1. Water Pollution
Chapter 21 (pgs )

2. Section 21.1 Water Pollution Problem
Objectives:
Explain the link between water pollution and human disease.
Identify the major types of water pollutants and their sources.
Think Critically
Medical waste on NY and NJ beaches, warnings not to eat shellfish in Delaware because of bacteria in the water, an oil slicks near Texas and Alaska discolor beaches and damage ecosystems.
What is the major cause of these problems?
How can these problems be stopped?

3. Water Pollution Problem
For many years, people dumped garbage
into waterways
As waters became contaminated,
infectious diseases (cholera, typhoid, dysentery) became more common
In 1885 in Chicago, 90,000 people died from a cholera outbreak
German doctor, Robert Koch, linked cholera outbreaks to contaminated water
People realized contaminated water was a problem and began dumping garbage further out at sea
But garbage in the ocean affects the ocean ecosystem and drifts back to shore

5. Sewage Sewage – water that carries organic wastes from humans
and industry
Comes from toilets, sinks, washing machines, and industrial equipment
The U.S. dumps approx. 8.9 trillion liters of sewage into the ocean each year
Most of this waste is treated, but some may not be treated and can contain toxic chemicals and metals
Also, in many developing countries, sewage is not treated at all

6. Sewage Treatment Plants
Sewage Treatment Plant – a facility that
processes raw sewage before the sewage is
returned to surface water systems
Sewage is 1st passed through screens that filter out plastics, fabrics, and metal objects
Further processing includes the treatment of solid materials called sludge, and the addition of bacteria and purifying chemicals
Bacteria – break down organic pollutants
Chemicals (chlorine) sanitize and deodorize
These treatments do nothing to remove organic matter
This organic matter can lead to an excess of nutrients in the water which causes eutrophication

8. Pathogens Pathogens – parasites, bacteria,
and viruses that cause diseases in
living things
Many pathogens spend part of their
lifecycle in water – they enter the
water through infected raw sewage or animal wastes
Pathogens carried by water result in more human illness and death than any other environmental factor
With improved sanitation in developed countries diseases like cholera and typhoid are under control
In developing countries – still a problem!

9. Schistosomiasis
Disease caused by microscopic worms that enter through the skin of people who walk in water contaminated by infected human waste
The worms attack the liver, bladder, and intestines
Affects as many as 100 million people in the tropics and causes > 1 million deaths/year
Most common in Africa, the Middle East, and Egypt

10. Malaria Disease caused by a protozoan
Transmitted to humans by bite of infected mosquito
Water serves as the breeding ground for the mosquitos
Worldwide > 800 million people are infected with malaria
One million people die each year
Common in Africa, East Asia, and Latin America

11. Types of Water Pollution

12. Check For Understanding
1. What is sewage?
2. Create a flowchart that details the relationship between sewage, contaminated water, pathogens, and humans

13. Section 21.2 Chemical Pollutants
Objectives:
Examine the sources and effects of inorganic
and organic toxic chemicals
Describe the process of eutrophication and its
effects on lake ecosystems
Think Critically
Did you ever read the book “Alice’s Adventures in Wonderland”?
There was a character called the Mad Hatter.
Can you guess why he was called Mad?

14. Toxic Chemicals
Toxic chemicals – elements and molecules that are directly harmful to living things
Inorganic chemicals – elements or molecules not derived from organisms
Organic chemicals – molecules containing atoms of carbon that are derived from organisms

15. Inorganic Chemicals
Include acids, salts, heavy metals, and plant nutrients
Heavy metals – metallic elements with high atomic masses (lead, mercury, arsenic, chromium, etc) that are often from industrial processes
Plant nutrients – molecules that do not contain carbon but are needed for plant growth (phosphates, nitrates)
Enter water through seepage, runoff and direct discharge into lakes, rivers, and streams, and oceans

16. Minamata, Japan
Animals began to behave strangely – birds fell out of trees, cats acted crazy
Townspeople began to complain of headaches, dizziness, blurred vision, and numbness of hands and feet
The cause of symptoms turned out to be mercury poisoning
A plastics factory was discharging mercury directly into Minamata Bay
This contaminated the fish, which the people ate
Over 20 years, 8,000 people suffered paralysis or brain damage and several hundred people died.

17. Organic Chemicals Chemicals from living things or synthetically made
Gasoline, oils, plastics, some pesticides, fertilizers, solvents, and wood preservatives
Enter water as:
Wastes from petroleum refineries, chemical factories, and from canning, meat- packing, and food processing plants
Runoff from farmland
Crude oil spills

18. Exxon Valdez 1989- oil tanker ran aground off coast of Alaska
42,000 metric tons of crude oil gushed into Prince William Sound
Ecosystem was devastated and thousands of birds, mammals, and other organisms dies

19. Eutrophication
Fertilizers and detergents contain nutrients, phosphates, and nitrates
They enter the water system and promote the growth of algae and aquatic plants
When plants die, get huge amounts of decomposing bacteria
Bacteria use up all the oxygen and the fish die
More than 65% of the lakes in the U.S. are affected

21. Issues – Lake Erie: A Success Story
Read page 346 in your textbook
Answer Decision questions on a sheet of paper and hand in before class is over.

22. Check For Understanding
1. What is eutrophication?
2. Describe the difference between an organic and inorganic chemical. Give one example of water pollution by each.
3. The Exxon Valdez oil spill occurred because of human error. Can the possibility of human error ever be eliminated?

23. Section 21.3 Radioactivity and Thermal Pollution
Objectives:
Explain the problems of radioactive and thermal water pollution
Think Critically
Nuclear power plants can produce energy that does not pollute the air.
But, they also produce a lot of radioactive wastes that are hard to get rid of.
Do you think we should rely on nuclear energy?

24. Radioactivity Radioactive elements are used as
fuels in nuclear power plants, as medicines,
and in nuclear weapons
Radioactivity is very dangerous and radioactive wastes are difficult to handle
Whether a solid or a liquid, they may result in water pollution
In 1973, 1 million liters of radioactive waste leaked into the soil from the Hanford nuclear weapons site in Washington
The radiation contaminated the fish and drinking water
2,100 people were exposed to dangerous levels of radiation

25. Thermal Pollution A large increase in water temperature
due to human activity
Usually occurs in lakes, rivers, or shallow
bays near power plants or industrial sites
Affects ecosystems in several ways:
Increased water temperature decreases the amount of dissolved oxygen
Increased water temperature increases the body temperature of fish, which increases their metabolism so they need more oxygen
Fish suffocate because they can’t get enough oxygen
Higher temperatures of water is also destructive to developing fish eggs

26. Check For Understanding
1. What is thermal pollution?
2. Nuclear power plants produce large amounts of radioactive water? Why?

27. Section 21.4 Controlling Water Pollution
Objectives:
Identify government attempts to control water pollution.
Describe the problems involved in enforcing laws regarding water pollution.
Think Critically
Water pollution is found almost everywhere.
Laws have been made to control this pollution.
Why might these be hard to enforce?

28. Laws Beginning in 1898, laws were designed to control water pollution.
But, the laws were not strong enough and not enforced.
Individual states responsible for enforcing laws
Scientific reports on pollution were not accurate
Several sources could be responsible for pollution – who pats?
Little was known about the effects of pollution on ecosystems
The politics of industry (money or environment?)
In response Congress passed the Clean Water Act (1972) which was an attempt to set water quality standards for all states

29. Check For Understanding
1. What is being done to control water
pollution? Are these measures effective?
2. What can you do as an individual to reduce the effects of water pollution?
3. You are on the town planning community. A company that employs 75% of the people in your community has been cited for water pollution violations. The company says it will move if it is told to pay the fines. Will you vote to make the company pay?