Arsenic

Arsenic, a naturally occurring element, is found throughout the
environment; for most people, food is the major source of
exposure. Acute (short-term) high-level inhalation exposure to
arsenic dust or fumes has resulted in gastrointestinal effects
(nausea, diarrhea, abdominal pain); central and peripheral
nervous system disorders have occurred in workers acutely
exposed to inorganic arsenic. Chronic (long-term) inhalation
exposure to inorganic arsenic in humans is associated with
irritation of the skin and mucous membranes. Chronic oral
exposure has resulted in gastrointestinal effects, anemia,
peripheral neuropathy, skin lesions, hyperpigmentation, and
liver or kidney damage in humans. Inorganic arsenic exposure
in humans, by the inhalation route, has been shown to be
strongly associated with lung cancer, while ingestion of
inorganic arsenic in humans has been linked to a form of skin
cancer and also to bladder, liver, and lung cancer. EPA has
classified inorganic arsenic as a Group A, human carcinogen.

Arsine is a gas consisting of arsenic and hydrogen. It is
extremely toxic to humans, with headaches, vomiting, and
abdominal pains occurring within a few hours of exposure. EPA
has not classified arsine for carcinogenicity.