sulfur Dioxide
Colorless but pungent gas
Most comes from burning coal
Forms sulfur trioxide and sulfuric acid that settles back to Earth as acid deposition
Nitrogen Dioxide
Highly reactive, foul-smelling reddish brown gas that contributes to smog
Made in combustion engines

10. EPA sets standards for “Criteria Pollutants”
Tropospheric Ozone
Human activity forms ozone in the lower portion of the troposphere that acts as a pollutant
Secondary pollutant because it reacts with other components like sunlight, nitrogen oxides and volatile carbon-containing compounds
O3 can react and lose an oxygen molecule. That free molecule can injure living tissue
Particulate Matter
Solid or liquid that can be suspended in the atmosphere
Can damage respiratory tissue when inhaled
EPA classifies them by size
PM10 – 10 microns includes dust
PM2.5 – 2.5 microns includes pollution from combustion

11. EPA sets standards for “Criteria Pollutants”
Lead
Enters as a particulate pollutant
Tetraethyl lead and tetramethyl lead added to gasoline to improve engine performance but enters the atmosphere
Can enter the food chain and accumulate in body tissue causing nervous system issues
Lead has been phased out of gas in the US in the 80s
EPA monitoring finds a large number of Americans live in areas that exceed the concentration of critical pollution or where they regularly reach unhealthy levels

12. Agencies monitor emissions
Not only are the six criteria pollutants monitored, so are other pollutants that affect those criteria pollutants
Look at volatile organic compounds (VOCs)
Carbon-containing chemicals that are used in and emitted by vehicles and a wide variety of solvents, household chemicals, consumer items, and industrial processes
Hydrocarbons such as methane (natural gas), butane (lighter fluid), propane and octane (component of gasoline)
Human activity accounts for about half of VOC emissions while the rest is naturally occurring

13. Cleaning up and Preventing Pollution

14. Reducing Pollution Smog The Montreal Protocol
Having catalytic converts on cars to reduce pollution
Incentives for people to replace old cars or reduce amount of driving
Maps and information boards are posted in smog ridden areas
Expanded mass transportation
The Montreal Protocol
1987 treaty to reduce CFCs
Various additional agreements have been over the years for other pollutants and most have been phased out of products since then
However, due to the long residence time of many halocarbons, effects to the environment can persist long after regulations have been put in place
Also, there is no way to force countries to comply with global regulations but the Montreal Protocol has been considered a success in addressing global environmental problems for several reasons
Research developed rapidly
Engaged industries to help
Testing many methods and implementing the best options