Mercury

With great interest, we have read the article by Findik et al. entitled “Mercury concentration in maternal serum, cord blood, and placenta in patients withamalgam dental fillings: effects on fetal biometricmeasurements” that is published in the J Matern Fetal Neonatal Med, Early Online: 1–5, DOI: 10.3109/14767058.2016. 1140737. Findik et al. investigated the extent to  which mercury is transmitted from the mother to fetus via the umbilical cord in patients with  amalgam dental fillings, and its effect on fetal biometric measurements.

The chronic effects of cumulative, low-dose mercury exposure are underrecognized by both mainstream and alternative health authorities and, consequently, by the public. Mercury can cause or contribute to most chronic illnesses, including neurological disorders, cardiovascular disease, metabolic syndrome, chronic fatigue, fibromyalgia, adrenal and thyroid problems, autoimmunity, digestive disorders, allergies, chemical sensitivities, mental illness, sleep disorders, and chronic infections such as Lyme and Candida. Mercury toxicity should be suspected in individuals experiencing multiple health problems.
Diagnosis of chronic mercury toxicity is often difficult because the body’s natural defenses may mask or delay symptoms. Natural defenses are a function of genetic susceptibility, epigenetic factors, micronutrient status, and allostatic load (cumulative wear and tear on the body). Furthermore, individuals who retain mercury may counterintuitively show low levels in blood, urine, and hair.
The developmental window from conception through early childhood is one of extreme vulnerability to mercury. Mercury is an epigenetic toxicant (affecting future gene expression) as well as a neurotoxicant. Damage may be permanent; therefore, prevention is key.
For most people mercury is the most significant toxicant in the body. By promoting oxidative stress and depleting antioxidant defenses, including the glutathione system, mercury impairs the body’s response to toxicants in general including mercury itself.
Mercury toxicity creates a need for extra nutrition, both to repair damage and to provide ample enzyme cofactors that can push blocked enzymes. Carbohydrate intolerance can be a symptom of mercury toxicity, and fat can be a preferred fuel. Many people with chronic mercury toxicity have found a nutrient-dense diet to be a useful starting point for symptom relief. Individualized supplementation may also be helpful to overcome the extreme nutritional depletion and unnatural toxic state.

RESULTS:
Median maternal blood mercury concentration was 1.03μg/L, dietary mercury exposure was 0.15μg/kgbw/wk, and seafood intake was 217g/wk. Blood mercury concentrations were not associated with any language and communication scales. Increased dietary mercury exposure was significantly associated with improved SLAS scores when mothers had a seafood intake below 400g/wk in the adjusted analysis. Sibling matched analysis showed a small significant adverse association between those above the 90th percentile dietary mercury exposure and the SLAS scores. Maternal seafood intake during pregnancy was positively associated with the language and communication scales.

CONCLUSION:
Low levels of prenatal mercury exposure were positively associated with language and communication skills at five years. However, the matched sibling analyses suggested an adverse association between mercury and child language skills in the highest exposure group. This indicates that prenatal low level mercury exposure still needs our attention.

Mercury vapor is highly toxic to the human body. The present study aimed to investigate the occurrence of neuropsychological dysfunction in former workers of fluorescent lamps factories that were exposed to mercury vapor (years after cessation of exposure), diagnosed with chronic mercurialism, and to investigate the effects of such exposure on the Autonomic Nervous System (ANS) using the non-invasive method of dynamic pupillometry. The exposed group and a control group matched by age and educational level were evaluated by the Beck Depression Inventory and with the computerized neuropsychological battery CANTABeclipse – subtests of working memory (Spatial Span), spatial memory (Spatial Recognition Memory), visual memory (Pattern Recognition Memory) and action planning (Stockings of Cambridge). The ANS was assessed by dynamic pupillometry, which provides information on the operation on both the sympathetic and parasympathetic functions. Depression scores were significantly higher among the former workers when compared with the control group. The exposed group also showed significantly worse performance in most of the cognitive functions assessed. In the dynamic pupillometry test, former workers showed significantly lower response than the control group in the sympathetic response parameter (time of 75% of pupillary recovery at 10cd/m2 luminance). Our study found indications that are suggestive of cognitive deficits and losses in sympathetic autonomic activity among patients occupationally exposed to mercury vapor.

To estimate human exposure to methylmercury (MeHg), risk assessors often assume 95%-100% bioavailability in their models. However, recent research suggests that assuming all, or most, of the ingested mercury (Hg) is absorbed into systemic circulation may be erroneous. The objective of this paper is to review and discuss the available state of knowledge concerning the assimilation or bioavailability of Hg in fish and humans. In fish, this meant reviewing studies on assimilation efficiency, that is the difference between ingested and excreted Hg over a given period of time. In humans, this meant reviewing studies that mostly investigated bioaccessibility (digestive processes) rather than bioavailability (cumulative digestive + absorptive processes), although studies incorporating absorption for a fuller picture of bioavailability were also included where possible. The outcome of this review shows that in a variety of organisms and experimental models that Hg bioavailability and assimilation is less than 100%. Specifically, 25 studies on fish were reviewed, and assimilation efficiencies ranged from 10% to 100% for MeHg and from 2% to 51% for Hg(II). For humans, 20 studies were reviewed with bioaccessibility estimates ranging from 2% to 100% for MeHg and 0.2% to 94% for Hg(II). The overall absorption estimates ranged from 12% to 79% for MeHg and 49% to 69% for Hg(II), and were consistently less than 100%. For both fish and humans, a number of cases are discussed in which factors (e.g., Hg source, cooking methods, nutrients) are shown to affect Hg bioavailability. The summaries presented here challenge a widely-held assumption in the Hg risk assessment field, and the paper discusses possible ways forward for the field.

“Methods
A total of 45,557 general dentists and 5,101 pediatric dentists were invited to participate in a pre‐tested electronic survey. The survey consisted of 12 close‐ended questions using a 5‐point Likert Scale. The Qualtrics™ software was used to distribute the survey, followed by three reminders.

Results
Response rate was 5.2 percent for general dentists, and 17.6 percent for pediatric dentists. Sixty‐two percent of general dentists and 56 percent of pediatric dentists reported using amalgam. Most dentists disagreed with banning amalgam, while agreeing with installing amalgam separators. Environmentally conscious dentists were more likely to agree with banning amalgam and installing amalgam separators.

Conclusion
Responding dentists favor the continued use of dental amalgam. Their perspectives vary by several factors including dentists’ environmental consciousness. Policies toward minimizing amalgam’s environmental impact need to be implemented.”

Mercury (Hg) is a persistent bio-accumulative toxic metal with unique physicochemical properties of public health concern since their natural and anthropogenic diffusions still induce high risk to human and environmental health. The goal of this review was to analyze scientific literature evaluating the role of global concerns over Hg exposure due to human exposure to ingestion of contaminated seafood (methyl-Hg) as well as elemental Hg levels of dental amalgam fillings (metallic Hg), vaccines (ethyl-Hg) and contaminated water and air (Hg chloride). Mercury has been recognized as a neurotoxicant as well as immunotoxic and designated by the World Health Organization as one of the ten most dangerous chemicals to public health. It has been shown that the half-life of inorganic Hg in human brains is several years to several decades. Mercury occurs in the environment under different chemical forms as elemental Hg (metallic), inorganic and organic Hg. Despite the raising understanding of the Hg toxicokinetics, there is still fully justified to further explore the emerging theories about its bioavailability and adverse effects in humans. In this review, we describe current research and emerging trends in Hg toxicity with the purpose of providing up-to-date information for a better understanding of the kinetics of this metal, presenting comprehensive knowledge on published data analyzing its metabolism, interaction with other metals, distribution, internal doses and targets, and reservoir organs.

In the early 1830’s, a pair of European ‘dentists’ brought a novel material for filling teeth into the United States.  It was far less expensive and far easier to use than competing materials.  This new potential ease at which some could practice dentistry put pressure on a situation of conflict between the educated dental professional, and the uneducated dentist.  Quacks were the bane of the existence of an educated, gentleman dentist.  They were openly condemned in private circles and in the press but the dental ‘charlatan’ was not the only person in the line of fire. Those who used mercury amalgam were often lumped together, whether they be trained or otherwise, and treated with similar amounts of disdain from the professional societies.  The amalgam critics found ways to put down those who used amalgam in organizational publications and used essays, speeches, research, and case studies to support their efforts in keeping any dentist worth his salt from using amalgam.  This was a period of progress wherein the setting was just right for an all-out dental scandal that had a hand in the creation and collapse of the first dental society and is influencing the field of dentistry to this day.

Mercury (Hg) toxicity continues to represent a global health concern. Given that human populations are mostly exposed to low chronic levels of mercurial compounds (methylmercury through fish, mercury vapor from dental amalgams, and ethylmercury from vaccines), the need for more sensitive and refined tools to assess the effects and/or susceptibility to adverse metal-mediated health risks remains. Traditional biomarkers, such as hair or blood Hg levels, are practical and provide a reliable measure of exposure, but given intra-population variability, it is difficult to establish accurate cause-effect relationships. It is therefore important to identify and validate biomarkers that are predictive of early adverse effects prior to adverse health outcomes becoming irreversible. This review describes the predominant biomarkers used by toxicologists and epidemiologists to evaluate exposure, effect and susceptibility to Hg compounds, weighing on their advantages and disadvantages. Most importantly, and in light of recent findings on the molecular mechanisms underlying Hg-mediated toxicity, potential novel biomarkers that might be predictive of toxic effect are presented, and the applicability of these parameters in risk assessment is examined.

Common technological devices (e.g., mobile phones, mobile base stations, and magnetic resonance imaging machines and other wireless devices) produce electromagnetic fields (EMFs). Neurobehavioral and neurodevelopmental symptoms such as retarded memory, learning, cognition, and attention have been attributed to EMF exposure.[4] Of note, these symptoms are also attributed to ASD and attention deficit hyperactivity disorders. A recent in vivo study observed autism-relevant social abnormalities in mice exposed to extremely low-frequency EMFs during perinatal development.[5] This may indicate a potential direct link between EMFs and the prevalence of autism in specific window/s of vulnerability that would deserve further investigation. An indirect link might be also plausible since high-field magnetic resonance and microwave radiation emitted by common mobile phones have been reported to increase the release of mercury from dental amalgam fillings.[6,7] These recent evidence (2014), far from being conflictive, is consistent with our previous cumulative Hg exposure-based hypothesis of ASD (2011) and could be included as the fifth (v) additional environmental factor, synergistically contributing to the release of Hg in mothers with dental amalgam fillings, and increasing the probability of developing and/or aggravating autism among children. Nevertheless, this updated version of our hypothesis would require more extensive clinical confirmation and supporting evidence.