Mercury Poisoning - Introduction
Mercury is a silvery heavy metal and it is liquid at or near the room temperature and pressure. It can be found in deposits of cinnabar. This is actually the main source of mercury. Mercury is obtained from cinnabar by a process of reduction. Cinnabar, also known as mercuric sulfide, is a highly toxic substance and may be dangerous if ingested or inhaled in a form of dust. Apart from this chemical compound one more form of mercury which may cause poisoning is mercuric chloride (soluble form of mercury). Even inhalation of mercury vapor may cause poisoning. And finally, eating sea food contaminated with mercury can result in poisoning with this heavy metal. Toxic effects of this metal affect many organs such as heart, lungs, brain and kidneys.
Causes of Mercury Poisoning
This metal may be ingested or inhaled and these two paths are the most common ways of introducing mercury into the body. Even contact with this metal may allow its absorption through the skin and mucous membranes.
Mercury may be found in water, soil and air. Mercury from the air may eventually lead to its deposits in water and land. There it can be converted by certain microorganisms into one of the most poisonous compounds of mercury called methylmercury. Methylmercury usually enters the body with contaminated fish and shellfish.
Mercury poisoning may also occur from human-generated sources of mercury. This particularly refers to thermometers and fluorescent light bulbs which are not disposed properly. Definitely the most significant human-generated source of mercury is expelling from coal plants. Furthermore, other sources include cement production, caustic soda production, gold production, non-ferrous metal production and finally, biomass burning. Exposure and potential poisoning caused by mercury are also possible in clinics, hospitals and laboratories.
What are Effects of Mercury Poisoning
The effects of mercury poisoning generally depend on the dose and duration of the exposure to this metal. Chemical form also determines the intensity of the effects. And finally, the way the metal enters the body as well as the age and general health of the patient are several more factors which determine the severity of poisoning.
Acute mercury poisoning may cause inflammation or ulcerations of the mouth, loose teeth and bleeding gums. Furthermore, there is usually diarrhea, inflammation of colon and stomach cramps. Respiratory symptoms include coughing and there may even be cardiovascular manifestations of poisoning such as changes in blood pressure, weak pulse and chest pain.
In pregnant women methylmercury may cause impaired neurological development of fetus. The poisoning with methylmercury also affects memory and cognitive ability. And finally, it can affect motor, visual and language skills, coordination, lead to disturbances of vision and hearing. There is also muscle weakness.
Organic mercury compounds may cause permanent damage to the brain and nervous system while exposure to inorganic forms of this metal may affect nervous system, kidneys and gastrointestinal tract.
The symptoms of elemental mercury poisoning include headache and a variety of neuromuscular changes such as muscle weakness and atrophy, mood swings and nervousness. In higher doses elemental mercury leads to kidney or respiratory failure.