HEAVY METALS
The term heavy metal refers to any metallic chemical element that has a relatively high density and is toxic or poisonous at low concentrations. Examples of heavy metals include mercury, cadmium, arsenic, chromium, thallium, and lead.
Heavy metals are natural components of the Earth's crust. They cannot be degraded or destroyed. To a small extent they enter our bodies via food, drinking water and air. As trace elements, some heavy metals (e.g. copper, selenium, zinc) are essential to maintain the metabolism of the human body. However, at higher concentrations they can lead to poisoning. Heavy metal poisoning could result, for instance, from drinking-water contamination (e.g. lead pipes), high ambient air concentrations near emission sources, or intake via the food chain.
Heavy metals are dangerous because they tend to bioaccumulate. Bioaccumulation means an increase in the concentration of a chemical in a biological organism over time, compared to the chemical's concentration in the environment. Compounds accumulate in living things any time they are taken up and stored faster than they are broken down (metabolized) or excreted. If heavy metals enter and accumulate in body tissues faster than the body’s detoxification pathways can dispose of them, a gradual buildup of the toxins will occur.
Heavy metals can enter a water supply by industrial and consumer waste, or even from acidic rain breaking down soils and releasing heavy metals into streams, lakes, rivers, and groundwater.
The government agency ATSDR (Agency for Toxic Substances and Disease Registry), list the Top 20 Hazardous Substances (you can see this list at www.astdr.cdc.gov/cxcx3.html) and the top three toxic substances are 1. Arsenic 2. Lead and 3.Mercury. that should give you an idea of just how prevalent and deadly these toxins are---how concerned you should be about them.
Definition of Heavy Metal Poisoning
Heavy metal poisoning is the toxic accumulation of heavy metals in the soft tissues of the body.
Causes and symptoms
Most cases of heavy metal poisoning result from chronic low level exposure. In the last 50 years, human exposure to heavy metals has risen dramatically. This is the result of an exponential increase in the use of heavy metals in industrial processes and products. Today, chronic exposure comes from toxic waste dump and burn sites, agricultural chemical products, mercury amalgam dental fillings, lead-based paint, tap water, personal care products, chemical residues in processed foods and in the fish supply.
For example arsenic is found in pesticides, herbicides, fungicides, wood preservatives, paints, tobacco, seafood, manufacturing, microwaves, and lasers. Smoking cigarettes and working or playing on wood decks can also expose yo to high levels of arsenic. Arsenic also cause neurological damage as well as injury to your skin and circulatory system, and can also cause cancer.
Lead typically leaches into water from plumbing in older buildings(although lead pipes and plumbing fittings have been banned since August 1998, most older buildings still have the lead plumbing that deposits into the water) according to the EPA (Environmental Protection Agency), children and pregnant women are particularly susceptible to lead health risks.
Excess levels of mercury these days generally come from eating fish/shellfish or from dental amalgam fillings. If one has dental amalgam fillings made with mercury it is advisable to have them removed as the mercury is slowly leaching into your body and accumulating in your tissues.
Cadmium exposure can come from drinking out of a cracked cup or teapot, from drinking water, or from handling pigments or batteries; it is also present in the air and foods, particularly shellfish. Effects of cadmium toxicity include kidney damage, lung cancer, and possibly prostrate cancer. In addition, a new study linking cadmium to breast cancer shows that cadmium mimics estrogen in its effects on cell growth.
Symptoms of heavy metal poisoning will vary, depending on the nature and the quantity of the heavy metal ingested. Patients may complain of nausea, vomiting, diarrhea, stomach pain, headache, sweating, and a metallic taste in the mouth. Depending on the metal, there may be blue-black lines in the gum tissues. In severe cases, patients exhibit obvious impairment of cognitive, motor, and language skills. The expression "mad as a hatter" comes from the mercury poisoning prevalent in 17th century France among hatmakers who soaked animal hides in a solution of mercuric nitrate to soften the hair.
Here is a list of the most commonly found heavy metals and their individual symptoms:
Mercury
Mercury is an extremely heavy, odorless, silver colored liquid. Mercury exists as a natural element in the earth's crust. Elemental mercury is also known as metallic mercury, liquid mercury, liquid silver and quicksilver.
Symptoms of toxicity include:
The nervous system is very sensitive to all forms of mercury. Methylmercury and metallic mercury vapors are more harmful than other forms because more mercury in these forms reaches the brain. Exposure to high levels of metallic, inorganic, or organic mercury can permanently damage the brain, the kidneys, and the developing fetus. Effects on brain functioning may cause irritability, shyness, tremors, changes in vision or hearing, and memory problems.
Short-term exposure to high levels of metallic mercury vapors can cause problems such as lung damage, vomiting, diarrhea, skin rashes, and eye irritation.
You can also go to www.gotmercury.org/ to type in type and weight of fish to find it’s mercury levels!
Cadmium
Cadmium is a metallic element that occurs naturally in the earth’s crust. All soils and rocks contain some cadmium. Most cadmium used in the United States is extracted during the production of other metals like zinc and copper. Cadmium has many uses, including batteries, pigments, metal coatings, and plastics.
Symptoms of toxicity:
Breathing high levels of cadmium can damage the lungs. Eating food or drinking water with very high levels can irritate the stomach, leading to vomiting and diarrhea. Exposure to lower levels of cadmium over a long time builds up cadmium in the kidneys and possibly leads to kidney disease. Other long-term effects are lung damage and fragile bones.
According to the Environmental Protection agency, cadmium probably causes lung cancer and possibly causes prostate cancer.
Arsenic
Arsenic is a naturally occurring element widely distributed in the earth’s crust. It combines with oxygen and other elements to form inorganic arsenic compounds. Inorganic arsenic compounds have various industrial purposes, including the smelting of other metals such as lead, manufacture of some types of glass, and formulation of pesticides and fungicides. Inorganic arsenic compounds also can be used in pressure-treated wood.
Symptoms of toxicity:
People exposed to high levels of arsenic can have nausea and vomiting, diarrhea, anemia, and low blood pressure. These symptoms may be followed by a feeling of "pins and needles" in the hands and feet (neuropathy).
Chronic (long-term) exposure to arsenic can cause stomach ailments, headaches, fatigue, neuropathy, dark splotches on the skin, and small "corns" or "warts" on the palms of the hands, soles of the feet, and torso.
Chromium
Chromium is a naturally occurring element in rocks, animals, plants, soil, and volcanic dust and gases. Chromium is present in the environment in several different forms.
Some forms of chromium occur naturally in the environment and are essential nutrients in the human diet. Industrial processes generally produce other forms of chromium.
Symptoms of toxicity:
All forms of chromium can be toxic at high levels, but some forms are more toxic than others. Breathing high levels of chromium can cause irritation to the nose, such as runny nose and nosebleeds. Ingesting large amounts of chromium can cause stomach upsets and ulcers, seizures, and kidney and liver damage. Skin contact with certain chromium compounds can cause skin ulcers. Some people are extremely sensitive to chromium and can have allergic reactions consisting of severe redness and swelling of the skin.
One form of chromium compound can increase the risk of lung cancer (the EPA classifies it in air as a human carcinogen).
Lead
Lead is a naturally occurring metal found in small amounts in the earth’s crust. Lead can be found in all parts of our environment. Much of it comes from human activities that include mining, manufacturing, and burning fossil fuels.
Lead has many different uses. It is used to make batteries, ammunition, metal products (solder and pipes), and devices to shield X-rays. Because of health concerns, the amount of lead used in gasoline, paints, ceramics, and pipe solder has been dramatically reduced in recent years.
Symptoms of toxicity:
Lead can affect almost every organ and system in the body. The most sensitive system, particularly in children, is the central nervous system (which includes the brain). Slow development can occur in young children who have lead levels as low as 10 ug/dL. At hazardous levels, lead can decrease reaction time; cause weakness in fingers, wrists, or ankles; and affect the memory. Lead also can cause anemia, stomach problems, and high blood pressure.
Lead can cause cancer in lab animals but not enough studies in humans have been done to show whether lead causes cancer in humans.
Diagnosis
Heavy metal poisoning may be detected using blood and urine tests, hair and tissue analysis, or x ray.
In childhood, blood lead levels above 80 ug/dL generally indicate lead poisoning, however, significantly lower levels (>30 ug/dL) can cause mental retardation and other cognitive and behavioral problems in affected children. The Centers for Disease Control and Pevention considers a blood lead level of 10 ug/dL or higher in children a cause for concern. In adults, symptoms of lead poisoning are usually seen when blood lead levels exceed 80 ug/dL for a number of weeks.
Blood levels of mercury should not exceed 3.6 ug/dL, while urine levels should not exceed 15 ug/dL. Symptoms of mercury poisoning may be seen when mercury levels exceed 20 ug/dL in blood and 60 ug/dL in urine. Mercury levels in hair may be used to gauge the severity of chronic mercury exposure.
Since arsenic is rapidly cleared from the blood, blood arsenic levels may not be very useful in diagnosis. Arsenic in the urine (measured in a 24-hour collection following 48 hours without eating seafood) may exceed 50 ug/dL in people with arsenic poisoning. If acute arsenic poisoning is suspected, an x ray may reveal ingested arsenic in the abdomen (since arsenic is opaque to x rays). Arsenic may also be detected in the hair and nails for months following exposure.
Cadmium toxicity is generally indicated when urine levels exceed 10 ug/dL of creatinine and blood levels exceed 5 ug/dL.
Treatment
The treatment for most heavy metal poisoning is chelation therapy. A chelating agent specific to the metal involved is given either orally, intramuscularly, or intravenously. The three most common chelating agents are calcium disodium edetate, dimercaprol (BAL), and penicillamine. The chelating agent encircles and binds to the metal in the body's tissues, forming a complex; that complex is then released from the tissue to travel in the bloodstream. The complex is filtered out of the blood by the kidneys and excreted in the urine. This process may be lengthy and painful, and typically requires hospitalization. Chelation therapy is effective in treating lead, mercury, and arsenic poisoning, but is not useful in treating cadmium poisoning. To date, no treatment has been proven effective for cadmium poisoning.
In cases of acute mercury or arsenic ingestion, vomiting may be induced. Washing out the stomach (gastric lavage) may also be useful. The patient may also require treatment such as intravenous fluids for complications of poisoning such as shock, anemia, and kidney failure.
You can also go to www.gotmercury.org to type in type and weight of fish to find it’s mercury levels!
