Mercury, a naturally occurring toxic element, exists in several different forms such as metallic mercury, organic mercury compounds and inorganic mercury compounds. It is the only metal, which is found in liquid state at room temperature. Mercury poisoning is caused by the consumption of fish that contains mercury or through direct exposure to some mercury-containing products. This exposure can affect your immune system and other organs including heart, lungs, brain and kidneys. Let's understand in detail about the causes and effects that mercury poisoning has on the body.


Mercury poisoning occurs when a person inhales or ingests or comes in contact with mercury. Mercury is widely found in water, soil and air in various forms. Methylmercury is an extremely poisonous form of mercury. Mercury present in the air gets deposited onto land or into water and is converted to methylmercury by certain microorganisms. Fish and shellfish that contain methylmercury are the major sources of mercury poisoning in humans.

Human-generated sources of mercury exposure are another major cause of mercury poisoning. Mercury exposure can occur from breathing contaminated air or due to inadequate use or disposal of mercury-containing products, such as thermometers or fluorescent light bulbs. Coal plants expel about half of atmospheric mercury and are a major human-generated source of mercury exposure. Some other sources are cement production, caustic soda production, non-ferrous metal production, gold production and biomass burning. Mercury poisoning can also occur through exposure to mercury and its compounds that are used in dental clinics, hospitals and laboratories.


Mercury is an extremely reactive toxic element, which can cause a number of hazardous effects on your health. The severity of health effects of mercury poisoning depends upon the duration and dose of exposure, chemical form of mercury, route of exposure and age and health of the person exposed. Mercury poisoning can cause severe damage to central nervous system and kidneys. Acute mercury exposure can affect gastrointestinal and respiratory systems. In some cases, mercury poisoning can lead to inflammation of mouth, loose teeth and ulcerated and bleeding gums. It can also cause certain digestive tract problems such as diarrhea, inflamed colon and stomach cramps, respiratory problems such as persistent coughing and emphysema and cardiovascular problems such as blood pressure changes, weak pulse and chest pain.

Chemical Forms

Mercury exists in various chemical forms such as methylmercury, elemental mercury and organic and inorganic mercury compounds and each form shows specific symptoms. Let us take a look at them.

Methylmercury: Consumption of fish contaminated with methylmercury is a leading cause of mercury poisoning in the United States. If a pregnant woman consumes fish and shellfish contaminated with methylmercury, the fetus is exposed to methylmercury. The main health hazard of methylmercury on fetus and infants is impaired neurological development. It also affects memory, cognitive ability, language as well as motor and visual spatial skills in children. Methylmercury can cause lack of coordination of movements, disturbances in sensations, impairment of peripheral vision, hearing and speech and muscle weakness.

Organic and Inorganic Mercury Compounds: Organic and inorganic mercury compounds are absorbed through intestinal tract. But, organic compounds are more rapidly absorbed through ingestion as compared to inorganic compounds. Organic mercury can lead to irreversible damage to the brain and nervous system. Exposure to inorganic mercury can damage the gastrointestinal tract, kidneys and nervous system. It can cause symptoms such as memory loss, mental disturbances, mood swings, skin rashes and muscle weakness.

Elemental Mercury: When elemental or metallic mercury is inhaled in the form of vapors, it is absorbed through the lungs. It can give rise to the symptoms such as headache, neuromuscular changes such as muscle atrophy, muscle weakness, tremors, insomnia, disturbances in sensations and emotional changes such as irritability, mood swings and nervousness. Higher exposure of elemental mercury can cause respiratory failure or kidney failure.

When exposed to mercury, you should immediately consult the doctor. The diagnosis of mercury poisoning is done with the help of clinical signs, history of mercury exposure and determination of high mercury levels in the stomach, liver and kidneys. Chelation therapy is the standard treatment option for mercury poisoning. The only way to prevent hazardous effects of mercury poisoning is to avoid exposure to mercury and mercury compounds.

Disclaimer: This article is for informative purposes only and does not in any way attempt to replace the advice offered by an expert on the subject.