Friday, March 25, 2016

Heavy Metals: Toxicity Explained

Dear Readers,

This post was written by Ami Ingram, MD, the newest addition to the Vaughan Integrative Medicine (VIM) team.

- Dr. Vaughan

Environmental factors play an important part in the overall health and wellness of individuals and contribute significantly to community health. There is now a greater awareness of environmental toxins because of the publicity surrounding the Flint, Michigan water crisis. If you followed the news, you are aware of the toxic levels of lead in Flint’s water supply. While there are many sources of environmental toxins, one of the most prevalent is heavy metals.

Heavy metals are naturally occurring elements that have a high atomic weight and a high density compared to water. Some heavy metals are required in varying amounts by living organisms for proper cellular function; these metals include iron, cobalt, copper, manganese, molybdenum, and zinc. Other heavy metals include aluminum, antinomy, arsenic, beryllium, bismuth, cadmium, lead, mercury, nickel, platinum, thallium, thorium, tin, tungsten, and uranium. Many of these metals now have a wide distribution in the environment because they are used in industrial, domestic, agricultural, medical and technological applications. All metals are toxic at higher concentrations. The potential for a metal to become toxic depends on factors including the dose, the pathway of exposure, along with the age, gender or at the nutritional status of the individuals exposed to the metals.

Heavy metals become toxic when they accumulate to the point that they disrupt metabolic functions. This happens in two ways:

1. They accumulate and thereby disrupt function and vital organs and glands such as the heart, brain, kidneys, bone, liver, etc.

2. They displace the vital nutritional minerals from their original place, thereby hindering their biological function. For example, lead can displace iron and inhibit the body's ability to make hemoglobin.

The degree to which an individual will experience the symptoms of heavy metal toxicity vary greatly from person to person. Children and the elderly are more susceptible to experiencing symptoms. Some individuals never develop symptoms because they are genetically predisposed to more efficiently detoxifying the body. Other people may not show symptoms of toxicity for many years and late in life develop a chronic degenerative disease that is sometimes the result of slow ongoing exposure to toxins.

The American Academy of Environmental Medicine and the American College for the Advancement of Medicine teach that exposure to heavy metals contributes to an individual’s chance at being affected by cardiovascular disease, some cancers, and many neurodegenerative diseases including Alzheimer's, multiple sclerosis, ALS (Lou Gehrig's disease), and many other autoimmune diseases.

Each of the heavy metals has a slightly different effect on the body. Common symptoms of heavy metal toxicity include:
  • altered metabolism,
  • asthma and chronic lung disease,
  • cancer,
  • damaged immune system,
  • high blood pressure,
  • atherosclerotic cardiovascular disease – resulting in heart attacks, strokes, per referral vascular disease, and congestive heart failure,
  • neurodegenerative diseases,
  • psychiatric illnesses,
  • kidney and liver damage,
  • reproductive system diseases in both men and women, and
  • skin disorders.
The Agency for Toxic Substances and Disease Registry (ATSDR) provides information and fact sheets on many substances that are considered toxic including heavy metals, how exposure to the toxins occurs, and how they can impact human health. Three of the most common heavy metals that impact people's health are cadmium, lead, and mercury; here’s information from ATSDR on these three heavy metals:


Cadmium is a natural element in the earth's crust. It is usually found as a mineral combined with other elements such as oxygen (cadmium oxide), chlorine (cadmium chloride), or sulfur (cadmium sulfate, cadmium sulfide). All soils and rocks, including coal and mineral fertilizers, contain some cadmium. Most cadmium used in the United States is extracted during the production of other metals like zinc, lead, and copper. Cadmium does not corrode easily and has many uses, including batteries, pigments, metal coatings, and plastics.


  • Exposure to cadmium happens mostly in the workplace where cadmium products are made, for example a battery factory.
  • Living near industrial facilities which release cadmium into the air.
  • Cadmium is used in cigarette production therefore smoking cigarettes or breathing cigarette smoke exposes individuals to this potential toxin. 
  • Eating foods containing cadmium; low levels are found in all foods (highest levels are found in shellfish, liver, and kidney meats). 
  • Drinking contaminated water.
  • Breathing fumes from combustion of petrol and other fossil fuels (cadmium oxide is one of the main by-products of combustion). Living near or exercising along major roadways can cause exposure to high amounts of cadmium.
  • Yellow paints, especially oil paints are high in cadmium. 

Health Risks from Over-Exposure:

  • Breathing high levels of cadmium can severely damage the lungs. Eating food or drinking water with very high levels severely irritates the stomach, leading to vomiting and diarrhea.
  • Long-term exposure to lower levels of cadmium in air, food, or water leads to a buildup of cadmium in the kidneys and possible kidney disease. Other long-term effects are lung damage and fragile bones.
  • The Department of Health and Human Services (DHHS) has determined that cadmium and cadmium compounds are known human carcinogens.