The researchers note, “Studies (both genetic and behavioral) suggest that the extent of disease may be modulated not only by mercury levels but also by age (both of exposure and at testing) and genetic background.”
“An increasing evidence supports the role of industrial chemicals as contributors to the development of neurobehavioral disorders, including autism spectrum dis-orders, whose prevalence has progressively increased in recent years. Heavy metals, in particular, are recognized as neurodevelopmental toxins since they can be responsi-ble of fetal damages which lead to neurological defects, developmental delays, learning disabilities and behavioral abnormalities. Most of the reviewed studies reported a relationship between exposure to metals during perinatal and early childhood periods and increased risk for autism. Moreover, the effects resulting from co-exposure to multi-ple metals should not be underestimated, especially in the assessment of children who live in developing countries or near heavily contaminated sites.”
“The next few years will see the implementation stage (2014 to 2017), to be monitored by what the Convention calls the ‘Conference of the Parties’. The expected result for dental amalgam is a reduction in demand through increased efforts: at prevention, to use alternative materials where clinically indicated and to research improved alternative materials. NDAs should lead these efforts: failure to reduce demand, hence use, of dental amalgam could result in a recon-sideration of the special treatment and increased pressure for an outright ban.”
This hypothesis proposes that environmental toxicants entering the locus ceruleus can give rise to a variety of CNS disorders. Proposals are made for experiments to gain further evidence for this hypothesis. If it is shown that toxicants in the locus ceruleus are responsible for these conditions, attempts can be made to prevent the toxicant exposures or to remove the toxicants from the nervous system.
“The purpose of this study was to determine the effect of different irrigating solutions on mercury released from dental amalgam. Method and materials: Thirty samples of dental amalgam of similar size were prepared and exposed to a 10-ml solution of either 3% naocl, 17% EDTA, combination of 3% naocl + 17% EDTA solution,2% chlorhexidine, 3% naocl + 2% Chlorhexidine solution, saline solution-control group. For periods of 60 minutes. Mercury concentrations in the solutions were measured by using a cold-vapor atomic absorption Mercury Analyzer System, and the differences between the groups were statistically analyzed. Results-All amalgam samples exposed to 3%naocl , 17% EDTA ,combination of 3% naocl + 17% EDTA , 2% Chlorhexidine solution, 3%naocl + 2%chlorhexidine solution and saline (control) released mercury into solutions. Mercury released was significantly higher in naocl group (3.01) & EDTA + naocl (1.08) as compared to the other test solutions chlorhexidine + naocl (0.6), EDTA (0.29) chlorhexidine (0.24) & saline (0.24) . Chlorhexidine does not show any difference in mercury release with saline (control group).Conclusions. Naocl solutions commonly used for root canal cleaning and shaping cause mercury release from dental Amalgam and may alter its chemo-physical properties as a sealant for root perforations.”
“3923 observations from 2649 dentists were used to perform linear regression using multiple models. Models included individuals with or without imputed BMI, along with either repeated measures or initial observations only. Adjusted covariates included hand temperature, gender, age and BMI. Individuals with rheumatoid arthritis, diabetes, carpal tunnel syndrome (for median nerve models only), or hand temperatures interfering with the accuracy of the instrument were excluded. The main effect of cumulative exposure was found to be significant (p-value <0.05) in median nerve latency and amplitudes but insignificant in ulnar nerve measures. All models but ulnar nerve latency showed a highly significant interaction of cumulative exposure and age (p-value < 0.01).”
“At baseline, individuals with dental amalgam fillings have double the measured urine mercury compared to a control group of persons who have never had amalgam fillings. Removal of amalgam fillings decreases measured urine mercury to levels in persons without amalgam fillings. Although urine mercury levels in our sample are considered by Health Canada to be too low to pose health risks, removal of amalgam fillings reduced the likelihood of self-reported symptom deterioration and increased the likelihood of symptom improvement in comparison to people who retained their amalgam fillings.”
OBJECTIVE:
To examine biomarkers of methylmercury (MeHg) intake in women and infants from seafood-consuming populations globally and characterize the comparative risk of fetal developmental neurotoxicity.
METHODS:
A search was conducted of the published literature reporting total mercury (Hg) in hair and blood in women and infants. These biomarkers are validated proxy measures of MeHg, a neurotoxin found primarily in seafood. Average and high-end biomarkers were extracted, stratified by seafood consumption context, and pooled by category. Medians for average and high-end pooled distributions were compared with the reference level established by a joint expert committee of the Food and Agriculture Organization (FAO) and the World Health Organization (WHO).
FINDINGS:
Selection criteria were met by 164 studies of women and infants from 43 countries. Pooled average biomarkers suggest an intake of MeHg several times over the FAO/WHO reference in fish-consuming riparians living near small-scale gold mining and well over the reference in consumers of marine mammals in Arctic regions. In coastal regions of south-eastern Asia, the western Pacific and the Mediterranean, average biomarkers approach the reference. Although the two former groups have a higher risk of neurotoxicity than the latter, coastal regions are home to the largest number at risk. High-end biomarkers across all categories indicate MeHg intake is in excess of the reference value.
CONCLUSION:
There is a need for policies to reduce Hg exposure among women and infants and for surveillance in high-risk populations, the majority of which live in low-and middle-income countries.
EPA is proposing technology-based pretreatment standards under the Clean Water Act for discharges of pollutants into publicly owned treatment works (POTWs) from existing and new dental practices that involve the discharge of dental amalgam. The proposal would require dental practices to comply with requirements for controlling the discharge of dental amalgam pollutants into POTWs based on the best available technology or best available control technology and Best Management Practices.
To assess the effectiveness and safety of using fluoride toothpaste for young chil-dren, the Council recommended a systematic review of the evidence. The results of the review demonstrated that for children younger than 6 years, fluoride toothpaste use is effective in reducing caries. The evidence also showed that ingesting pea-sized amounts or more can lead to mild fluorosis.