Mercury poisoning (also known as hydrargyria or mercurialism) is a disease caused by exposure to mercury or its compounds. Mercury (chemical symbol Hg) is a heavy metal that occurs in several forms, all of which can produce toxic effects in high enough doses. Its zero oxidation state Hg0 exists as vapor or as liquid metal, its mercurous state Hg+ exists as inorganic salts, and its mercuric state Hg2+may form either inorganic salts or organomercury compounds; the three groups vary in effects. Toxic effects include damage to the brain, kidney, and lungs. Mercury poisoning can result in several diseases, including acrodynia (pink disease), Hunter-Russell syndrome,and Minamata disease.
Symptoms typically include sensory impairment (vision, hearing, speech), disturbed sensation and a lack of coordination. The type and degree of symptoms exhibited depend upon the individual toxin, the dose, and the method and duration of exposure.
How to Replace Mercury Fillings
Mercury fillings began being used in dentistry over 100 years ago. In recent years, the safety of these types of fillings (also known as amalgrams) has come under scrutiny. Mercury is well-known for its toxicity, and mercury fillings contain over 50 percent mercury. Holistic practitioners question the safety of having mercury fillings in our mouths, and wonder if ingestion of this toxin accounts for the rise in cancers and other chronic diseases over the last few decades. Because of these concerns, removal of mercury fillings is becoming a common procedure among holistic dentists.
Difficulty: Moderately Challenging
Instructions
Things You’ll Need:
Holistic dentist
1) Visit a holistic doctor first. A naturopath or other doctor experienced in dealing with toxic metals can put you on an immune-system boosting protocol prior to removing your mercury fillings. Through the use of certain herbs like garlic and specific vitamins, you can help prepare your body for the procedure.
2) Locate a dentist who is experienced with replacing mercury fillings and practices mercury-free dentistry. Many dentists will not have experience performing this procedure. During filling removal, you could potentially be exposed to high amounts of mercury, so picking an experienced practitioner will help maintain safety.
3) Schedule your appointment. Remember, your appointment may take several hours, depending on the number of fillings you have to remove.
4) Go to your appointment. Make sure your dentist offers you an alternative source of oxygen during the removal procedure, to ensure you aren’t inhaling any mercury gas. Also, your dentist should cool the fillings before removal, cut them into chunks, use a high-volume suction system, and use rubber dams inside the mouth.
5) After your appointment, consider taking chlorella. Chlorella is an algae that has been touted for its ability to bind with heavy metals and remove them from the body. Chlorella can be found in virtually any health food store.
Methylmercury exposure
Outbreaks of methylmercury poisoning have made it clear that adults, children, and developing fetuses are at risk from dietary exposure to methylmercury. During these poisoning outbreaks some mothers with no symptoms of nervous system damage gave birth to infants with severe disabilities and it became clear that the developing nervous system of the fetus may be more vulnerable to methylmercury than is the adult nervous system. Mothers who are exposed to methylmercury and breast-feed their babies may also expose their infant children through their milk.
Signs and symptoms
Common symptoms of mercury poisoning include peripheral neuropathy (presenting as paresthesia or itching, burning or pain), skin discoloration (pink cheeks, fingertips and toes), swelling, anddesquamation (shedding of skin).
Because mercury blocks the degradation pathway of catecholamines, epinephrine excess causes profuse sweating, tachycardia (persistently faster-than-normal heart beat), increased salivation, andhypertension (high blood pressure). Mercury is thought to inactivate S-adenosyl-methionine, which is necessary for catecholamine catabolism by catechol-o-methyl transferase.
Affected children may show red cheeks, nose and lips, loss of hair, teeth, and nails, transient rashes, hypotonia (muscle weakness), and increased sensitivity to light. Other symptoms may includekidney disfunction (e.g. Fanconi syndrome) or neuropsychiatric symptoms such as emotional lability, memory impairment, or insomnia.
Thus, the clinical presentation may resemble pheochromocytoma or Kawasaki disease.
Inorganic mercury compounds
Mercury occurs inorganically as salts such as mercury (II) chloride. Mercury salts primarily affect the gastro-intestinal tract and the kidneys, and can cause severe kidney damage; however, as they can not cross the blood-brain barrier easily, mercury salts inflict little neurological damage without continuous or heavy exposure. As two oxidation states of mercury form salts (Hg+ and Hg2+), mercury salts occur in both mercury(I) (or mercurous) and mercury(II) (mercuric) forms. Mercury(II) salts are usually more toxic than their mercury (I) counterparts because their solubility in water is greater; thus, they are more readily absorbed from the gastrointestinal tract.
Mercuric cyanide
Mercuric cyanide (also known as Mercury (II) cyanide), Hg(CN)2, is a particularly toxic mercury compound. If ingested, both life-threatening mercury and cyanide poisoning can occur. Hg(CN)2 can enter the body via inhalation, ingestion, or passage through the skin. Inhalation of mercuric cyanide irritates the throat and air passages. Heating or contact of Hg(CN)2 with acid or acid mist releases toxic mercury and cyanide vapors that can cause bronchitis with cough and phlegm and/or lung tissue irritation. Contact with eyes can cause burns and brown stains in the eyes, and long time exposure can affect the peripheral vision. Contact with skin can cause skin allergy, irritation, and gray skin color.
Mercury cyanide was used in two murders in New York in 1898. The perpetrator, Roland B. Molineux, sent poisoned medicines to his victims through the US mail. The first victim, Henry Barnett, died of mercury poisoning twelve days after taking the poison. The second victim, Catherine Adams, died of cyanide poisoning within 30 minutes of taking the poison. As in the suicide cases, the difference between the two cases may be attributed to differences in the acidities of the solutions containing the poison, or to differences in the acidities of the victims’ stomachs.
The drug NAP (n-acetyl penicillamine) has been used to treat mercury poisoning with limited success.
Organic mercury compounds
Compounds of mercury tend to be much more toxic than the element itself, and organic compounds of mercury are often extremely toxic and have been implicated in causing brain and liver damage. The most dangerous mercury compound, dimethylmercury, is so toxic that even a few microliters spilled on the skin, or even a latex glove, can cause death.
Methylmercury is the major source of organic mercury for all individuals. It works its way up the food chain through bioaccumulation in the environment, reaching high concentrations among populations of some species. Larger species of fish, such as tuna or swordfish, are usually of greater concern than smaller species.
(FDA) and the U.S. Environmental Protection Agency (EPA) advise women of child-bearing age, nursing mothers, and young children to completely avoid swordfish, shark, king mackerel and tilefish. Limit consumption of albacore (“white”) tuna to no more than 6 oz (170 g) per week, and of all other fish and shellfish to no more than 12 oz (340 g) per week.
Prevention
Mercury poisoning can be prevented (or minimized) by eliminating or reducing exposure to mercury and mercury compounds. To that end, many governments and private groups have made efforts to regulate heavily the use of mercury, or to issue advisories about its use. For example, the export from the European Union of mercury and some mercury compounds has been prohibited since 2010-03-15.[29] The variability among regulations and advisories is at times confusing for the lay person as well as scientists.
Country |
Regulating
agency |
Regulated activity |
Medium |
Type of mercury compound |
Type of limit |
Limit |
|---|---|---|---|---|---|---|
| US | OSHA | occupational exposure | air | elemental mercury | Ceiling (not to exceed) | 0.1 mg/m³ |
| US | OSHA | occupational exposure | air | organic mercury | Ceiling (not to exceed) | 0.05 mg/m³ |
| US | FDA | drinking | water | inorganic mercury | Maximum allowable concentration | 2 ppb(0.002 mg/L) |
| US | FDA | eating | sea food | methylmercury | Maximum allowable concentration | 1 ppm |
| US | EPA | drinking | water | inorganic mercury | Maximum contaminant level | 2 ppb (0.002 mg/L) |
The EPA issued recommendations in 2004 regarding exposure to mercury in fish and shellfish. The EPA also developed the “Fish Kids” awareness campaign for children and young adults on account of the greater impact of mercury exposure to that population
Prognosis
Many of the toxic effects of mercury are partially or wholly reversible, either through specific therapy or through natural elimination of the metal after exposure has been discontinued. However, heavy or prolonged exposure can do irreversible damage, particularly in fetuses, infants, and young children. Young’s syndrome is believed to be a long term consequence of early childhood mercury poisoning. Mercuric Chloride may cause cancer as it has caused increases in several types of tumors in rats and mice, while methyl mercury has caused kidney tumors in male rats. The EPA has classified mercuric chloride and methyl mercury as possible human carcinogens (ATSDR, EPA)
Detection in biological fluids
Mercury may be measured in blood or urine to confirm a diagnosis of poisoning in hospitalized victims or to assist in the forensic investigation in a case of fatal overdosage. Some analytical techniques are capable of distinguishing organic from inorganic forms of the metal. The concentrations in both fluids tend to reach high levels early after exposure to inorganic forms, while lower but very persistent levels are observed following exposure to elemental or organic mercury. Chelation therapy can cause a transient elevation of urine mercury levels.
Dental amalgam
Dental amalgam, an alloy of about 50 percent elemental mercury, was first introduced in France in the early 19th century.
In 2002, Maths Berlin, Professor Emeritus of Environmental Medicine and chair of the 1991 World Health Organization Task Group on Environmental Health Criteria for Inorganic Mercury, published an overview and assessment of the scientific literature published between November 1997-2002 as part of a special investigation for the Swedish Government on amalgam related health issues. The report concluded: “With reference to the fact that mercury is a multipotent toxin with effects on several levels of the biochemical dynamics of the cell, amalgam must be considered to be an unsuitable material for dental restoration.”
Dental amalgam controversy
The dental amalgam controversy refers to the conflicting views over the use of amalgam as a filling material mainly because it contains the element mercury. The concern centers on the health effects of toxicity or allergy which may be associated with constant mercury exposure, particularly as a potential cause of chronic illnesses, autoimmune disorders, neurodegenerative diseases, birth defects, oral lesions, and mental disorders. Scientists agree that dental amalgam fillings leach mercury into the mouth, but studies vary widely in the amount. Estimations run from 1-3 µg/day (FDA) up to 27 µg/day (Patterson).The effects of this exposure is also disputed, and currently dental amalgam is approved for use in most countries, although Norway, Denmark and Sweden are notable exceptions.
A 2006 Zogby International poll of 2,590 US adults found that 72% of respondents were not aware that mercury was a main component of dental amalgam, and 92% of respondents would prefer to be told about mercury in dental amalgam before receiving it as a filling. A 1993 study published in FDA Consumer found that 50% of Americans believed fillings containing mercury caused health problems. Some dentists, (including a member of the FDA’s Dental Products Panel) suggest that there is an obligation to inform patients that amalgam contains mercury.
Dentists who advocate the use of amalgam point out that it is durable, cheap, and easy to use. On average, resin composites last only half as long as dental amalgam, although more recent studies find them comparable to amalgam in durability, and dental porcelain is much more expensive. However, the gap between amalgam and composites may be closing. Further, concerns have been raised about themendocrine disrupting (in particular, estrogen-mimicking) effects of plastic chemicals such as Bisphenol A used in composite resins.
In addition to health and ethics issues, opponents to dental amalgam fillings point to the negative externalities of water contamination and environmental damage of mercury, especially since its use by dentists goes largely unregulated in many places, including the United States. The WHO reports that mercury from amalgam and laboratory devices accounts for 53% of total mercury emissions. Separators may dramatically decrease the release of mercury into the public sewer system, where dental amalgams contribute one-third of the mercury waste, but they are not required in the United States
Exposure
A study conducted by measuring the intraoral vapor levels over a 24-hour period in patients with at least nine amalgam restorations showed the average daily dose of inhaled mercury vapor was 1.7 µg (range from 0.4 to 4.4 µg), which is approximately only 1% of the threshold limit value of 300 to 500 µg/day established by the World Health Organization, based on a maximum allowable environmental level of 50 µg/day in the workplace. The World Health Organization (WHO) notes that exposure can be greatly increased by personal habits such as bruxism or gum-chewing, and cites a report which found a 5.3 fold increase in mercury levels after chewing, eating, or toothbrushing. They report that amalgam is estimated to contribute 50% of mercury exposure in adults. In the studies the WHO reviews, daily mercury exposure estimates range from 3 μg/day to 9 μg/day.
A Swedish study of autopsies examined the mercury levels in brains and kidneys and found a strong correlation with the number of amalgam fillings. A German study found that mercury urinary excretion was significantly higher in those with dental amalgam fillings.
The NIDR Amalgam Study, performed on a cohort of an adult military population of 1127 healthy males, found that based on their cross-sectional data, it is estimated that, on average, each ten-surface increase in amalgam exposure is associated with an increase of 1 ug/L mercury in urine concentration.
Research on monkeys has shown that mercury released from dental amalgam restorations is absorbed and accumulates in various organs such as the kidney, brain, lung, liver, gastro-intestinal tract, the exocrine glands. It was also found to have crossed the placental barrier in pregnant rats and proven to cross the gastrointestinal mucosa when amalgam particles are swallowed after amalgam insertion or after removal of old amalgam fillings.
Various diagnostic methods exist to detect the level of mercury in the body, including blood tests, urine tests, stool tests, saliva tests, DMPS or DMSA chelation urine tests, hair analysis and others. Opinions differ on which of these tests, if any, is the most accurate, although mainstream scientific research tends to place the most weight on chelation urine tests or stool tests when trying to assess chronic levels, or on blood or urine tests when trying to assess recent acute exposure.
The degree of accuracy which can be expected from urine based mercury tests given the observations cited above (outlining the drop in mercury excretion levels, after two years, in children with amalgam fillings despite a constant or increased magnitude in the level of mercury exposure) indicates the possibility of clear limitations in the efficacy of urine based mercury tests as an accurate statistic for the purposes of dental studies.
Further, none of these tests can link mercury levels to dental amalgams for methodological reasons, except (a) on an epidemiological scale; or (b) through measuring levels before and after dental work. Studies have investigated both angles and results have differed, fueling the controversy since the scientific data remains inconclusive and has not yet proven either safety or danger.
Health effects
Peer-reviewed scientific studies have come to opposite conclusions on whether the mercury exposure from amalgam fillings causes health problems. A 2004 systematic review conducted by the Life Sciences Research Office, whose clients include the FDA and NIH, concluded that “the current data are insufficient to support an association between mercury release from dental amalgam and the various complaints that have been attributed to this restoration material”. A peer-reviewed Journal of the Canadian Dental Association article holds that “it seems likely that humans may have evolved with a threshold level for mercury below which there is no response or observable adverse health effects”. Another review published in 2005 by the Freiburg University Institute for Environmental Medicine found that “mercury from dental amalgam may lead to nephrotoxicity, neurobehavioural changes, autoimmunity, oxidative stress, autism, skin and mucosa alterations or non-specific symptoms and complaints”, that “Alzheimer’s disease or multiple sclerosis has also been linked to low-dose mercury exposure”, and that “removal of dental amalgam leads to permanent improvement of various chronic complaints in a relevant number of patients in various trials.”
In 2002, the Food and Drug Administration issued a statement on dental amalgam which asserted that “no valid scientific evidence has shown that amalgams cause harm to patients with dental restorations, except in the rare case of allergy”. A 1991-1997 study of 3162 patients in Sweden and Germany found that 719 of those with mercury fillings, or 23 percent, tested positive for systemic allergic sensitivity to inorganic mercury on the MELISA lymphocyte proliferation test. In a smaller group of 85 patients who suffered from symptoms resembling Chronic Fatigue Syndrome and had their amalgams replaced with composites and metal-free ceramics, “over 78 percent reported improvement in health status as compared to the period prior to metal removal.”
In 2001, the United States National Health and Nutrition Examination Survey of 31,000 adult Americans, NHANES III, covering 1988-94, was published by the National Center for Health Statistics (NCHS). It isstatistically valid for all 180,000,000 adult Americans. The survey found that the number of dental fillings was significantly correlated to incidence of cancer, thyroid conditions, mental conditions, diseases of the nervous system including MS, diseases of the respiratory and genito-urinary systems, and disorders of the eye, circulatory and respiratory systems.
At the time of the survey (1988–94), the vast majority of dental fillings placed were silver amalgam.
However, the FDA, various supreme court judges and others vehemently DENY that these findings or any others of a similar nature have any correlation nor do they sufficiently demonstrate causation.
A 2003 monograph on mercury toxicity from the World Health Organization concluded that:
- Studies on humans and animals have demonstrated that dental amalgam contributes significantly to mercury body burden in humans with amalgam fillings.
- Dental amalgam is the most common form of exposure to elemental mercury in the general population, constituting a potentially significant source of exposure to elemental mercury, with estimates of daily intake from amalgam restorations ranging from 1 to 12.5 μg/day, the majority of dental amalgam holders being exposed to less than 5 μg mercury/day.
- Intestinal absorption varies greatly among the various forms of mercury, with elemental mercury (as found in amalgam) being the least absorbed form (<0.01%)
- Absorption also varies according to individual factors such as gum chewing and bruxism (tooth grinding).
- The number of restorations – amalgam or otherwise – is declining, largely due to improved dental hygiene, in all industrialised countries examined declining by 38% since the 1970s in the USA and over 65% in the ten years from 1986 in the UK
- Although several studies have demonstrated that some mercury from amalgam fillings is absorbed, no relationship was observed between the mercury release from amalgam fillings and the mercury concentration in basal brain.
- However, in the same report it was concluded that “…even at very low mercury levels, subtle changes in visual system function can be measured.”
Removal of amalgam fillings
Some practitioners may also recommend that patients with amalgam fillings have them removed and replaced, particularly if the patient is experiencing the symptoms that they attribute to the use of amalgam. These professionals recommend that unprotected amalgam removal should be avoided even in routine dental procedures to avoid exposure to mercury vapor and amalgam particulate matter.
Attempts in lawsuits
Organizations opposed to amalgam use, such as Consumers for Dental Choice, claim to have over 65,000 studies on file implicating amalgam fillings as the cause of a diversity of health disorders. These studies have been used in various lawsuits, and were the main contributing factor to the passage of Californian legislation concerning the issuing of warnings to patients about mercury, and to the federal bill introduced in 2002 proposing that amalgam fillings be made illegal after 2006.
