1. 6.3 - Hazards and Benefits of compounds

2. Mercury - Description
An element present naturally in the environment at low levels.
Added to the environment by burning coal.
Mercury becomes concentrated (more in a smaller space) in the environment.
Bacteria in the environment change mercury into a more dangerous chemical (METHYLMERCURY)

3. Mercury – helpful characteristics
Useful in pulp and paper mills (used to manufacture chlorine to bleach paper).
Used in some thermometers

4. Mercury – harmful characteristics
Toxic – causes mercury poisoning (rashes, numbness, tremors, slurred speech, tooth loss, reproductive issues and birth defects)
Can build up to dangerous levels in food in the environment (e.g. fish)
Lasts a long time in the environment (spills are hard to clean up)

5. CFC’s (Chlorofluorocarbons) – description
Gases that are not harmful to humans (non-toxic and nonflammable), but can do damage to the environment (the ozone layer).

6. CFC’s – Helpful characteristics
Was used in refrigeration units (fridges and air conditioners)
Was used in aerosol spray cans and some asthma medications (propellant)

7. CFC’s – harmful characteristics
Destroys the ozone layer (a layer of protective gases surrounding the Earth that prevents UV rays from reaching the Earth).
Created a hole in the ozone layer that may take until to completely close.

8. Benzene - Description
A hazardous chemical that is both toxic can flammable
Can be used safely with precautions
A regulated substance (special permits must be obtained for its use).

9. Benzene – helpful characteristics
Used to make dyes, detergents, medications (e.g. aspirin), acetate

10. Benzene – harmful characteristics
Toxic (cancer hazard)
Flammable

11. Pesticides (and POP’s (persisitant organic pollutants)– Description
Any chemicals used to control a “pest” – e.g. herbicides, insecticides.
POP’s do not break down in the environment and can build up in body tissues

12. Pesticide and POP’s – helpful characteristics
Pesticides are used to eliminate unwanted organisms from an area in which they can cause problems – e.g. DDT is an insecticide that is used to kill mosquitoes and is effective in helping to prevent the spread of diseases like malaria that are transmitted by mosquitoes.

13. Pesticides – harmful characteristics
Persistant organic pollutants build up in the environment and can reach toxic levels in animals
Pesticides can harm potentially useful organisms in the environment if not specific to the pest

14. 1. Is water a chemical? explain
All matter is made of chemicals. If it contains atoms, it is a chemical.

15. 4. List 3 reasons why hazardous chemicals continue to be produced in our society.
They are useful for an important process
There is no other alternate chemical that can be used
When used carefully and under controlled conditions, their hazards can be controlled.

16. 5. How can mercury in a dry cell end up in the environment?
When dry cells are thrown into the garbage, their outer casings can begin to break down. The mercury inside the cells can then seep out and get into the water or soil around the landfill area. If water from the landfill is able to reach a waterway, the mercury can then move to different areas.

17. 9. What are 3 uses of benzene?
Used to make acetate
Used in dyes
Used in detergents
Used to make aspirin

18. 10. Benzene is a regulated substance. What does this mean?
A ‘regulated substance’ is one that must be used according to strict guidelines that are regularly reviewed and revised.

19. 11. What ways of handling benzene help it to be used safely?
It must be kept in sealed systems, and workers must wear masks with activated charcoal filters.

20. 14.In the future, will you recycle cellphone batteries or throw them out?
Cellphone batteries may contain hazardous chemicals (e.g. mercury, cadmium, lead) which can escape from the casing of the battery and enter the atmosphere. These chemicals can reach toxic levels in organisms in the environment.

21. 15. How are pollution in the environment and human health related?
Pollutants in the environment can build up in organisms in the environment. As animals that are higher on the food chain eat these organisms, the toxins build up in larger levels. Humans are the top of our food chain. Eating organisms with pollutants in them can lead to poisoning.