From The National Kidney Foundation: according to investigators at Johns Hopkins and Tufts-New England Medical Center, a recently-published study based on the National Health and Nutrition Examination Survey estimated that there are 26,000,000 adults with evidence of kidney disease in the United States alone and most are completely unaware of their condition. This number increases the most recent estimates of the rate of chronic kidney disease (CKD) by 30%, from 10% of the U.S. population (1988-1994) to 13.1% (1999-2004).
So how does this tie into the dental amalgam issue ? Below is an excellent write up from The Natural Recovery Plan.
Mercury exposure and mercury levels in kidneys and genitourinary system
Dental amalgam has been documented by hundres of medical lab tests and Government agencies to be the largest source of mercury in most who have amalgam dental fillings (over 120 million Americans), and to be the largest source of mercury in kidneys, where it bioaccumulates. Studies have found the number of dental amalgam fillings, chewing on amalgam, and fish consumption were positively associated with Urinary-HgC.
The number of amalgam surfaces has a statistically significant correlation to the mercury level in the renal (kidney) cortex. One study found levels ranging from 21 to 810 ppb. A study of levels in kidney donors found an average of 3 times higher mercury level in those with amalgams versus those without. Studies found the number of amalgam surfaces has a statistically significant correlation to urine mercury level. Mercury levels of dental personnel average at least 2 times that of controls for urine. Sweden, which voted to phase-out use of mercury in fillings, is the country with the most exposure and health effects studies regarding amalgam, and urine levels in dental professionals from Swedish and European studies ranged from 0.8 to 30.1 mcg/l with study averages from 3.7 to 6.2 mcg/l. The Swedish safety guideline for mercury in urine is 5.6 nmol Hg/nmol (11.6 mcg/l). Study averages for other countries ranged from 3.3 to 36 microgram/litre (mcg/l). A large survey of dentists at the Norwegian Dental Association meeting found that the mean mercury level in 1986 was 7.8 mcg/l with approximately 16% above 13.6 mcg/l, and for 1987 found an average of 8.6 mcg/l with approximately 15% above 15.8 mcg/l, with women having higher levels than men in general.
A U.S. national sample of dentists provided by the American Dental Association had an average of 5.2 mcg/l. In that large sample of dentists, 10% of dentists had urine mercury levels over 10.4 mcg/l and 1% had levels over 33.4 mcg/l, indicating daily exposure levels of over 100 mcg/day. Researchers from the University of Washington School of Dentistry and Department of Chemistry tested a sample of dentists at an annual ADA meeting. The study found that the dentists had a significant body burden of mercury and the group with higher levels of mercury had significantly more adverse health conditions than the group with lower exposure.
Another study of a group of 194 U.S. male dentists with mean urine mercury level of 3.3 mcg/l and 233 female dental assistants with mean urine mercury level of 2.0 mcg/l considered effects of polymorphism in brain-derived neurotrophic factor (BDNF) as well as mercury levels. The study found significant effects of mercury level on 9 measures of neurologicial deficits for the dentists and on 8 measures of neurological deficits for dental assistants, as well as a significant difference relating to BDNF.
A group of dental students taking a course involving work with amalgam had their urine tested before and after the course was over. The average urine level increased by 500% during the course. But dental staff have been found to have mercury retention and kidney effects that tend to cause lower measured levels of mercury in urine tests.
III. Toxic effects of mercury (& toxic metals) on kidneys and genitourinary system
Mercury has been found to be nephrotoxic (toxic to kidneys). Mercury exposure has been shown to adversely affect kidney function in occupational and animal studies, and also in those with more than average number of amalgam fillings. Richardson (Health Canada) has estimated that about 20% of the population suffers a subclinical impairment of kidney or CNS function related to amalgam mercury.
Inorganic mercury exposure has been found to exert a dose-dependent cytotoxicity by generating extremely high levels of hydrogen peroxide, which is normally quenched by pyruvate and catalase. HgCl2 also has been found to impair function of other organelles such as lysomones that maintain transmembrane proton gradient, and to decrease glutathione peroxidase activity in the kidneys while upregulating heme oxidase function. The Government’s toxic level for mercury in urine is 30 mcg/l, but adverse effects have been seen at lower levels and low levels in urine often mean high mercury retention and chronic toxicity problems. For this reason urine tests are not a reliable measure of mercury toxicity.
A survey of over 60,000 U.S. dentists and dental assistants with chronic exposure to mercury vapour and anaesthetics found increased health problems compared to controls, including significantly higher liver, kidney, and neurological diseases. A recent study in Scotland found similar results. Some studies have found increased risk of lung, kidney, brain, and CNS system cancers among dental workers.
Mercury causes interruption of the cytochrome C oxidase system/ATP energy function and blocks enzymes needed to convert porphyrins to adenosine tri phosphate (ATP) causing progressive porphyrinuria, resulting in low energy, digestive problems, and porphyrins in urine.
Mercury and toxic metals have been found to be common toxic exposures that have been found to cause increased permeability of the kidney epithelial and brush border cells.
In men, including workers occupationally exposed to mercury, U-HgC was positively associated with the kidney markers, especially with NAG, but to some extent also with A1M and albumin.
The primary detoxification/excretion pathway for mercury absorbed by the body is as mercury-glutathione compounds through the liver/bile loop to faeces, but some mercury is also excreted though the kidneys in urine and in sweat. A high fibre diet has been shown to be helpful in mercury detoxification. The range of mercury excreted in urine per day by those with amalgams is usually less than 15 mcg, but some patients are much higher.
A large NIDH study of the U.S. military population with an average of 19.9 amalgam surfaces and range of 0 to 60 surfaces found the average urine level was 3.1 mcg/l, with 93% being inorganic mercury. The average in those with amalgam was 4.5 times that of controls and more than the U.S. EPA maximum limit for mercury in drinking water. The average level of those with over 49 surfaces was over 8 times that of controls. The same study found that the average blood level was 2.55 mcg/l, with 79% being organic mercury. The total mercury level had a significant correlation to the number of amalgam fillings, with fillings appearing to be responsible for over 75% of total mercury. From the study results it was found that each 10 amalgam surfaces increased urine mercury by approx. 1 mcg/l. A study of mercury species found blood mercury was 89% organic and urine mercury was 87% inorganic.
In a population of women tested In the Middle East, the number of fillings was highly correlated with the mercury level in urine, mean = 7 mcg/l. Amalgam has also been found to be the largest source of organic mercury in most people. Nutrient transport and renal function were also found to be adversely affected by higher levels of mercury in the urine.
Significant correlations between increasing urine mercury concentrations and prolonged motor and sensory distal latencies were established. Chronic immune activation is common in CFS, with increase in activated CD8+ cytotoxic T-cells and decreased natural killer (NK) cells. Numbers of suppressor-inducer T cells and NK cells have been found to be inversely correlated with urine mercury levels. CFS patients usually improve and immune reactivity is reduced when amalgam fillings are replaced. Neurological effects have been documented at very low levels of exposure (urine Hg<4 mcg/l), levels commonly received by those with amalgam fillings.
Mercury has been documented to be a common cause of hypothyroidism and autoimmune thyroiditis. Studies have also established a “clear association” between the presence of thyroid antibodies in pregnant women and spontaneous abortions, as well as a connection between maternal thyroid disease and babies born with heart, brain, and kidney defects.
Metals tend to cause cellular acidic conditions which lead to disease and measuring urine acidity is useful in this regard. Normal acidity is pH of about 6.8.
Read the rest of the article here….