Total Mercury Concentrations In Blood Research Articles

Impact of environmental mercury exposure on the blood cells oxidative status of fishermen living around Mundaú lagoon in Maceió – Alagoas (AL), Brazil

Mercury in the aquatic environment can lead to exposure of the human population and is a known toxic metal due to its capacity for accumulation in organs. We aimed to evaluate the mercury level in the blood and urine of fishermen and correlate it with the level of oxidative stress in blood cells. We show in this case-control study that the fishermen of the exposed group (case) of Mundaú Lagoon (Maceió - Alagoas, Brazil) have higher concentrations of total mercury in the blood (0.73–48.38 μg L−1) and urine (0.430–10.2 μg L−1) than the total mercury concentrations in blood (0.29–17.30 μg L−1) and urine (0.210–2.65 μg L−1) of the control group. In the blood cells of fishermen, we observed that the lymphomononuclear cells produced high levels of reactive oxygen species (61.7%), and the erythrocytes presented increased lipid peroxidation (151%) and protein oxidation (41.0%) and a decrease in total thiol (36.5%), GSH and the REDOX state (16.5%). The activity of antioxidant system enzymes (SOD, GPx, and GST) was also reduced in the exposed group by 26.9%, 28.3%, and 19.0%, respectively. Furthermore, hemoglobin oxygen uptake was decreased in the exposed group (40.0%), and the membrane of cells presented increased osmotic fragility (154%) compared to those in the control group. These results suggest that mercury in the blood of fishermen can be responsible for causing impairments in the oxidative status of blood cells and is probably the cause of the reduction in oxygen uptake capacity and damage to the membranes of erythrocytes.

Decreased plasma thiol antioxidant capacity precedes neurological signs in a rat methylmercury intoxication model

The main target organ for MeHg is the nervous system, and its neurological dysfunction remains irreversible. Therefore, predictive biomarkers associated with individual susceptibility to MeHg and future clinical severity are needed to protect against the progression of MeHg toxicity. In this study, we demonstrated that plasma thiol antioxidant capacity (-SHp) is a useful predictive biomarker associated with future clinical severity using MeHg-intoxicated rats administered 1 mg/kg/day for 4 weeks. Blood samples were collected from the subclavian vein of each rat once a week to examine total blood mercury concentrations and the levels of plasma oxidative stress markers. Time course analyses of the correlation between these weekly blood examination values and hind limb crossing signs score after 4 weeks of MeHg exposure were performed, and plasma -SHp levels after 2 weeks of MeHg exposure showed strong correlations with future hind limb crossing sign scores. Neuropathological changes also developed in parallel with hind limb crossing sign scores. Quantitative analysis of vacuolar areas in the spinal cord showed a strong correlation with hind limb crossing sign scores. In conclusion, evaluation of plasma -SHp levels allowed us to detect individuals at risk for health damage and could protect the sensitive population against MeHg toxicity.

Subsistence fishing in the Eeyou Istchee (James Bay, Quebec, Canada): A regional investigation of fish consumption as a route of exposure to methylmercury

Fishing is part of the traditional activities of Indigenous people in Canada. However, it is also a route of exposure to methylmercury, a known neurotoxicant, and this is a concern for those who rely on fish as part of their diet. The probable weekly intake (PWI) of methylmercury from six species of fish was calculated for Indigenous community members (N = 1406), grouped by age and sex, and compared to Canadian and international provisional reference doses to assess exposure. Mixed-effects regression models were also used to estimate the input of methylmercury into the blood, and Hazard Quotients (HQ) were used to assess potential effects. Of the species of fish in our study, walleye and lake trout contributed the most to methylmercury intake. There was a positive association between the consumption of walleye and the total blood mercury concentrations of mercury in women and men (R2A = 0.40 and 0.47, respectively), and to a lesser extent, children. Similar results were observed for the consumption of lake trout. The 95th-percentile HQ for girls (3.16) and boys (3.18) from the consumption of lake trout was relatively high, and to a lesser extent, so was the HQ for walleye and pike. The consumption of some species of fish increases the exposure to methylmercury, however, taking a balanced approach, there are health benefits associated with the consumption of fish that must be considered. To mitigate future exposure to methylmercury, we recommend follow-up blood monitoring and local-geospatial-based assessments.

Long-term monitoring of mercury in adult saltmarsh sparrows breeding in Maine, Massachusetts and New York, USA 2000-2017.

Here we report on the results of a long-term study of mercury exposure in a songbird species, the saltmarsh sparrow (Ammodramus caudacutus). We measured total mercury concentrations in blood (n = 840) and feathers (n = 560) of adult saltmarsh sparrows at six locations between 2000 and 2017: Rachel Carson National Wildlife Refuge (RCNWR) in Wells, Maine; Scarborough Marsh State Wildlife Management Area in Scarborough, Maine; Parker River National Wildlife Refuge on Plum Island, Massachusetts; Pine Neck Preserve in Southampton, Long Island, New York; and North Cinder and North Green Sedge Islands off the coast of Long Island, New York. During the 12-17 year sampling periods, we found that mercury exposure differed by site and year but there was no consistent temporal trend across sites. Blood mercury concentrations declined only at RCNWR in Maine. We also found seasonal variation in blood mercury concentrations and a positive relationship between mercury concentrations of blood and innermost primary feather, but not between blood and tail feather.

An association of blood mercury levels and hypercholesterolemia among Korean adolescents

PurposeA few experimental studies have suggested that mercury exposure might be associated with dyslipidemia, possibly through its interference with the activities of genes and enzymes involved in lipid metabolism. Mercury exposure has been associated with the risk of dyslipidemia and cardiovascular disease in previous adult studies. However, only a few studies have been conducted in pediatric populations. We aimed to assess the associations between total blood mercury concentrations and lipid profiles in Korean adolescents. MethodsThe study population comprised 1890 adolescents (963 males and 927 females; age: 10–19 years) who participated in the Korea National Health and Nutrition Examination Survey 2010–2013 and 2016 and whose fasting blood samples were obtained to determine their blood mercury concentrations and lipid profiles. We analyzed the distribution of lipid profiles and the prevalence of dyslipidemia based on the total blood mercury concentrations. ResultsThe geometric mean of the blood mercury concentration was 1.89 μg/L and was significantly higher in males (1.96 μg/L) than in females (1.83 μg/L). The total cholesterol and low-density lipoprotein (LDL) cholesterol levels significantly increased as the blood total mercury concentration increased in males, not in females. High-density lipoprotein cholesterol and triglyceride levels did not show significant associations with total blood mercury levels. The prevalence of hyper-LDL-cholesterolemia also significantly increased in the highest blood mercury quartile group compared with that in the lowest blood mercury quartile group in males (P-for-trend <0.001). Male adolescents in the highest total blood mercury quartile group were found to be at higher risk of hypercholesterolemia than those in the lowest quartile group after adjusting for the covariates including obesity [odds ratios (95% confidential interval): 3.72 (1.03–13.4)]. Total blood mercury quartile showed a positive linear relationship with the risk of hyper-LDL-cholesterolemia after controlling for the covariates in males. ConclusionOur results suggest the potential association between mercury exposure and the risk of hyper-LDL-cholesterolemia in male adolescents.

Biomonitoring of mercury and persistent organic pollutants in Michigan urban anglers and association with fish consumption.

The 32-mile Detroit River and surrounding tributaries have been designated as a Great Lakes Area of Concern due to pollution from decades of municipal and industrial discharges, sewer overflows and urban development. Key pollutants in fish samples from the Detroit River include mercury, polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (DDE), dioxins and furans. A biomonitoring study was conducted to assess exposures to these persistent toxic substances in Detroit urban shoreline anglers who may be at high exposure risk due to consumption of locally caught fish. Using a modified venue-based sampling approach, 287 adult shoreline anglers along the Detroit River were recruited and participated in the program. Study participants provided blood and urine specimens and completed a questionnaire following informed consent. We examined percentile estimates for total blood mercury, PCBs, DDE, and dioxin-like total toxic equivalency (TEQ) concentrations among study participants. Multiple linear regression was used to identify important predictors of contaminant concentrations. Participants consumed a median of 64 Detroit River caught fish meals in the past year. The Detroit urban anglers' median total blood mercury concentrations was 3.2 times higher than that for the general adult U.S. population. PCB concentrations among the Detroit anglers aged 18-39 years were higher than the U.S. population of the same race/ethnicity. Elevated levels of DDE and total TEQ concentrations were not observed in the cohort. Eating more locally caught fish was associated with higher total blood mercury and serum PCB concentrations. The biomonitoring data served to inform public health officials and help guide environmental public health actions to reduce harmful exposures.

MON-037 An Association of Blood Mercury Levels and Hypercholesterolemia among Korean Adolescents

Purpose: Mercury exposure has been associated with the risk of dyslipidemia and cardiovascular disease in previous adult studies. However, there is little research on pediatric populations on this subject. We aimed to assess the associations between total blood mercury concentrations and lipid profiles in Korean adolescents. Methods: The study population comprised 1,890 adolescents (963 boys and 927 girls; aged 10-19 years), who participated and obtained fasting blood samples for blood mercury concentrations and lipid profiles in the Korea National Health and Nutrition Examination Survey (KNHANES) 2010-2013, 2016. We analyzed the distribution of lipid profiles and prevalence of dyslipidemia according to total blood mercury concentrations. Results: The geometric mean of the total blood mercury levels were 1.97 and 1.83 μg/L in boys and girls, respectively. As the blood mercury concentration increases, total cholesterol and low-density lipoprotein (LDL) cholesterol levels significantly increased. However, high-density lipoprotein (HDL) cholesterol and triglyceride levels did not show significant associations with total blood mercury levels. The prevalence of hyper-LDL-cholesterolemia also significantly increased in the highest blood mercury quartile group compared with the lowest group (8.9% vs. 5.1%, P-for-trend = 0.002). After adjusting for the covariates including obesity, those in the highest total blood mercury quartile were found to be at an increased risk of hypercholesterolemia than in the lowest quartile in boys [odds ratios (95% confidential interval): 3.72 (1.03-13.4)]. The association between total blood mercury quartile and the risk of hyper-LDL-cholesterolemia showed a positive linear relationship after controlling for the covariates in boys [Quartile 2 = 7.5, Quartile 3 = 10.3, Quartile 4 = 16.3]. Conclusion: Our results suggest the potential association between mercury exposure and the risk of hyper-LDL-cholesterolemia in adolescents. Keywords: Adolescent, Blood, Mercury, Dyslipidemia

Very low-level prenatal mercury exposure and behaviors in children: the HOME Study

BackgroundMercury is toxic to the developing brain, but the lowest concentration associated with the development of behavior problems is unclear. The purpose of this study was to examine the association between very low-level mercury exposure during fetal development and behavior problems in children.MethodsWe used data from 389 mothers and children in a prospective pregnancy and birth cohort study. We defined mean prenatal mercury concentration as the mean of total whole blood mercury concentrations in maternal samples collected at 16- and 26-weeks of gestation, delivery, and neonatal cord blood samples. We assessed parent-reported child behavior up to five times from two to 8 years of age using the Behavioral Assessment System for Children (BASC-2). At 8 years of age, we assessed self-reported child anxiety using the Spence Children’s Anxiety Scale (SCAS). We used multiple linear mixed models and linear regression models to estimate the association between mean prenatal mercury concentrations and child behavior and anxiety, respectively.ResultsThe median prenatal total blood mercury concentrations was 0.67 μg/L. Overall, we did not find statistically significant associations between mean prenatal mercury concentrations and behavior problems scores, but a 2-fold increase in mercury concentrations at 16-weeks gestation was associated with 0.83 point (95% CI: 0.05, 1.62) higher BASC-2 anxiety scores. Maternal and cord blood mercury concentrations at delivery were associated with parent-reported anxiety at 8 years.ConclusionWe found limited evidence of an association between very-low level prenatal mercury exposure and behaviors in children, with an exception of anxiety.

Total mercury exposure in early pregnancy has no adverse association with scholastic ability of the offspring particularly if the mother eats fish

There is a public perception that relatively low doses of mercury found in seafood are harmful to the fetal brain but little consistent evidence to support this. In earlier publications we have shown no adverse associations between maternal total blood mercury levels and child behaviour, early development or cognitive function as measured by IQ. However, for IQ the lack of adverse association was conditional upon the mother being a fish eater.In this paper we analyse further data from the Avon Longitudinal Study of Parents and Children (ALSPAC), this time examining whether prenatal exposure to total mercury is associated with the child's scholastic abilities in reading, spelling, phoneme awareness, mathematics and science; the number of participants with prenatal mercury and relevant test results varied from 1500 to 2200. Multiple regression was used to assess relationships between prenatal total blood mercury concentrations and 16 different test results, after taking account of a variety of potential confounders; in parallel, logistic regression was used to determine associations with the risk of the child being in the lowest 15% of each score. Analyses were repeated stratifying for fish consumption and sex of the child.There was no evidence of harm associated with the level of total mercury, provided the mother ate fish during pregnancy. This was particularly true for tests of mathematics and science. We conclude that women should be confident that eating fish in pregnancy is beneficial for their unborn child.

Geographic and temporal patterns of variation in total mercury concentrations in blood of harlequin ducks and blue mussels from Alaska

We compared total mercury (Hg) concentrations in whole blood of harlequin ducks (Histrionicus histrionicus) sampled within and among two geographically distinct locations and across three years in southwest Alaska. Blue mussels were collected to assess correlation between Hg concentrations in locally available forage and birds. Mercury concentrations in harlequin duck blood were significantly higher at Unalaska Island (0.31±0.19 mean±SD, μg/g blood) than Kodiak Island (0.04±0.02 mean±SD, μg/g blood). We found no evidence for annual variation in blood Hg concentration between years at Unalaska Island. However, blood Hg concentration did vary among specific sampling locations (i.e., bays) at Unalaska Island. Findings from this study demonstrate harlequin ducks are exposed to environmental sources of Hg, and whole blood Hg concentrations are associated with their local food source.

수은 고노출 지역 초등학생의 수은노출수준과 노출요인 연구

Objectives: Blood mercury levels among adults living in certain areas of the Gyeongsang Provinces have been shown to be very high (Kunwee County 29.6 μg/L, Yeongcheon-city 26.7 μg/L). The purpose of this project was to determine mercury exposure levels in schoolchildren and factors related with their mercury levels in high mercury exposure areas identifyed by the 2007 Korea National Environmental Health Survey. Methods: From June to September 2010, 1,097 students from grades 3 to 6 at 19 elementary schools participated in this study, including 294 students from 10 elementary schools in Kunwee County, 529 students from Yeongcheon City, 122 students from two elementary schools in Pohang City, North Gyeongsang Province, and 152 students from two elementary schools in Ulsan Metropolitan City. Biological samples from schoolchildren, including whole blood, urine and hair, were collected to measure total mercury at the time of a health check up. Information about children was collected by questionnaire. Total mercury concentrations in blood were measured using the Direct Mercury Analyzer 80 with the gold-amalgam collection method. Results: The mean mercury levels were 2.70 μg/L in 1,091 blood samples, 2.25 μg/g-creat. in 820 urine samples and 1.03 μg/g in 1,064 hair samples. Blood mercury levels in the schoolchildren was slightly higher than the result of 2.4 μg/L from a 2006 survey of elementary school children on exposure and health effects of mercury by the National Institute of Environmental Research. However, 0.3% and 4.5% of participants exceeded the reference level of blood mercury by CHBMII (15 μg/L) and the US EPA (5.8 μg/L), respectively. The reference level of urine by CHBMII (20 μg/L) was exceeded by 0.4% of participants. As factors, residence period in the study areas, residence type, father’s education level and income all showed significant associations with mercury level in the biological samples. The number of dental amalgam sides showed an association with urine mercury. Fish intake preference and fish intake frequency were important factors in mercury levels. In particular, intake of shark meat and recent intake of shark meat were associated with higher mercury levels. In this regard, participation in the performance of an ancestral rite showed a relation with higher mercury levels. Conclusion: The intake of shark meat was very important factor to high mercury exposure level. It is recommended to monitor and manage students with high mercury exposures who exceeded CHBM II and EPA guidelines, and include blood mercury testing in the Children’s Health check up for this province.

Blood mercury concentrations in pregnant and nonpregnant women in the United States: National Health and Nutrition Examination Survey 1999-2006

Prenatal exposure to methylmercury is associated with adverse neurologic development in children. We examined total blood mercury concentrations and predictors of higher blood mercury concentrations in pregnant and nonpregnant women. We analyzed data from 1183 pregnant and 5587 nonpregnant women aged 16-49 years from the 1999-2006 National Health and Nutrition Examination Survey (NHANES). We estimated geometric mean blood mercury concentrations and characteristics associated with higher mercury concentrations (≥3.5 μg/L) in crude and adjusted linear and logistic regression models. After adjusting for age and race/ethnicity, geometric mean blood mercury concentrations were clinically similar but significantly lower for pregnant (0.81 μg/L; 95% confidence interval [CI], 0.71-0.91) and nonpregnant women of childbearing age (0.93 μg/L; 95% CI, 0.87-0.99); 94% of pregnant and 89% of nonpregnant women had blood mercury concentrations below 3.5 μg/L. The most significant predictor of higher blood mercury concentrations for both pregnant and nonpregnant women was any seafood consumption vs no consumption in the last 30 days (odds ratio, 18.7; 95% CI, 4.9-71.1; odds ratio, 15.5; 95% CI, 7.5-32.1, respectively). Other characteristics associated with ≥3.5 μg/L blood mercury concentrations were older age (≥35 years), higher education (greater than high school), and higher family income to poverty ratio (3.501+) for both pregnant and nonpregnant women. Pregnancy status was not strongly associated with blood mercury concentrations in women of childbearing age and blood mercury concentrations above the 3.5 μg/L cut were uncommon.

Total blood mercury concentrations in the U.S. population: 1999-2006

We describe the distribution and demographic characteristics of total blood Hg levels in the U.S. general population among persons ages 1 year and older who participated in the 2003-2006 National Health and Nutrition Examination Survey (NHANES). We also describe trends in the total blood Hg of children ages 1-5 (n=3456) and females ages 16-49 during 1999-2006 (n=7245). In the combined 2003-2006 survey periods, the geometric means for non-Hispanic blacks, 0.853microg/L (95% confidence interval [CI], 0.766-0.950microg/L), and non-Hispanic whites, 0.833microg/L (95% CI, 0.752-0.922microg/L), were higher than the geometric mean for Mexican Americans, 0.580microg/L (95% CI, 0.522-0.645microg/L). Also in 2003-2006, regression analysis of log total blood Hg with age, race/ethnicity and gender showed that total blood Hg levels in the population exhibited a quadratic increase with age (p<0.0001), peaking at ages 50-59 in non-Hispanic blacks and whites, at ages 40-49 in Mexican Americans, and then declining at older ages. Over the four survey periods (1999-2006), regression analysis showed that total blood Hg levels increased slightly for non-Hispanic white children and decreased slightly for non-Hispanic black and Mexican American children. Over the same four survey periods, female children had slightly higher total blood Hg levels than males (0.356 vs. 0.313microg/L, p=0.0050) and total blood Hg levels in non-Hispanic black women aged 16-49 years were significantly higher than in non-Hispanic white women (1.081 vs. 0.850microg/L, p<0.0001) and in Mexican American women (1.081 vs. 0.70microg/L, p<0.0001).

Mercury concentrations and space use of pre-breeding American avocets and black-necked stilts in San Francisco Bay

We examined factors influencing mercury concentrations in pre-breeding American avocets (Recurvirostra americana) and black-necked stilts (Himantopus mexicanus), the two most abundant breeding shorebirds in San Francisco Bay, California. We tested the effects of species, site, sex, year, and date on total mercury concentrations in blood of pre-breeding adult birds and used radio telemetry to determine space use and sites of dietary mercury exposure. We collected blood from 373 avocets and 157 stilts from February to April in 2005 and 2006, radio-marked and tracked 115 avocets and 94 stilts, and obtained 2393 avocet and 1928 stilt telemetry locations. Capture site was the most important factor influencing mercury concentrations in birds, followed by species and sex. Mercury concentrations were higher in stilts (geometric mean: 1.09 microg g(-1) wet weight [ww]) than in avocets (0.25 microg g(-1) ww) and males (stilts: 1.32 microg g(-1) ww; avocets: 0.32 microg g(-1) ww) had higher levels than females (stilts: 1.15 microg g(-1) ww; avocets: 0.21 microg g(-1) ww). Mercury concentrations were highest for both species at the southern end of San Francisco Bay, especially in salt pond A8 (stilts: 3.31 microg g(-1) ww; avocets: 0.58 microg g(-1) ww). Radio telemetry data showed that birds had strong fidelity to their capture site. Avocets primarily used salt ponds, tidal marshes, tidal flats, and managed marshes, whereas stilts mainly used salt ponds, managed marshes, and tidal marshes. Our results suggest that variation in blood mercury concentrations among sites was attributed to differences in foraging areas, and species differences in habitat use and foraging strategies may increase mercury exposure in stilts more than avocets.

Blood Levels of Total and Organic Mercury in Residents of the Upper St. Lawrence River Basin, Québec: Association with Age, Gender, and Fish Consumption

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.