How Exposure to Mercury Impacts You and Your Body


Mercury is one of nature’s most toxic heavy metals and is found in air, water, and soil. If present, it starts to impact our health when in direct contact with this metal through physical contact, breathing or intake. This exposure can lead to neurological, cardiovascular (heart-related), digestive, hormonal, and dermatological (skin-related) issues.

Mercury has no positive role in the human body; a safe level of mercury exposure is challenging to determine. It can be present in the environment in several different forms. While all forms of mercury are toxic to humans, the pattern of toxicity varies with its chemical structure, the route of exposure, the amount, the duration and timing of exposure, and the vulnerability of the person exposed.

Mercury exists in three different forms:

  • Elemental mercury – a silvery, shiny, volatile liquid that gives off a colourless, odourless vapour at room temperature
  • Inorganic mercury – compounds that are formed when elemental mercury combines with other elements such as oxygen, sulphur, or chlorine, creating compounds called mercury salts.
  • Organic mercury – compounds created when elemental mercury combines with carbon, such as methyl mercury.

Elemental (Metallic) Mercury

Exposure to metallic mercury most often occurs when metallic mercury is spilt or when a product that contains metallic mercury breaks exposing mercury to the air. If you have been exposed to metallic mercury and are concerned, you should consult your physician.

When exposed to metallic mercury, the primary health effect is when it is inhaled as a vapour, it can be absorbed through the lungs. Symptoms of acute and prolonged exposures include:

  • Tremors
  • Emotional changes (such as mood swings, irritability, nervousness, excessive shyness)
  • Insomnia
  • Neuromuscular changes (such as weakness, muscle atrophy and twitching)
  • Headaches
  • Disturbances in sensations
  • Changes in nerve responses
  • Poor performance on tests of mental function.
  • Higher exposures may also cause kidney effects, respiratory failure, and death.

Inorganic Mercury Compounds

High exposure to inorganic mercury may damage the gastrointestinal tract, the nervous system, and the kidneys. Both inorganic and organic mercury are absorbed through the gastrointestinal tract and affects other systems through this route. Symptoms of high exposure to inorganic mercury include:

  • Skin rashes and dermatitis
  • Mood swings
  • Memory loss
  • Mental disturbances

Organic Mercury Compounds (Methyl Mercury)

In the environment, mercury can change from one form to another. For example, methyl mercury accumulates in all fish, especially predatory ones. Methyl mercury is absorbed via the digestive tract and circulated throughout the body. It quickly enters the brain, where it may remain for an extended period. In a pregnant woman, it can be absorbed by the fetus via the placenta. Methyl mercury can also be passed through breast milk from the mother to the infant.

A child’s developing nervous system is sensitive to methyl mercury. Subject to the degree of exposure, the consequences can include a decrease in I.Q., delays in walking and talking, lack of coordination, blindness, and seizures. Extreme exposure in adults can lead to health effects such as personality changes, tremors, deafness, changes in vision, loss of muscle coordination and sensation, memory loss, intellectual impairment, and even death.


Mercury is unsafe in any form or by any route of exposure. Understanding the three types of mercury and their common exposure routes will help prevent unnecessary exposure to this dangerous heavy metal.