OK, OK... lettuce it is then.
Here you go.. something for everyone.
Queenie to answer your question, heavy metal is by definition any metallic chemical element that has a relatively high density and is toxic or poisonous at low concentrations. Examples of heavy metals include mercury (Hg), cadmium (Cd), arsenic (As), chromium (Cr), thallium (Tl), and lead (Pb). Heavy metals are natural components of the Earth's crust. They cannot be degraded or destroyed.
Hope you found that helpful somewhat.