Chapter 16: Air Pollution Flashcards
According to the EPA how many millions of tons of air pollution are released into the atmosphere each year in the U.S?
147 million tons; Not including carbon dioxide or wind-blown soil
Due to legislative acts, which developed countries have reduced air pollution in the last 30 years?
Europe, North America, and Japan
Which country has the most air pollution?
China
How many of the world’s smoggiest cities are in China?
7 out of 10
The word pollution comes from which Latin word?
Pollutus
What does pollutus mean?
Dirty or unclean
What are 5 examples of natural air pollution?
Volcanoes, sea spray, trees, pollen and spores, and viruses and bacteria
Primary Pollutants
Pollutants released directly into the air in a harmful form
Secondary Pollutants
Formed by chemical reaction that occur in mixing air. Become harmful after reaction. Solar energy often provides the energy for reaction.
Fugitive Emissions
Pollutants that don’t go through a smokestack. The most massive is dust. Dust comes from soil erosion, mining rock crushing, and building construction. Fugitive emissions also come from leaks in equipment.
Clean Air Act of 1970
Designated 7 major pollutants with mandated levels
What are the 7 “conventional” or “criteria” pollutants considered to be the most harmful to human health and welfare?
- Sulfur dioxide
- Nitrogen oxides
- Carbon monoxide
- Particulates (aerosols)
- Hydrocarbons
- Photochemical oxidants
- Lead
Catalytic Converter
Device attached to the exhaust system of a motor vehicle to eliminate CO (carbon monoxide). Half of the CO released in the U.S. comes from motor vehicles. These devices also help eliminate NO2 (nitrogen dioxide) from auto exhaust.
Scrubbers
Used in smokestacks. Use fine mists of CaCO3 (Calcium carbonate) or CaO (Calcium oxide) solution to wash pollutants out of smoke.
Electrostatic Precipitator
Removes particles by putting a negative charge on them, attracting them to plates to be scraped off later. Good for removing PM-10 (particulate matter smaller than 10 mm in size).
What are examples of primary pollutants?
Carbon Monoxide (CO) Carbon Dioxide (CO2) Nitrous Dioxide (NO2) Nitrous Oxide (NO) Sulfur Dioxide (SO2) Most hydrocarbons and suspended particles
What are examples of secondary pollutants?
Sulfuric Acid (H2SO4) Sulfur Trioxide (SO3) Nitric Acid (HNO3) Ozone (O3) Hydrogen Peroxide (H2O2) Most Nitrates (NO3) and Sulfate ions (SO4-2)
Photochemical Smog
The unpleasant brown air pollution that sits over most large cities on warm, sunny days. (Brown haze)
What are sources of photochemical smog?
Cars and sunlight
Heat Island Effect
Increased heat in large cities due to machinery, buildings and lack of natural surroundings.
Temperature Inversion
Traps pollutants, warm air sits atop cooler air preventing the cool air from rising.
Acid Deposition
Occurs when oxides of sulfur and nitrogen are oxidized (combine with oxygen) in the atmosphere then react with water vapor and form acids.
Acid deposition is usually not as much of a problem at the source, but miles downwind. (Sources have been identified hundreds of miles away.)
Acidic particulates creates what?
Acid rain, snow, sleet, hail and fog
What are examples of the acids deposited?
Sulfuric acid (H2SO4) and sulfate ions (SO4-2) Nitric acid (HNO3) and nitrate ions (NO3-)
