Objectives

1. Section 25.3 Protecting Land and Water Objectives Summarize the threats that hazardous wastes pose to human health. Identify three sources of water pollution. Describe three solutions for protecting land and water.

2. Fact Local health departments closely monitor the quality of tap water. Bottled water is less closely regulated. By drinking tap water, you also save money and reduce plastic waste. Why do you think this myth exists? Myth It is healthier to drink bottled water than tap water.

3. Waste Disposal • Waste that can be broken down by microorganisms is called biodegradable waste. • In addition to biodegradable wastes, humans create wastes that are not, or are only partially, biodegradable.

4. Hazardous Wastes • A hazardous waste is any waste that is either flammable, explosive, corrosive, or toxic to humans or other living things. • Each year, millions of tons of hazardous wastes are produced in the United States alone. • Hazardous wastes build up in the environment and threaten the health of plants and animals, including humans.

5. Landfills • A landfill is a permanent storage area where garbage and other wastes are deposited and covered with soil. • Landfills are widely used for disposal of solid and liquid wastes. • Many landfills are at or near full capacity and suitable space to build new landfills is running out. • Recycling is the process of reclaiming raw materials from discarded products and using them to create new products.

7. Sources of Water Pollution • Bodies of water such as lakes, rivers, and oceans have always been used to dispose of wastes. • If the wastes are biodegradable and the amount is small, microorganisms can break them down. • Wastes from household, industrial, and agricultural sources can cause pollution of water resources.

8. Household Sewage • The waste material carried from toilets and drains is referred to as sewage. • If released into the environment too rapidly, sewage can make water foul-smelling and deadly to fish and other organisms. • Sewage also contains bacteria and viruses that can cause disease. • In 1972, the Clean Water Act required communities to treat their raw sewage before releasing it into the environment.

9. Household Cleaners • Household cleaners can be a source of pollution if they contain phosphates, which can harm water plants and animals, or harsh chemicals such as chlorine. • Chlorine in high concentrations is toxic to all forms of life.

10. Industrial Waste • Many industrial wastes are extremely hazardous or non-biodegradable, or both. • Industrial wastes include such things as dyes, acids, solvents, and heavy metals such as mercury, lead, and cadmium. • In the past, it was common for industrial wastes to be discharged into ground and surface waters, contaminating organisms that lived in or drank the water. • Today, although there is much greater regulation to prevent such contamination, some of these pollutants are still a problem.

11. For: More on health effects of mercury Click above to go online.

12. Agricultural Runoff • The water that drains from land into streams is called runoff. • Runoff can carry with it many kinds of substances that pollute water supplies. • Runoff from agricultural land often contains chemicals applied to crops to control weeds and insect pests.

13. Nontoxic Housecleaning Materials buckethot waterbaking sodasoap flakescornstarchwhite vinegarstirrerspongerags or paper towels

14. Nontoxic Housecleaning In a bucket, make a nontoxic, all-purpose cleaner by adding 1/2 tablespoon of baking soda and 1/8 cup of soap flakes to 1/2 gallon of hot water. Stir until all ingredients are completely dissolved. Moisten a sponge with the cleaning solution and clean your desktop or another surface that your teacher selects. Note how easily and effectively the cleaner works. Try This

15. Moisten a rag or paper towel with the glass cleaner. According to your teacher’s instructions, try cleaning a window or mirror. Make a nontoxic glass cleaner by adding 1 tablespoon of cornstarch and 1/4 cup of white vinegar to 1/2 gallon of warm water. Stir well. Nontoxic Housecleaning Try This

16. How well did the cleaners work? How do they compare with commercially prepared products you have used? How do you think most people dispose of cleaning products? What effect do you think disposing of cleaning products has on the environment? What are the benefits and drawbacks of making your own nontoxic cleaners? Nontoxic Housecleaning Think and Discuss

17. Maintaining Environmental Health • The environmental damage to land and water—and in turn, the damage to human health—is a serious problem. • Cleaning up waste sites, improving waste management, and conserving natural resources are three solutions for protecting land and water.

18. Cleaning Up Waste Sites • The EPA has placed over 1,000 of the most dangerous hazardous waste sites on a national priority list for cleanup. • These so-called “Superfund” sites are found in every state. • Thousands of other hazardous waste sites are being cleaned up by state governments or by private companies.

19. Proper Disposal of Wastes • Today, legal dump sites for hazardous chemicals are designed to prevent the escape of wastes into the surrounding environment. • Many communities have collection centers where residents can turn in hazardous wastes. • Many companies have also developed ways to reduce the amount of wastes they generate in the first place or to recycle their wastes.

20. Conservation • Losing natural land areas can make pollution worse. • Conservation is one key to slowing down the rate at which natural areas are lost. • Conservation is the protection and preservation of the natural environment by managing natural resources wisely and developing land for new construction responsibly.

21. What You Can Do • Reduce by creating less waste in the first place. • Reuse by finding other uses for objects or by donating them rather than discarding them. • Recycle by keeping separate from the trash any materials that can be reprocessed into new products.

22. Vocabulary biodegradable waste Waste that can be broken down by microorganisms. hazardous waste Waste that is either flammable, explosive, corrosive, or toxic to humans or other living things. landfill A permanent storage area where garbage and other wastes are deposited and covered with soil. recycling The process of reclaiming raw materials from discarded products and using them to create new products.

23. Vocabulary sewage Waste material carried from toilets and drains. runoff Water that drains from land into streams and other water bodies. conservation The protection and preservation of the natural environment by managing natural resources wisely and developing land for new construction responsibly.

24. QuickTake Quiz Click to start quiz.

25. End of Section 25.3 Click on this slide to end this presentation.