Chapter 2
• Air
• Chapter 2
• The Air Pollution Problem
• Air is a mixture of gases.
– Nitrogen ____ and Oxygen ___ followed by trace amounts of Argon, CO2, and WV.
• Air pollution is the contamination of the atmosphere by wastes from sources such as industrial burning and automobile exhausts.
• Earliest reference to air pollution dates back to ______.
• All major air pollution disasters have occurred in industrialized areas.
• Substances that pollute the air can be in the form of solids, liquids, or gases.
• Most air pollution is the result of human activities, but some pollutants are natural, including dust, pollen, spores, and sulfur dioxide from volcanic eruptions.
• Primary and Secondary Pollutants
• A primary pollutant is a ______by human or natural activity. An example would be soot from smoke.
• A secondary pollutant is a pollutant that forms in the atmosphere by ______. An example would be ground-level ozone.
• Ground level ozone forms when the emission from cars react with the UV rays of the sun and then mix with the oxygen in the atmosphere
• Outdoor Pollutants
• Particulates – ______.
– Ex. Ash, dust, and traces of metals.
• Oxides – ______.
– Forms acid when it chemically reacts with water.
– Most of the gaseous pollutants come from these chemicals.
• Photochemical Smog – ______.
• ______(CFCs) – compounds of C, Cl, and F once used in refrigerators, air conditioners, aerosol cans, and in the production of polystyrene.
• Smog
• Smog is urban air pollution composed of a mixture of smoke and fog produced from industrial pollutants and burning fuels.
Smog results from chemical reactions that involve sunlight, air, automobile exhaust, and ozone.
Pollutants released by vehicles and industries are the main causes of smog.
• Indoor Pollutants
• Improving air circulation can reduce the amount of pollutants in your home.
• The combination of particulates, gases, and other chemicals contained in cigarette smoke makes ______.
• Radon System-______
• Short-Term Effects of Air Pollution on Health
• Many of the effects of air pollution are short-term and reversible if their exposure to air pollution decreases.
• For example: headache; nausea; irritation to the eyes, nose and throat; coughing; tightness in the chest; and upper respiratory infections, such as bronchitis and pneumonia.
• Pollution can also make the conditions of asthma and emphysema worse for certain individuals.
• Long-Term Health Effects of Air Pollution
• Long-term effects on health that have been linked to air pollution include ______.
• Long-term exposure to air pollution may worsen medical conditions suffered by older people and may damage the lungs of children.
• Air Pollution and Living Things
• Air pollution has been linked to many health problems.
• Carbon Monoxide (CO) – prevents ______hemoglobin reducing it from reaching cells and resulting in stress and death at high levels.
• Cigarette smoking is a factor in causing lung cancer, emphysema, and heart disease.
• Asbestos
• Asbestos is ______-.
• Asbestos is primarily uses as an insulator and as a fire retardant, and it was used extensively in building materials.
• However, for all of its uses, the government banned the use of most asbestos products in the ______.
• Asbestos fibers can cut and scar the lungs, causing the disease asbestosis.
• Victims of the disease have more and more difficulty breathing and may eventually die of heart failure.
• Other Health Issues
• Emphysema – ______.
• Cancer – ______.
• The US loses up to $10 Billion worth of crops each year because of air pollution.
• Industrial air pollutants can contaminate farmland and grazing areas leading to high levels of lead and zinc.
• Global Effects of Air Pollution
• Three major air pollution problems threatening the global environment:
– Acid Precipitation
– Ozone Depletion
– Global Warming
• A temperature inversion is the atmospheric condition in which ______.
The warmer air above keeps the cooler air at the surface from moving upward. So, pollutants are ______.
If a city is located in a valley, it has a greater chance of experiencing temperature inversions (as seen in LA).
• What Causes Acid Precipitation?
• Acid precipitation is precipitation, such as rain, sleet, or snow, that contains a high concentration of acids, often because of the pollution of the atmosphere.
• When fossil fuels are burned, they ______.
• When these oxides combine with water in the atmosphere they form ______.
• Acid Precipitation
• Acid precipitation has become more common in the last 200 years due to ______-.
• What Causes Acid Precipitation?
• This acidic water flows over and through the ground, and into lakes, rivers, and streams.
• Acid precipitation can kill living things, and can result in the decline or loss of some local animal and plant populations.
• What Causes Acid Precipitation?
• A pH number is ______(basicity) of a system.
• Each whole number on the scale indicates a tenfold change in acidity.
• A pH of ______, a pH of ______, and a pH of ______.
• Pure water has a pH of ______, while normal precipitation has a pH of about ______.
• What Causes Acid Precipitation?
• Normal precipitation is slightly acidic because atmospheric carbon dioxide dissolves into the precipitation and forms carbonic acid.
• Precipitation is considered acid precipitation if it has a pH of ______
• The pH of precipitation in the eastern U.S. and Canada ranges from ______, with the most acidic precipitation occurring around Lake Erie and Lake Ontario.
• Acid shock is ______.
• This phenomenon causes large numbers of fish to die, and affects the reproduction of fish and amphibians that remain. They produce fewer eggs, and those eggs often do not hatch. The offspring that do survive often have birth defects and cannot reproduce.
• International Conflict
• One problem in controlling acid precipitation is that pollutants may be released in one geographical area and fall to the ground hundreds of kilometers away.
• For example, much of the acid precipitation that falls in southeastern Canada results from pollution produced in the northeastern United States.
• Ozone Depletion
• O3 – Ozone Gas
• Atmospheric ozone helps life on Earth by ______.
• Found in the ______.
• ______gas on Earth’s surface.
• Hole in the Sky
• Early 1980’s, scientists discovered a thin area, or hole, in the ozone layer over the South Pole.
• UV radiation can cause sunburn, blindness, and skin cancer as well as severe crop damage.
• Causes of Ozone Depletion
• Ozone depletion will continue because ______.
• Chlorine and fluorine are the atoms responsible for destroying ozone molecules.
• Global Warming
• Light energy enters the atmosphere and is absorbed at the surface. Light energy is changed to heat. Heat energy is radiated back to space in the form of infrared radiation.
• The Greenhouse Effect
• CO2 is the most significant greenhouse gas emitted in large quantities by humans.
• Greenhouse effect got its name because heat is ______.
• Ice cores – long cylinders of ice that are drilled and removed from deep within a sheet of polar ice.
• Ways to reduce Greenhouse Gases in the atmosphere:
– Electric Cars
– Solar Power
– Increasing Fuel Efficiency Standards
• Effects of Greenhouse Gas Pollution
• During the past 150 years, levels of atmospheric CO2 has increased due to increased fossil fuel use.
• Global Warming – an increase in Earth’s average surface temperature caused by an increase in greenhouse gases.
• Some computer models project that Earth’s temperatures will rise by 2 – 4 degrees C.
• Ice Caps will melt, coastal areas will flood, weather patterns will change, salt water will enter freshwater aquifers.
• 22.4 Controlling Air Pollution
• The Clean Air Act, passed in 1970 and strengthened in 1990, gives the Environmental Protection Agency (EPA) the authority to regulate vehicle emissions in the United States.
• The EPA required the gradual elimination of lead in gasoline, decreasing lead pollution by more than 90 percent in the United States.
• In addition, catalytic converters, required in all automobiles, clean exhaust gases of pollutants before pollutants are able to exit the tail pipe.
• The ______requires many industries to use scrubbers or other pollution-control devices.
• Scrubbers remove some of the more harmful substances that would otherwise pollute the air.
• ______is a machine that moves gases through a spray of water that dissolves many pollutants. Ammonia is an example of a pollutant gas that can be removed from the air by a scrubber.
• ______are machines used in cement factories and coal-burning power plants to remove dust particles from smokestacks.
• In an electrostatic precipitator, gas containing dust particles is blown through a chamber containing an electrical current.
• An electric charge is transferred to the dust particles, causing them to stick together and to the sides of the chamber.
• Natural Air Pollution Controls
• Precipitation is the most effective natural method of removing particulates and aerosols from the air.
• Two ways to remove CO2:
– ______
– ______