Mercury Toxicity

Mercury is a common environmental contaminant, and many of us are unknowingly predisposed to mercury toxicity. It is the most poisonous, non-radioactive, naturally occurring substance on our planet. There is no safe level of mercury because even one atom of it in the body is doing some harm to it.

Mercury exists in three forms: elemental mercury, inorganic mercury compounds (primarily mercuric chloride), and organic mercury compounds (primarily methyl mercury). All forms of mercury are quite toxic, and each form exhibits different health effects. These forms of mercury differ in their degree of toxicity and in their effects on the nervous, digestive and immune systems, and on lungs, kidneys, skin and eyes.

All humans are exposed to some level of mercury. Most people are exposed to low levels of mercury, often through chronic exposure (continuous or intermittent long term contact). However, some people are exposed to high levels of mercury, including acute exposure (exposure occurring over a short period of time, often less than a day). An example of acute exposure would be mercury exposure due to an industrial accident.

Forms of Mercury

  • Elemental mercury or metallic mercury is the element in its pure, ‘un-combined’ form. It is a shiny, silver-white metal that is liquid at room temperature, but is rarely found in this form in nature. If not sealed off, mercury slowly evaporates into the air, forming a vapour. The quantity of vapour formed increases as temperatures rise. Elemental mercury is traditionally used in thermometers and some electrical switches.


  • Inorganic mercury compounds or mercury salts, more commonly found in nature, include mercuric sulphide (HgS), mercuric oxide (HgO) and mercuric chloride (HgCl2). Most of these are white powders or crystals, except for mercuric sulphide which is red and turns black after exposure to light. Some mercury salts, such as mercury chloride, also form vapour, but they stay in the air for a shorter time than elemental mercury because they are more soluble in water and more reactive.



  • Organic mercury is formed when mercury combines with carbon and other elements. Examples of organic mercury compounds are dimethylmercury, phenylmercuric acetate and methylmercuric chloride. The form most commonly found in the environment is methylmercury.

Sources of Mercury

Mercury can enter the body through the lungs, through food and water, and by direct physical contact.

  • Dental Amalgams – Commonly used silver amalgam dental fillings contain about 50 percent mercury. Older dental fillings may contain higher amounts. There is increasing evidence that mercury is leached from dental amalgam and that mercury can vaporize from fillings. Fillings which crack can also be a source of mercury toxicity. Silver amalgam fillings also generate negative electrical potentials in the mouth which can detrimentally affect one’s health status. There are alternatives to silver amalgam fillings, including gold alloys and composite quartz-resin materials.
  • Large Fish – The concentration of mercury in fish varies directly with the size of the fish, inasmuch as mercury is more concentrated at each step upward as one goes up the food chain. Tuna and swordfish are the most common fish contaminated with mercury. Most swordfish are kept off the market today for this reason. Albacore tuna has been found to be safer than the larger species of tuna. While fish contain selenium, which helps to neutralize the toxic effects of mercury, we do not recommend eating tuna fish more than twice a week, due to mercury contamination.
  • Water Supplies – Mercury in industrial waste is a common water contaminant. Mercury used in fungicides and slimicides easily finds its way into water supplies. Sewage sludge is commonly contaminated with mercury.
  • Seeds Treated With Mercurial Fungicides – Mercury is commonly used as a treatment to prevent fungal growth on seeds.
  • Medications – Because of its bacteriostatic properties, mercury is a common ingredient in antiseptics (Mercurochrome, Merthiolate) and contact lens solution. Mercury is also found in the thiazide diuretics and in some hemorrhoid medications.
  • Congenital Mercury Toxicity – Methylmercury easily crosses the placenta into the growing fetus. Other mercurial compounds pass with less ease. Mercury compounds can also be transferred through breast milk to nursing babies. Levels in breast milk are about five percent of those of blood. It is believed that fetuses are the group most susceptible to mercury toxicity. Infants excrete mercury more slowly than adults.
  • Other – Mercury is widely used in industry and in a variety of products, e.g., felt, fungicides, algicides used in swimming pools, adhesives, floor waxes, fabric softeners, slimicides, and in the production of chlorine.


Mercury toxicity may occur when you are exposed to toxic amounts of mercury due to:

  • Breathing airborne mercury vapors
  • Eating contaminated food, especially fish or shellfish—Larger and older fish tend to have the highest levels of mercury.
  • Drinking water contaminated with mercury (rare)
  • Practicing religious or folk medicine rituals that include mercury

Metallic mercury can be found in consumer products, such as fluorescent light bulbs, batteries, thermostats, and old thermometers. Mercury, combined with other elements, is also found in some types of dental fillings. Research has not shown that this type of filling is harmful to people. Although thimerosol is no longer used in vaccines in the United States, the mercury-containing compound is still used in some countries. Research has not shown that it is harmful to people.

Symptoms of Mercury Toxicity

Respiratory System

Up to 80% of inhaled mercury vapour is absorbed through the lungs. From here it travels to all the other tissues and organs of the body in the circulation, but particularly concentrates within the kidney, liver and brain. Effects and symptoms include –

  • Asthma
  • Bronchitis
  • Breathlessness
  • Persistent cough and
  • Bad breath

Changes in mood

Mercury is also known to have profound effects upon mood including –

  • Fears
  • Anxieties
  • Irritability
  • Fits of anger
  • Panic attacks
  • Mood swings
  • Loss of self-confidence
  • Withdrawal
  • Being easily embarrassed
  • Feeling overwhelmed
  • Feeling easily discouraged
  • A loss of sense of humour and
  • Life seems an endless, joyless struggle

Effects on Mental Health

  • Hallucinations
  • Depression
  • A persistent death wish
  • Suicide attempts
  • Obsessive-Compulsive Disorders
  • Manic-Depressive Disorder
  • Panic disorders and
  • Schizophrenia spectrum disorders

Compromised cognitive function

Mercury is both highly neurophilic (which means that it binds tightly to nerves) and highly lipophilic (which means that it binds tightly to fats). When distributed around the body in the circulation it is absorbed into the nerve endings that regulate all the functions of the body (the autonomic nervous system). From there it slowly tracks up the nerves into the central nervous system, in what is known as retrograde axonal transport. Mercury can produce a host of mental, emotional, and behavioural changes and what are considered ‘psychiatric’ disorders by disrupting neurotransmitters, interfering with endocrine gland function and hormones and causing destruction of nervous pathways.

  • Poor memory
  • Difficulty multitasking
  • Difficulty finding words
  • A lack of initiative
  • An inability to concentrate
  • An inability to make decisions and
  • Lack of motivation

Reproductive and sexual function

Mercury is also recognized to collect in the reproductive organs in both men and women where it can cause a variety of disorders including infertility. Symptoms include –

  • A low or non-existent libido
  • Precocious or late puberty and
  • Infertility

In women, the effects of mercury on reproductive function include –

  • Heavy, missed or irregular periods
  • Severe period pains
  • Pre-menstrual tension (PMT)
  • Miscarriages and
  • Still births

In men, mercury accumulates in the reproductive organs and particularly the testes causing –

  • Impotence
  • Premature ejaculation and
  • Low sperm count, defective sperm and sperm with poor motility


Peripheral nervous system symptoms

The profound disruption of nerve structure and function leads to difficulty with motor nerve function including –

  • Difficulty articulating words
  • Numbness and tingling
  • Clumsiness
  • Difficulty doing fine tasks such as typing or adding numbers on a calculator
  • Tremors
  • Ticks and twitches (especially of the face and eyes)
  • A loss of coordination and
  • Restless legs

The cardiovascular system

In particular, mercury seems to collect in the heart muscle and valves and has been found at 22,000X the levels found in the blood. Mercury is strongly associated with elevated levels of homocysteine and cholesterol and heart attacks.

It also causes red blood cells to rupture and replaces the iron in haemoglobin so that the oxygen carrying capacity of the blood can be reduced by half. Mercury also causes a weakening in the walls of the small blood vessels leading to a reduced blood supply to the organs and tissues. The cardiovascular symptoms of mercury poisoning include –

  • Heart palpitations
  • An irregular heart beat
  • Angina or chest pain
  • A racing heart beat
  • Either an abnormally slow or rapid heart rate
  • Low or high blood pressure
  • Frequently feeling faint
  • Elevated blood cholesterol and homocysteine levels and
  • Easy bleeding and bruising.

Dental Symptoms

Mercury also collects in very high concentrations in the jaw bones and the soft tissues of the mouth. This is a result of it being a heavy metal that literally sinks to the bottom of each body compartment including the jaws and pelvis and the fact that mercury is driven into the tissues of the mouth which act as a cathode to the anode of the amalgam fillings.

Mixing gold and amalgam restorations in the mouth is also recognised to increase the amount of mercury vapour given off several fold and placing gold crowns over amalgam cores particularly drives mercury into the surrounding bone.

  • Bleeding gums
  • Periodontal (gum) disease
  • Mouth ulcers
  • A metallic taste
  • Excessive salivation
  • A loss of the sense of taste
  • A burning, red, inflamed mouth
  • ‘Bald’ patches on the tongue or cheeks (includes geographical tongue) and
  • Dark spots on gums (‘amalgam tattoos’)

Effects on Ears

  • Dizziness
  • Vertigo
  • Poor balance
  • Tinnitus (ringing or whining noises in the ears)
  • Pain in the ear canals
  • Poor hearing and deafness and
  • Difficulty interpreting what you hear.

Endocrine System

Symptoms of mercury poisoning in the endocrine system include:

  • Hypoglycaemia and dysglycaemia (low and poorly controlled blood sugar respectively)
  • Hypothyroidism (an underactive thyroid gland)
  • Hypoadrenalism (under-functioning adrenal glands)
  • Constant fatigue (adrenal and thyroid gland exhaustion) and
  • A poor physiological response to stress.

Skin Hair and Nails

  • Cold, clammy skin
  • Dry skin
  • Peeling or flaking skin on the hands, feet and face
  • A puffy face
  • Red, flaky skin around the eyes
  • Thick, red skin on hands & feet
  • Pricking, stabbing, fizzing or crawling sensations in the skin (vermiculation)
  • Very itchy rashes
  • Eczema and psoriasis
  • Excessive perspiration
  • An inability to sweat or
  • Night sweats
  • Loss of axillary, pubic, body or head hair
  • Greying of hair
  • Dry, thin, wiry, dull hair and
  • Weak, flaky nails that split and tear easily


  • Chronic sinusitis
  • Poor sense of smell
  • Chronic or recurrent rhinitis
  • Nasal congestion
  • A persistently sore throat and
  • Chronic tonsillitis


  • Intermittent visual blurring
  • Deteriorating peripheral vision or ‘tunnel’ vision
  • Bulging eyes
  • Sensitivity to light
  • Difficulty focussing
  • Poor colour vision
  • Poor night vision and
  • Difficulty moving the eyes

Immune System

  • Chronic, recurrent or frequent infections.
  • Chronic or recurrent yeast infections – Mercury actively promotes the overgrowth of yeasts such as Candida albicans causing thrush, ‘jock’ itch and athlete’s foot.
  • The development of allergies and sensitivities – Mercury alters the ratios of T-helper cells to T-suppressor cells so that the immune response is turned on more readily but not terminated, leading the immune system to over-react to a wide variety of foods and chemicals.
  • Autoimmune diseases – Mercury binds to proteins on the surface of the cells of the body (the histocompatibility complex), leading the immune system to identify them as being foreign and initiating one of the 100 or more autoimmune diseases such as multiple sclerosis, scleroderma or Hashimoto thyroiditis.
  • Various cancers – The undermining of the immune response and in particular the disabling of the natural killer cells leads to the development of one of the most prevalent immune deficiency disease of all: cancer.
  • Water retention (especially of the legs) and
  • Swollen lymph nodes (especially in the neck).

Digestive System

  • The development of food sensitivities and intolerances
  • Abdominal cramps and pain
  • Constipation and/or diarrhoea
  • Irritable bowel syndrome
  • Malabsorption
  • Leaky gut
  • Gastroenteritis
  • Nausea and
  • Heartburn


  • A profound exhaustion and fatigue (chronic fatigue syndrome and fibromyalgia)
  • Low body temperature
  • Cold hands and feet
  • Unexplained changes in weight
  • Changes in appetite
  • Excessive thirst
  • Headaches and migraines
  • Anaemia
  • Difficulty getting to sleep
  • Early waking
  • Insomnia and
  • Sleepiness during the day


  • Fibromyalgia
  • Chronic fatigue syndrome (CFS)
  • Rheumatoid arthritis (RA)
  • Multiple sclerosis (MS)
  • Parkinson’s disease
  • Alzheimer’s disease (AD)
  • Colitis
  • Crohn’s disease
  • Autoimmune diseases
  • Attention deficit hyperactivity disorder (ADHD)
  • Autism and
  • Cancer