A Guide to Heavy Metals and Their Health Effects

Know Your Heavy Metals

By Marie Be

Guest Writer For Wake Up World

Everyday, the body is exposed to toxins and heavy metals, absorbing small amounts of contaminants. Not much, but enough that  they can accumulate in the body. With ongoing exposure, the body can become overwhelmed, natural detoxification pathways become clogged, and chronic toxicity can be the result.

Heavy metal toxicity has a slow degenerative effect on the body. For example, some heavy metals inhibit the cellular function, which is to protect the organism from oxidative damage, reducing the effectiveness of this antioxidant defense system for detoxification. (1) Other heavy metals act as molecular “mimics” of nutritionally essential trace elements; depleting the body from cofactors essential to cellular regeneration.

Diagnosing metal toxicities can be difficult and is often overlooked by health practitioners. Aside from acute toxicity where the symptoms are apparent, the symptoms and health effects of low to chronic toxicity may often resemble other diseases.

There is still very few  adequate method to test metal toxicity within the body. For this reason, a careful analysis of dietary, environmental, and occupational exposure history is one of the most important tools to help you evaluate your likelihood of  toxicity  — so  it pays to know your heavy metals!

The toxicity of heavy metals depends on a number of factors:

  1. Symptoms vary according to the type of metal, the total dose absorbed, and whether the exposure was acute or chronic.
  2. The age of the person can also influence toxicity. For example, young children are more susceptible to the effects of lead exposure. They absorb several times the percent ingested compared with adults and their brains are still forming; even brief exposures may influence developmental processes.
  3. The route of exposure is also important. For example, mercury is relatively inert in the gastrointestinal tract and also poorly absorbed through intact skin, yet inhaled or injected mercury may have disastrous effects.

There are several metals with documented toxicities and varying risk of unintentional overexposure.


Mercury is considered one of the most dangerous toxic metals because it enhances the distribution and retention of other heavy metals (2) . Mercury can distribute to many organs, but may concentrate in the brain and kidneys. (3) It can also cross the placenta and be found in breast milk. (4)

Mercury exerts its toxic effects by competing with and displacing iron and copper from the active site of enzymes involved in energy production. This induces mitochondrial dysfunction and oxidative damage, destroying cell membranes and accelerating cellular aging within the body cells. Mercury destroys cellular defense and impedes energy generation. It also causes widespread toxicity and symptoms in several organ systems: nervous system (eg, personality changes, tremors, memory deficits, loss of coordination); cardiovascular system (eg, increased risk of arterial obstruction, hypertension, stroke, atherosclerosis, heart attacks, and increased inflammation); GI tract (eg, nausea, diarrhea, ulceration); and kidneys. Mercury may also accumulate in the thyroid and increase the risk of autoimmune disorders (5), and may cause contact dermatitis. (6)

The most common form of mercury intoxication comes from ingesting mercury salts from water or food. Mercury salts are highly soluble and stable in water, which enables them to be readily taken up and biotransformed to methylmercury by certain fish. Biotransformed mercury is readily absorbed through the GI tract within the human body. Although humans can excrete small amounts of mercury in urine or feces as well as via exhalation or sweating, they lack an active robust mechanism for mercury excretion, allowing levels to accumulate with chronic exposure. (7) Detoxing is therefore primordial to counteract mercury accumulation within the body.


Lead toxicity is one of the most frequently reported unintentional toxic heavy metal exposures in children. (8) Lead has no known beneficial function in human metabolism. Exposure is often through contaminated with paint (toys, containers, jewelry, etc.), food packaging or water pipes. Lead can be absorbed through the skin; lead acetate can be found in some cosmetic products. Children absorb lead up to 8-times more efficiently than adults. (9)

Following exposure, lead mimics calcium. This means it is most absorbed and stored in the bones where it can remain for decades. Conditions that cause release of calcium from the bones (fracture, pregnancy, age-related bone loss) will also release stored lead from bones, thus allowing it to enter into the blood and other organs. In addition to disrupting calcium metabolism, lead can mimic and displace magnesium and iron from certain enzymes that construct the building blocks of DNA (nucleotides) and disrupt the activity of zinc in the synthesis of heme – the carrier of oxygen in red blood cells. (10)

Low lead exposure is associated with increases in hypertension risk and reduction in kidney function. In children, low level lead exposure can result in several developmental disorders (accelerated skeletal growth, cognitive deficits and IQ decline, slowed growth and delayed sexual maturation). Higher levels of lead exposure affect the endocrine glands, thyroid, reproductive hormones, brain (causing conditions such as brain lesions, cognitive deficits, and behavioral changes), and can cause anemia. In children, higher levels can manifest as colic. (11)

Although lead can leave the body through feces or urine, the human body lacks an active robust mechanism for lead excretion, allowing levels to accumulate with chronic exposure. Detoxing is therefore primordial to counteract lead accumulation within the body.


Acute cadmium intoxication is a potentially fatal, but very rare. Chronic exposure to cadmium presents a larger threat to human health. Cadmium has no known beneficial role in human metabolism. Cadmium is found in soil and ocean water, and up to 10% of the cadmium ingested from dietary sources, such as food and water, is absorbed by the body. It is readily absorbed through the inhalation of cigarette smoke and can be absorbed through the skin.

Cadmium binds to red blood cells and is transported throughout the body where it concentrates in the liver, kidneys, testes, pancreas, and spleen. (12) Cadmium mimics zinc, disrupting zinc metabolism. There are about 3000 different enzymes and structural proteins in human metabolism that require zinc for their activity and are potential targets of cadmium toxicity. Chronic cadmium exposure can result in the accumulation of cadmium complexes in the kidney (potentially leading to renal failure), decreased bone mineralization, and decreased lung function; it is also a known human carcinogen. (13)

Cadmium is excreted slowly and may remain in the body for more than 20-30 years. Detoxing is therefore primordial to counteract cadmium accumulation within the body.


Although arsenic is not technically a heavy metal, this metalloid nevertheless holds significant potential for adverse health outcomes. Arsenic is one of the more commonly reported sources of unintentional intoxication. (14) It occurs naturally in the environment as both inorganic (the less abundant, more toxic form) and organic (the less toxic, more abundant form) arsenic. The most common route of exposure in humans is consumption of arsenic-containing food or drinking water. Seafood contains the highest concentrations of organic arsenic; cereals and poultry are also important sources. Arsenic can also be inhaled or absorbed through the skin.

Inorganic arsenic binds to hemoglobin in red blood cells and is rapidly distributed to the liver, kidneys, heart, lungs, and to a lesser degree the nervous system, GI tract, and spleen; it can also cross the placenta. Arsenic binds and depletes lipoic acid in cells, interfering with the production of chemical energy. Acute exposure to inorganic arsenic may cause nausea, vomiting, profuse diarrhea, arrhythmia, a decrease in red and white blood cell production, loss of blood volume (hypovolemic shock), burning or numbness in the extremities, and encephalopathy. (15) Chronic inorganic arsenic exposure can result in anemia, neuropathy, or liver toxicity within a few weeks to months. Longer exposure (3-7 years) can also result in characteristic skin lesions (areas of hyperpigmentation or keratin-containing lesions) on the palms and soles of the feet.

Severe exposure can lead to loss of circulation to extremities, which can become necrotic and gangrenous. Chronic exposure to arsenic has been associated with several types of cancer.

Some inorganic arsenic can be converted to organic arsenic compounds in the liver, reducing harm within the body. The kidneys can also excrete arsenic compounds, with a small amount retained in keratin-rich tissues (eg, nails, hair, and skin). When exposure to arsenic is chronic, accumulation in the kidneys and liver can lead to increase toxicity. Detoxing these organs will assist them in keeping your body clean. (16)


Iron toxicity is the most common metal toxicity worldwide. The classic symptom of iron overload is skin hyperpigmentation (to a bronze or grey color) due to deposits of iron and melanin complexes in the skin. The liver, as a primary source of iron storage, is particularly susceptible to overload and related damage. (17) Iron toxicity is also associated with joint disease (arthropathy), arrhythmia, heart failure, increased atherosclerosis risk, and increases in the risk of liver, breast, gastrointestinal, and hematologic cancers. (18)


Aluminum is the most abundant metal in the earth’s crust. It occurs naturally in most foods and water. For most people, daily exposure through food is of 3-10 mg. (19) Elevated levels of aluminum are commonly found in the brains of some Alzheimer’s patients and could play a major role the development of Alzheimer’s disease. (20)

A Word on Detoxing

The human body was naturally designed to revitalize itself in a balanced environment. But with the  prevalence  of so many  toxic practices today, our environment is less than balanced. Our environment is  becoming increasingly toxic, and  so are  our body systems. As heavy metals accumulate  in  the body, toxic stress increases, impacting the function of our vital processes – and  our vitality. That’s why today, detoxing needs to be a way of life

Initially, the  stress that  heavy metal exposure causes on the body can be reduced with appropriate detoxes/cleanses that  fully support the body’s natural elimination and regeneration process. Once the toxic load is reduced and the body’s natural functions improve, unavoidable  environmental  exposures over time can be mitigated through wise dietary choices and regular  cleanses. To find out more about natural detox options, check out my previous articles on  natural detox support, flushing your toxins  and transdermal detoxing.


  1. Reddy CC, Scholz RW, Massaro EJ. Cadmium, methylmercury, mercury, and lead inhibition of calf liver glutathione S-transferase exhibiting selenium-independent glutathione peroxidase activity. Toxicology and Applied Pharmacology.1981;61(3):460-468.
  2. Houston, M. C. Role of mercury toxicity in hypertension, cardiovascular disease, and stroke. J Clin Hypertens (Greenwich). 2011;13(8):621–7
  3. ATSDR. Mercury ToxFAQ. 2000:1–2. Available online at http://www.atsdr.cdc.gov/toxfaqs/tfacts46_metallic_mercury.pdf
  4. Yang J, Jiang Z, Wang Y, Qureshi IA, Wu XD. Maternal-fetal transfer of metallic mercury via the placenta and milk. Annals of clinical and laboratory science. Mar-Apr 1997;27(2):135-141.
  5. Gallagher, C. M. C., and Meliker, J. R. J. Mercury and thyroid autoantibodies in U.S. women, NHANES 2007-2008. Environ Int. 2012;40:39–43
  6. Caravati, E. M., Erdman, A. R., Christianson, G., Elemental mercury exposure: an evidence-based consensus guideline for out-of-hospital management. Clin Toxicol (Phila). 2008;46(1):1–21
  7. Sällsten G, Kreku S, Unosson H. A small dose of ethanol increases the exhalation of mercury in low-level-exposed humans. J Toxicol Environ Health A. 2000 May 26;60(2):89-100
  8. Bronstein, A. C., Spyker, D. A., Cantilena, L. R., Jr, Rumack, B. H., and Dart, R. C. 2011 Annual Report of the American Association of Poison Control Centers’ National Poison Data System (NPDS): 29th Annual Report. Clin Toxicol (Phila). 2012;50(10):911–1164
  9. Abelsohn AR, Sanborn M. Lead and children: clinical management for family physicians. Can Fam Physician. 2010 Jun;56(6):531-5
  10. Kirberger, M., Wong, H. C., Jiang, J., and Yang, J. J. Metal toxicity and opportunistic binding of Pb(2+) in proteins. J. Inorg. Biochem. 2013;125:40–9
  11. ATSDR. Toxicological Profile For Lead. 2007b;:1–582. Available online at http://www.atsdr.cdc.gov/toxprofiles/tp13.pdf
  12. Sigel, A., Sigel, H., and Sigel, R. Cadmium: from toxicity to essentiality. 2013;
  13. Inicropi, M. S., Amantea, D., Caruso, A., and Saturnino, C. Chemical and biological properties of toxic metals and use of chelating agents for the pharmacological treatment of metal poisoning. Arch Toxicol. 2010;84(7):501–20 Thévenod, F., and Lee, W.-K. Toxicology of cadmium and its damage to mammalian organs. Met Ions Life Sci. 2013;11:415–90
  14. Bronstein, A. C., Spyker, D. A., Cantilena, L. R., Jr, Rumack, B. H., and Dart, R. C. 2011 Annual Report of the American Association of Poison Control Centers’ National Poison Data System (NPDS): 29th Annual Report. Clin Toxicol (Phila). 2012;50(10):911–1164
  15. ATSDR. Toxicological Profile For Arsenic. 2007a:1–559. Available online at http://www.atsdr.cdc.gov/toxprofiles/tp2.pdf
  16. Rusyniak DE, Furbee RB, Kirk MA. Thallium and arsenic poisoning in a small midwestern town. Ann Emerg Med. 2002 Mar;39(3):307-11
  17. Ibrahim, D., Froberg, B., Wolf, A., and Rusyniak, D. E. Heavy Metal Poisoning: Clinical Presentations and Pathophysiology. Clinics in Laboratory Medicine. 2006a;26(1):67–97
  18. Siddique A, Kowdley KV. Review article: the iron overload syndromes. Aliment Pharmacol Ther. 2012 Apr;35(8):876-93
  19. Kremastinos, D. T., and Farmakis, D. Iron overload cardiomyopathy in clinical practice. Circulation. 2011;124(20):2253–63. Hewitt CD, Savory J, Wills MR. Aspects of aluminum toxicity. Clin Lab Med. 1990 Jun;10(2):403-22
  20. Lemire, J., and Appanna, V. D. Aluminum toxicity and astrocyte dysfunction: a metabolic link to neurological disorders. J. Inorg. Biochem. 2011;105(11):1513–7. Percy, M. E., Kruck, T. P. A., Pogue, A. I., and Lukiw, W. J. Towards the prevention of potential aluminum toxic effects and an effective treatment for Alzheimer’s disease. J. Inorg. Biochem. 2011;105(11):1505–12

Previous articles by Marie Be:

About the author:

Marie Be  150x150 BURN: Health Impacts of Sunscreen Found to be Worse Than UV Damage!Marie Be’s inspiration comes from her mom who always challenged common assumptions and sought to understand for herself the major issues concerning her family and the choices she made on their behalf. She raised Marie and her brother in a rural environment, feeding them the best organic foods, and focused on building strong immune systems in her children through the use of natural plants, herbs and  minerals.

As a fiery teenager, Marie travelled the world in search of purpose and dreamed of positively influencing our society. While earning her first two degrees, in architecture and sustainable development, she worked for Greenpeace and many other organizations of change. Her experience taught her that change cannot be imposed; she now aims at inspiring individuals through education and awareness.

Marie moved to Vancouver to undertake a Masters in Regenerative Sustainability under the supervision of a Nobel Peace Prize recipient. Teaching workshops on well-being, she started observing a widespread desire in our society for both physical and environmental health and sustainability. Feeling the winds of change, Marie founded  Earth for the Sun.

Earth for the Sun was inspired by  nature, the source of life.  By tuning in that source, by acquiring knowledge on ancient herbal traditions as well as new technologies, Marie believes it is possible to use nature’s intelligence and deliver simple and effective health products.  Check out  Earth for the Sun  for more information.


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