- Before HFCs were developed as replacements for CFCs as refrigerants, a family of compounds
called hydrochlorofluorocarbons (HCFCs) were developed to replace CFCs. Though these compounds
contained chlorine atoms, they were still less damaging to the ozone layer than CFCs. Why is
this? What are some common HCFC refrigerants? Are HCFCs as safe as HFCs? Why or why not?
- What is dioxin? Where does dioxin come from? How does it affect living things? How can
dioxin be dealt with?
- What is the greenhouse effect? Is it related to the problem of ozone depletion?
- Ozone is sometimes used instead of chlorine to destroy germs in drinking water. What are the
advantages and disadvantages of using ozone to treat drinking water instead of chlorine?
- What is acid rain and what are its causes? Can acid rain be caused by natural causes as
well as human activity?
- Gasoline, methanol, and hydrogen can all be used to power automobiles. What kind of exhaust
does each fuel produce? Which is the least harmful?
- What are nuclear fusion and nuclear fission? Why is fusion a potentially safer way to
generate electricity than fission? Why isn't fusion used to generate electricity today?
- What is particulate matter? Is this matter solid, liquid or gas? Where does it come from?
What are its effects on human health?
- Mercury, cadmium, and lead are all heavy metals, and can be toxic. Where are some sources
of mercury, cadmium and lead pollution, and what are the health risks of these three metals?
- What is polystyrene foam, and what does it have to do with ozone-depletion?
- What are some common soil contaminants? Where do they come from and what are their dangers?
How can bioremediation be used to combat soil pollution? What are some advantages and
disadvantages of bioremediation?
- Tires are a persistent pollution problem. Why are old tires difficult to recycle? Discuss at least one experimental tire-recycling processes.
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