Evaluation of the mercury exposure of dental amalgam patients by the Mercury Triple Test

Abstract

Aims: To establish and analyse reference data for the mercury burden of patients with and without amalgam fillings. Methods: Atomic absorption spectroscopy was used to quantify Hg concentrations in the scalp hair and urine (before and after application of dimercaptopropane sulphonate), and Hg release from dental amalgams (using a newly developed, amalgam specific chew test), in 2223 subjects. Results: 50th centiles were 1.3 mg Hg/g creatinine in basal urine, 32 mg Hg/g creatinine after DMPS application, 454 ng Hg/g in hair, and 27 mg Hg per g of chewing gum, which corresponds to about 1 mg Hg released per minute of chewing. Total Hg intake (from ambient air, drinking water, food, and amalgams) of most patients is well below the provisioned tolerable weekly intake (PTWI) defined by the WHO, unless extremely Hg rich food is consumed on a regular basis. However, for patients exceeding the 75thcentile in chew tests, total Hg intake exceeds the PTWI by about 50%, even at the low limit of intake from food. In the absence of occupational exposure, significant Hg release from dental amalgams is a necessary but insufficient condition to obtain a high long term body burden. After removal of dental amalgams, chew tests no longer exhibit oral Hg exposure, while basal urine Hg content and DMPS induced excretion display a exponential decrease (half life about 2 months in both cases). Conclusions: A standardised procedure for evaluation of the magnitude and origin of the Hg burden of individuals has been developed, which, by comparison with the database presented here for the first time, can serve as a diagnostic tool.

Fish consumption, low-level mercury, lipids, and inflammatory markers in children

“…Second, we measured total Hg in our samples and therefore cannot address the relationship between the various forms of Hg (elemental, ionic, organometallic) and elevated acute-phase proteins and adrenocortical dysfunction. While most of the Hg present in human originates from fish in the food supply in the form of MeHg (Ravichandran 200) we cannot exclude the possible contributions of other Hg species such as elemental Hg exposure through dental amalgams, especially in gum chewers (Hansen et al 2004). Third, if we consider that most of the total blood Hg is found as MeHg, we must also take into account that the whole-body half-life of MeHg is estimated to be 70–80 days (Aberg et al 1969; US EPA 1997) and that health behaviors and dietary characteristics likely vary as these children age.…”

Chelation: Harnessing and Enhancing Heavy Metal Detoxification—A Review

“…Nevertheless, these shortcomings do not fundamentally invalidate the concept; work in this regard has started. Hansen et al established such norms for protocol involving an oral DMPS test with four hour urine collection, among 2223 citizens in Luxembourg [101]. …”

Dental Amalgam Exposure and Urinary Mercury Levels in Children: The New England Children’s Amalgam Trial

“…Amalgam restorations can discharge elemental inorganic mercury (Hg 0 ) into the oral cavity, mostly through vapor, which may then be absorbed into the bloodstream and reach various tissues and organs. A common biomarker for average Hg 0 exposure is urinary mercury (U-Hg), expressed either as a concentration (micrograms per liter) or excretion (micrograms per hour or micrograms per gram creatinine) ( Hansen et al 2004 ; Kingman et al 1998 ; Morton et al 2004 ; Olstad et al 1987 ). U-Hg is assumed to reflect the kidney burden of mercury, which accounts for Hg 0 only; this Hg 0 results primarily from direct Hg 0 sources (e.g., dental amalgam discharge) but may also be a product of demethylation of organic (methyl) mercury (MeHg) (e.g., from fish consumption) or other environmental exposures ( Barregard 1993 ; Clarkson et al 1988 ; Johnsson et al 2005 ).…”