Chapter Questions
Why are heavy metals toxic to organisms?
List four sources of lead exposure. Explain a source of the lead for each of the four major exposure parhways.
Characterize the mandatory use of unleaded gasoline on the extent of $\mathrm{Pb}$ contamination.
How does $\mathrm{Pb}$ affect plants? Nonhuman animals?
Which human systems are affected by $\mathrm{Pb}$ poisoning? Why would human bone be a tissue of interest in $\mathrm{Pb}$ toxicity?
Describe four biochemical effects of $\mathrm{Pb}$.
Cadmium exposure to animals and plants is largest from which source? What other sources exist for cadmium exposure?
List several effects of cadmium on plants.
Why is inhaled $\mathrm{Cd}$ more dangerous than ingested $\mathrm{Cd}$ ?
List the biochemical effects of $\mathrm{Cd}$.
What are the biological roles of mercury?
What are the toxic effects of $\mathrm{Hg}$ on plants? On nonhuman animals?
What are the effects of temperature on $\mathrm{Hg}$ bioaccumulation in animals? Why?
What is the major source of methylmercury in the human diet?
What are the biochemical effects of $\mathrm{Hg}$ in animals?
Discuss several biochemical protective mechanisms against $\mathrm{Hg}$ toxicity.