Detoxing Heavy Metals

When considering the environmental impact of mobilized metals, the “big three”, mercury, lead, and cadmium, are in the limelight. Less so is perhaps mercury, which is being displaced from industrial processes by the introduction of new technologies, With relatively well-defined point sources of lead contamination, the major spread of lead in the environment has been partly curbed by the introduction of unleaded gasoline. (3)

Reduction of the toxic heavy metals in industry in recent years is helpful but the problem lies in the fact that many of the potential sources of these contaminants are old, and are now breaking down in the environment.

Let’s look at these individually in a little more detail.

Mercury

Mercury poisoning cases have been reported in many parts of the world, resulting in many deaths every year. Mercury exposure leads to harmful effects on almost every organ and system. It should be considered a silent threat to the environment and human life, through the world. (4)

Mercury is utilized in the electrical industry (switches, thermostats, batteries), dentistry (dental amalgams), and numerous industrial processes including the production of caustic soda, in nuclear reactors, as antifungal agents for wood processing, as a solvent for reactive and precious metal, and as a preservative of pharmaceutical products (10)

Humans exposure to mercury usually take place via eating mercury-contaminated food, dental care procedures using amalgams, using mercury-based, thermometers, and sphygmomanometer, occupational exposure (e.g. mining) and using fluorescent light bulbs and batteries (4)

Mercury toxicity is not often included in the differential diagnosis of common subjective complaints such as fatigue, anxiety, depression, odd paresthesias, weight loss, memory loss, and difficulty concentrating, but these are the symptoms of low-grade chronic mercury exposure. (11)

Amalgam (Mercury) fillings

Mercury used in amalgam fillings has become a major concern, so often the amalgam fillings are removed. Unfortunately, this does not completely free the body of mercury as some will leach into the body after the fillings are removed.

Significant deposits of mercury, previously non-existent, were found in the lungs, kidneys, endocrine organs, liver, and heart with abnormal low-voltage ECGs of patients after amalgam fillings were removed. (2)

Such mercury contamination may then contribute to intractable infections or pre-cancer. However, these mercury deposits, which commonly occur in such cases, were successfully eliminated by the oral intake of 400 mg of Chinese parsley (Cilantro) daily for average weight adults. (2)

Lead

Lead is a naturally occurring bluish-gray metal present in small amounts in the earth’s crust. Although lead occurs naturally in the environment, anthropogenic activities such as fossil fuels burning, mining, and manufacturing contribute to the release of high concentrations. Lead has many different industrial, agricultural and domestic applications. It is currently used in the production of lead-acid batteries, ammunition, metal products (solder and pipes), and devices to shield X-rays. (10)

Exposure to lead occurs mainly via inhalation of lead-contaminated dust particles or aerosols, and ingestion of lead-contaminated food, water, and paints. Adults absorb 35 to 50% of lead through drinking water and the absorption rate for children may be greater than 50%. (10)

Toxic effects of Lead

Lead is the most systemic toxicant that affects several organs in the body including the kidneys, liver, central nervous system, hematopoietic system, endocrine system, and reproductive system. Lead exposure usually results from lead in deteriorating household paints, lead in the workplace, lead in crystals and ceramic containers that leach into water and food, lead use in hobbies, and lead use in some traditional medicines and cosmetics. (10)

There are many published studies that have documented the adverse effects of lead in children and the adult population. In children, these studies have shown an association between blood level poisoning and diminished intelligence, lower intelligence quotient-IQ, delayed or impaired neurobehavioral development, decreased hearing acuity, speech and language handicaps, growth retardation, poor attention span, and anti-social and diligent behaviors. (10)

In the adult population, reproductive effects, such as decreased sperm count in men and spontaneous abortions in women have been associated with high lead exposure. Acute exposure to lead induces brain damage, kidney damage, and gastrointestinal diseases, while chronic exposure may cause adverse effects on the blood, central nervous system, blood pressure, kidneys, and vitamin D metabolism. (10)

Cadmium

Cadmium is a heavy metal of considerable environmental and occupational concern. It is widely distributed in the earth’s crust at an average concentration of about 0.1 mg/kg. The highest level of cadmium compounds in the environment is accumulated in sedimentary rocks, and marine phosphates contain about 15 mg cadmium/kg (10)

The main routes of exposure to cadmium are via inhalation or cigarette smoke, and ingestion of food. Skin absorption is rare. Human exposure to cadmium is possible through a number of several sources including employment in primary metal industries, eating contaminated food, smoking cigarettes, and working in cadmium-contaminated workplaces, with smoking being a major contributor. (10)

Other sources of cadmium include emissions from industrial activities, including mining, smelting, and manufacturing of batteries, pigments, stabilizers, and alloys. Cadmium is also present in trace amounts in certain foods such as leafy vegetables, potatoes, grains and seeds, liver and kidney, and crustaceans and mollusks, liver, mushrooms, shellfish, mussels, cocoa powder, and dried seaweed. (10)

Toxic effects of Cadmium

Chronic inhalation exposure to cadmium particulates is generally associated with changes in pulmonary function and chest radiographs that are consistent with emphysema [95]. Workplace exposure to airborne cadmium particulates has been associated with decreases in olfactory function [96]. Several epidemiologic studies have documented an association of chronic low-level cadmium exposure with decreases in bone mineral density and osteoporosis. (10)

Cadmium is a severe pulmonary and gastrointestinal irritant, which can be fatal if inhaled or ingested. After acute ingestion, symptoms such as abdominal pain, burning sensation, nausea, vomiting, salivation, muscle cramps, vertigo, shock, loss of consciousness and convulsions usually appear within 15 to 30 min. Acute cadmium ingestion can also cause gastrointestinal tract erosion, pulmonary, hepatic or renal injury and coma. (10)