1. Approaches to Pollution Management
Complete #5 on the worksheet

2. Toxicology and Trash

3. Toxicology Toxicology—measure of how harmful a substance is
Potential harm is dependent on
Dosage
Bioaccumulation—some molecules are absorbed & stored in specific organs or tissues at levels higher than normally would be expected
Biomagnification—levels of some toxins in the environment are magnified as they pass through a food web
DDT, PCBs, & some radioactive isotopes
Chemical interactions that can decrease or multiply the effects of a toxin

4. Toxicology
Poison—chemical that has an LD50 of 50 mg or less per kg of body weight
LD50—median lethal dose
The amount of chemical that in one dose that kills exactly 50% of the animals in a test population within a 14 day period

5. Toxicology Toxicity Testing
Dose-response curves—shows the effects of various dosages of a toxic agent on a group of test organisms
X-axis plot concentration of toxin & y-axis plots response
Usually follows an S-shaped curve

6. Toxicology
LD50 Practice

7. Solid and Hazardous Waste

8. Love Canal
Between , Hooker Chemical sealed multiple chemical wastes into steel drums and dumped them into an old canal excavation.
In 1953, the canal was filled and sold to Niagara Falls school board for $1.
The company inserted a disclaimer denying liability for the wastes.

9. In 1957, Hooker Chemical warned the school not to disturb the site because of the toxic waste.
In 1959 an elementary school, playing fields and homes were built disrupting the clay cap covering the wastes.
In 1976, residents complained of chemical smells and chemical burns from the site.

10. President Jimmy Carter declared Love Canal a federal disaster area.
The area was
abandoned in
1980.

11. Love Canal sparked creation of the Superfund law (CRCLA), which forced polluters to pay for cleaning up abandoned toxic waste dumps.
It reminds us that:
a) we never really throw anything away
b) wastes often do not stay put
c) preventing pollution is much safer and cheaper than trying to clean it up!
Video (11min)

12. Superfund
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)
Identifies abandoned hazardous waste dump sites
Protects and cleans up groundwater near such sites
Cleaning up the hazardous chemical at the site
Requiring responsible parties to pay for the cleanup
When no responsible party can be found, EPA draws money out of the Superfund for cleanup
25% of cleanups have been paid for by the superfund

13. Superfund
The Superfund law was designed to have polluters pay for cleaning up abandoned hazardous waste sites.
Only 70% of the cleanup costs have come from the polluters, the rest comes from a trust fund financed until 1995 by taxes on chemical raw materials and oil.

14. Waste
Solid waste: any unwanted or discarded material we produce that is not a liquid or gas.
Municipal solid waste (MSW) “garbage”: produce directly from homes.
Industrial solid waste: produced indirectly by industries that supply people with goods and services.
Hazardous (toxic) waste: threatens human health or the environment because it is toxic, chemically active, corrosive or flammable.

15. The United States produces about a third of the world’s solid waste and buries more than half of it in landfills.
About 98.5% is industrial solid waste.
The remaining 1.5% is MSW.
About 55% of U.S. MSW is dumped into landfills, 30% is recycled or composted, and 15% is burned in incinerators.

16. Recycling
Primary (closed loop) recycling: materials are turned into new products of the same type (aluminum cans, newspaper)
Secondary recycling: materials are converted into different products.
Used tires shredded and converted into rubberized road surface.
Newspapers transformed into cellulose insulation.

17. Recycling Advantages Disadvantages Reduces pollution Saves energy
Reduces mineral demand
Reduces greenhouse gas emissions
Reduces solid waste
Important part of economy
Disadvantages
May lose money for items such as glass and most plastics
Reduces profits from landfills or incinerators
Source separation is inconveinent

18. Burning Solid Waste
Globally, MSW is burned in over 1,000 large waste-to-energy incinerators, which boil water to make steam for heating water, or space, or for production of electricity.
Japan and a few European countries incinerate most of their MSW.

20. Waste Incineration Advantages Disadvantages Reduces trash volume
Less need for landfills
Less water pollution
Concentrates hazardous material into ash
Sale of energy reduces cost
Modern controls reduce air pollution
Disadvantages
Expensive to build
Costs more than hauling to a landfill
Difficult to site because of citizen opposition
Some air pollution
Output approach that encourages waste production

21. Sanitary MSW Landfill

22. Landfill Design
The bottom liner - layers of clay or other synthetic material (clay, plastic, or composite) placed on compacted soil.
The bottom of the landfill is sloped and pipes along the bottom collect leachate. The leachate is then pumped away and treated at a plant.

23. Landfill Design
Trash is dumped onto the landfill and consistently layered with soil to promote safer and better decomposition.
A cover is placed over the landfill to keep water out (to prevent eventual leachate formation).
Landfills also must have a system to dispose of methane gas.

25. North Wake Landfill (Now Closed)

26. Landfills Advantages Disadvantages No open burning Little odor
Built quickly
Low operating costs
Can handle large amounts of waste
Land can be used for other purposes
Disadvantages
Noise and traffic
Dust
Groundwater contamination
Slow decomposition
Discourages recycling, reuse, and waste reduction

27. Hazardous Waste Long-Term Storage
Hazardous waste can be disposed of on or underneath the earth’s surface, but without proper design and care this can pollute the air and water.
Deep-well disposal: liquid hazardous wastes are pumped under pressure into dry porous rock far beneath aquifers.
Surface impoundments: excavated depressions such as ponds, pits, or lagoons into which liners are placed and liquid hazardous wastes are stored.

28. Long-Term Storage
Long-Term Retrievable Storage: Some highly toxic materials cannot be detoxified or destroyed. Metal drums are used to stored them in areas that can be inspected and retrieved.
Secure Landfills: Sometimes hazardous waste are put into drums and buried in carefully designed and monitored sites.

29. Secure Hazardous Waste Landfill
In the U.S. there are only 23 commercial hazardous waste landfills.

30. Brownfields
Brownfields are abandoned industrial and commercial sites that are contaminated (e.g. factories, old landfills, gas stations).
450,000 – 600,000 sites exist in the U.S., many of them in economically stressed inner cities.
Many of these sites can be cleaned up and reborn as parks, athletic fields and neighborhood.

31. U.S. Hazardous Waste Regulations
Two major federal laws regulate the management and disposal of hazardous waste in the U.S., RCRA and CERCLA:
Resource Conservation and Recovery Act (RCRA) – 1976, 1984
Requires EPA to identify hazardous wastes & set standards for their management
Primary goal - protect human health and environment from the potential hazards of waste disposal.
Calls for conservation of energy and natural resources, reduction in waste generated, and environmentally sound waste management practices.

32. A Few Stats…….
60 to 80% of solid and hazardous waste produced could be eliminated through a combination of waste reduction, reuse, and recycling.
5% of MSW is recycled or composted while 35% could be.
Video: Story of Stuff
(20 min)