Infantile allergic diseases: a cohort study prenatal fish intake and mercury exposure context.

BACKGROUND: Allergic diseases (ADs) have been increasingly reported in infants and children over the last decade. Diet, especially the inclusion of fish intake, may help to lower the risk of ADs. However, fish also, can bioaccumulate environmental contaminants such as mercury. Hence, our study aims to determine what effects the type and frequency of fish intake have on ADs in six-month-old infants, independently and jointly with mercury exposure. METHODS: This study is part of the prospective birth cohort: Mothers and Children's Environmental Health (MOCEH) study in South Korea. Data was collected on prenatal fish intake, prenatal mercury concentration and ADs for infants aged six months for 590 eligible mother-infant pairs. Logistic regression analysis was conducted to evaluate the risk of prenatal fish intake and mercury concentration on ADs in infants. Finally, interaction between fish intake and mercury concentration affecting ADs in infants was evaluated. Hazard ratios of prenatal fish intake on ADs in 6 month old infants were calculated by prenatal mercury exposure. RESULTS: Logistic regression analysis showed that white fish (OR: 0.53; 95% CI 0.30-0.94; P < 0.05) intake frequency, once a week significantly decreased the risk of ADs in infants. Stratification analysis showed that consuming white fish once a week significantly reduced the hazard of ADs (HR: 0.44; 95% CI 0.21-0.92; P < 0.05) in infants in the high-mercury (≥ 50th percentile) exposure group. CONCLUSION: The result indicates that prenatal white fish intake at least once a week reduces the risk of ADs in infants, especially in the group with high prenatal mercury exposure.

HgCl2 exposure mediates pyroptosis of HD11 cells and promotes M1 polarization and the release of inflammatory factors through ROS/Nrf2/NLRP3.

Mercury (Hg) is a serious metal environmental pollutant. HgCl2 exposure causes pyroptosis. When macrophages are severely stimulated, they often undergo M1 polarization and release inflammatory factors. However, the mechanisms by which mercuric chloride exposure induces macrophage apoptosis, M1 polarization, and inflammatory factors remain unclear. HD11 cells were exposed to different concentrations of Hg chloride (180, 210 and 240 nM HgCl2). The results showed that mercury chloride exposure up-regulated ROS, C-Nrf2 and its downstream factors (NQO1 and HO-1), and down-regulated N-Nrf2. In addition, the expressions of focal death-related indicators (Caspase-1, NLRP3, GSDMD, etc.), M1 polarization marker CD86 and inflammatory factors (TNF-α, IL-1ß) increased, and the above changes were related to mercury. Oxidative stress inhibitor (NAC) can block ROS/ NrF2-mediated oxidative stress, inhibit mercury-induced pyroptosis and M1 polarization, and effectively reduce the release of inflammatory factors. The addition of Vx-765 to inhibit pyroptosis can effectively alleviate M1 polarization of HD11 cells and reduce the expression of inflammatory factors. HgCl2 mediates pyroptosis of HD11 cells by regulating ROS/Nrf2/NLRP3, promoting M1 polarization and the release of inflammatory factors.

KEAP1 polymorphisms and neurodevelopmental outcomes in children with exposure to prenatal MeHg from the Seychelles Child Development Study Nutrition Cohort 2.

BACKGROUND: Humans differ in the metabolism of the neurotoxicant methyl mercury (MeHg). This variation may be partially due to variation in genes encoding the transcription factor Nuclear factor E2-related factor 2 (NRF2) and its negative regulator Kelch-like ECH-Associated Protein 1 (KEAP1), which regulate glutathione and related transporter and antioxidant proteins that play a role in the metabolism and neurotoxicity of MeHg. AIM: To elucidate a potential risk from genetic variation in NFE2L2 (encoding NRF2) and KEAP1 toward prenatal mercury exposure and child neurodevelopmental outcomes at 20 months and 7 years of age in a population with variable prenatal exposure to MeHg from maternal fish consumption. MATERIAL AND METHODS: Nutrition Cohort 2 is a mother-child cohort in the Republic of Seychelles. Children were genotyped for NFE2L2 (rs2364723, rs13001694) and KEAP1 (rs8113472, rs9676881) polymorphisms (N = 1285 after removing siblings). Total mercury (Hg) was measured in cord blood as a biomarker for prenatal MeHg exposure. Child neurodevelopmental outcomes included the Bayley Scales of Infant Development II administered at 20 months of age, and outcomes across multiple neurodevelopmental domains from 14 tests administered in children and 3 instruments completed by parents when children were 7 years of age. RESULTS: The mean cord blood MeHg concentration was 34 (95% CI 11, 75) µg/L. None of the four polymorphisms had a significant association (p < 0.05) with either cord MeHg or neurodevelopmental test results at 20 months. There were no significant associations between either NFE2L2 polymorphism and any developmental test scores. At 7 years, children carrying KEAP1 rs8113472 CA showed significantly worse performance on psychomotor function than children with the CC variant (finger tapping, dominant hand: ß - 1.19, SE 0.34; finger tapping, non-dominant hand: ß - 0.92, SE 0.31) and worse social communication (SCQ Total: ß 0.65, SE 0.27). Children carrying rs8113472 AA, versus children with CC, showed significantly better performance on social communication (SRS Total: ß - 8.88, SE 3.60). Children carrying KEAP1 rs9676881 AG, versus children with GG, showed significantly worse performance on psychomotor function (trailmaking A time: ß 8.66, SE 3.37) and cognition (KBIT Matrices: ß - 0.96, SE 0.36). CONCLUSION: No associations between NFE2L2 and KEAP1 polymorphisms and MeHg concentration were identified. However, at 7 years, KEAP1 polymorphisms were associated with differences in neurodevelopmental outcomes in children from a population with high fish intake.

Prenatal exposure to selenium, mercury, and manganese during pregnancy and allergic diseases in early childhood: The Japan Environment and Children's study.

BACKGROUND: Prenatal exposure to metallic elements may adversely affect early childhood health. However, more evidence is needed as population-based cohort studies are currently limited. OBJECTIVES: We aimed to examine the associations between prenatal metallic (mercury, selenium, and manganese) exposure and the risk of allergic diseases in early childhood until three years of age. METHODS: The data from 94,794 mother-infant pairs, who participated in the Japan Environment and Children's study, were used in this study. Prenatal metallic element exposure was measured in maternal blood collected during mid-pregnancy. The incidence of atopic dermatitis, food allergies, asthma, and allergic rhinitis during the first three years of life was prospectively investigated using self-reports of physician-diagnosed allergies. A multivariable modified Poisson regression model was used to estimate the cumulative incidence ratio and their 95% confidence intervals of allergic diseases associated with prenatal exposure to mercury, selenium, and manganese. We further evaluated the interaction between mercury and selenium exposures in this association. RESULTS: We confirmed 26,238 cases of childhood allergic diseases: atopic dermatitis, food allergies, asthma, and allergic rhinitis in 9,715 (10.3%), 10,897 (11.5%), and 9,857 (10.4%), 4,630 (4.9%), respectively. No association was found between prenatal mercury or manganese exposure and the risk of allergic diseases. Prenatal selenium exposure was inversely associated with atopic dermatitis, food allergies, allergic rhinitis, and any allergic diseases, but not with asthma. These inverse associations were more pronounced for lower mercury exposures than for higher exposures. CONCLUSIONS: Our findings suggest that prenatal exposure to selenium may be beneficial for reducing the risk of atopic dermatitis, food allergies, allergic rhinitis, and any allergic diseases in early childhood, especially with lower prenatal mercury exposure.

Mercurial risk from dental amalgam use in a population of Moroccan dentists: A latent class regression approach.

BACKGROUND: Dentists using dental amalgam are chronically exposed to low doses of elemental mercury. The complex toxico-kinetics of this systemic toxicant results in polymorphic and variable clinical phenotypes. In this context, adapted statistical methods are required to highlight potential adverse effects of occupational mercury exposure on dentists' health. OBJECTIVE: The present study aims to analyze the distribution of self-reported subjective symptoms, commonly associated with chronic mercury poisoning, according to occupational mercury exposure in a population of Moroccan liberal dentists. METHODS: In order to achieve the defined objectives, a three-step latent class regression was fitted. First a latent class analysis was performed to cluster the studied population according to their declared symptoms. Dentists were then classified in the defined latent classes based on their posterior probabilities. Finally, a logistic regression is fitted to identify predictors associated with the latent classes' membership. RESULTS: The final obtained model showed acceptable calibration and discrimination. Its interpretation revealed that the increase of the frequency of amalgam use was associated with significant higher odds of belonging to the high risk latent class. CONCLUSIONS: The present study represents an initial step towards the development of diagnosis model that predict clinical profiles according to occupational mercury exposure.

Contact sensitisation in oral lichen planus: An Australian perspective.

BACKGROUND: The role of contact sensitisation in the pathogenesis of oral lichen planus (OLP) has not been clearly defined. OBJECTIVE: We aimed to evaluate relevant contact sensitisers in OLP. METHODS: A retrospective study was conducted on OLP patients who underwent patch testing from 1 January 2006 to 31 December 2020 at an Australian tertiary dermatology institution, compared to cheilitis patients patch tested over the same time period. RESULTS: Ninety-six OLP patients and 152 cheilitis patients were patch tested during the 15-year period. Seventy-one (73.9%) OLP patients and 100 (65.8%) cheilitis patients recorded one or more relevant reactions. Forty-three (44.8%), 22 (22.9%), 21 (21.9%) and 17 (17.7%) OLP patients had relevant reactions to mercury-related chemicals, amalgam, spearmint and carvone, respectively, compared to 6 (3.9%), 3 (2.0%), 4 (2.6%) and 0 (0%) cheilitis patients, respectively (p-value <0.001 each). Four (4.2%) OLP patients had relevant positive reactions to sodium metabisulfite, compared to none in the cheilitis group (p-value 0.021). CONCLUSION: While dental amalgam is used less frequently these days, we report that mercury (found in amalgam) and additionally spearmint and carvone are relevant sensitisers in OLP in Australia. Sodium metabisulfite may also be a relevant sensitiser in OLP, which has not previously been reported.

Clinical Spectrum of Mercury Poisoning in India: Case-series from a Poison Control Center.

BACKGROUND: Mercury is a naturally occurring heavy metal that finds wide application in industrial and household settings. It exists in three chemical forms which include elemental (Hg0 ), inorganic mercurous (Hg+) or mercuric (Hg++) salts, and organic compounds. All forms are highly toxic, particularly to the nervous, gastrointestinal, and renal systems. Common circumstances of exposure include recreational substance use, suicide or homicide attempts, occupational hazards, traditional medicines, and endemic food ingestions as witnessed in the public health disasters in Minamata Bay, Japan and in Iraq. Poisoning can result in death or long-term disabilities. Clinical manifestations vary with chemical form, dose, rate, and route of exposure. AIMS AND OBJECTIVES: To summarize the incidence of mercury poisoning encountered at an Indian Poison Center and use three cases to highlight the marked variations observed in clinical manifestations and long-term outcomes among poisoned patients based on differences in chemical forms and routes of exposure to mercury. MATERIALS AND METHODS: A structured retrospective review of the enquiry-database of the Poison Information Center and medical records of patients admitted between August 2019 and August 2021 in a tertiary care referral center was performed. All patients with reported exposure to mercury were identified. We analyzed clinical data and laboratory investigations which included heavy metal (arsenic, mercury, and lead) estimation in whole blood and urine samples. Additionally, selected patients were screened for serum voltage-gated potassium ion channels (VGKC)- contactin-associated protein-like 2 (CASPR2) antibodies. Three cases with a classical presentation were selected for detailed case description. RESULTS: Twenty-two cases were identified between August 2019 and August 2021. Twenty (91%) were acute exposures while two (9%) were chronic. Of these, three representative cases have been discussed in detail. Case 1 is a 3.5-year-old girl who was ought to the emergency department with suspected elemental-mercury ingestion after biting a thermometer. Clinical examination was unremarkable. Chest and abdominal radiography revealed radiodense material in the stomach. Subsequent serial radiographs documented distal intestinal transit of the radiodense material. The child remained asymptomatic. This case exemplifies the largely nontoxic nature of elemental mercury ingestion as it is usually not absorbed from the gastrointestinal tract. Case 2 is a 27-year-old lady who presented with multiple linear nodules over both upper limbs after receiving a red intravenous injection for anemia. Imaging revealed metallic-density deposits in viscera and bones. Nodular biopsy was suggestive of mercury granulomas. A 24-hour urine mercury levels were elevated. She was advised chelation therapy with oral dimercaptosuccinic acid (DMSA). Case 3 is a 22-year-old lady who presented with acrodynia, neuromyotonia, tremulousness, postural giddiness, tachycardia, and hypertension for 2 months, associated with intractable, diffuse burning pain over the buttocks and both lower limbs, 1 month after completing a 3-week course of traditional medications for polycystic ovarian syndrome. A 24-hour urine normetanephrine levels and mercury levels were markedly elevated. Serum anti-VGKC antibodies were present. She was treated with glucocorticoids and oral DMSA with a favorable clinical response. CONCLUSIONS: The clinical manifestations of mercury toxicity are highly variable depending on the source, form, and route of mercury exposure and are related to its toxicokinetics.

Clinicopathological features and long-term prognosis of glomerular diseases associated with mercury-containing cosmetics.

OBJECTIVE: The pathological types and long-term prognosis of glomerular diseases related to mercury exposure are unclear. This study retrospectively examined 41 cases of glomerulonephropathy caused by mercury-containing cosmetics. METHODOLOGY: Forty-one subjects with glomerular diseases presumably caused by mercury-containing cosmetics were selected. Clinical features, kidney biopsy, treatment, and follow-up data were collected. RESULTS: All patients were female with an average age of 39.4 ± 6.6 years at diagnosis. Median time of exposure to mercury-containing cosmetics was six months, and average urine mercury level was 66.80 ± 38.55ug/(g·Cr). Most patients presented with nephrotic syndrome. Renal histopathology showed membranous nephropathy in 22 patients (53.65%), minimal change disease in 13 patients (31.71%), IgA nephropathy with minimal change disease in 5 patients (12.20%), and focal segmental glomerulosclerosis in 1 patient. Median time of exposure to mercury was longer and the proportion of patients with autoantibodies (mainly antinuclear antibodies) was higher in patients with membranous nephropathy. Both blood phospholipase A2 receptor -Ab and kidney tissue phospholipase A2 receptor were negative. Thirty-six patients received glucocorticosteroids and/or immunosuppressants. Five patients were treated with an angiotensin receptor blocker, and nine patients were treated with chelation therapy. The median follow-up time was 40 months (range 27-94). All patients achieved complete remission, and the median time to complete remission was one month. They all successfully discontinued the drugs without relapsing; withdrawal time was 26 months. CONCLUSION: Membranous nephropathy was the most common pathological type in mercury-induced glomerular disease. Patients were sensitive to glucocorticosteroids and immunosuppressants and achieved complete remission quickly. Contrary to primary glomerulonephritides, patients with mercury-induced glomerular diseases had no relapses after withdrawal of the mercury containing cosmetics.

Global Human Threat: The Potential Synergism between Mercury Intoxication and COVID-19.

The COVID-19 pandemic affected billions of people worldwide, and exposure to toxic metals has emerged as an important risk factor for COVID-19 severity. Mercury is currently ranked as the third toxic substance of global concern for human health, and its emissions to the atmosphere have increased globally. Both COVID-19 and mercury exposure present a high prevalence in similar regions: East and Southeast Asia, South America and Sub-Saharan Africa. Since both factors represent a multiorgan threat, a possible synergism could be exacerbating health injuries. Here, we discuss key aspects in mercury intoxication and SARS-CoV-2 infection, describing the similarities shared in clinical manifestations (especially neurological and cardiovascular outcomes), molecular mechanisms (with a hypothesis in the renin-angiotensin system) and genetic susceptibility (mainly by apolipoprotein E, paraoxonase 1 and glutathione family genes). Literature gaps on epidemiological data are also highlighted, considering the coincident prevalence. Furthermore, based on the most recent evidence, we justify and propose a case study of the vulnerable populations of the Brazilian Amazon. An understanding of the possible adverse synergism between these two factors is crucial and urgent for developing future strategies for reducing disparities between developed and underdeveloped/developing countries and the proper management of their vulnerable populations, particularly considering the long-term sequelae of COVID-19.

[Report on a case of significant increase in urine mercury due to excessive mercury in cosmetics].

Mercury is highly toxic and can be absorbed through skin contact. From December 5, 2020 to February 16, 2021, occupational disease laboratory of the First People's Hospital of Baiyin received 30 urine mercury test samples from a beauty salon in Lanzhou City. The test results showed that 28 samples exceeded the normal value (normal value: 4 µg/g Cr) . 15 patients were treated with sodium dimertopropyl sulfonate for mercury removal and tiopron for liver protection, and the prognosis was good.

Status of cosmetic safety in Malaysia market: Mercury contamination in selected skin whitening products.

BACKGROUND: Concern on cosmetic safety has been a subject of interest in recent years and is commonly associated with the exposure of the consumers to chemicals and impurities such as mercury contamination. Moreover, cancellations of notified cosmetic products were recurrently being reported by the Malaysia authority, namely the National Pharmaceutical Regulatory Authority (NPRA). Among the cosmetic categories was skin whitening product, which is still in high demand whilst reported to cause health risks. Besides, low number of studies on cosmetic safety and mercury contamination were recorded in Malaysia. The lack of scientific evidence on the safety and risks of the ingredients used in cosmetic formulation is a major concern to many consumers. OBJECTIVE: The aim of this study was to identify the presence of mercury in skin whitening products, and to identify products containing mercury with the concentration exceeding the limitation of 1 ppm. METHODOLOGY: A total of 104 whitening products were selected from the market via random sampling technique. The mercury concentration was determined by accredited laboratory, and the results were later compared with the cosmetic guideline of Malaysia and the list of banned products issued by NPRA. RESULTS: A total of 51.9% (n = 54) whitening products were found registered under the NPRA Quest system and remaining 48.1% (n = 50) were non-registered products. None of the whitening products listed mercury as an ingredient, but laboratory analysis showed 15.4% (n = 16) of the products contained mercury with the concentration exceeding the maximum limit of 1 ppm. A total of 87.5% of the whitening products (14 out of 16) containing high mercury concentration were non-registered products which were not registered in NPRA Quest system. The exceeded concentration recorded ranged between 1.81 ppm and 838 123 ppm. Besides that, 50% (8 out of 16) of the products were found in the list of banned products issued by the NPRA of Malaysia. CONCLUSIONS: This study presents the status of cosmetic products, particularly the skin whitening products available in Malaysia market. Concern arises when some of the products were found to have presence of harmful substances such as mercury. Even though the presence of mercury in a cosmetic product can either be non-intentional or intentionally used by the manufacturer in the cosmetic formulation, the impact of the ingredient can cause health risk to the users.

Mercury Exposure and Risk of Type 2 Diabetes: A Systematic Review and Meta-Analysis.

Methods: Scopus and PubMed databases were systematically searched from their inception to November 2021 to obtain pertinent studies. Standardized mean differences (SMDs) with corresponding 95% confidence intervals (CIs) were calculated to evaluate the difference in Hg levels between people with and without T2DM. The association of the Hg exposure with T2DM was assessed using a random-effects model by pooling the odds ratios (ORs) and 95% CIs. Results: A total of 17 studies, with 42,917 participants, aged ≥18 years, were analyzed. Overall, Hg levels were significantly higher in T2DM patients compared with non-T2DM controls (SMD = 1.07; 95%CI = 0.59 to 1.55, P ≤ 0.001), with significant heterogeneity across studies (I2 = 96.1%; P=≤0.001). No significant association was found between Hg exposure and risk of T2DM in the overall analysis and subgroup analysis based on the source of sample and study design. However, higher exposure to Hg was related to reduced risk of T2DM in men (OR = 0.71; 95%CI = 0.57 to 0.88), but not in women. No significant evidence for publication bias was detected. Conclusions: Although the Hg level in T2DM is significantly higher than that of nondiabetics, there was no association between Hg exposure and the overall risk of T2DM. Nevertheless, our study shows that higher exposure to Hg might reduce the risk of T2DM in men.

Health risk assessment for human exposure to mercury species and arsenic via consumption of local food in a gold mining area in Colombia.

The risk to human health from exposure to certain pollutants through the consumption of fruits, tubers, and fish were evaluated in a settlement located in a Colombian area highly impacted by gold mining activities. The concentrations of mercury (Hg) and arsenic (As) in edible food tissues and methylmercury (MeHg) in fish were determined for risk assessment. A questionnaire-based dietary survey was answered by 178 residents of three population groups: children (CHD), women of childbearing age (WCBA), and the rest of the population (RP). The estimated weekly intake (EWI) of MeHg presented values of 1.9 and 2.4 times higher than the provisional tolerable weekly intake (1.6 µg/kg BW/week) recommended by the FAO/WHO for CH and WCBA, respectively. The results of the HQ values of As and Hg for different food were above the safety level (HQ < 1) for most of the groups. For Hg, the highest HQ values correspond to fish, whereas for As in most of the food, but specially in fruits. The total target hazard quotients (HI) were higher than 1, in all the groups (except for CHD that consume tubers) indicating potential non-carcinogenic health risks. The values of carcinogenic risk (CR) for As through exposure to food ranged from 1.2·10-4 to 7.7·10-4, well above than the safety level of US EPA risk (10-4-10-6), suggesting the probability of carcinogenic risk for the entire population via ingestion. Therefore, safety control mechanisms and environmental education strategies should be applied to address food intake, associated with good agricultural practices to provide solutions to protect the health of the residents in areas affected by gold mining activities.

Pre and postnatal exposure to mercury and sexual development in 9-year-old children in Spain: The role of brain-derived neurotrophic factor.

Early exposure to mercury has been related to endocrine disruption. Steroid hormones play a crucial role in neural cell migration, differentiation, etc., as well as protecting against several neurotoxic compounds. We investigate the relation between mercury exposure and children's sexual development, and we evaluate the possible influence of different brain-derived neurotrophic factor (BDNF) polymorphisms on this association. Our study sample comprised 412 9-year-old children participating in the INMA cohort (2004-2015). Mercury concentrations were measured at birth (cord blood) and at 4 and 9 years of age (hair). Sexual development was assessed by levels of sex steroid hormones (estradiol and testosterone) in saliva and the Tanner stages of sex development at 9 years (categorized as 1: prepuberty and >1: pubertal onset). Covariates and confounders were collected through questionnaires during pregnancy and childhood. Polymorphisms in the BDNF gene were genotyped in cord blood DNA. Multivariate linear regression analyses were performed between mercury levels and children's sexual development by sex. Effect modification by genetic polymorphisms and fish intake was assessed. We found marginally significant inverse associations between postnatal exposure to mercury (at 9 years) and testosterone levels (ß[95%CI] = -0.16[-0.33,0.001], and -0.20[-0.42,0.03], for boys and girls, respectively). Additionally, we found that prenatal mercury was negatively associated with Tanner stage >1 in boys. Finally, we found significant genetic interactions for some single nucleotide polymorphisms in the BDNF gene. In conclusion, pre and postnatal exposure to mercury seems to affect children's sexual development and BDNF may play a role in this association, but further research would be needed.

Nephrotic syndrome of minimal change disease following exposure to mercury-containing skin lightening cream: A case report and literature review.

Long-term exposure to mercury-containing skin lightening cream can cause mercury-related nephropathy, among which, membranous nephropathy (MN) and minimal change disease (MCD) are the main pathological types. In contrast to these two conditions, MCD with IgA deposition is not a common disease. In the present study, we report a 65-year-old Asian woman who developed nephrotic syndrome following long-term use of mercury-containing skin lightening cream. The urine mercury level of the patient was significantly increased, and the results of the renal biopsy indicated diagnosis of MCD with IgA deposition. Following three courses of treatment with sodium dimercaptopropane sulfonate (DMPS) alone and discontinuation of the skin cream, the symptoms of the patient were relieved without use of glucocorticoids, with proteinuria turning negative and a significant reduction in urine mercury levels. During the 6-month follow-up period, routine urinalysis remained normal. By reviewing relevant published literature, we summarized the pathological characteristics, possible mechanism of action, and treatment strategies of mercury poisoning-related MCD. The possibility of mercury poisoning should be considered for patients with nephropathy and history of use of skin lightening cosmetics. In these patients, the urine mercury levels should be measured in time so that mercury removal therapy can be implemented early.

Dental amalgam: the history and legacy you perhaps never knew?

Much has been written about dental amalgam. Over many years, it has served the profession well, yet on environmental grounds its use is being phased down. This article seeks to explore key milestones in the history and development of this versatile material, as well as highlighting how international standards have assisted in reducing environmental mercury contamination.

Preventive planning against mercury over-exposure among Moroccan dentists using multidimensional statistical methods.

BACKGROUND: Mercury used in dental amalgams constitutes a significant source of chronic exposure to this heavy metal among dentists. Thus, the safety of dental amalgam remains a controversial issue despite its long history of use. In Morocco, most studies about dental mercury were mainly focused on the environmental risk related to the management of mercury-contaminated waste. OBJECTIVE: In order to evaluate the occupational exposure to mercury among liberal dentists practicing in two Moroccan regions, a multidimensional statistical approach was used to analyze the collected data. The main objective was to help establishing a targeted prevention plan aiming to reduce the mercury exposure among Moroccan dentists. METHODS: Fifteen variables from 146 dentists were elected for a three-step classification procedure: a multiple correspondence analysis followed by a hierarchical ascendant clustering consolidated by the k-Means algorithm. RESULTS: Three homogenous clusters were identified. The most important one includes 57.5% of the population as well as the majority of the risky factors. The characterization of these clusters allows proposing concise guidelines for a targeted preventive plan. CONCLUSIONS: A real mercurial risk has been observed in the studied population. However, its impact on health as well as the efficiency of simple preventive recommendations remains to be unveiled.

Biocompatibility of Amalgam vs Composite - A Review.

The Minamata Convention resulted in restrictions in the use of amalgam in daily dental practice. This opens up new discussions about the biocompatibility of amalgam, but also of composites as alternative materials. In the following review article, these issues will be discussed in more detail to provide dentists with a knowledge base for themselves and for communication with their patients. In addition to mercury in amalgam or monomers in composites, bisphenol A and nanoparticles generated during the grinding, polishing or removal of restorations must also be included in the biocompatibility evaluation. In laboratory tests, these substances cause toxic reactions, and bisphenol A also exhibits estrogen-like effects. However, it must be taken into account that the concentrations used in laboratory tests are much higher than in clinical practice. Thus, both amalgam and composite can be used in the general population. Nevertheless, for scientifically, politically and legally defined risk groups (e.g. dental personnel, allergic persons, pregnant or lactating women, children under 15 years of age, people with certain systemic diseases), indication restrictions and precautionary measures must be observed. The well-known amalgam discussion has taught us the importance of thorough and open risk communication with the patient.

Comprehensive Review Regarding Mercury Poisoning and Its Complex Involvement in Alzheimer's Disease.

Mercury (Hg) is considered one of the most widespread toxic environmental pollutants, which seems to have multiple effects on organisms even at low concentrations. It has a critical role in many health problems with harmful consequences, with Hg primarily targeting the brain and its components, such as the central nervous system (CNS). Hg exposure was associated with numerous CNS disorders that frequently trigger Alzheimer's disease (AD). Patients with AD have higher concentrations of Hg in blood and brain tissue. This paper aims to emphasize a correlation between Hg and AD based on the known literature in the occupational field. The outcome shows that all these concerning elements could get attributed to Hg. However, recent studies did not investigate the molecular level of Hg exposure in AD. The present review highlights the interactions between Hg and AD in neuronal degenerations, apoptosis, autophagy, oxidative stress (OS), mitochondrial malfunctions, gastrointestinal (GI) microflora, infertility and altering gene expression.