Reply #30: Mercury from a thermometer, if swallowed

[quaoar]

is usually not toxic because it is not absorbed by the stomach. It normally passes through the bowels.

The dangerous form of mercury is organic mercury, which is introduced into the food chain as a by-product of coal-fired power plants:

What is the most common source of organic mercury poisoning?

In the general population, the main source of mercury poisoning is the ingestion of mercury- contaminated food, usually fish. When lake, river or ocean water is contaminated with methyl-mercury compounds, the mercury accumulates and magnifies in the flesh of the fish. Organic mercury concentrations can be more than 1,000 times greater in the fish than in the surrounding water. People who eat fish as a main component of their diet may be at risk. If a river or lake is known to be polluted with mercury, fish eaters are warned to decrease their weekly intake of fish.

http://www.calpoison.org/public/mercury.html

What are the signs and symptoms of organic mercury poisoning?

Organic mercury compounds are very damaging. They are toxic by ingestion, inhalation, and skin and eye contact. These mercury compounds can attack all body systems. They can cause nausea, vomiting, lack of appetite, weight loss, abdominal pain, diarrhea, kidney failure, skin burns and irritation, respiratory distress, swollen gums and mouth sores, drooling, numbness and tingling in the lips, mouth, tongue, hands and feet, tremors and incoordination, vision and hearing loss, memory loss, personality changes and headache. Allergic reactions can also occur.

Methyl-mercury, usually from contaminated food, is very dangerous to pregnant women. Methyl-mercury causes profound mental retardation, cerebral palsy, seizures, spasticity, tremors, and incoordination, along with eye and hearing damage in the unborn baby as a result of the mother's exposure. Organic mercury passes into the breast milk as well.