1. Water Pollution

2. Water Pollution Problem
For many years, people dumped garbage
into waterways
Contamination caused: diseases such as cholera, typhoid, dysentery
In 1885 in Chicago, 90,000 people died from a cholera outbreak
Robert Koch- German doctor, linked cholera outbreaks to contaminated water
People realized contaminated water was a problem and began dumping garbage further out at sea
What is the problem with this??

4. Sewage Sewage – water that carries organic wastes from humans
and industry
Where does it come 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

5. Sewage Treatment Plants
Sewage Treatment Plant – a facility that
processes raw sewage before the sewage is
returned to surface water systems
Sewage screens that filter out plastics, fabrics, and metal objects  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 can cause eutrophication.
Eutrophication: excess of nutrients in a lake or body of water What do you think about this? Good or bad?

7. 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  cause human illness and even death
With improved sanitation in developed countries diseases like cholera and typhoid are under control
In developing countries – still a problem!

8. Malaria Disease caused by a protozoan Humans infected by 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

9. Types of Water Pollution

10. 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

11. Inorganic Chemicals 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

12. Heavy Metals Poisons
Heavy metals are metallic elements with high atomic masses (that’s why their called HEAVY)
EX: Arsenic, lead, nickel chromium and mercury
Many heavy metals find their way into ground water as by-products of manufacturing products. EX: Plastics, paint
In 17th century France mercury was used to treat material for hat-making.
How might the hat-makers be exposed to mercury?
What were the effects of mercury poisoning on the hat makers?
Emotional disturbances
Lack of coordination
Shyness

13. Organic Chemicals
Chemicals from living things or synthetically made, contain the element CARBON
Gasoline, oils, plastics, some pesticides, fertilizers, solvents, and wood preservatives
Enter water as:
Wastes from petroleum refineries, chemical factories, food processing plants
Runoff from farmland
Crude oil spills

14. Minamata, Japan
Animals began to behave strangely – birds fell out of trees, cats acted crazy
Townspeople: headaches, dizziness, blurred vision, and numbness of hands and feet
The cause of symptoms turned out to be mercury poisoning
A plastics factory- dumped 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.

15. 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

16. Eutrophication
Fertilizers and detergents contain nutrients, phosphates, and nitrates
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

18. Radioactivity Radioactive elements fuels in nuclear power
plants, as medicines, and in nuclear weapons
Dangerous and 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

19. Thermal Pollution A large increase in water temperature
due to human activity
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

20. Laws 1898  laws were designed to control water pollution.
The laws were not strong enough and not enforced.
Little was known about the effects of pollution on ecosystems
The politics of industry (money or environment?)
Clean Water Act (1972): Congress passed this act which was an attempt to set water quality standards for all states