NRSC 221 Lecture Notes - Arsenic, Intellectual Disability, Primitive Reflexes

• School: McGill University
• Department: Natural Resource Sciences
• Course: NRSC 221
• Professor: Maggie Kilgour

Document Summary

Some metals are xenobiotics they have no useful role in human physiology. The first, second, third and sixth hazards respectively on the list are heavy metals: lead, mercury, arsenic and cadmium. Exposure to metals can occur through a variety of routes: metals may be inhaled as dust or fumes. Metals can also be ingested involuntarily from food and drink. The amount of actually absorbed from the digestive tract can vary widely, depending on the chemical form of the metal and the age and nutrional status of the individual. Once a metal is absorbed it distributes in tissues and organs. Excretion typically occurs primarily through the kidneys and digestive tracts, but metals tend to persist in some storage sties like the liver, bones and kidneys for years or decades. Toxicity of metals commonly involves the brain and the kidney, but other manifestation occurs, and some metals such as arsenic are clearly capable of causing cancer.