Chapter 4 Air 2009 Delmar Cengage Learning Bell

Bell Work: • 1) What are the major sources of pollution in the air?

Life on Earth • Life depends on air, water, and soil – Slight changes

Life on Earth • Air – colorless, odorless, and tasteless mixture of gases •

Air Quality • Air is essential for life – Humans require approximately 21 percent

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 © 2009 Delmar, Cengage Learning • radioactive dust • chlorofluorocarbons (CFCs) • pesticide spray materials • others

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 •

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 –

Radioactive Dust and Materials • Damage from radiation includes – skin burns – sickness

Video: • https: //www. youtube. com/watch? v=1 DNj. Jd 2 Yf. A © 2009

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

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 frictionresistant 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?

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 1800 s: 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

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

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 account @Ms. Halbohm. • 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 CO 2 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

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 –

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? ) © 2009 Delmar, Cengage Learning