© 2009 Delmar, Cengage Learning Chapter 4 Air

© 2009 Delmar, Cengage Learning Bell Work: 1) What are the major sources of pollution in the air? 2) What are some issues these pollutants cause?

© 2009 Delmar, Cengage Learning Life on Earth Life depends on air, water, and soil –Slight changes may occur in composition Changes favor some organisms Other organisms diminish in number

© 2009 Delmar, Cengage Learning Life on Earth Air –colorless, odorless, and tasteless mixture of gases 78 percent nitrogen 21 percent oxygen 1 percent mix of other gases

© 2009 Delmar, Cengage Learning Air Quality Air is essential for life –Humans require approximately 21 percent oxygen –Brain will die in approximately 4 to 6 minutes if deprived of oxygen

© 2009 Delmar, Cengage Learning Air Quality Air is a shared resource –Air currents move air around the world –We cannot control the air currents –Therefore we have a responsibility to control what goes into it

© 2009 Delmar, Cengage Learning Threats to Air Quality sulfur compounds hydrocarbons nitrous oxides and lead carbon monoxide radon gas radioactive dust chlorofluorocarbons (CFCs) pesticide spray materials others

© 2009 Delmar, Cengage Learning Sulfur Naturally occurring pale yellow element Found in –coal and crude oil When these are burned, sulfur is released –combines with moisture in atmosphere –forms sulfuric acid = acid rain –damages trees, plants, and metals

© 2009 Delmar, Cengage Learning Hydrocarbons By-products of combustion or burning –Could be a major problem Because of prevalence of vehicles and factories

© 2009 Delmar, Cengage Learning Hydrocarbons Effects of combustion can be minimized by –stack scrubbers in industrial plants –crankcase ventilation –exhaust gas recirculation –air injection –engine refinements

© 2009 Delmar, Cengage Learning Nitrous Oxides and Lead Compounds containing nitrogen and oxygen –5 percent of pollutants in automobile exhaust –most difficult and costly to remove Catalytic converters help

© 2009 Delmar, Cengage Learning Nitrous Oxides and Lead Before 1986, all gasoline contained lead –Tetraethyl lead = poisonous product still used in developing countries Major pollutants but declining

© 2009 Delmar, Cengage Learning Carbon Monoxide Colorless, odorless, and deadly poisonous gas –Beware of leaky exhaust systems running engine in enclosed space Reducing CO emissions –Engines should be in good repair and properly tuned

© 2009 Delmar, Cengage Learning Radon Colorless, radioactive gas –formed by disintegration of radium –usually escapes at low, harmless rates Sometimes houses constructed over radon source –Gas enters through basement cracks or sump holes –Must seal cracks or continuously ventilate house

© 2009 Delmar, Cengage Learning Radioactive Dust and Materials Material emitting radiation –dust from atomic explosion –materials contaminated by atomic accidents

© 2009 Delmar, Cengage Learning Radioactive Dust and Materials Damage from radiation includes –skin burns –sickness –heredity damage –death

© 2009 Delmar, Cengage Learning Video: 1DNjJd2YfAhttps:// 1DNjJd2YfA

© 2009 Delmar, Cengage Learning Next: You have an activity to work on that goes over air pollution. You need to finish the first part in class, and the second part I will post on the website for your homework.

© 2009 Delmar, Cengage Learning Chlorofluorocarbons (CFCs) Highly stable group of compounds consisting of –chlorine, fluorine, carbon, and hydrogen –Used as aerosol propellants and refrigeration gas Migrate up into atmosphere, where chlorine atoms destroy ozone Being replaced by less-polluting agents

© 2009 Delmar, Cengage Learning Ozone Layer Located approximately 15 miles above Earth –Filters out harmful ultraviolet radiation

© 2009 Delmar, Cengage Learning CFCs and Ozone Layer Evidence suggests ozone layer is decreasing because of CFCs –Problems with skin cancer, immune system International conference in 1987 –agreed to cutbacks in CFCs

© 2009 Delmar, Cengage Learning Ozone “Hole” Chlorine atoms of CFCs destroy ozone Scientist have seen effect over south pole –Ozone is less dense or thinner –Referred to as the “hole in the ozone layer” –known to cause skin damage –linked to increased rates of skin cancer

© 2009 Delmar, Cengage Learning Particulates Small particles suspended in air –appear as smoke or dust clouds –tiny, light-weight particles –harmful to respiratory disease sufferers Can be removed from gas emissions by –scrubbing –electrostatic precipitators

© 2009 Delmar, Cengage Learning Pesticide Spray Materials Materials used to control pests –Chemicals mixed with water and sprayed Pollutants if they contain toxic materials –or if harmful to more than target Generally harmful to the air –if not used exactly as specified by government and the manufacturer

© 2009 Delmar, Cengage Learning Asbestos Heat- and friction- resistant material –used extensively in the past brakes, clutch, shingles, insulation, ceiling panels Asbestos fibers damaging to lungs –cause disease and death State and federal laws require removal

© 2009 Delmar, Cengage Learning Asbestos can contribute to cancer

© 2009 Delmar, Cengage Learning Bell Work: 1) What is “the greenhouse effect”? 2) What causes it?

© 2009 Delmar, Cengage Learning Next: I have a interests survey I want you to take, then, I want you to share what you want to see in this class this year. Then, we will continue on with class for the day.

© 2009 Delmar, Cengage Learning Air pollution can change the genetic makeup of a population England in 1800s: burning coal –Air polluted with dark soot that settled and darkened bark of trees Moths hide on bark –Soot darkened the bark over time –Light moths were easily spotted by predators –Over time darker moths increased

© 2009 Delmar, Cengage Learning

Can air pollution change the genetic makeup of the human population? Hole in ozone poses greater risk for people with less natural protection from UV damage How might human population change over time?

© 2009 Delmar, Cengage Learning Greenhouse Effect Sunlight passes through clear object (glass), which absorbs energy –Heats builds up in air on opposite side –Observed under skylights, auto windshields, greenhouses On Earth, the atmosphere acts as clear object –Sunlight passes through atmosphere warms surface of Earth –Surface radiates and reflects heat –Atmosphere traps heat in Earth’s climate is warmed

© 2009 Delmar, Cengage Learning

Greenhouse Gases Carbon Dioxide (CO 2 ) –May account for approximately 50 percent of global warming by 2020 –Product of combustion Combustion sources –manufacturing, automobiles, electricity production, air conditioners, small engines

© 2009 Delmar, Cengage Learning Greenhouse Gases Green plants absorb CO 2 –However, plants being removed around planet –But expulsion of CO 2 increasing

© 2009 Delmar, Cengage Learning Greenhouse Gases Chlorofluorocarbons –Damage ozone –CFC use has decreased –However, CFCs still escape and affect ozone May account for approximately 25 percent of global warming by 2020

© 2009 Delmar, Cengage Learning Greenhouse Gases Methane –Comes from naturally decaying plant materials Many sources, both human-made and natural –Can be captured and used as fuel Some large farms capture gas from manure Use gas to fuel generators = electricity

© 2009 Delmar, Cengage Learning Greenhouse Gases Methane –May account for approximately 15 percent of global warming by 2020

© 2009 Delmar, Cengage Learning Greenhouse Gases Nitrous Oxide (N 2 O) –Troublesome pollutant from gasoline engines increasing numbers of gasoline engines increasing additions of nitrous oxide –May account for approximately 10 percent of global warming by 2020

© 2009 Delmar, Cengage Learning Next: I want you to use your phones to research pollution causes in our area and send your summary on the article to my classroom twitter I will put the account up on the smartboard so the whole class can see. You must send one tweet by the end of class today to receive full credit. If you finished your CO2 packet, turn it in today. If you haven’t yet, it needs to be turned in by Friday for full credit.

© 2009 Delmar, Cengage Learning Do First: Answer the following questions by either writing them down or sending them to me on Twitter: 1) Name two causes of global warming (be specific). 2) Name two effects global warming has on not just the environment but also the economy.

© 2009 Delmar, Cengage Learning Climate Change Evidence indicates that heat is building up –Creating changes in average global temperature –Warming trend: serious environmental threat Scientists are sounding an alarm –We must reduce or stabilize greenhouse effect

© 2009 Delmar, Cengage Learning Climate Change Accumulation of greenhouse gases concerns most scientists –Recent upward trend in temperature –Evidence of dangerous warming of global environment –Human activity seems to be contributing factor

© 2009 Delmar, Cengage Learning Climate Change Risks associated with climate change justify action Evidence suggests a human influence on climate –Scientists are calling for early action –Global reduction of greenhouse gas emissions beginning immediately

© 2009 Delmar, Cengage Learning Climate Change Financial as well as environmental advantages in acting on greenhouse gas emissions –Greenhouse gas-reduction policies Many have benefits that outweigh costs

© 2009 Delmar, Cengage Learning Atmospheric Ozone High-altitude ozone good –Protects planet from ultraviolet radiation

© 2009 Delmar, Cengage Learning Surface-Level Ozone Ozone near planet surface decreases air quality –decreases crop yields –$1 billion/year to lost crop yields –Cutting ozone by 40 percent = extra $2.78 billion

© 2009 Delmar, Cengage Learning Maintaining and Improving Air Quality Stop using CFCs. Provide adequate ventilation in buildings. Check buildings for radon gas. Use exhaust fans to remove indoor pollutants.

© 2009 Delmar, Cengage Learning Maintaining and Improving Air Quality Clean and service furnaces, air conditioners, and ventilation systems regularly. Remove sawdust, wood chips, paint spray, welding fumes, and dust to assure systems function at most efficient levels.

© 2009 Delmar, Cengage Learning Maintaining and Improving Air Quality Keep gasoline and diesel engines properly tuned and serviced. Keep all emissions systems in place and properly serviced on motor vehicles.

© 2009 Delmar, Cengage Learning Maintaining and Improving Air Quality Observe all codes and laws regarding outdoor burning. Report any suspicious toxic materials to police or other authorities. Reduce the use of pesticide sprays as much as possible. Use pesticide spray according to label directions.

© 2009 Delmar, Cengage Learning Regulating Air Quality Laws exist to –prevent loss of air quality –clean up air quality problems

© 2009 Delmar, Cengage Learning Regulating Air Quality Clean Air Act –1963, 1967: reductions in industrial pollution –1970: eliminate tall smokestacks, requires plans –1970, 1990: new agencies to interpret and enforce laws

© 2009 Delmar, Cengage Learning

Next: We are going to watch a video on how climate change is affecting the Antarctic. You will need to write down at least 10 facts about the video and be prepared to write a summary on the video when it is finished.

© 2009 Delmar, Cengage Learning Exit Slip 10/2 1.Name two methods to maintain and improve air quality. 2.For each method, state how it improves air quality (what type of air pollution does it address?)