Mercury and Mink. II. Experimental methyl mercury intoxication.
Adult female mink were fed rations containing 1.1, 1.8, 4.8, 8.3 and 15.0 ppm mercury as methyl mercury chloride over a 93 day period. Histopathological evidence of injury was present in all groups. Mink fed rations containing 1.8 to 15.0 ppm mercury developed clinical intoxication within the experimental period. The rapidity of onset of clinical intoxication was directly related to the mercury content of the ration. Mercury concentration in tissue of mink which died were similar, despite differences in mercury content of the diets and time of death. The average mercury concentration in the brain of mink which died was 11.9 ppm. The lesions of methyl mercury poisoning are described and criteria for diagnosis are discussed. (+info)
Mercury toxicity due to the smelting of placer gold recovered by mercury amalgam.
A 19-year-old man developed tremor in both hands and fatigue after starting work at a placer gold mine where he was exposed to mercury-gold amalgam. Examination revealed an intention tremor, dysdiadochokinesis and mild rigidity. The 24-h urinary mercury concentration reached a peak of 715 nmol/l (143 ug/l) shortly before the clinical examination, after which he was removed from working in the gold room [Mercury No. Adverse Effect Level: 250 nmol/l (50 ug/l)]. On review 7 weeks later his tremor had almost resolved and the dysdiadochokinesis and rigidity had gone. The 24-h urinary mercury concentration had fallen to 160 nmol/l (32 ug/l). The principal exposure to mercury was considered to be the smelting of retorted gold with previously unrecognized residual mercury in it. The peak air concentration of mercury vapour during gold smelting was 0.533 mg/m3 (Mercury Vapour ACGIH TLV: 0.05 mg/m3 TWA). Several engineering and procedural controls were instituted. This episode occurred at another mine site, unrelated to Mount Isa Mines Limited. (+info)
Mercury intoxication presenting with hypertension and tachycardia.
An 11 year old girl presented with hypertension and tachycardia. Excess urinary catecholamine excretion suggested phaeochromocytoma but imaging studies failed to demonstrate a tumour. Other symptoms included insomnia and weight loss, and she was found to have a raised concentration of mercury in blood and urine. Mercury intoxication should be considered in the differential diagnosis of hypertension with tachycardia even in patients presenting without the skin lesions typical of mercury intoxication and without a history of exposure. (+info)
Heavy metal nephropathy of rodents.
Heavy metal nephropathy is a pathologic entity of the renal tubular epithelium of rats, evoked by lead, gold, and other heavy metals. It is characterized acutely by coagulative necrosis, subacutely by cortical fibrosis, and chronically by cytomegaly and karyomegaly. Finally, adenomas develop, some of which become malignant. (+info)
A young man with a heavy heart.
A 34 year old man presented with acute chest pain. His ECG was very abnormal but stable and he was treated with opiate analgesia. When his condition did not improve, chest radiography and cardiac ultrasound were performed. Both revealed metal dense deposits in the heart. On questioning, the patient revealed that he had self injected with mercury 15 years before. Self injection of elemental mercury is rare but well described and normally used by those who are suicidally depressed or who seek to improve sexual or athletic performance. Intravenous mercury may be deposited in the right heart and can result in ECG abnormalities, which may later be mistaken for changes due to coronary or other cardiac disease and result in inappropriate medication and hospitalisation. (+info)
Chronic insomnia in workers poisoned by inorganic mercury: psychological and adaptive aspects.
Insomnia is one of the symptoms of inorganic mercury poisoning (IMP). The objective of this study is to analyze the chief psychological aspects in the adjustment of workers with chronic insomnia associated with IMP. For this purpose the Preventive Clinical Interview and the Ryad Simon Operational Adaptive Diagnostic Scale (Escala Diagnostica Adaptativa Operacionalizada-EDAO) were utilized. Fifteen subjects with mean age of 40 years (10 males and 5 females) were studied. Nine were diagnosed with High Adaptive Inefficacy, five with Moderate Inefficient Adaptation and only one with Mild Inefficient Adaptation. Impairment occurred in four adaptive sectors: affective relationship, social-cultural, productivity and organic. Adaptive efficiency indicated that in all the 15 subjects studied the adaptive solutions were frustrating and led to psychic suffering and/or environmental conflict confirming the severity of the involvement in chronic IMP. (+info)
Occupational and environmental toxicology of mercury and its compounds.
Mercury exists in various chemical forms. The important forms from a toxicological viewpoint are the metallic form, also called the elemental form, the divalent inorganic forms and methylmercury compounds. Elemental (Hg0) mercury has a high vapor pressure and the vapor causes a number of cases of poisoning via inhalation. Classical mercury poisoning is characterized by a triad of signs, namely tremors, erethism and gingivitis. Mercurial erethism, which is characterized by behavioral and personality changes such as extreme shyness, excitability, loss of memory, and insomnia are also observed. Recently, the effects of mercury exposure at levels around 0.05 mg/m3 or lower have been of concern and may include minor renal tubular damage, increased complaints of tiredness, memory disturbance and other symptoms, subclinical finger tremor, abnormal EEG by computerized analysis and impaired performance in neurobehavioral or neuropsychological tests. Abnormal gait, dysarthria, ataxia, deafness and constriction of the visual field are typical of the symptoms of methylmercury poisoning observed in Minamata and Iraqi outbreaks, as well as in occupational methylmercury poisoning cases. Furthermore, an infant born to a mother with excessive methylmercury consumption showed various neurological disturbances and delayed development. Since several populations are believed to be still exposed to methylmercury through the consumption of fish and sea mammals, neurobehavioral deviations in children of these populations have recently been investigated. (+info)
Mercury in hair as an indicator of total body burden.
Hair is known to concentrate mercury, and in general the concentration of mercury in hair is proportional to and many times higher than its concentration in the blood. The variation of the mercury concentration in human head hair was used to follow the history of poisoning in people who ingested grain treated with methylmercury. Instrumental neutron activation analysis was used for mercury determination. The initial rising slope of mercury concentration along the hair was proportional to the daily intake of methylmercury per kg of body weight. The ratio of the concentration of methylmercury in human head hair to the average body concentration was found to be about 137. By using this ratio and measuring mercury concentration in hair, the total body burden can be calculated. In the patients studied, the peak body burden ranged from 0.8 to 4.4 mg/kg in cases showing mild symptoms, from 1.5 to 6 mg/kg in cases with moderate symptoms, and from 3 to 12 mg/kg in cases with severe symptoms. The curve of the variation in mercury concentrations along the hair was also used to calculate the biological half-life of methylmercury in man. Forty-eight cases were studied and it was found that the frequency curve (population distribution curve) was grouped into two distinct regions. In about 90% of the population the biological half-life of methylmercury was 35-100 days, and 10% showed high values of 110-120 days. (+info)