Zinc
Inhaling large amounts of zinc (as zinc dust or fumes from smelting or welding) can cause a specific short-term disease
called metal fume fever

EPA has determined that because of lack of information, zinc is not classifiable as to its human carcinogenicity.

1.5 How can zinc affect my health?

Inhaling large amounts of zinc (as zinc dust or fumes from smelting or welding) can cause a specific short-term disease
called metal fume fever. However, very little is known about the long-term effects of breathing zinc dust or fumes.

Taking too much zinc into the body through food, water, or dietary supplements can also affect health. The levels of zinc
that produce adverse health effects are much higher than the Recommended Dietary Allowances (RDAs) for zinc of 11
mg/day for men and 8 mg/day for women. If large doses of zinc (10-15 times higher than the RDA) are taken by mouth
even for a short time, stomach cramps, nausea, and vomiting may occur. Ingesting high levels of zinc for several months
may cause anemia, damage the pancreas, and decrease levels of high-density lipoprotein (HDL) cholesterol.

Eating food containing very large amounts of zinc (1,000 times higher than the RDA) for several months caused many
health effects in rats, mice, and ferrets, including anemia and injury to the pancreas and kidney. Rats that ate very large
amounts of zinc became infertile. Rats that ate very large amounts of zinc after becoming pregnant had smaller babies.
Putting low levels of certain zinc compounds, such as zinc acetate and zinc chloride, on the skin of rabbits, guinea pigs,
and mice caused skin irritation. Skin irritation from exposure to these chemicals would probably occur in humans. EPA
has determined that because of lack of information, zinc is not classifiable as to its human carcinogenicity.
http://www.atsdr.cdc.gov/toxprofiles/phs60.html