Mercury Concentrations, Health, and Marine Food Consumption across Four Eastern Caribbean Populations: Insights from a Novel Community-based Study

Elevated blood Hg at recommended seafood consumption rates in adult seafood consumers.

W13/L2 - Commercial toxicology prediction systems — the current status and the road ahead

Mercury concentrations in bald eagles across an impacted watershed in Maine, USA

Abstract. Autistic Disorder can happen due to neurological expressions as the effects of environmental poisons in children who had genetical deficiency history. Current study found that increasing of mercury (Hg) concentration in hairs had significant correlation towards increasing of autisme level of severity. Hair analysis may identify the history of mercury’s exposure in human. This analytical correlational descriptive study aimed to identify mercury (Hg) concentration in children with autistic disorder at YAKARI Autism Foundation in Medan and at State Disability School in Binjai. This study also aimed to analyze the correlation between the Hg concentration and the symptoms’ level of severity. Hair samples were taken from 17 children with autistic disorder and 17 normal children (at similar age and sex). Mercury concentrations were analyzed by using ICP-OES. CARS were used to examine the autism symptoms’ level of severity. Majority of autistic disorder subjects (70.6%) had severe autism symptoms. Mean of Hg concentrations in autism subjects was 1,82 ppm ± 0,52 and in normal subjects was 0,91 ppm ± 0,68. Furthermore, mean of Hg concentrations in autistic disorder subjects was significantly higher than in normal subjects (p < 0,05). However, there was no significant difference on Hg concentrations between mild-fair and fair-severe autistic subjects’ categories. The findings of this study explain that the severity of autism symptoms in the autistic disorder subjects do not influenced by Hg concentrations within their body. Therefore, unidentified factors in this study might be contribute to the severity of autism symptoms. Future studies related epigenetics need to be conducted in order to explore another factors contribute to the severity of autism symptoms. Keywords: autistic disorder, CARS, mercury (Hg), hair analysis

Recent studies have shown that the complementary analysis of mercury (Hg) concentrations and stable isotopic ratios of nitrogen (δ15N) and carbon (δ13C) can be useful for investigating the trophic influence on the Hg exposure and accumulation in marine top predators. In this study, we propose to evaluate the interspecies variability of Hg concentrations in phocids from polar areas and to compare Hg bioaccumulation between both hemispheres. Mercury concentrations, δ15N and δ13C were measured in fur from 85 individuals representing 7 phocidae species, a Ross seal (Ommatophoca rossii), Weddell seals (Leptonychotes weddellii), crabeater seals (Lobodon carcinophagus), harbour seals (Phoca vitulina), grey seals (Halichoerus grypus), ringed seals (Pusa hispida) and a bearded seal (Erignathus barbatus), from Greenland, Denmark and Antarctica. Our results showed a positive correlation between Hg concentrations and δ15N values among all individuals. Seals from the Northern ecosystems displayed greater Hg concentrations, δ15N and δ13C values than those from the Southern waters. Those geographical differences in Hg and stable isotopes values were likely due to higher environmental Hg concentrations and somewhat greater number of steps in Arctic food webs. Moreover, dissimilarities in feeding habits among species were shown through δ15N and δ13C analysis, resulting in an important interspecific variation in fur Hg concentrations. A trophic segregation was observed between crabeater seals and the other species, resulting from the very specific diet of krill of this species and leading to the lowest observed Hg concentrations.

The relationship between mercury (Hg) concentrations in fish muscle and fish growth rates was assessed for 54 walleye Sander vitreus, 52 northern pike Esox lucius, and 35 lake trout Salvelinus namaycush populations throughout the Province of Quebec, Canada. We used the von Bertalanffy growth model to estimate the ages of fish specimens for a given length, and Hg concentrations in fish specimens at standardized length were determined via a quadratic regression model. Measured values of Hg concentrations in walleyes, northern pike, and lake trout were then correlated to the estimated age at standardized length for each population (375, 675, and 550 mm, respectively). A model‐II regression was performed to describe the existing relationships. Growth rates were positively related to Hg concentrations in walleyes and northern pike (when three outliers were excluded), whereas no correlation was observed for lake trout. Our findings demonstrate that slower‐growing walleyes and northern pike have higher Hg concentrations at standardized length. For these fish species, growth rate could be used as an integrated proxy to predict Hg concentration in fish muscle on a regional scale. Our findings support the contention that biodilution can be an important factor regulating mercury concentrations in fish. Thus, our findings suggest that proper control of fish growth rate through fishing pressure, lake ecology, and watershed management could be used by fisheries management authorities to minimize the toxic risk associated with Hg exposure from fish consumption.

Seafood consumption is the primary source of mercury (Hg) exposure, particularly among coastal populations. Hg exposure during pregnancy has been associated with cognitive impairment, as well as decrements in memory, attention, fine motor skills, and other markers of delayed neurodevelopment, although results are conflicting. High Hg hair concentrations in persons from coastal Florida, USA, have been previously reported. The purpose of the current study was to determine the concentrations of total Hg (THg) in the hair of pregnant women from this area and to assess the relationships between THg concentration, knowledge of the risks of mercury exposure, and dietary patterns among participants. Participants (n = 229) were recruited at prenatal clinics. Their mean total hair Hg concentration was 0.31 + 0.54 µg/g, lower or similar to US data for women of child-bearing age. Hair THg concentration was associated with consumption of locally caught fish and all seafood, a higher level of education, and first pregnancy. Eighty-five percent of women were aware of the risks of mercury exposure during pregnancy; over half reported a decrease in seafood consumption during pregnancy. Awareness of Hg in fish was marginally associated with lower hair THg concentration (p = 0.06) but reduction in seafood consumption during pregnancy was not.

Significance of fingernail and toenail mercury concentrations as biomarkers for prenatal methylmercury exposure in relation to segmental hair mercury concentrations

Recent progress on our understanding of the biological effects of mercury in fish and wildlife in the Canadian Arctic

Health effects of mercury ingested through consumption of seafood

Health effects of mercury ingested through consumption of seafood

Gold extracted by Hg-amalgamation process, which can cause both health and environmental problems, is widespread in South East Asia including Myanmar, Laos, Cambodia, and Thailand. Small-scale gold mining operations have been carried out since the year 2000 in Phanom Pha District, Phichit Province, Thailand. Since no data is available for evaluating Hg exposure, an investigation of mercury (Hg) contamination and exposure assessment was carried out at this mine site. Environmental monitoring illustrated the total Hg in water was as high as 4 μg/l while Hg in sediment ranged between 102 to 325 μg/kg dry weight. Both Hg deposition from the air (1.28 μg/100 cm2/day) and concentration in surface soil (20,960 μg/kg dry weight) were elevated in the area of amalgamation. The potential of Hg exposure to miners as well as to schoolchildren was assessed. The concentrations of Hg in urine of 79 miners who were directly (group I) or indirectly (group II) involved in the gold recovery operation were 32.02 and 20.04 μg/g creatinine, respectively, which did not exceed regulatory limits (35 μg/g creatinine). Hair Hg levels in both groups (group I and group II) also were not significantly higher than the non-exposed group. In terms of risk factors, gender and nature of food preparation and consumption were the two significant variables influencing the concentration of Hg in urine of miners (P < 0.05). A hazard quotient (HQ) was estimated based on the inorganic Hg exposure of individual miners. The HQ values of group I were in a range 16 to 218 times higher than the safety level set as 1. By comparison the group II HQ index was very low (0.03–0.39). The miners in group I who worked and ate food from this area experienced potentially high exposure to Hg associated with the mining process. In a second Hg exposure assessment, a group of 59 schoolchildren who attended an elementary school near the gold mine site was evaluated for Hg exposure. A slightly higher Hg urine concentration was detected in group I and group II (involved and not involved in gold recovery) at average levels of 15.82 and 9.95 μg/g creatinine, respectively. The average Hg values for both groups were below the established levels indicating no risk from Hg intake. Average Hg hair level in all schoolchildren (0.93 μg/g) was not significantly higher than reference group. There were two variables (gender and personal hygiene) which affected the concentration of Hg in urine of schoolchildren (P < 0.05). The result (HQ) also suggested that schoolchildren were not at risk (< 1). Schoolchildren involved in gold mining activities showed some indirect exposure to Hg from the adults working in mining area.

Seasonal mercury in an endangered primate from fragmented karst forest: Does behavioral observation advance ecotoxicological risk assessment?

Nitric oxide (NO) is a potent vasodilator with multiple protective effects involved in the regulation of cardiovascular functions. Endothelial NO synthase (eNOS) gene polymorphisms and environmental factors, such as mercury (Hg) exposure, may influence NO levels and increase the risk of cardiovascular damage. The aim of this study was to determine the role of the T-786C and Glu298Asp polymorphisms of the eNOS gene on nitrite concentrations following Hg exposure in humans. It was postulated that Hg exposure might decrease circulating nitrite concentrations and that variants in the eNOS gene might enhance the adverse effects of Hg resulting in increased risk of cardiovascular disease. Blood samples were collected from 202 volunteers exposed to methylmercury (MeHg) following fish consumption. Blood Hg concentrations (BHg) were determined by inductively coupled plasma–mass spectrometry and nitrite plasma concentration by a chemiluminescent method. The mean Hg concentration was 50.5 ± 35.4 μg/L and mean nitrite concentration was 251.4 ± 106.3 nM. There were no significant differences in age, arterial blood pressure, body mass index, heart rate, and concentrations of Hg and nitrite concentrations between the genotype groups . When data were grouped together (TC + CC and TT group), there were still no marked differences. A multiple regression model indicated that decreased NO production was predominantly due to Hg, age, and gender. Polymorphisms did not seem to influence this effect. Our findings suggest that eNOS gene polymorphisms (T-786C and Glu298Asp) are not associated with an increased risk for cardiovascular diseases in MeHg-exposed subjects.

BackgroundFish consumption is common among the cultures of Hawaii, and given public health attention to mercury exposure in pregnancy, it is important to better understand patterns of fish consumption and mercury in pregnancy. This study examined the influence of maternal fish consumption during pregnancy on umbilical cord mercury (Hg) concentrations in a multiethnic cohort of women in Hawaii.MethodsThis secondary analysis of a prospective cohort pilot study examined antenatal seafood consumption and neonatal outcomes in Hawaii. The first 100 eligible women who consented were enrolled. After delivery, umbilical cord blood and a dietary survey were obtained.ResultsMost women (86%) consumed seafood during the month prior to delivery. Overall, 9% of women consumed more than the recommended limit of 12 ounces/week. Seafood consumption varied significantly by ethnicity and income, with 30% of poor women consuming more than the recommended limit. Seafood consumption did not vary by age or education.Umbilical cord blood Hg levels were 5 μg/L or more in 44% of women. Filipina were significantly less likely to have elevated Hg levels compared with non- Filipina (p < .05). Mercury levels did not vary by other demographic characteristics.Women reporting consumption exceeding 12 ounces fish per week were significantly more likely to have cord blood Hg levels of 5 μg/L or more, but mean Hg concentrations were not significantly higher (6.1 ± 3.3 v 5.0 ± 3.7). The odds ratio for elevated Hg, however, was significant among seafood-consumers compared with non-consumers (5.7; 95% confidence interval: 1.2, 27.1).ConclusionsDespite Environmental Protection Agency (EPA) guidelines, a significant portion of pregnant women consumed more than the recommended amount of seafood, which was associated with race and income. Further, almost half of study participants had cord blood Hg concentrations at or exceeding 5 μg/L.