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Les amalgames dentaires constituent des matériaux d'obturation utilisés pour le traitement des lésions carieuses depuis plus de 150 ans. Cependant le mercure servant de base à la préparation des amalgames est universellement considéré comme un toxique très dangereux pour l'être humain. L'objectif de ce travail est de monter à travers un cas clinique certains signes locaux et généraux d'intoxication au mercure, les précautions à prendre lors de la dépose des amalgames, ainsi que les solutions de remplacements actuels qu'on doit proposer à nos patients. En réalité la toxicité des amalgames n'est que la partie émergée de l'iceberg. Les autres métaux employés en dentisterie peuvent également provoquer des problèmes importants en induisant des effets galvaniques, des intolérances, des allergies, des réactions d'intoxication ou de sub-intoxication. En matière de santé publique, ces motifs justifient amplement l'intérêt que tout thérapeute doit accorder aux alternatives prothétiques n'incluant pas de métal. Dental amalgams are dental filling materials which have been used to fill cavities caused by tooth decay for more than 150 years. However, mercury used as a basis for the preparation of amalgams is universally regarded as toxic and thus very dangerous for the human being. This clinical case report aimed to describe some local and general signs of mercury poisoning, to emphasize necessary precautions during amalgam filling and to highlight current replacement techniques that should be proposed to our patients. In effect, amalgam toxicity is just the tip of the iceberg. Other metals used in dentistry can cause significant problems bringing about galvanic effects, intolerances, allergies, toxic and subtoxic reactions. In public health, this is a sufficient reason to justify therapists’ interest in non-metal prosthetic alternatives.

Exposure to metallic mercury can cause severe accidental intoxications in children, whose clinical symptoms can vary depending on the route of administration, the dose, as well as the time and duration of the exposure. It has become unusual in France, yet it must be considered when taking a patient's medical history in cases of multisystemic involvement without a clear explanation.We report the case of a 12-year-old patient hospitalized because of a cough, poor general condition, chills, night sweats, psychomotor retardation, and skin lesions that had been developing for several weeks. The initial clinical examination also revealed sinus tachycardia, arterial hypertension, and abolition of osteotendinous reflexes. Complementary examination results were normal apart from a glomerular proteinuria without renal failure. When interviewing the mother, she reported that the child had played with mercury balls 3 months earlier. The suspicion of poisoning was confirmed by blood and urine analysis as well as renal biopsy showing an aspect of membranous glomerulonephritis with IgG and C3 depositions. An intoxication via a transdermal route being unlikely on healthy skin, the Regional Health Agency's survey concluded that chronic intoxication had occurred by inhalation of the mercury spread on the floor at the time of the exposure, which was then vacuum cleaned and released again by the contaminated vacuum cleaner. The patient's outcome was favorable within a few weeks after initiating DMSA chelation therapy.Mercury poisoning should be considered in cases of a multisystemic disorder without clear explanation, in order to intervene quickly and thus prevent irreversible renal and neurological consequences.

Dental amalgam is a metallic restorative material that is used for direct filling of carious lesions since many years. The use of this material generates solid and particulate wastes that present potential challenges to the environment. This study was carried out to assess amalgam use and waste management protocols practiced by Moroccan and Burkinabe dentists. A cross-sectional study was made of 79 in Rabat, Sale and Temara in Morocco and 56 in Ouagadougou, Bobo-Dioulasso in Burkina-Faso. The results showed that 69.5% of dental amalgam waste in Morocco vs 49.9% in Burkina-Faso was disposed with household waste which is a problem for both the environment and a risk to human being. Proper methods of dental amalgam waste disposal should be carried out to prevent indirect mercury poisoning for human.

Blaise Pascal's serious physiological disorders could be the consequence of a long exposition to mercury fumes as he was studying the first device of vacuum. Weakness headache, paralysis of the lower limbs were described by his sisters. Probably such were the causes of his bad health and of the disorders which hit him until his death.

Louis Melsen was born at Louvain, he spent four years in Paris, working in Dumas's laboratory. Four letters from Melsens to Chevreul, since 1951 to 1880, are commented on. Two letters relate to Van Helmont and common interest of the two scientists in history of sciences. The others recall Melsens's proposal that potassium iodide can cure and prevent lead and mercury poisoning, and Chevreul's researches about colours seeing.

Mercury is a widespread heavy metal with potential severe impacts on human health. Exposure conditions to mercury and profile of toxicity among humans depend on the chemical forms of the mercury: elemental or metallic mercury, inorganic or organic mercury compounds. This article aims to reviewing and synthesizing the main knowledge of the mercury toxicity and its organic compounds that clinicians should know. Acute inhalation of metallic or inorganic mercury vapours mainly induces pulmonary diseases, whereas chronic inhalation rather induces neurological or renal disorders (encephalopathy and interstitial or glomerular nephritis). Methylmercury poisonings from intoxicated food occurred among some populations resulting in neurological disorders and developmental troubles for children exposed in utero. Treatment using chelating agents is recommended in case of symptomatic acute mercury intoxication; sometimes it improves the clinical effects of chronic mercury poisoning. Although it is currently rare to encounter situations of severe intoxication, efforts remain necessary to decrease the mercury concentration in the environment and to reduce risk on human health due to low level exposure (dental amalgam, fish contamination by organic mercury compounds…). In case of occupational exposure to mercury and its compounds, some disorders could be compensated in France. Clinicians should work with toxicologists for the diagnosis and treatment of mercury intoxication.

There is some debate concerning a possible relationship between dental fillings and multiple sclerosis. Many patients ask their dentist to remove fillings.Dental fillings contain mercury (more than 50%) which can cross the blood-brain barrier. Massive mercurial intoxication is neurotoxic both for the central and peripheral nervous system. Dental fillings release as much mercury in 24 hours as is ingested in a normal meal, i.e. a level well under the neurotoxicity level.Mercurial poisoning is histologically, clinically, immunologically, and toxicollogically different from multiple sclerosis. Based on data available today, it is not warranted to propose removing dental fillings.

Mercury pulmonary embolism following intentional or accidental injection of metallic mercury are uncommon. Generally, there are few clinical signs (acute pneumopathy in 50% of the cases). Chest x-ray shows multiple and bilateral point opacities with a metallic density. We present two cases of mercury pulmonary embolism after intentional intravenous mercury injection (one attempted suicide and one HIV+ drug addict).

A young patient suffering from schizophrenia had intense headaches and photophobia which were induced by intra-ocular injections of mercury. The clinical diagnosis was established once foreign bodies were visualized on regular X-rays of the patients skull. The mercury intoxication in combination with the secondary irreversible lesions to the eyes necessitated a bilateral enucleation and the use of a chelating treatment with sodium-dimercapto-1-propane sulfate (DMP). Automutilation is a very rare and dramatic complication of schizophrenia. The psychiatric handling and meaning of such dramatic automutilation is discussed in this case report together with a recent review of the toxicologic treatment of mercury intoxication in humans.

Mercury poisoning is a rare cause of hypertension in children. Urinary excretion sometimes remains low despite severe clinical intoxication.A 32 month-old girl was admitted with hypertension, tachycardia, apathy, irritability and excessive sweating. Erythromelalgia and neurologic symptoms permitted the diagnosis of acrodynia. Urine mercury remained normal until chelation. Captopril significantly increased urine mercury concentration but failed to improve clinical manifestations. Clinical improvement required infusions of BAL for 5 days then oral dimercaptosuccinic acid for 3 months. Metal vapors originated from the mercury which spilled from a broken thermometer onto the carpet.Low basal urine mercury could be associated with real mercury poisoning. Small amounts of metal mercury held in a thermometer could produce a high level of mercury vapor leading to intoxication in young children. The binding capacity of metal ions by captopril could be used to increase urine mercury output. Nevertheless, captopril therapy fails to improve acrodynia. Total elimination of mercury requires long-term therapy with BAL or dimercaptosuccinic acid.An unexpected mode of intoxication and low basal urine mercury are not decisive arguments against mercury poisoning, which is the only cause of acrodynia.

Erythromelalgia is an acrosyndrome characterized by paroxysmal manifestations associating erythema, local sensations of warmth and pain which improve with exposure to cold. Childhood forms, exceptional and usually primary, are quite severe and particularly resistant to treatment. The search for a causal agent is most often negative and the pathogenesis remains to be determined. We report a case of erythromelalgia observed in a 4-year-old girl, her father and her younger sister. This case was particular due to an association with mercury poisoning. The symptomatology was improved after different therapeutic attempts including Clomipramide and, particularly effective, rerigerating socks (D(r) Comet, CNES, Toulouse). In the literature we were unable to find any case of erythromelalgia related to mercury poisoning. The cases of familial erythromelalgia reported suggest X-linked dominant transmission. Finally, this case demonstrated the difficulties in diagnosing and treating erythromelalgia, especially in the child.

The activity of the dentists generates nuisances due, for instance, to the use of biocontaminating aerosols and the emission of waste containing mercury. These two points are thoroughly reviewed in order to raise risk-awareness. As first and main victims of these nuisances, dentists must learn preventive methods and how to implement them. Anti-polluting methods are explained which are effective and easy to apply though sometimes not very well know and IDF recommendations are recalled.

The carbo-hydroxamic-2 chromone acid (sodium salt) shows a higher protective action in vivo than in vitro against mercury chloride induced intoxications. The higher effect observed in vivo might be due to the activity itself of the chromone cycle which added up to that of the carbo-hydroxamic acid function. This latter alone appears in vitro. The antihyaluronidasic properties of this protective agent allow it to prevent the toxic substances to be diffused.

A 58-year-old laboratory-glassware manufacturer was referred to hospital because of coarse "tremor" of the upper extremities of 16-months-duration. Examination showed severe intention and action myoclonus, confirmed by electromyographic recording, slight memory impairment but was otherwise normal. Mercury levels were high in blood and urine (not in CSF) and, as other causes of myoclonus were excluded, inorganic mercury poisoning, was diagnosed. Only slight unilateral intention tremor persisted after dimercaprol treatment. Inhalation of mercury vapor was the mode of contamination. Myoclonus is the hallmark of severe inorganic mercury intoxication, the main clinical and pathological aspects of which are briefly discussed.

Seven cases of acute intoxications by inhalation of metallic vapors are reported. The metals involved were zinc in three cases, tin in one case and mercury in three cases. The severity of the respiratory symptoms was dependent from the inhalated metal. The inhalation of zinc or tin vapors produced an acute limited pneumonitis. A lesional pulmonary oedema and acute interstitial fibrosis with lethal outcome was observed in two cases of intoxication by mercury vapors. The treatment by dimercaptopropanol used in mercury intoxications, increased urinary mercury excretion, but did not improve the pulmonary symptoms.

The technique consists in employing successively an extraction method using the dithizone-carbon tetrachloride system, at 4 different pH values, then thin-layer chromatography on silica gel, to identify and separate Ag, Cd, Co, Cu, Hg, Ni, Pb, and Zn in the form of their dithizonates. Sensitivity is of the order of 10(-7) g ion/l. This method is directly applicable in hydrology; after destruction of organic matter in the case of biological samples (blood, urine, excrement). We have applied it in toxicological analysis together with other methods for the detection of copper, lead, mercury and zinc in cases of poisoning.

The authors report four cases of acute mercury poisoning in children ranged from one week to twelve years of age. All were of favourable course and one of them is particularly well-documented with regard to mercury excretion. Case reports are followed by a clinical study of mercury intoxication with a review of literature about recent therapeutic advances.

A 27 year old agricultural worker presented about one month after treating cereal seeds with an alcoxyalkyl mercurial derivative, an encephalopathy with a confusional state, a cerebellar stato-kinetic syndrome, an intention tremor and grand mal epileptic fits. Treatment with dimercaprol produced a clinical improvement on the fourth day with a fall in blood mercury from 3.5 mug to 2.2 mug whilst urinary excretion of mercury remained low. A fortnight later the patient was completely cured. Although less common than collective poisoning by ingestion, organo-mercurial encephalopathies due to occupational exposure are a real danger although it is not known whether the relative rareness of published cases is due only to lack of observance of security rules or to individual sensitivity which might be due to increased absorption of mercury through the lungs or skin. This case shows that although alkyl mercurial derivatives are reputed to be the most dangerous, alcoxyalkyl derivatives may also cause encephalopathies. Also, as long as non-toxic substances remain unavailable for use in agriculture, one should emphasise the necessity of careful observance of the security rules during manipulation of these products.

We have performed several cross-sectional epidemiological surveys among workers exposed to cadmium, mercury vapour or manganese in order to assess : their early biological or functional effects; the biological tests allowing an assessment of the amount of metal absorbed or stored in the body; the acceptable exposure levels. Studies have also been carried out among persons exposed to inorganic arsenic in order to define its inactivation mechanism and to develop a biological test of exposure. The kidney is the main critical organ following long-term exposure to cadmium. To prevent the occurrence of renal changes in the majority of male workers exposed to cadmium, its concentration in renal cortex should not exceed 215 micrograms/g (wet weight), and that in urine : 10 micrograms/g creatinine. A blood cadmium level of 1 microgram/100 ml has been suggested as maximum tolerable level for long-term exposure. Prolonged exposure to mercury vapour may lead to renal and neurological disturbances. The preclinical signs of nephrotoxicity are correlated with the amount of mercury absorbed which may be assessed by monitoring the mercury level in urine. The neurotoxic effects (particularly tremor) are mainly related to the integrated exposure (duration and intensity). A maximal permissible level of 50 micrograms Hg/g urinary creatinine is proposed to prevent the occurrence of these toxic effects. An exposure to manganese dust for 7 years on the average at a level below the maximum allowable airborne concentration (5 mg/m3) recommended by the ACGIH in the USA may still lead to a slight reduction in psychomotor and spirometric performances and interfere with calcium metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)

Classically, the histological lesion observed in a drug-or heavy metal-induced nephrotic syndrome is membranous glomerulonephritis. We report two cases of "toxic" nephrotic syndrome with unusual histological features. One was secondary to mercury intoxication and the other, to D-penicillamine in a patient with rheumatoid arthritis. In both cases, renal biopsy revealed minimal glomerular changes. The proteinuria rapidly disappeared after exposure to the toxic agent was discontinued. Genetic factors and a disregulation of the immune system with lymphokine production may be responsible for these renal changes. This study demonstrates that renal biopsy is necessary in this clinical setting.

The use of skin-lightening preparations appears to be a problem for the coloured women in Africa as well as for the Black People in general. The mercurial creams occupy a place of choice into the most useful products for the skin depigmentation. An epidemiological study from twenty senegalese women using mercurials cosmetics has permitted to determine a mean value of 155,75 +/- 75,38 ppm Hg in scalp hair while the normal level is less than 10 ppm. An experimental study was realised with monkeys (Papio papio) treated with a soap containing mercuric biiodide. This study has shown, after only three months of experimentation, a significative augmentation of mercury levels in all the organs and specially in the kidneys and the hair.

We present the results of an inquiry about the hydrargyric risk run by the staff of an odonto-stomatological laboratory. A second laboratory in which mercury was not used, served as a control. It would appear that the staff in the laboratory where the practician uses amalgam have a level of mercury higher than that of the staff working in the control laboratory. This level reaches the maximum in the middle of the day and returns to the same level as that of the controls after the nights rest outside the polluted atmosphere. These results are discussed in the light of our findings and of facts obtained from literature.

Rats have been exposed for periods of 120 to 240 minutes to an atmosphere containing 6 +/- 0.7 mg per cu.m mercury vapor. All rats developed an acute respiratory distress which lead to death within 2 to 210 hours (mean 53.5 h). Microscopical examination of the lungs showed an oedema rich in fibrin, an epithelial necrosis, hyaline membranes and in two cases an interstitial fibrosis. Mercury levels in the lungs ranged between 0.5 and 9.37 micrograms per gramme wet weight. The activity of pulmonary superoxide dismutase was decreased to 1.57 +/- 0.66 micrograms per mg of soluble proteins, compared with the level of 5.01 +/- 0.76 micrograms per mg in control rats. This study confirm the pulmonary toxicity of mercury vapors observed in human intoxication.

We report the case of a 25-year-old woman who voluntary swallowed mercuric oxycyanide and presented an anuric acute renal failure. The treatment was classically based upon the use of chelating agents and haemodialysis. Recovery of renal function was excellent. We discuss then more widely the clinical, physiopathologic and therapeutic aspects of acute intoxication with inorganic mercury salts.

Membranous glomerulonephritis (MGN) is one of the well documented manifestations of autoimmunity during chronic mercuric chloride (HgCl2) intoxication. We have carried out immunological investigation of the T cell functions in a patient presenting an HgC12-induced MGN. Circulating auto-antibodies and immune complexes were absent from the serum. Lymphocyte transformation with HgCl2 over a wide range of doses (10(-3) to 10(-8) M) was negative. E rosettes, mitogen reactivity, allogeneic reactivity evidenced by a one way mixed lymphocyte culture gave slightly diminished results. These findings contrasted with a severe impairment of the stimulative ability of lymphocytes. This defect might be related to the inability of D, DR products to be exposed at the cell surface and impeding the allogeneic recognition by foreign lymphocytes. This lymphocyte defect in the course of an HgC12 MGN in man would be correlated with lymphocyte abnormalities found in experimental HgC12-treated rats. The results of this study would favour the hypothesis of a direct role of HgC12 on lymphocyte rather than a direct action on glomerular basement membrane.