Hair Mercury Levels in Pregnant Women: Fish Consumption as a Determinant of Exposure.

The consumption of fish in food may contain mercury, a harmful element and dangerous chemical detrimental to human health. The purpose of this study was to determine the mercury level in the hair of pregnant women with different fish intakes in their diets. The concentration of total mercury in hair was determined using an atomic absorption spectrometer. In this study, 98 pregnant women were invited to participate (aged from 18 to 48 years). The mean content of mercury in the hair of pregnant women in Northwestern Russia was 0.428 mg/kg (ranging from 0.018 to 3.1 mg/kg). As a result, 22% of women had mercury values above 0.58 mg/kg, which is considered dangerous for the fetus. The hair mercury concentration in a village area was higher than that in a city area (i.e., 0.548 mg/kg and 0.326 mg/kg). Moreover, the maximum level of mercury was noted for a group of pregnant women who consumed more than 5 kg/month of fish and fish products. Furthermore, the consumption of freshwater fish in the diet leads to a higher mercury content in the hair of pregnant women than the consumption of marine fish.

Effects of lipid extraction on stable isotope ratios of carbon and nitrogen in muscles of freshwater fish.

The extraction of lipids by the Folch method from the muscles of all the fish studied led to statistically significant differences in the values of δ15N. At the same time, lipid extraction led to a statistically significant increase in δ13C in pike and roach, and to a statistically insignificant decrease in δ13C in perch and bream. Thus, lipid extraction cannot serve as a universal method of sample preparation for the analysis of the isotopic composition of carbon (13C/12C) and nitrogen (15N/14N) in fish muscles. The differences between the δ13C values in the samples before and after lipid extraction were statistically investigated by different models. It is shown that mathematical correction method models can be used, but the results are depending on the fish types.

High variability of mercury content in the hair of Russia Northwest population: the role of the environment and social factors.

PURPOSE: The purpose of this work is to study mercury levels in the hair of different social and demographic groups of the population of the Vologda region in Northwest Russia. This region is selected due to a heterogeneous distribution of rivers and lakes-a resource base for fishing. METHODS: The mercury content was determined in the hair from the root with a length of about 2 cm. The concentration of total mercury in human hair was determined by the atomic absorption method without preliminary sample preparation using an RA-915M mercury analyzer and a PYRO-915 + pyrolysis unit. RESULTS: The average level of mercury in the human hair was 0.445 µg/g (median 0.220 µg/g). The concentration of mercury in the hair of people older than 44 years (0.875 µg/g) was three times higher than in the hair of children under 18 years of age (0.270 µg/g). People who eat fish less than once per month had a hair mercury concentration of 0.172 µg/g, for 1-2 times a month 0.409 µg/g, once a week 0.555 µg/g, and several times a week 0.995 µg/g. The concentration of mercury in the hair of smokers (0.514 µg/g) was higher than in the hair of non-smokers (0.426 µg/g). CONCLUSION: Significantly higher concentrations of mercury were observed in the hair of participants from the western part of the region, where reservoirs are the main commercial sources of fish products. The data showed that the main source of people's mercury intake was fish.

Factors affecting the mercury concentration in the hair of young residents of the Vologda region, Russia.

The main aim of this study was to assess the level of mercury accumulation in the hair of students studying in the Vologda Region, Russia. Particular attention is devoted to clarifying the relationship between the metal concentration in the hair and the amount of fish in the diet. It was found that the mercury content in the hair of Vologda Region residents aged 17-21 is in the range from less than 0.002 mg/kg to 1.69 mg/kg, the median of the indicator for the entire sample is 0.14 mg/kg. The median value of mercury content in the hair of males (0.12 mg/kg) is lower than in the hair of females (0.16 mg/kg). The lowest metal concentrations were observed in individuals living in the city of Cherepovets and the highest metal concentration among the entire sample and in females in the western areas, and males in the eastern areas of the Vologda Region. The concentration of metal in the hair of the urban population is lower than in subjects living in rural areas. A higher metal content in the hair was recorded in individuals whose diet usually contains fish twice a month.

Long-term dynamics of total mercury in surficial bottom sediments of the Volga River's reservoir in central Russia.

The long-term dynamics of mercury in bottom sediments of Uglich Reservoir were examined. Samples of the 0-5-cm surface layer of bottom sediment collected during research expeditions in 1958, 1977, 1991, and 2012 were analyzed. An increase in the average mercury concentration from 1958 to 1977 (0.440 ± 0.039 and 0.668 ± 0.065 mg/kg d.w., respectively) was followed by a decrease in 2012 (0.260 ± 0.021 mg/kg d.w.). During all years except 1991, a significant correlation was found between mercury content and the amount of organic matter in the sediments (r = 0.54-0.87, p < 0.01), flow velocity (r = 0.38-0.53, p < 0.01), and the rate of sedimentation in the reservoir (r = - 0.51 to - 0.69, p < 0.01). Calculations based on these results and previously published data from the study region on the density of atmospheric mercury precipitation showed that the watershed as a whole received 2.4-3.0 t on an annual basis, and in the same period, the water surface received 9.7-12.8 kg of mercury. The bottom sediment contained 4.31 (2012)-7.40 (1977) tons of mercury. Thus, most of the mercury in the Uglich Reservoir is assumed to originate from runoff and terrigenous sources within the watershed.