1. The Pollution Problem

2. Upsetting the Balance The balance of the environment can be upset by how humans obtain + use natural resources Use renewable natural resources faster than they can be replaced Damage one resource in the process of obtaining or using another

3. Pollution Pollution is the introduction of harmful products or substances into the environment. Most pollution is the result of human activities.

4. The Trail of Pollution To make a can of soda… The aluminum must be removed from the ground, where digging scars the land. Chemicals used in the factory to produce aluminum become waste that is discarded and ends up in a river as pollutants. The fuel burned to make the aluminum into a can produces smoke that pollutes the air. The process used to make the soda to go into the can also produces pollutants. The consumer buying the can disposes of it as litter, another form of pollution.

5. Sources & Solutions Large amount of pollution is tied directly to energy use. Heavy dependence on fossil fuels Activities involved in finding and using them have led to land, air, and water pollution Solutions: New ways to regulate + reuse materials Alternative energy to replace fossil fuels

6. Main Types of Pollution Land Air Water

7. Land Pollution Most of energy used (90%) comes form fossil fuels Solar, wind, water and other alternative energy resources = 5% Nuclear energy = 5% Obtaining both fossil fuels and nuclear energy can pollute the Earth

8. Coal Coal mining near the surface badly damages the land and causes soil and land pollution Fertile topsoil is buried under tons of rock When rock is exposed to precipitation, acids and other harmful chemicals seep into the ground, polluting the soil and land

9. Hazardous Wastes Wastes from factories may pollute the land with toxic chemicals, called hazardous wastes Can cause death or serious damage to human health When improperly stored in barrels buried in dumps by factories, the wastes seep into the soil

10. Management of Hazardous Wastes Best solution is to produce less hazardous wastes! In some cases, industries can reuse the wastes Other wastes might be chemically treated to change the toxic substances they contain into nontoxic substances

11. Radioactive Wastes Radioactive wastes – wastes produced as a result of the production of energy in nuclear power plants. Classified as either high-level or low-level High-level wastes = used fuel rods from a nuclear reactor Low-level wastes = contaminated equipment used in the power plant

12. Disposing of Radioactive Wastes Low-level wastes decay quickly High-level wastes may have half-lives of 10,000 years or more! In the past, high-level wastes were sealed in concrete or glass containers. The containers usually began to corrode or leak.

13. New Methods of Disposal Wastes can be buried in rock formations = geologic disposal Disposal in ocean beds is another alternative Some scientists have suggested shooting rockets carrying high-level wastes into the sun

14. Solid Wastes Solid wastes – useless, unwanted or discarded materials (garbage) Include agricultural wastes, commercial and industrial wastes, and household wastes Americans produce about 11 billion tons of solid wastes every year

15. Sanitary Landfills Cover solid waste dumps with thick layers of soil All garbage is compacted and covered at least once a day with a layer of soil Once filled they can be used as parks

16. Problems with Landfills When compacted garbage begins to decompose and methane gas is produced, it burns easily and is a fire hazard Wastes can ooze out of landfills and pollute the surrounding soil The biggest problem is finding a place to put them

17. Burning Garbage Burning garbage in open dumps and incinerators was once used Releases harmful gases, so the practice is being halted. Some buildings use waste-to-energy incinerators. The heat produced converts water into steam which is then used to generate electricity or heat the building.

18. Recycling Solid Waste Most environmentalists prefer recycling Recycling not only gets rid of solid waste but also creates useful materials

19. Air Pollution Main causes of air pollution = release of carbon dioxide into the atmosphere Due to deforestation + fossil fuel burning Sulfur dioxide is another air polluter that comes from the burning of fossil fuels. Very dangerous to humans at a high concentration. Sulfur in the atmosphere leads to acid rain

20. Natural Air Pollutants Natural air pollutants can include: Smoke from wild fires Methane released from livestock Volcanic eruptions

21. Consequences of Air Pollution Increased CO 2 levels trap more heat = Greenhouse Effect More CO 2 in atmosphere  GLOBAL WARMING

22. Acid Rain When emissions of sulfur dioxide and nitric oxide mix with clouds, they lower the water vapor’s pH – making it more acidic Acid rain = lower than pH of 5.6 Burn low-sulfur coal to reduce risks, but it’s expensive

23. Acid Rain & Trees

24. Smog Smog – thick, brownish haze formed when hydrocarbons, carbon monoxide, and several other gases react in sunlight Contains chemicals that irritate the eyes and make breathing difficult Very dangerous for people with asthma Can also damage or kill plants

25. A City in Smog

26. Indoor Air Pollution Some appliances used in homes and offices give off potentially dangerous gases Often the houses are insulated to be energy efficient Pollutants that might otherwise escape through cracks are trapped inside. One of the leading causes of indoor pollution is smoking

27. Water Pollution More and more of the water on Earth is becoming unusable. Shortage of water due to water pollution Obtaining + using energy resources are the major causes

28. Ocean Dumping At one time, solid wastes were commonly towed offshore and dumped into the ocean Much of the debris has washed up on beaches Today some debris is still dumped 

29. Point Sources Point sources – direct sources of water pollution that can be reduced and monitored Waste products from: factories sewage systems power plants underground coalmines oil wells

30. Non-Point Sources Non-point source – not as easily identified/controlled rain or snow picking up pollutants in groundwater runoff of fertilizers from farms storm water drainage from lawns, parking lots, and streets

31. Sources of Water Pollution Acid Rain Strip Mining Oil Spills Nuclear Power Hazardous Wastes Sewage and Agricultural Runoff

32. Acid Rain… Again! Falls into lakes, rivers, and streams increases water’s acidity kills many organisms living in the water

33. Strip Mining Strip mining for coal releases pollutants run off into lakes and streams seep in to the soil to contaminate groundwater

34. Oil Spills Petroleum is found under the ocean floor. To get it, offshore oil wells are constructed. Drilling accidents occur and large amounts of oil spill into the oceans. Also occur when tankers carrying oil are damaged. Tankers also deliberately flush waste oil into the ocean, killing plants and animals

35. Nuclear Power Cold water from lakes and rivers is used to cool the reactors in nuclear power plants A lot of hot water is generated and is discharged into lakes This temperature increase is called thermal pollution since organisms die when temperatures rise

36. Radioactive Wastes Radioactive wastes stored in underground containers may leak and pollute groundwater Pollution of the oceans occurs if these wastes are dumped in the ocean

37. Sewage Sewage – waste material carried away by sewers and drains Greatest threat to human health Sometimes dumped directly into streams Contains disease-causing bacteria and viruses… drinking water may become contaminated

38. Danger to Fish Fish living in polluted water can’t be eaten Untreated sewage is harmful to the fish and other organisms that live in the water

39. Agricultural Runoff When fertilizers and their chemicals run off the land into a lake, they stimulate the growth of algae The algae then use up the oxygen in the lake Pesticides also enter the water

40. What Can Be Done About Pollution? Pollution can be reduced by: Conserving energy Finding cleaner ways to use energy Making sure that wastes are disposed of in the safest possible ways

41. Conservation Conservation – the wise use of natural resources to ensure they will not used up too quickly or used in a way that will damage the environment Nonrenewable resources last longer Pollution is reduced

42. Examples of Conservation Recycling Carpooling Public Transportation Insulate homes Use less water

43. Scrubber Systems The burning of coal has been made less damaging to the environment by the use of scrubber systems. Works like a shower: As sulfur oxides are released from burning coal, a high-pressure spray of water dissolves the oxides before they can react with the water vapor Used on smokestacks

44. Oil Drilling and Spills New methods have been used to drill for oil under the ocean floor in order to reduce underwater leaks Several new methods have been developed for cleaning up oil spills with vacuum systems Oil-eating bacteria have also been developed

45. Waste Disposal Hazardous waste should be separated from industrial waste Hazardous waste should be reused or recycled when possible The waste should be treated chemically to destroy the toxic materials they contain The wastes should be buried in landfills with many safeguards to prevent leaks

46. Everyone’s Responsibility Pollution is mainly caused by the activities of people It is important to realize that the activities of people can also reduce pollution! Everyone can help!