Total Blood Mercury Research Articles

Blood mercury concentrations in common bottlenose dolphins from the Indian River Lagoon, Florida: Patterns of social distribution

AbstractSocial network analysis has been shown to be effective in studying the social structure of cetacean populations. Common bottlenose dolphins (Tursiops truncatus) inhabiting the Indian River Lagoon (IRL), Florida, have among the highest concentrations of total mercury (THg) in blood reported worldwide. The purpose of this study was to examine the relationship between THg concentrations in IRL dolphins and their social affiliations. Whole blood samples from 98 dolphins with photo‐identification sighting histories were collected between 2003–2007 and 2010–2012. Dolphins were categorized into approximate tertiles of low (mean 199.7 μg/L), medium (mean 366.8 μg/L), and high (mean 990.5 μg/L) THg exposure. Social associations between individual dolphins were defined by the proportion of sightings documented with another known individual. Social network measures of individuals and associations between dyads were examined to determine differences among THg categories. Strong social affiliations of individuals within the highest category of THg were found (P = 0.04), suggesting shared exposures among dolphins foraging in specific areas of the estuary. Network measures of strength and affinity were significantly higher in the highest exposure category. This report used social network analysis as a novel way to examine patterns of exposure to an environmental contaminant in a cetacean population.

Mercury, eicosapentanoic acid and docosahexaenoic acid demonstrate limited effect on plasma paraoxonase-1 activity and blood pressure among avid seafood consumers in the Long Island Study of Seafood Consumption, NY, USA.

Moderate fish consumption is recommended for prevention of coronary heart disease (CHD) as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) have known beneficial effects on risk factors such as reducing blood pressure (BP) and increasing paraoxonase-1 (PON-1) activity. However concomitant methylmercury (MeHg) exposure from fish consumption may mitigate these benefits and the net effect on BP and PON-1 activity has not been extensively studied in western populations consuming diverse seafood types. We studied the correlation between EPA, DHA and Hg levels with BP and PON-1 activity in a population of avid seafood consumers. Two hundred and eighty-eight avid seafood consumers from Long Island, NY had blood samples drawn for total blood mercury (THg), plasma EPA and DHA levels, and plasma PON-1 activity. Average systolic blood pressure (SBP), diastolic blood pressure (DBP) and pulse pressure (PP) were measured. Subjects' mean EPA+DHA was 4.9% total fatty acids, mean THg was 7.6mcg/L. Mean SBP was 122.5mmHg, mean DBP 70.3mmHg, mean PP 52.2mmHg and mean PON-1 activity 421.2U/L. THg was not associated with any of the BP measures in adjusted linear regression models; EPA+DHA was significantly inversely associated with PP (p=0.02). THg was associated with a significant increase in PON-1 activity (p=0.04), while EPA+DHA was associated with a significant decrease in PON-1 activity (p=0.007); although the size of the effects was small. Our findings suggest blood THg and serum DHA+EPA levels have limited relationship to BP and PON-1 activity, and may not be important modulators of these known CHD risk factors in this population of avid seafood consumers.

Prenatal exposure to mercury and neuropsychological development in young children: the role of fish consumption.

Vulnerability of the central nervous system to mercury exposure is increased during early development. The aim of this study is to evaluate the association between prenatal exposure to mercury and child neuropsychological development in high-fish-intake areas in Spain. Study subjects were 1362 children, participants in the INMA (Environment and Childhood) birth cohort study. Cord blood total mercury (CB-Hg) and cord polyunsaturated fatty acids (PUFA) concentrations were analysed in samples collected between 2004 and 2008. Child neuropsychological development was assessed at age 4-5 years by the McCarthy Scales of Children's Abilities (MSCA). Socio-demographic, lifestyle and dietary information was obtained by questionnaires administered during pregnancy and childhood. The geometric mean of CB-Hg was 8.8µg/L [95% confidence interval (CI) 8.4, 9.2]. A doubling in CB-Hg was associated with higher scores in most of the MSCA scales ( β =1.29; 95% CI 0.28, 2.31 for the general cognitive scale). The association between CB-Hg and the scores obtained on the scales was inverse among children whose mothers consumed fewer than three weekly servings of fish during the first trimester of pregnancy, although confidence intervals did not exclude the null ( β =-1.20; 95% CI -2.62, 0.22 for the perceptive-manipulative scale and β =-3.06; 95% CI -6.37, 0.24 for the general cognitive scale). An inverse association between CB-Hg and the scores on the motor scale was also suggested for children with an n-6/n-3 PUFA ratio above the median ( β =-0.23; 95% CI -0.87, 0.40, interaction p -value=0.03). The relationship between CB-Hg concentrations and child neuropsychological development was influenced by maternal nutritional factors, such as fish consumption and the PUFA status.

Body burden of heavy metals among HIV high risk population in USA

ObjectiveHIV high risk population may face not only the threat of HIV infection but also a higher chance of exposure to environmental contaminants. However, no previous studies have examined the body burden of environmental pollutants including heavy metals among HIV high risk populations. The aim of this study was to investigate whether adults aged 20–59 years old at high risk of HIV infection have higher blood levels of heavy metals compared to those with low risk of HIV infection in United States. Material and methodsWe used the National Health and Nutrition Examination Survey (NHANES) 1999–2010 to compare exposures to heavy metals including cadmium, lead, and total mercury by HIV risk status. ResultsThe results showed that people at high risk of HIV had higher blood concentrations of all heavy metals compared to their counterparts with lower HIV risks. In multivariate linear regression models, HIV risk status was significantly associated with increased blood cadmium, lead, and total mercury after adjusting for age, sex, race, education, and poverty income ratio. ConclusionsOur study suggests that people at high risk of HIV have significantly higher body burden of heavy metals including cadmium, lead, and mercury compared to those with low risk of HIV. Further longitudinal study collecting more pollutants are warranted to determine the potential health effects of these elevated pollutants on both HIV-infected and HIV high-risk populations.

Mercury and drought along the lower Carson River, Nevada: IV. Snowy egret post-fledging dispersal, timing of migration and survival, 2002–2004

This telemetry study is an extension of our 1997–2006 research on historical mercury contamination on snowy egrets (Egretta thula) up to ~ 20 days of age. Findings from initial studies at the mercury-contaminated Carson River colony at Lahontan Reservoir (LR) and a similar-sized reference (REF) colony on the Humboldt River included mercury-related physiological, biochemical, histopathological and reproductive effects up to ~20 days of age; with poor water years (2000–04), i.e., reduced prey availability, exacerbating effects. Herein, we compare timing of dispersal and migration at LR vs. REF, but the primary question now addressed is “whether survival of young mercury-exposed snowy egrets from LR would be further compromised beyond ~20 days of age? ” Based upon telemetry signals until 90–110 days of age (including dead bird counts and survival rate estimates), we conclude that mercury did not further compromise survival. Dead bird counts and survival rate estimates included time in the colony when fed by adults, plus the critical period when young dispersed from the colony to forage independently. The extended drought during this 3-year study was most critical in 2002 when production of ~20d old egrets at LR was only 0.24 young/nest. In 2002, survival rates were low at both colonies and we documented the highest counts of dead egrets for both colonies. We suggest the losses in 2002 beyond 20 days of age were more a function of prey availability influenced by drought than exposure to mercury, especially at LR, because higher mercury concentrations, higher survival rates and fewer dead birds were documented at LR in 2003 when water conditions improved. Furthermore, total mercury (THg) in blood in 2003 was more than double 2002 (geometric mean, 3.39 vs 1.47µg/g wet weight (ww). This higher THg exposure at LR in 2003 was associated with a redistribution of parent and post-dispersal feeding activities upstream (where there was higher mercury from historic mining) related to slightly improved water levels. When comparing the 3-year telemetry findings based upon ~20d old young at LR (blood THg, geo. means 1.47, 3.39 and 1.89µg/g ww), we found no evidence that age at dispersal, Julian date at dispersal, timing of migration, or pre-migration survival (~20 to ~100 days post-hatch) were adversely affected by elevated mercury.

Prenatal exposure to low-level methylmercury alters the child's fine motor skills at the age of 18 months

ObjectivesTo compare motor, cognitive and language characteristics in children aged 18 months who were prenatally exposed to low-level methyl-mercury (MeHg), and to analyze the eventual differences in these characteristics in relation to cord blood THg concentration. Patients and methodsThe total number of 205 child-mother pairs was included in the study, and total cord blood mercury was measured in 198 of them. Out of the 198 already measured samples, 47 of them have also been tested for methyl-mercury in cord blood. Data regarding the 47 samples of MeHg levels has been used for calculating the correlation between cord blood THg and cord blood MeHg. MeHg and THg showed a significant correlation (r=0.95, p<0.05). One month after the delivery, mothers were asked to complete the questionnaire regarding socioeconomic factors, breastfeeding of their infants, and dietary habits during pregnancy. Neurodevelopmental assessment of motor, cognitive and language skills were conducted on 168 children using The Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III). Regarding the cord blood THg concentration, 135 children were divided in 4 quartile groups. Their neurodevelopmental characteristics have been compared. ResultsThe cord blood THg concentration median and inter-quartile range was 2.98ng/g (1.41–5.61ng/g). There was a negative correlation between cord blood THg concentration and fine motor skills (rho=−0.22, p=0.01). It is evident that children grouped in 2nd ,3rd and 4th quartile had statistically significant lower fine motor skills assessment related to those grouped in 1st quartile (2nd quartile −1.24, p=0.03; 3rd quartile −1.28, p=0.03; 4th quartile −1.45, p=0.01). The differences in fine motor skills assessments between children in 2nd and 3rd and 3rd and 4th quartile were not statistically significant. ConclusionIntrauterine exposure to low-level THg (MeHg) is associated with alterations in fine motor skills at the age of 18 months.

Associations of blood mercury, inorganic mercury, methyl mercury and bisphenol A with dental surface restorations in the U.S. population, NHANES 2003–2004 and 2010–2012

The potential adverse health effects of mercury from amalgam and bisphenol A (BPA) from composite resin have been significant concerns. It is unclear whether dental restorative materials significantly contribute to mercury or BPA levels. The purpose of this study is to use NHANES data including 14,703 subjects (2003–2004: n=7514; 2011–2012: n=7189) to examine the association between Dental Surface Restorations (DSR) and blood total mercury (THg), inorganic mercury (IHg), methyl mercury (MeHg) and urinary BPA through the stratification of covariates and multivariate analysis. Subjects were divided into three groups based on the number of dental surface restorations (DSRs, 0, 1–8, >8). Blood THg and IHg in 2003–2004 were significantly higher in the subjects with DSR (geometric mean of 0.48, 0.69 and 1.17μg/l for THg; 0.32, 0.33 and 0.39μg/l for IHg with DSR 0, 1–8 and >8). Similarly, increases of THg, IHg and MeHg were also observed in 2013–2014 (geometric mean of 0.51, 0.69 and 0.99μg/l for THg; 0.40, 0.49 and 0.66μg/l for MeHg; 0.20, 0.22 and 0.29μg/l for IHg with DSR 0, 1–8 and >8). Linear regression model analysis revealed blood THg and IHg in 2003–2004 and THg, IHg and MeHg in 2011–2012 were quantitatively associated with the number of DSRs. A dramatic decrease in urinary BPA from 2003 to 2004–2011–2012 was observed, but no significant increase with DSRs in either period of study. In conclusion, significant increases in blood THg, IHg, and MeHg in the subjects with DSRs are confirmed in a nationally representative population, a critical step in assessing the potential risk of adverse effects from dental restorative materials, but no association between dental fillings and urinary BPA was found.

Exposure to toxic metals during pregnancy in the Moscow region of Russia

Mounting evidence suggests that heavy metal exposure affect early life and can impact the developing brain. WHO has developed a standardized methodology for HBM surveys in maternities in order to assess prenatal exposure to mercury and other toxic metals . The goal of the survey in Russia was to adapt methodology to Russian settings and to provide preliminary, internationally comparable exposure data on prenatal exposure. The survey was designed as a cross-sectional, involving 120 women in birth from randomly selected six maternities of the Moscow Region. Mercury was determined by AAS with cold vapor; determination of lead, cadmium and arsenic was done using ICP MS. Levels of total mercury in maternal hair (geometric mean 0.21 µg/g), cord blood (0.89 µg/L) and maternal urine (0.27 µg/L) in this population were similar to those in other European countries with relatively low fish consumption. Geometric mean for lead in cord blood was 8 µg/L. No biomarker values for mercury and lead exceeded levels recommended by WHO or national agencies in the USA and Germany. Geometric mean for cadmium in urine was 0,20 µg/L, 13,3% of women exceeded health-related HBM-1 value recommended by German Commission for children; in 3,3% -for adults. Total arsenic concentrations in maternal urine (geometric mean 21,9 µg/L ; 95th percentile 142,5 µg/L ) were higher than NHANES 95th percentile for adults. Consumption of all types of fish at least once per week during the third trimester of pregnancy compared to fish consumption less than once per month was significantly associated with 31% (95% confidence interval 4%; 66%) higher predicted geometric mean level of total mercury in hair, 38% (9%; 74%) higher level in cord blood and 36% (2%; 81%) higher level in maternal urine. Adverse effects of prenatal exposures to studied pollutants in the general population of women in birth can be substantial. The application of standardized approaches will enhance targeted interventions.

Low-level methylmercury exposure through rice ingestion in a cohort of pregnant mothers in rural China

BackgroundRice ingestion is an important dietary exposure pathway for methylmercury. There are few studies concerning prenatal methylmercury exposure through rice ingestion, yet the health risks are greatest to the developing fetus, and thus should be investigated. ObjectivesOur main objective was to quantify dietary methylmercury intake through rice and fish/shellfish ingestion among pregnant mothers living in southern China, where rice was a staple food and mercury contamination was considered minimal. MethodsA total of 398 mothers were recruited at parturition, who donated scalp hair and blood samples. Total mercury and/or methylmercury concentrations were measured in biomarkers, in rice samples from each participant's home, and in fish tissue purchased from local markets. Additional fish/shellfish mercury concentrations were obtained from a literature search. Dietary methylmercury intake during the third trimester was equivalent to the ingestion rate for rice (or fish/shellfish)×the respective methylmercury concentration. ResultsDietary methylmercury intake from both rice and fish/shellfish ingestion averaged 1.2±1.8µg/day (median=0.79µg/day, range=0–22µg/day), including on average 71% from rice ingestion (median: 87%, range: 0–100%), and 29% from fish/shellfish consumption (median 13%, range: 0–100%). Median concentrations of hair total mercury, hair methylmercury, and blood total mercury were 0.40µg/g (range: 0.08–1.7µg/g), 0.28µg/g (range: 0.01–1.4µg/g), and 1.2µg/L (range: 0.29–8.6µg/L), respectively, and all three biomarkers were positively correlated with dietary methylmercury intake through rice ingestion (Spearman's rho=0.18–0.21, p≤0.0005), although the correlations were weak. In contrast, biomarkers were not correlated with fish/shellfish methylmercury intake (Spearman's rho=0.04–0.08, p=0.11–0.46). ConclusionsAmong pregnant mothers living in rural inland China, rice ingestion contributed to prenatal methylmercury exposure, more so than fish/shellfish ingestion.

Associations Between Fish Consumption and Contaminant Biomarkers With Cardiovascular Conditions Among Older Male Anglers in Wisconsin.

The aim of this study was to determine fish consumption habits and contaminant exposures associated with adverse cardiovascular outcomes among older male anglers. One hundred fifty-four men aged 50 years and older living and fishing in Wisconsin completed a detailed survey and provided hair and blood samples. Associations between fish consumption and body burdens of several contaminants, with self-reported cardiovascular outcomes, were evaluated. Consuming fish species with higher methyl mercury content was positively associated with odds of angina, coronary heart disease (CHD), or heart attack, while consuming fattier species was negatively associated with high blood pressure or high cholesterol. Total mercury in blood was associated with 27% higher odds of heart attack, and certain classes of polychlorinated biphenyls were positively associated with CHD. Total mercury exposures may affect cardiovascular outcomes. Educational interventions promoting consumption of fish low in methyl mercury among older male anglers are needed.

Mobilization of mercury from lean tissues during simulated migratory fasting in a model songbird.

The pollutant methylmercury accumulates within lean tissues of birds and other animals. Migrating birds catabolize substantial amounts of lean tissue during flight which may mobilize methylmercury and increase circulating levels of this neurotoxin. As a model for a migrating songbird, we fasted zebra finches (Taeniopygia guttata) that had been dosed with 0.0, 0.1, and 0.6 parts per million (ppm) dietary methylmercury and measured changes in blood total mercury concentrations (THg) in relation to reductions in lean mass. Birds lost 6–16% of their lean mass during the fast, and THg increased an average of 12% and 11% in the 0.1 and 0.6 ppm treatments, respectively. Trace amounts of THg in the 0.0 ppm control group also increased as a result of fasting, but remained extremely low. THg increased 0.4 ppm for each gram of lean mass catabolized in the higher dose birds. Our findings indicate that methylmercury is mobilized from lean tissues during protein catabolism and results in acute increases in circulating concentrations. This is a previously undocumented potential threat to wild migratory birds, which may experience greater surges in circulating methylmercury than demonstrated here as a result of their greater reductions in lean mass.

Total Blood Mercury Levels and Depression among Adults in Korea: Korea National Health and Nutrition Examination Survey 2010–2013

Background: Depression is a significant public health problem in Korea, and high levels of exposure to the known neurotoxicant mercury can elicit neuropsychiatric symptoms. Many studies further suggest that chronic low-level exposure to mercury can be linked to depression, though this association remains unclear. Methods: Cross-sectional associations between cases and symptoms of depression and total blood mercury levels were assessed in 7,624 adults as part of the Korea National Health and Nutrition Examination Survey 2010–2013. The likelihood of receiving a diagnosis of depression in relation to the level of mercury in the blood was calculated as an odds ratio (OR) using multivariable logistic regression analysis. Similarly, the likelihood of experiencing depressive symptoms was also calculated. Results: Logistic regression analysis revealed no association between total blood mercury levels and cases of depression. With regard to depressive symptoms, logistic regression analysis of the unadjusted survey data revealed that higher total blood mercury levels were associated with a lower incidence of depression when data from the <25% and 25%–50% mercury quartiles (OR, 0.743; 95% confidence interval [CI], 0.851–0.951) were compared with data from the <25% and 50%–75% mercury quartiles (OR, 0.686; 95% CI, 0.535–0.880). However, this association disappeared for the ≥75% mercury quartile. Furthermore, no association was observed after adjusting for confounding variables. Conclusion: Based on the results of our statistical analyses, we conclude that no association exists between total blood mercury levels and depression status/depressive symptoms in Korean adults.

Effects of prenatal exposure to methylmercury in children auditory processing

Abstract Objective: to assess the central auditory processing of children exposed to mercury during the prenatal period. Design/Study sample: this study evaluated 90 children age eight to ten years, of both genders divided into two groups according to the levels of mercury exposure during the prenatal period: the study group (SG) was composed of children who had total mercury levels in umbilical cord blood samples equal or higher than 8µg/L, and the control group (CG) of children who had Mercury levels lower than 8µg/L. The procedures included a questionnaire, tonal threshold audiometry, word recognition audiometry, tests that assess auditory processing skills; and analysis of the total levels of mercury in umbilical cord blood samples collected at birth. Result: The SG presented mean total mercury in umbilical cord blood of 19.36µg/L and the CG had mean of 4.78µg/L. Regarding the tests that assess central auditory processing, the SG showed worse performance than the CG, and there was a statistically significant difference observed in the Staggered Spondaic Word Test. Conclusion: Children presented disorders in the tests that assess central auditory processing, indicating a possible effect of prenatal exposure to mercury in the central auditory system.

Low-level gestational exposure to mercury and maternal fish consumption: Associations with neurobehavior in early infancy

BackgroundStudies examining the effects of low-level gestational methylmercury exposure from fish consumption on infant neurobehavioral outcomes in the offspring are limited and inconclusive. Our objective was to examine the effects of low-level gestational exposure to methylmercury on neurobehavioral outcomes in early infancy. MethodsWe assessed neurobehavior of 344 infants at 5-weeks using the NICU Network Neurobehavioral Scale (NNNS). Gestational mercury exposure was measured as whole blood total mercury (WBTHg) in maternal and cord blood. We collected fish consumption information and estimated polyunsaturated fatty acid (PUFA) intake. We examined the association between gestational mercury exposure and NNNS scales using regression, adjusting for covariates. ResultsGeometric mean of maternal and cord WBTHg were 0.64 and 0.72μg/L, respectively. Most mothers (84%) reported eating fish during pregnancy. Infants with higher prenatal mercury exposure showed increased asymmetric reflexes among girls (p=0.04 for maternal WBTHg and p=0.03 for cord WBTHg), less need for special handling during the assessment (p=0.03 for cord WBTHg) and a trend of better attention (p=0.054 for both maternal WBTHg and cord WBTHg). Similarly, infants born to mothers with higher fish consumption or estimated PUFA intake also had increased asymmetric reflexes and less need for special handling. In models simultaneously adjusted for WBTHg and fish consumption (or PUFA intake), the previously observed WBTHg effects were attenuated; and higher fish consumption (or PUFA intake) was significantly associated with less need for special handling. ConclusionsIn a cohort with low level mercury exposure and reporting low fish consumption, we found minimal evidence of mercury associated detrimental effects on neurobehavioral outcomes during early infancy. Higher prenatal mercury exposure was associated with more frequent asymmetric reflexes in girls. In contrast, infants with higher prenatal mercury exposure and those whose mothers consumed more fish had better attention and needed less special handling, which likely reflect the beneficial nutritional effects of fish consumption.

Associations between prenatal mercury exposure and early child development in the ALSPAC study

IntroductionThere is evidence that high levels of mercury exposure to the pregnant woman can result in damage to the brain of the developing fetus. However there is uncertainty as to whether lower levels of the metal have adverse effects on the development of the infant and whether components of fish consumption and/or the selenium status of the woman is protective. MethodsIn this study we analysed data from the Avon Longitudinal Study of Parents and Children (ALSPAC) (n=2875–3264) to determine whether levels of total blood mercury of pregnant women collected in the first half of pregnancy are associated with the development of the offspring at ages 6, 18, 30 and 42 months. The developmental measures used maternal self-reported scales for individual types of development (fine and gross motor, social and communication skills) and total scores. Multiple and logistic regression analyses treated the outcomes both as continuous and as suboptimal (the lowest 15th centile). The statistical analyses first examined the association of prenatal mercury exposure with these developmental endpoints and then adjusted each for a number of social and maternal lifestyle factors; finally this model was adjusted for the blood selenium level. ResultsTotal maternal prenatal blood mercury and selenium ranged from 0.17 to 12.76 and 17.0 to 324μg/L respectively. We found no evidence to suggest that prenatal levels of maternal blood mercury were associated with adverse development of the child, even when the mother had consumed no fish during pregnancy. In general, the higher the mercury level the more advanced the development of the child within the range of exposure studied. For example, the fully adjusted effect sizes for total development at 6 and 42 months were +0.51 [95%CI +0.05, +1.00] and +0.43 [95%CI +0.08, +0.78] points per SD of mercury. For the risk of suboptimal development the ORs at these ages were 0.90 [95%CI 0.80, 1.02] and 0.88 [95%CI 0.77, 1.02]. In regard to the associations between blood mercury and child development there were no differences between the mothers who ate fish and those who did not, thus implying that the benefits were not solely due to the beneficial nutrients in fish. ConclusionsWe found no evidence of adverse associations between maternal prenatal blood mercury and child development between 6 and 42 months of age. The significant associations that were present were all in the beneficial direction.

Dental associations with blood mercury in pregnant women.

ObjectivesThere is curiosity concerning the source of mercury that is absorbed into the mother's blood and which may affect the developing fetus. This study therefore sets out to determine the extent to which dental amalgam (DA) may contribute to total blood mercury (TBHg) levels of pregnant women in the UK.MethodsWhole blood samples and information on diet and socio‐demographic factors were collected from pregnant women (n = 4484) enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC). The whole blood samples were assayed for total mercury levels using inductively coupled plasma dynamic reaction cell mass spectrometry (ICP‐DRC‐MS), and the women were retrospectively asked about features of their dental care during the pregnancy. Linear regression was used to estimate the relative contributions of DA to TBHg levels (log‐transformed) based on R 2 values, compared to the results from dietary and socio‐demographic variables.ResultsThe contribution to the variance of the mothers' TBHg levels by dental variables was 6.47%, a figure comparable to the 8.75% shown for seafood consumption in this population. Dietary and dental variables explained 20.16% of the variance, with socio‐demographic variables contributing only a further 3.40%. The number of amalgams in the mouth at the start of pregnancy accounted for most of the variance in dental variables.ConclusionsDental amalgam contributes a comparable amount of variance in TBHg to seafood consumption in this population. However, because the measures of DA exposure were imprecise, these findings are likely to be an underestimate. There is no evidence to date in the literature that fetal exposures to mercury from maternal DAs have adverse effects on the developing child, but long‐term studies are warranted.

Biomonitoring of Lead, Cadmium, Total Mercury, and Methylmercury Levels in Maternal Blood and in Umbilical Cord Blood at Birth in South Korea.

With rising concerns of heavy metal exposure in pregnancy and early childhood, this study was conducted to assess the relationship between the lead, cadmium, mercury, and methylmercury blood levels in pregnancy and neonatal period. The study population included 104 mothers and their children pairs who completed both baseline maternal blood sampling at the second trimester and umbilical cord blood sampling at birth. The geometric mean maternal blood levels of lead, cadmium, total mercury, and methylmercury at the second trimester were 1.02 ± 1.39 µg/dL, 0.61 ± 1.51 µg/L, 2.97 ± 1.45 µg/L, and 2.39 ± 1.45 µg/L, respectively, and in the newborns, these levels at birth were 0.71 ± 1.42 µg/dL, 0.01 ± 5.31 µg/L, 4.44 ± 1.49 µg/L, and 3.67 ± 1.51 µg/L, respectively. The mean ratios of lead, cadmium, total mercury, and methylmercury levels in the newborns to those in the mothers were 0.72, 0.04, 1.76, and 1.81, respectively. The levels of most heavy metals in pregnant women and infants were higher in this study than in studies from industrialized western countries. The placenta appears to protect fetuses from cadmium; however, total mercury and methylmercury were able to cross the placenta and accumulate in fetuses.

Factors associated with total mercury concentrations in maternal blood, cord blood, and breast milk among pregnant women in Busan, Korea.

This study investigated the concentration of total mercury (THg) in maternal blood, cord blood, and breast milk, and its association with dietary factors. A total of 127 pregnant women in Busan, Korea were recruited. Maternal blood, cord blood, and breast milk were collected at 36 weeks of gestation, at delivery, and at one week after birth, respectively. Information about dietary habits and other factors were obtained from each subject. The mean THg concentrations in maternal blood, cord blood, and breast milk were 3.12±1.36 μg/L, 5.46±2.41 μg/L, and 0.91±2.08 μg/L, respectively. Positive correlations were found between log-transformed THg concentrations in maternal blood and cord blood (r=0.829, p<0.001), and between maternal blood and breast milk (r=0.296, p=0.001). Multiple linear regression analysis showed that the log-transformed concentration of THg in maternal blood was positively correlated with fish consumption (β=0.345, p<0.0001) and negatively correlated with bean consumption (β=-0.055, p=0.048). Fish consumption (β=0.482, p<0.0001) and maternal age (β=0.025, p=0.033) were positively associated with the concentration of THg in cord blood, while negative correlations were found for bean consumption (β=-0.134, p=0.027) and parity (β=-0.172, p=0.015). Beef consumption (β=0.031, p=0.007) was positively associated with log-transformed THg concentrations in breast milk, while negative correlations were found for bean consumption (β=-0.019, p=0.003) and maternal age (β=-0.083, p=0.004). Our study found that both the dietary and demographic factors differently affected to THg concentrations among samples of maternal blood, cord blood, and breast milk.

781 Comparing Bone Structure and Bone Metabolism Between Long-Term Proton Pump Inhibitor Users and Non-Users

Background: Some metals and heavy metals are an essential part of the human diet, but some, in high enough doses can result in adverse health effects ranging from runny nose to multi-organ failure. There have been anecdotal reports that a gluten-free diet can result in an increase in arsenic consumption. Only a fraction of individuals that currently adhere to a gluten free diet (GFD) do so for medical reasons, such as celiac disease. Most people chose to go gluten free for a variety of reasons. Aim: To determine if a GFD, or having CD makes a difference in the amounts of certain metal toxins and heavy metals that may occur in gluten free foods. Methods: The NHANES survey is a rigorous sampling of the US population. We have previously determined by questionnaire and serum testing those subjects with celiac disease and those who avoid gluten without a diagnosis of celiac disease. Data base was used to compare the blood and urine levels of predetermined toxic metals in different subsets of the US population. The first comparison determined the differences between individuals on a GFD (N=148) and individuals not on a GFD (16,817). The second comparison was between individuals that were seropositive for CD (tTG-positive, EMApositive) (N=57) and seronegative for CD (tTG-negative, EMA-negative) (N=14,644), followed by a comparison of undiagnosed-CD patients (N=56), non-CD persons who avoid gluten (NCPWAGs)(N=134), and the general U.S. population(N=16,723). The last comparison was between all celiac patients (undiagnosed and diagnosed)(N=68) against non-CD patients (PWAGs and the general population)(N=16,857). Blood laboratory tests that were examined were lead, cadmium, total mercury; urinary laboratory tests examined were total arsenic, cobalt, thallium, strontium, tin, antimony, barium, cadmium, cesium, molybdenum, manganese, lead, tungsten, and uranium. Results: A GFD resulted in increases of blood lead (p<0.0001), blood total mercury (p<0.0001), blood cadmium (p=0.0006), urinary arsenic (p=0.0031), and urinary tin (p=0.0011) as compared to individuals not a gluten free diet. However, there were no differences in tested metal levels between people with and without a gluten free diet. NCPWAGs had almost double the blood lead than undiagnosed celiacs (p<0.0001) and higher levels of blood lead (p<0.0001), blood total mercury (p<0.0001), blood cadmium (p=0.0147), urinary arsenic (p=0.0028), and urinary tin (p= 0.0004) than the general population. Conclusions: These results suggests an association between a GFD and higher levels of blood lead, blood mercury, blood cadmium, urinary arsenic, and urinary tin. It is suggested that individuals on a GFD be monitored for these bioaccumulating metals.

Sex Differences in Antioxidant Activity in Sub‐Chronic Low‐Level Inorganic Mercury Exposure

In order to investigate sex differences on the effects of inorganic mercury on antioxidant enzymes in different compartments, male and female albino rats were exposed to mercury (0.5, 1.0 and 1.5mg/kg) for 12 weeks. At the end of mercury exposure, total mercury in liver, kidney and whole blood was determined using Inductively‐Coupled Plasma Spectrometry (ICP‐MS) while superoxide dismutase (SOD) and catalase (CAT) activities in the liver, kidney, plasma and erythrocytes were determined by standard methods. Inhibition of CAT and SOD in plasma and erythrocyte characterised the effects of inorganic mercury in female animals with the same trend in SOD of male but vice versa in CAT respectively. Inorganic mercury exposure inhibited CAT by 23% (liver) and 84% (kidney); SOD by 30% (liver) and 16% (kidney) respectively in female animals. In the male animals, a 26% inhibition of SOD was observed in the &lt;a name=”_GoBack”&gt;&lt;/a&gt;liver whereas CAT was inhibited by 66% in the kidney. Correlation analysis shows a negative relationship between tissue mercury levels and the two antioxidant enzymes specifically in female. Our findings support sex differences in the effects of mercury on depletion of antioxidant enzymes.