Frequently Asked Questions
- May cause damage to the central nervous function, cardiovascular and gastrointestinal system, lungs, kidneys, liver, endocrine glands and bones.
- Chronic heavy metal exposure may increase the risk of some cancers.
- It’s not possible to avoid exposure to toxic metals, as the body is always exposed to other sources, such as food, beverages, air.
- It’s possible to reduce the risk of metal toxicity, through lifestyle changes, and dietary changes, which promote the excretion of ingested heavy metals.
- Pregnant woman run the risk of toxic exposure to the developing foetus, as the mobilisation of stored lead from the mother’s bones may leak into the bloodstream, and result in chronic rather than acute lead exposure in the mother.
- The severity and health outcomes depend on several factors, type and form of the element, route of exposure (oral, inhalation, topical or ocular), duration of exposure, and the person’s individual susceptibility.
- Sudden exposure to some metals, like aluminium dust, or breaking a mercury thermometer, can effect multiple organ systems, such as the GI tract, cardiovascular system, nervous system, endocrine system, kidneys, hair and nails.
- Acute exposure to metals like mercury, gold, nickel, etc. may cause allergic reactions.
- Chronic toxicities are manifested over time from chronic exposure to relatively low concentrations, like sustained environmental exposure.
- Has no know benefit in the human body.
- Its ability to affect and distribute and retain other heavy metals, makes it the most dangerous toxic metals.
- It can be ingested via metallic mercury or mercury salts, inhalation of mercury vapour.
- Mercury salts in water are highly soluble and stable, which is readily taken up and bio transformed to methylmercury by certain fish.
- Absorbed via the GI tract, and is a major source of mercury exposure in humans.
- A mercury compound made in a lab, can be absorbed through the skin.
- We excrete mercury in small amounts through urine and faeces, exhalation and sweat.
- This makes it possible for mercury levels to accumulate with chronic exposure.
- When inhaled it may distribute too many organs, but is concentrated in the brain and kidneys. May also go into the placenta and be found in breast milk.
- Mercury exerts its effects by displacing iron and copper from the active site of enzymes used in energy production. Thus causes cell dysfunction and oxidative damage.
- It damages cell membranes and cholesterol particles by oxidative stress.
- May cause toxicity and symptoms in several organ systems like nervous system, cardiovascular system, GI tract, and kidneys.
- It may also accumulate in the thyroid, and increase immune disorders, and cause contact dermatitis.
- Most frequently leading cause of metal toxicity in children.
- Environmental exposure through lead-paint, food stored in lead cans, and ceramic jars, contaminated water from lead pipes.
- Inhalation and oral ingestion is also a common exposure to humans.
- Children absorb it easier than adults, through lead paint-chips or dust, and toys, also things that are painted with lead based paint.
- It mimics calcium, that’s most absorbed in the bones of children and adults, and may remain there for a long time.
- Conditions that release stored lead in the body such as bone fractures, pregnancy and age-related bone loss, which then enter the blood stream and organs.
- Lead is excreted by the body through urine and faeces.
- Lead can also mimic magnesium, iron and replace them, and damage cells that help build DNA, and also disrupt activity of zinc and the carrier of oxygen in red blood cells.
- Low level of lead exposure, may increase blood pressure and decrease kidney function. Higher levels will effect endocrine glands, reproductive hormones, and lower vitamin D levels. In the brain it can cause brain lesions, cognitive deficits, behavioural changes, and anaemia.
- Acute intoxication is fatal but very rare.
- Chronic exposure is more fatal to humans.
- It’s found in soil, ocean water, and is ingested daily from dietary sources like food and water, and absorbed by the body.
- It can also be inhaled via cigarette smoke and through the skin. Which makes it bind to red blood cells and transports it through the body to the kidneys and liver.
- It is also found in the testes, pancreas and spleen, and is excreted slowly but can stay in the body for up to 20 years.
- It mimics zinc, and disrupts the metabolism of it.
- It interferes with the cellular balance of zinc, and zinc or iron deficiencies, and increase cadmium absorption.
- Too much exposure may lead to renal failure, decrease in bone mineralization, decreased lung function.
- It’s an element with both metal and non-metal chemical characteristics.
- Occurs naturally in the environment as inorganic (more toxic form, less available), and organic (less toxic, but easily available)
- Most common exposure in people is through food and water containing arsenic.
- Seafood contains the highest concentration of organic arsenic, as well as cereals and poultry.
- Can also be inhaled, and absorbed by the skin.
- Inorganic arsenic binds to haemoglobin in red blood cells and when absorbed gets distributed to the liver, kidneys, heart, lungs and nervous system, GI tract and spleen and placenta in a lesser form.
- These compounds are mostly excreted by the kidneys, and some get retained in the skin, nails and hair (Keratin rich tissues).
- Acute inorganic exposure may cause nausea, vomiting, diarrhoea, arrhythmia, and a decrease in white and red blood cell production, and blood volume loss, burning/numbness in extremities and encephalopathy.
- Chronic inorganic exposure may cause anaemia, neuropathy, and liver toxicity. Longer periods of exposure cause skin lesions on the palms and soles of feet
- Severe exposure can lead to loss of circulation in extremities, which may become gangrenous. It is also associated to some types of cancer (skin, lung, liver, bladder and kidney)
- Other metals:
- Iron –Most common metal toxicity. A symptom for Iron overload is hyperpigmentation, caused by the iron and melanin found in the skin. The liver is the primary source of storage and an excess of iron may cause damage. Iron toxicity may cause – joint disease, arrhythmia, heart failure, atherosclerosis risks, and increase risk of liver, breast, gastrointestinal and hematologic cancers.
- Aluminium –The most abundant metal found in the earth’s crust, and is naturally found in food and water.
- Copper – Plays an important role in human nutrition. Excessive copper is found in people with Wilson’s disease, which can be neurotoxic. Unintentional exposure is more frequently reported than those of arsenic.
- Exposure can come from the environment or home, and may be acute or chronic.
- Could come from contaminated food, air, water, dust, living near a hazardous waste site or manufacturing plant that releases metal contaminants, exposure of too many metal containing pesticides, paints, cosmetics, improper disposal or cleaning of toxic metal items (broken thermometer)
- Lead-containing plumbing
- Lead-based paint
- Leaded gasoline
- Food grown in lead-rich soil
- Eating fish/shellfish contaminated with methylmercury
- Breathing contaminated air, or through skin contact in a workplace
- Release of mercury vapour during metal fillings removed by a dentist
- Thermometers, that break and contain mercury
- Fluorescent and mercury lamps, thermostats, barometers, and wall switches manufactured before 1991
- Skin lightening products, antiseptics containing mercury salts
- Groundwater containing arsenic minerals
- Wood preservatives
- Some insecticides, herbicides, fungicides, cotton desiccants, paints and pigments
- Cigarette smoke
- Food consumed that contain calcium
- Contact with solar panels and electric batteries
- Abdominal pain
- Central nervous system dysfunction
- Heart problems
- Finger or toenail discolouration
Careful analysis of dietary, environmental and occupational exposure history is needed for evaluation
There are some metal tests that can be done:
- Blood tests – Lead toxicity is only indicative in blood levels if exposure is more than 90 days. Arsenic toxicity is cleared rapidly from the blood, so this test may vary on early stages of intoxication.
- Urine tests – Indicates cumulative exposure to the total body burden for some metals and recent exposure for others. Urinary arsenic can increase after seafood consumption. Measurement of urine metal concentrations are done with a chelator, which may show stored toxic metals
- Hair and nail analysis– Used to determine cumulative exposure to cadmium, lead, arsenic and mercury
- X-Ray fluorescence– Non-invasive technique for assessing tissue deposits of metals. Used to detect cadmium in kidneys, and lead in bones.
- Decontaminate the area
- Remove contaminated clothing
- Remove the individual, where the exposure occurred
- Indicated for acute metal toxicities
- This is done by putting water into the stomach by a tube to wash out its contents, used in arsenic and lead poisoning
- Emesis (Induced vomiting) is suggested for removal of metals within the stomach, it’s not always effective for removing large amounts of solids.
- Bowel irrigation- putting water into the bowel to wash out the contents. Used for macroscopic particles of some metals, like lead, which can go through intestines easily and larger particles may require surgery to remove.
- Activated charcoal is used to bind ingested toxic metals, but does not work for mercury and iron.
Chelators used currently are:
- Help to eliminate metals toxic and non-toxic from the body
- These therapies are more effective when administered close to time of exposure.
- Dimercaprol – For acute lead toxicity in children and adults, and acute inorganic arsenic or mercury toxicity. It is given by intramuscular injection, several times per day over a period of a few days. Side effects include vomiting, excess salivation, watery eyes, runny nose, and injection site pain.
- DMPS – Oral medication, used for arsenic and cadmium, and mercury chelation. It increases urinary excretion of mercury, and improves symptoms. It does not however alter blood mercury levels. A side effect is an allergic rash.
- Succimer (DMSA) – Treats lead toxicity that is mild in children and adults, and acute arsenic and mercury intoxication. Side effects are diarrhoea and vomiting, metallic taste, increase in liver enzymes, rash, chills, decrease in white blood cell counts
- Prussian blue – Oral chelator for thallium or cesium poisoning in children and adults. Side effects are constipation, abdominal pain, and blue colour of the stool.
- EDTA –Treats moderate lead poisoning. Given slowly, by continuous intravenous infusion. Side effects are headache, fatigue, chills, fever, myalgia, anorexia, nasal congestion, watery eyes, anaemia, clotting abnormalities, and kidney failure.
- Penicillamine – Oral treatment for lead, mercury and copper poisoning. Not used as its potential for serious complications, allergic reactions, anaemia, severe low white blood cell count and kidney failure.
- Iron chelators– Several types used for treating metabolic iron overload, and acute iron intoxication. Injectable iron chelators remove iron from abnormal tissue stores, but not where there is an active iron usage. Side effects are skin rash, hypotension, respiratory distress, eye/ear toxicity, acute neurological toxicity.
- This is the study of gene expression changes when exposed to toxins, and is a useful method and more sensitive and quick assessment for metal toxicity.
New Chelation therapies
- Uses chemical chelators which have several adverse effects, like kidney overload, cardiac arrest, mineral deficiency and anaemia. Magnetic chelators have an additional advantage, as they can be magnetically directed to specific organs of interest.
Maintain good occupational hygiene
Reduce workers contact with metal toxins, remove fumes, follow proper hazardous management procedures, and substitute safer materials. People should learn about the substances they are working with, wear required protective equipment, use proper skin and hand hygiene, decontaminate the workplace before leaving.
Reduce general exposure
Understanding the sources of metal exposure is important. One must become familiar with the symptoms of toxicity, and the first aid procedures when ingesting substances. Read the product labels and understand them. Use the proper waste discarding facilities available. Also avoid mercury fillings to reduce mercury exposure.
One should make sure that the body’s detoxification pathways are working optimally to avoid heavy metal toxicity. These therapies work by reducing the metal absorption from the gut and binding toxic metals in blood and the tissues, thus drawing them out of the body and reducing free-radical damage.
Adequate intake of essential trace minerals can reduce the toxic metal absorption
Use fish oil supplements instead of high-mercury fish
Best to limit consumption of high-mercury fish in adults to one serving per week. Pregnant woman, nursing mothers and young children should avoid eating high mercury fish as it can affect the foetal brain, as it is more sensitive than an adult brain. High quality fish oil is a good alternative to Omega-3 fatty acids.
It helps with the mercury and lead absorption and also increases toxic metal excretion. By using a selenium supplement the mercury accumulation can be reduced over a short period of time.
Modified citrus pectin
It increases the urinary excretion of arsenic, mercury, cadmium and lead. Blood levels of lead decrease and urinary lead excretion increased.
Natural occurring dissolved silicon found in mineral water appears to antagonize the metabolism of aluminium and help to reduce the risk of Alzheimer’s, and support cognitive function.
A free-radical scavenger that protects against oxidative damage caused by lead, mercury and cadmium. Also prevents the absorption of lead and reduces the cellular uptake and decreases cellular toxicity
It’s an antioxidant, which helps to repair damage caused by heavy metals, and is also a strong inducer of oxidative stress in tissues. It also helps to curb delirious effects in people with heavy metal toxicity
It’s a cofactor in sulphur containing amino acid metabolism and is also a precursor to heavy metal chelators. By not using folic acid supplementation during pregnancy causes high blood cadmium levels.
It helps with the protection of metal-catalysed oxidative damage. Can increase the bio-accessibility of iron and zinc.
Binds and immobilises mercury and methylmercury from contaminated water. Mercury deposits were recorded to be absent after treatments followed.
Alpha-Lipoic acid and Glutathione
ALA and glutathione reduces some of the adverse effects in blood parameters, and reduces the haemoglobin concentration caused by intoxication with lead, cadmium and copper. It reduces oxidative stress and improves kidney tissue enzymes.
It reduces oxidative stress caused by heavy metal toxicity. Chronic exposure to toxic metals can decrease cysteine levels, and is also useful as a complete protein which helps to provide additional amino acids, that could block the entry of metals into the nervous tissue.
Essential amino acid found in plant and animal proteins. It combines with many toxic substances and breaks them down to less harmful forms, and then excreted from the body. It’s an important detoxifier of heavy metals. Glycine reduces oxidative stress and chronic cadmium toxicity.
Some of the probiotic bacteria minimize toxic exposure and trap heavy metals. They can decrease multiple strains of heavy metals that are combined.
It’s a green algae that binds to cadmium, zinc, copper and lead, and is used to detoxify water of metal contaminants. It helps lower bioavailability and accelerates excretion of methylmercury and cadmium, and reduces lead induced bone marrow toxicity.