Mercury

“The Parties to this Convention,
Recognizing that mercury is a chemical of global concern owing to its long-range atmospheric transport, its persistence in the environment once anthropogenically introduced, its ability to bioaccumulate in ecosystems and its significant negative effects on human health and the environment,
Recalling decision 25/5 of 20 February 2009 of the Governing Council of the United Nations Environment Programme to initiate international action to manage mercury in an efficient, effective and coherent manner…”

PURPOSE:

Markers of mercury (Hg) exposure have shown both positive and negative associations with cardiovascular disease (CVD). We assessed the association between serum Hg (S-Hg) and risk of cardiovascular disease in a prospective population-based cohort, with attention to the roles of dental health and fish consumption.

METHODS:

Total mortality, as well as morbidity and mortality from acute myocardial infarction (AMI) and stroke, was followed up for 32 years in 1,391 women (initially age 38-60), in relation to S-Hg at baseline, using Cox regression models. Potential confounders (age, socioeconomic status, serum lipids, alcohol consumption, dental health, smoking, hypertension, waist-hip ratio, and diabetes) and other covariates (e.g., fish consumption) were also considered.

RESULTS:

Hazard ratios (HR) adjusted only for age showed strong inverse associations between baseline S-Hg and total mortality [highest quartile: hazard ratio (HR) 0.76; 95% confidence interval (CI) 0.59-0.97], incident AMI (HR 0.56; CI 0.34-0.93), and fatal AMI (HR 0.31; CI 0.15-0.66). Adjustment for potential confounding factors, especially dental health, had a strong impact on the risk estimates, and after adjustment, only the reduced risk of fatal AMI remained statistically significant.

CONCLUSIONS:

There was a strong inverse association between Hg exposure and CVD. Likely, reasons are confounding with good dental health (also correlated with the number of amalgam fillings in these age groups) and/or fish consumption. The results suggest potential effects of dental health and/or fish consumption on CVD that deserve attention in preventive medicine.”

“Our show today concerns everyone of you watching who’s ever had a cavity filled because if your filling is made with silver, it probably also contains the highly toxic element mercury.”

“The Doctors’ Investigative Reporter, Melanie Woodrow, explores one woman’s startling claim that the mercury in her dental fillings may have led to her diagnosis of multiple sclerosis. Watch as Melanie visits CTI Science, a bio-technology company in Kentucky, where Boyd E. Haley, Ph.D. demonstrates how much mercury is emitted from a silver amalgam filling in a laboratory setting.”

“BACKGROUND:

Fibromyalgia (FM) is a disease of unknown etiology. Inflammation could be one of the mechanisms behind this disease.
OBJECTIVES:

We studied the frequency and clinical relevance of metal allergy in FM patients.
METHODS:

Fifteen female FM patients were included in the study. Metal allergy was measured by a lymphocyte transformation test, MELISA®. Ten healthy age-matched women were used as controls for in vitro studies. Reduction of metal exposure in the FM patients was achieved by replacement of dental metal restorations and by the avoidance of known sources of metal exposure. Objective health assessment was performed 5 years after treatment. Subjective health assessment was established by a questionnaire, completed 2, 5 and in some cases 10 years after the start of the study. Follow-up MELISA was also performed.
RESULTS:

All FM patients tested positive to at least one of the metals tested. The most frequent reactions were to nickel, followed by inorganic mercury, cadmium and lead. Some healthy controls responded to inorganic mercury in vitro but most of the tests were negative. Objective examination 5 years later showed that half of the patients no longer fulfilled the FM diagnosis, 20% had improved and the remaining 30% still had FM. All patients reported subjective health improvement. This correlated with the normalisation of metal-specific responses in vitro.
CONCLUSION:

Metal allergy is frequent in FM patients. The reduction of metal exposure resulted in improved health in the majority of metal-sensitized patients. This suggests that metal-induced inflammation might be an important risk factor in a subset of patients with FM.”

“Objectives: This pilot study aimed to evaluate the effect of dental amalgam, a restorative material, on children by measuring the mercury concentration in the urine as well as the number of teeth filled with dental amalgam.

Methods: Twenty children enrolled in grades 1-4 of two elementary schools in Daegu participated in this study. One trained dentist performed oral examinations and removed amalgam restorations from the teeth with a high and low speed handpiece. In order to measure the urinary mercury concentrations, urine samples were collected from all participants at baseline and immediately and 24 hours after removal of the dental amalgam restorations.

Results: The mean number of teeth from which the amalgam restorations was removed was 9.8 while the mean urinary mercury concentrations at baseline, immediately, and 24 hours after removal of dental amalgam restorations were 2.66, 2.76, and 2.76 μg/g creatinine, respectively. The mean urinary mercury concentration increased consistently after amalgam restoration removal. For those participants whose removed amalgamated surfaces were more than 11, the mean urinary mercury concentration immediately after amalgam restoration removal and 24 hours after removal increased consistently but showed no significant difference.

Conclusions: This study demonstrated that dental amalgam restoration was related to urinary mercury concentration, and these findings present a possibility of mercury accumulation in the body. Therefore, we suggest future longitudinal studies to ensure the safety of children exposed to mercury by establishing criteria for amalgam removal.”

“Human milk is usually the only source of food for infants during the first 4 to 5 months of their life. Maternal environmental mercury exposure is directly related to fish consumption or amalgam filling. In this research, 38 human milk samples were collected from mothers of Lenjan area who were not occupationally exposed with mercury. Mercury concentration in human milk was determined by AMA254 Mercury Analyzer. A level of mercury was examined in relation to somatometric, demographic and dental amalgam parameters. Obtained results showed that only dental amalgam significantly increased the mercury level in human milk (p< 0.001). The mean mercury concentrations in milk of mothers without teeth fillings (n= 13), with one to three teeth fillings (n?= 10), and four to eight teeth fillings (n= 15) were 2.87, 5.47, and 13.33 µg/l, respectively. The result of this study also showed a positive correlation of mercury milk levels with the number of teeth fillings of the mother (p< 0.05, r= 0.755). The estimated weekly intake of mercury of a breastfed infant in this study was, in some cases, higher than provisional tolerance weekly intake recommended by FAO/WHO, which pose a threat to their health.”

Anthropogenic activities have enriched mercury in the biosphere by at least a factor of three, leading to increases in total mercury (Hg) in the surface ocean. However, the impacts on ocean fish and associated trends in human exposure as a result of such changes are less clear. Here we review our understanding of global mass budgets for both inorganic and methylated Hg species in ocean seawater. We consider external inputs from atmospheric deposition and rivers as well as internal production of monomethylmercury (CH₃Hg) and dimethylmercury ((CH₃)₂Hg). Impacts of large-scale ocean circulation and vertical transport processes on Hg distribution throughout the water column and how this influences bioaccumulation into ocean food chains are also discussed. Our analysis suggests that while atmospheric deposition is the main source of inorganic Hg to open ocean systems, most of the CH₃Hg accumulating in ocean fish is derived from in situ production within the upper waters (<1000 m). An analysis of the available data suggests that concentrations in the various ocean basins are changing at different rates due to differences in atmospheric loading and that the deeper waters of the oceans are responding slowly to changes in atmospheric Hg inputs. Most biological exposures occur in the upper ocean and therefore should respond over years to decades to changes in atmospheric mercury inputs achieved by regulatory control strategies. Migratory pelagic fish such as tuna and swordfish are an important component of CH₃Hg exposure for many human populations and therefore any reduction in anthropogenic releases of Hg and associated deposition to the ocean will result in a decline in human exposure and risk.

“BACKGROUND:

Toxic metal exposure (e.g. Hg, Pb, As) exposure is known to induce significant adverse effects on human brain function. The aim this study was to assess toxic metal body-burden in relation to potential brain dysfunction in patients diagnosed with neurological disorders (NDs).

MATERIAL/METHODS:

The Liberty Institutional Review Board (Deland, FL) approved the present study. Quantitative, fractionated, random urinary porphyrin testing (µg/L) from the Clinical Laboratory Improvement Act/Amendment (CLIA)-approved Laboratory Corporation of America (LabCorp) and cortical perfusion index (CPi) values from single-photon-emission-computed-tomography (SPECT) brain scans were employed to evaluate a prospective cohort of qualifying patients with diagnosed NDs (n=52) presenting for medical care at an endocrinology practice in the Cincinnati, OH area.

RESULTS:

Patients with more severe in comparison to mild brain dysfunction had significant increases in the mean urinary concentration of uroporphyrins (uP), coproporphyrins I (cP I), and total cP (cP I + III), as well as a trend towards significantly increased mean urinary concentration of pentacarboxyporphyins (5cxP) and cP III. A significant positive correlation between Hg body-burden associated porphyrins (5cxP + cP I + cP III) and increased brain dysfunction was observed.

CONCLUSIONS:

The present study associated brain dysfunction with Hg body-burden in a cohort of patients diagnosed with NDs, but the contributions of other heavy metals or genetic factors cannot be ruled-out. Additional studies should be conducted to evaluate the consistency of the present findings with examinations of other populations.”

This report reviews the literature, describes the use of mercury in odontology, and raises issues of concern for human health. In odontology and dental clinics,1 mercury may be found in dental amalgam and measuring devices such as thermometers and blood pres-sure cuffs (sphygmomanometers, tensiometers). Studies have shown elevated concentra-tions of mercury in the ambient air in dental settings. This mercury vapor may enter the body through inhalation and be transported to different organs throughout the body where it can accumulate. This report recommends developing a program to minimize the use of mercury, lessen  the potential for exposure, and control mercury waste. This will benefit dental workers by decreasing their exposure to this toxic material and will reduce environmental impacts from mercury in solid waste, in the air, and in wastewater.