Subcutaneous injections of mercuric chloride induce an autoimmune glomerulonephritis with both granular and linear IgG deposits along the glomerular capillary wall and proteinuria. This disease is due to a T cell dependent polyclonal B cell activation responsible for production of antibodies against self (glomerular basement membrane, immunoglobulins, DNA, myeloperoxydase) and non self (sheep red blood cells, trinitrophenol (TNP)) components. Increase in serum IgE concentration is the hallmark of this disease. To determine if mercury vapours have pathogenic effects is an important problem of public health. The aim of this study was, first to compare the effects of mercury vapour exposure to those of mercury injections and, second, to compare the effects of high doses to those of low doses of mercury. Two exposure levels were studied corresponding to a mercury absorption of 13.1 mumol/week per kg body wt. and 1.7 mumol/week per kg body wt. during a 5-week period. It will be shown that, whereas the mercury concentration in the kidneys was similar in injected--and vapour exposed--rats, the mercury concentration in blood at the end of the exposure was about twice as high in the injected animals. Blood concentration of mercury was related to dose level but kidney content of mercury was similar in all groups, in spite of a dose difference by a factor of seven between low and high exposure. Mercury vapour and HgCl2 injections both trigger autoimmunity to the same extent and, in both cases the extent of autoimmune manifestations was dose-dependent.
Increased consumption of lake fish was associated with higher blood mercury concentrations among 289 residents of Southwest Quebec living on the southern bank of the Upper St. Lawrence River System. This increase in blood mercury was reflected in the organic fraction and to a lesser extent with total blood mercury. Repeat analyses on a small subpopulation showed a correlation coefficient between time 1 and time 2 of approximately 0.7 for total mercury and for organic mercury. With one exception, blood total mercury concentrations were less than 5 ppb. Blood mercury concentrations were higher among men than women. One individual had much higher total mercury concentrations in blood (i.e., 70 ppb) which were attributed to fish consumption based on medical and dietary history. The values for these subjects are compared with other North American data on blood mercury levels.
Elevated concentrations of mercury (Hg) are commonly found in the traditional foods, including fish and marine mammals, of Inuit living in Canada's Arctic. As a result, Inuit often have higher dietary Hg intake and elevated Hg blood concentrations. However, these same traditional foods are excellent sources of essential nutrients. The goals of this study were 1) to identify the traditional food sources of Hg exposure for Inuit, 2) to estimate the percentage of Inuit who meet specific nutrient Dietary Reference Intakes and/or exceed the Toxicological Reference Values (TRVs), and 3) to evaluate options that maximize nutrient intake while minimizing contaminant exposure. A participatory cross-sectional survey was designed in consultation with Inuit in 3 Canadian Arctic jurisdictions (Nunatsiavut, Nunavut, and the Inuvialuit Settlement Region). Estimated intakes for EPA (20:5n3) and DHA (22:6n3) met suggested dietary targets, and estimated selenium (Se) intake fell within the Acceptable Range of Oral Intake. Estimated intakes of Hg (rs = 0.41, P
OBJECTIVE: Few biomarkers for dietary intake of various food groups have been established. The aim of the present study was to explore whether selenium (Se), iodine, mercury (Hg) or arsenic may serve as a biomarker for total fish and seafood intake in addition to the traditionally used n-3 fatty acids EPA and DHA. DESIGN: Intake of fish and seafood estimated by an FFQ was compared with intake assessed by a 4 d weighed food diary and with biomarkers in blood and urine. SETTING: Validation study in the Norwegian Mother and Child Cohort Study (MoBa). SUBJECTS: One hundred and nineteen women. RESULTS: Total fish/seafood intake (median 39 g/d) calculated with the MoBa FFQ was comparable to intake calculated by the food diary (median 30 g/d, rS = 0.37, P
RefSource: Public Health Nutr. 2009 Dec;12(12):2536-7
Breast milk is the ideal nutrient for the newborn, but unfortunately also a route of excretion for some toxic substances. Very little attention has been paid to breast milk as a source of exposure to toxic elements. The dose-dependent excretion is breast milk and the uptake in the neonate of inorganic mercury, methylmercury and lead were studied in an experimental model for rats and mice. The transfer of mercury from plasma to milk was found to be higher in dams exposed to inorganic mercury than to methylmercury. In contrast, the uptake of mercury from milk was higher in the sucklings of dams exposed to methylmercury than to inorganic mercury. Pre- and postnatal exposure to methylmercury resulted in increased numbers and altered proportions of the thymocyte subpopulation and increased lymphocyte activities in the offspring of mice and also effects on the levels of noradrenaline and nerve growth factor in the developing brain of rats. Mercury in blood and breast milk in lactating women in Sweden was studied in relation to the exposure to mercury from, fish and amalgam. Low levels were found; the mean levels were 0.6 ng g-1 in milk and 2.3 ng g-1 in blood. There was a statistically significant correlation between mercury levels in blood and milk, showing that milk levels were approximately 30% of the levels in blood. Inorganic mercury exposure from amalgam was reflected in blood and milk mercury levels. Recent exposure to methylmercury from consumption of fish was reflected in mercury levels in the blood but not in milk.(ABSTRACT TRUNCATED AT 250 WORDS)