1. Monitoring air quality Lesson Objective: Students will identify chemical factors in the environment that might affect the health and distribution of living things,

2. Take a deep breath…  The air you breath is mainly nitrogen (78%), and oxygen (21%), carbon dioxide (0.03), argon (less than 1%), and traces of hydrogen and neon.

3. If you took a deep breath in Beijing you might find the air irritates your throat (and eyes).  These would be indications of poor air quality.

4. Studies have linked toxic air pollution in Southern California to cancer and complications with birth.  By measuring pregnant women's exposure to chemicals emitted by local traffic (nitrogen oxides and particulate matter), researchers found the risk for preeclampsia increased by as much as 42% at the highest exposures. The risk for "very preterm delivery” increased by as much as 128% for women exposed to the highest levels.

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7. Edmonton  At times Alberta Health Services issues an advisory because of temperature “air-inversion events.”

8. Temperature inversion…  Occurs when the cold air is near the ground and there is a layer of warmer air above it.  The cold air isn’t able to rise or mix and pollutants are able to build up.  Inversions are common during the fall and winter in Alberta.

10. Like water quality, air quality is determined by the # of potentially harmful Chemicals.  Air quality can be determined by:  Measuring the levels of pollutants in the air.  Estimating the amount of emission from pollution sources.

11. Sulfur Dioxide (SO 2(g) )  Is a major air pollutant that forms both smog and acid rain.  It can affect your respiratory system (throat and lungs) and irritate your eyes.

12. Major source of of sulfur dioxide is industrial processes.  In Alberta, the major source is the oil and gas industry.  Sulfur dioxide, and other oxides, form when oxygen combines with sulfur.

13. Scrubbers  Industrial and electrical generating plants use devices called scrubbers to reduce sulfur dioxide emissions by up to 99%.

14. Scrubbers use limestone (calcium carbonate) to convert SO 2 into a useful product.  Sulfur dioxide reacts with calcium carbonate to produce gypsum (calcium sulfate). Gypsum can be used in manufacturing (gypsum board/plaster board).

15. Sulfur Dioxide and Limestone Reaction

16. Nitrogen oxides  NO x(g) are also major pollutants that form both smog and acid rain, and affect the respiratory system and eyes.  “x” indicates that nitrogen oxides are mixtures of NO (g) and NO 2(g), and sometimes other oxides of nitrogen.

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18. Nitrogen monoxide gas  Happens when nitrogen formed by burning fuels combines with oxygen.  This then combines with oxygen in the atmosphere to to form nitrogen dioxide, which is a brownish gas.  This is the gas that gives smog its distinctive colour. 18

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20. Carbon monoxide  Called the silent killer because it is a colourless and odourless gas.  The main source of carbon monoxide from human activities is motor vehicles. Other sources are the combustion of wood (fireplaces, wood stoves) and natural gas, industrial processes, airplanes, and even cigarette smoking. 20

22.  If inhaled, carbon monoxide reduces the amount of oxygen carried by the blood. 22

23. Carbon Monoxide Poisoning  Can cause headaches, sleepiness, chest pains, brain damage and death.  Technologies such as catalytic converters convert carbon monoxide into carbon dioxide. 23

24. Ground level Ozone  Is a harmful pollutant (unlike in the upper atmosphere where it protects from ultraviolet light).  So the chemical, ozone, is an example of how a chemical may be beneficial in one situation, and harmful in another. 24

25. Ozone (O 3(g) ) is an odourless, colourless gas with 3 oxygen atoms.  At ground level, it forms from reactions between oxygen, nitrogen oxides, and compounds called volatile organic compounds (VOCs).  In the presence of sunlight, VOCs are organic compounds that evaporate easily.  Some plants and trees emit VOCs, but most VOCs come from human-made products such as solvents and gasoline. 25

26. Some cities…  Issue warnings on days where ozone levels are expected to be high so people with respiratory problems can stay indoors.  Ozone is especially harmful to people with lung diseases such as asthma, and anyone with a cold.  Children are at higher risk because their lungs are still developing. 26

28. Ground level ozone  Can seriously harm crops such as wheat, soybeans, and onions.  It can also cause materials, such as plastics, to deteriorate more rapidly. 28

29. Monitoring the Atmosphere  Carbon Dioxide as a Greenhouse Gas: One person (breathing), one car, and one bonfire don’t add much carbon dioxide into the air.  But consider the huge amount of carbon dioxide added to the atmosphere by billions of people, millions of cars, and millions of fires worldwide. 29

30. The Greenhouse effect 30

31. Life on earth thrives because we live in a natural greenhouse.  Some gases in the atmosphere act like the glass in a greenhouse.  They trap heat from the Sun’s radiant energy.  This heat keeps Earth at temperatures that allow things to live, grow and reproduce. 31

32. The atmospheric gases that trap heat are called greenhouse gases.  Water vapour, carbon dioxide, methane and nitrogen oxides are all greenhouse gases. 32

33. The enhanced greenhouse effect.  Many scientists support the theory that human activities, such as burning fossil fuels and clearing the land, contribute to an enhanced greenhouse effect.  The greater concentration of gases traps even more heat, and this increases the overall temperature on Earth.  This temperature increase worldwide is called global warming. 33

34. Effects of global climate change:  More violent storms, flooding of coastal areas from melting icecaps, and greater ranges in the spread of diseases. 34

35. Global Warming  Scientists have concluded that global warming is taking place and that it is caused at least in part by human activities.  Natural elements such as volcanic eruptions and forest fires may also play be a part of the cause of global warming.  Some countries have started to reduce carbon dioxide emissions. 35

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37. The Ozone Layer  Is a natural formation of ozone 15 to 50 km above the Earth’s surface.  Has been monitored by scientists since the 1970s.  The layer is becoming thinner, allowing more UV radiation to reach Earth’s surface.  Some areas are so thin that they are called “holes” in the ozone. 37

38. Harmful effects:  Increased occurrence of skin cancer and cataracts.  Organisms like plankton are sensitive to UV exposure, so increased UV radiation can cause plankton to die.  This would affect all animals that feed on plankton. 38

39. The role of Chlorofluorocarbons  The thinning of the ozone layer is caused by our use of chemicals called chlorofluorocarbons (CFCs).  Refrigerators, aerosol cans, fire extinguishers, air conditioners- all use CFCs.  The chemicals move from the lower atmosphere where we use them, to the upper atmosphere. 39

40. In the upper atmosphere…  UV radiation breaks CFCs down into substances, such as chlorine, that destroy ozone.  One chlorine atom can remove 100 000 ozone molecules.  There is a “hole” over the south pole. Extremely cold temps in that area cause ice particles to form in the upper atmosphere, which speeds up the reaction that removes the ozone molecules. 40

41. Many countries recognize the danger…  To the ozone from the use of CFCs, and they have signed international agreements on reducing their use of these chemicals.  Monitoring substances such as CFCs is an important step in reducing their harmful effects. 41

42. Carbon Capture  Carbon dioxide is captured and injected into depleted oil reservoirs for enhanced oil recovery (EOR).  A major concern is leakage of captured/sequestered carbon dioxide. 42

44. Complete:  Check & Reflect, page 228, #s 1-7  Check & Reflect, page 233, #s 1-8 44