Hair Mercury Concentrations Research Articles

Real and potential mercury accumulation in human scalp of adolescents: a case study.

Mercury (Hg) concentration in human hair is used to estimate methylmercury (MeHg) exposure and establish a reference dose for MeHg intake. In this study, Hg accumulation and MeHg intake were evaluated in relation to fish consumption habits in adolescents from two coastal areas: Angra do Heroísmo (Azores archipelago) and Murtosa (Portuguese mainland). Results showed that Hg concentration and MeHg intake increased with increasing fish consumption. In spite of that, Hg concentrations remained relatively low when compared with World Health Organization "no observed adversary effect level"; therefore, risk for mercury exposure should not be considered. Adolescents revealed a similar range of Hg concentrations (0.03-2.60μgg(-1)) in scalp hair, apart from being exposed to natural or anthropogenic Hg source (Azores and Mainland, respectively). Nevertheless, Mainland volunteers generally exhibited higher values of Hg accumulation, being approximately 50% of the results above 1μgg(-1). Hg concentrations increased in both adolescent groups according to the weekly rate of fish meals, however, not linearly in the highest fish consumption rates. In fact, considering the adolescents' group having over one fish meal per week, the Hg bioaccumulation pattern found in the respective scalp hair suggests the ability of the human body to induce a self-protection response, probably mitigating Hg levels in the blood when experiencing increasing Hg exposure due to fish uptake. Actual and potential mercury levels in human scalp of adolescents probably diverge as fish consumption increases, the effective Hg uptake being lower than the expected, reducing risk to human health.

'Fishy' Make-up on the Hook for Mercury Exposure: A Case Series.

This report examines the source and outcome of four Barbadian women with extremely high hair mercury concentrations (361-5617 µg/g inorganic mercury) due to topical application of mercury containing skin-lightening cosmetics. Inorganic hair and urine mercury analysis was done at the toxicological centre laboratory of the Institut National de Santé Publique du Québec (Standard Council of Canada accredited). The clinical examinations were performed on location at the Queen Elizabeth Hospital of Barbados. Urine samples [7-135 µg/L, normal < 2 µg/L] revealed elevated mercury concentrations signifying systemic exposure. Reported symptoms during the clinical examination were consistent but nonspecific to chronic mercury exposure. Evidently, cosmetics containing dangerous levels of mercury are still available for purchase in Barbados and should be entirely banned.

Mercury content in hairs of mother-child pairs in Slovakia as a biomarker of environmental exposure

Abstract The mercury content in hairs was determined in the framework of the European funded projects COPHES and DEMOCOPHES to test the feasibility of an EU-HBM (Human Biomonitoring) approach generating comparable data. The aim of the Slovak participation in DEMOCOPHES was to obtain and contribute the Slovak data to the harmonization of Human Biomonitoring. Pre-analytical and analytical phase for mercury in hair measurements and activities developed for the harmonization analysis within COPHES/ DEMOCOPHES projects were conducted under a strict quality assurance program (QA/QC). Total mercury in hair was determined by thermal decomposition-gold amalgamation atomic absorption spectroscopy (AMA- 254 Advanced Mercury Analyzer.) Two interlaboratory comparison investigations (ICIs) and two external quality assessment schemes (EQUAS) were conducted before the beginning of the COPHES/DEMOCOPHES projects. The laboratory successfully completed both ICIs and EQUAS schemes and was allowed to analyze all DEMOCOPHES samples of the Slovak Republic. In summary, 129 mother-child pairs were recruited to pilot study of DEMOCOPHES in Slovakia from two different locations representing urban and rural environment. The analyzed data from Slovakia showed relationship between frequency of fish meals consumption (especially sea fish and sea food products) and mercury concentrations in hair of mothers and children. The exposure levels for a sampled population in Slovakia (children 0.092 (0.080-0.106) [μg.g-1], mother 0.130 (0.113-0.148) [μg.g-1]) are below the EU level (children 0.145 (0.139-0.151) [μg.g-1], mother 0.225 (0.216-0.234) [μg.g-1]) up to an order of magnitude lower than the limit medically important (FAO/WHO health-based guidance value of 2.3 μg.g-1 JECFA - Joint FAO/WHO Expert Committee on Food Additives).

Hair mercury association with selenium, serum lipid spectrum, and gamma-glutamyl transferase activity in adults.

The primary objective of the research is to estimate the dependence between hair mercury content, hair selenium, mercury-to-selenium ratio, serum lipid spectrum, and gamma-glutamyl transferase (GGT) activity in 63 adults (40 men and 23 women). Serum triglyceride (TG) concentration in the high-mercury group significantly exceeded the values obtained for low- and medium-mercury groups by 72 and 42%, respectively. Serum GGT activity in the examinees from high-Hg group significantly exceeded the values of the first and the second groups by 75 and 28%, respectively. Statistical analysis of the male sample revealed similar dependences. Surprisingly, no significant changes in the parameters analyzed were detected in the female sample. In all analyzed samples, hair mercury was not associated with hair selenium concentrations. Significant correlation between hair mercury content and serum TG concentration (r = 0.531) and GGT activity (r = 0.524) in the general sample of the examinees was detected. The respective correlations were observed in the male sample. Hair mercury-to-selenium ratios significantly correlated with body weight (r = 0.310), body mass index (r = 0.250), serum TG (r = 0.389), atherogenic index (r = 0.257), and GGT activity (r = 0.393). The same correlations were observed in the male sample. Hg/Se ratio in women did not correlate with the analyzed parameters. Generally, the results of the current study show the following: (1) hair mercury is associated with serum TG concentration and GGT activity in men, (2) hair selenium content is not related to hair mercury concentration, and (3) mercury-to-selenium ratio correlates with lipid spectrum parameters and GGT activity.

Mercury pollution in the Sonbhadra district of Uttar Pradesh, India, and its health impacts

The Sonbhadra district in the Singrauli area of Uttar Pradesh, India, has many coal mines and thermal power plants and is a critically polluted area. Many residents of this area reported adverse health conditions which may be linked to metal pollution, especially of mercury investigated here.In May 2012, samples of water (23), soil (7), blood, hair, and nails from persons showing adverse health conditions selected at random were collected and analyzed for total mercury by atomic absorption spectrometry.Twenty percent drinking water samples contained mercury from 3 to 26 μg L−1 (3–26 times the permissible limit). Soil samples had 0.5–10.1 mg kg−1 Hg.The average concentrations of mercury in human blood, hair, and nails were found to be 34 μg L−1, 7.4 mg kg−1, and 0.8 mg kg−1, respectively. Mercury concentrations in the blood of these persons were 45 and 28 μg L−1 on average in the case of men and women. This is much higher than the safe level of 5.8 μg L−1 set by the United States Environmental Protection Agency (USEPA).It was concluded that all residents of Sonbhadra sampled could be suffering from mercury toxicity as the area is polluted by Hg released from the coal-fired thermal power plants.

Prevalencia de mercurio y plomo en población general de Bogotá 2012/2013

Establishing mercury and lead prevalence in a sample of people living in Bogotá, potential effects on their health and the relationship with areas of environmental exposure. This was a cross-sectional study involving a randomly and proportionally distributed sample of 401 people living in Bogotá, according to locality and their high, medium and low risk environmental exposure. A medical assessment was made and lead (in blood) and mercury levels (blood, hair, urine) quantified. A preliminary descriptive analysis was made. The participants were aged 3-91 years-old (mean 46), the most frequently occurring occupation was that of housewife (45.1%, n=181). Mean mercury concentration in hair was 1µg/g, 3.13 µg/L in blood and 0.29 µg/L in urine; lead in blood was found to be 8.62 µg/dL. Fifty-four people (13.5%) had higher concentrations than international reference values for mercury (WHO) and 10 (2.5%) for lead (CDC). Clinical findings were non-specific; exposure areas did not seem to relate to the concentrations found. A significant percentage of the study population had high mercury and/or lead levels and such high prevalence highlights the need for identifying and controlling sources of exposure to mercury and lead which could have adverse consequences regarding the health of Bogotá'’s general population.

Significance of nail mercury concentrations as a biomarker of prenatal methylmercury exposure in relation to segmental hair mercury concentrations at parturition

Significance of nail mercury concentrations as a biomarker of prenatal methylmercury exposure in relation to segmental hair mercury concentrations at parturition

Hair toxic element content in adult men and women in relation to body mass index.

The primary objective of the current study was to estimate the hair toxic metal content in adults in relation to body mass index. A total of 1,229 persons including 719 women and 510 men were examined. All subjects were divided into two age groups: 1 and 2 periods of adulthood. All men and women were also subdivided into groups in relation to their values of body mass index (BMI): underweight, normal weight, overweight and obese. Hair aluminium (Al), beryllium (Be), cadmium (Cd), mercury (Hg), lead (Pb) and tin (Sn) content was evaluated using mass spectrometry with inductively coupled plasma. It has been shown that increase in body weight is accompanied by elevated hair cadmium content in women. At the same time, no significant alteration of hair cadmium concentration was observed in males. Higher values of scalp hair mercury and lead content were observed in men and women with increased body mass index independently of their age. BMI-related elevation of hair tin content was registered only in men of the first period of adulthood. A significant correlation between hair metal content and the values of BMI was observed for mercury independently of the gender of the subjects, whereas BMI values correlated significantly with hair cadmium levels in women and lead and tin levels in men. It has been also estimated that hair cadmium, mercury and lead levels in men exceed the respective values in women.

Hair mercury concentrations and fish consumption patterns in Florida residents.

Mercury exposure through the consumption of fish and shellfish represents a significant public health concern in the United States. Recent research has demonstrated higher seafood consumption and subsequent increased risk of methylmercury exposure among subpopulations living in coastal areas. The identification of high concentrations of total mercury in blood and skin among resident Atlantic bottlenose dolphins (Tursiops truncatus) in the Indian River Lagoon (IRL), a coastal estuary in Florida, alerted us to a potential public health hazard in the contiguous human population. Therefore, we analyzed hair mercury concentrations of residents living along the IRL and ascertained their sources and patterns of seafood consumption. The total mean mercury concentration for 135 residents was 1.53 ± 1.89 µg/g. The concentration of hair mercury among males (2.02 ± 2.38 µg/g) was significantly higher than that for females (0.96 ± 0.74 µg/g) (p < 0.01). Log transformed hair mercury concentration was significantly associated with the frequency of total seafood consumption (p < 0.01). Individuals who reported consuming seafood once a day or more were 3.71 (95% CI 0.84–16.38) times more likely to have a total hair mercury concentration over 1.0 µg/g, which corresponds approximately to the U.S. EPA reference dose, compared to those who consumed seafood once a week or less. Hair mercury concentration was also significantly higher among individuals who obtained all or most of their seafood from local recreational sources (p < 0.01). The elevated human mercury concentrations mirror the elevated concentrations observed in resident dolphins in the same geographical region. The current study is one of the first to apply the concept of a sentinel animal to a contiguous human population.

Selenium and mercury concentrations in harbor seals (Phoca vitulina) from central California: Health implications in an urbanized estuary

We measured total selenium and total mercury concentrations ([TSe] and [THg]) in hair (n=138) and blood (n=73) of harbor seals (Phoca vitulina) from California to assess variation by geography and sex, and inferred feeding relationships based on carbon, nitrogen, and sulfur stable isotopes. Harbor seals from Hg-contaminated sites had significantly greater [THg], and lesser [TSe] and TSe:THg molar ratios than seals from a relatively uncontaminated site. Males had significantly greater [THg] than females at all locations. Sulfur stable isotope values explained approximately 25% of the variability in [THg], indicating increased Hg exposure for seals with a greater use of estuarine prey species. Decreased [TSe] in harbor seals from Hg-contaminated regions may indicate a relative Se deficiency to mitigate the toxic effects of Hg. Further investigation into the Se status and the potential negative impact of Hg on harbor seals from Hg-contaminated sites is warranted.

Fish consumption and hair mercury levels in women of childbearing age, Martin County, Florida.

The health effects of mercury in humans are mostly on the developing nervous system. Pregnant women and women who are breastfeeding must be targeted in order to decrease mercury exposure to the populations at highest risk-infants, unborn fetuses, and young children. This purpose of this study is to understand the demographics of fish-consumption patterns among women of childbearing age (including pregnant women) in Martin County, Florida, and to analyze the associations of mercury levels in participants' hair with socio-demographic variables in order to better design prevention messages and campaigns. Mercury concentrations in hair samples of 408 women ages 18-49 were assessed. Data on demographic factors, pregnancy status, fish consumption, and awareness of fish advisories were collected during personal interviews. Data were analyzed using descriptive statistics and multivariate logistic regression. The geometric and arithmetic means of hair mercury concentration were 0.371 and 0.676 µg/g of hair. One-fourth of the respondents had a concentration ≥1 µg/g of hair. Consuming a higher number of fish meals per month, consumption of commercially purchased or locally caught fish higher in mercury, White race and income ≥$75,000 were positively associated with the likelihood of having higher hair mercury levels. This study confirms the existence of a higher overall mean hair mercury level and a higher percentage of women with ≥1 µg/g hair mercury level than those reported at the national level and in other regional studies. This suggests the need for region-specific fish consumption advisories to minimize mercury exposure in humans.

Exposure to mercury among Spanish preschool children: Trend from birth to age four

The purpose of this study is to describe the total hair mercury concentrations and their determinants in preschool Spanish children, as well as to explore the trend in mercury exposure from birth to the age four. This evolution has been scarcely studied in other birth cohort studies.The study population was 580 four year old children participating in the INMA (i.e. Childhood and Environment) birth cohort study in Valencia (2008–2009). Total mercury concentration at age four was measured in hair samples by atomic absorption spectrometry. Fish consumption and other covariates were obtained by questionnaire. Multivariate linear regression models were conducted in order to explore the association between mercury exposure and fish consumption, socio-demographic characteristics and prenatal exposure to mercury.The geometric mean was 1.10µg/g (95%CI: 1.02, 1.19). Nineteen percent of children had mercury concentrations above the equivalent to the Provisional Tolerable Weekly Intake proposed by WHO. Mercury concentration was associated with increasing maternal age, fish consumption and cord blood mercury levels, as well as decreasing parity. Children whose mothers worked had higher mercury levels than those with non working mothers. Swordfish, lean fish and canned fish were the fish categories most associated with hair mercury concentrations. We observed a decreasing trend in mercury concentrations between birth and age four. In conclusion, the children participating in this study had high hair mercury concentrations compared to reported studies on children from other European countries and similar to other countries with high fish consumption. The INMA study design allows the evaluation of the exposure to mercury longitudinally and enables this information to be used for biomonitoring purposes and dietary recommendations.

Children’s personal exposure to PM10 and associated metals in urban, rural and mining activity areas

There has been limited study of children’s personal exposure to PM10 and associated metals in rural and iron ore mining activity areas where PM10 concentrations can be very high. We undertook a small study of 70 children where 13 children were recruited in an area of iron ore mining processing and shipping, 15 children from an area in the same region with no mining activities, and 42 children in an urban area. Each child provided a 24h personal exposure PM10 sample, a first morning void urine sample, a hair sample, time activity diary, and self administered questionnaire. Children’s 24h personal PM10 concentrations were low (median of 28μgm−3 in the mining area; 48μgm−3 in the rural area and 45μgm−3 in the urban area) with corresponding outdoor PM10 concentrations also low. Some very high personal PM10 concentrations were recorded for individuals (>300μgm−3) with the highest concentrations recorded in the mining and rural areas in the dry season. PM10 concentrations were highly variable. Hair aluminium, cadmium and manganese concentrations were higher in the iron ore activity area, while hair mercury, copper and nickel concentrations were higher in the urban area. Factors such as season and ventilation appear to be important but this study lacked power to confirm this. These results need to be confirmed by a larger study and the potential for absorption of the metals needs to be established along with the factors that increase exposures and the potential for health risks arising from exposure.

Neurotoxicity from prenatal and postnatal exposure to methylmercury

The extent to which postnatal methylmercury exposure contributes to neurobehavioral delays is uncertain. Confounding may occur because the child's dietary exposure likely correlates with the mother's. This conundrum was examined in the Faroese birth cohort 1 born in 1986–1987. Exposure parameters included mercury concentrations in maternal hair at parturition, cord blood, and child blood and hair at the age-7 clinical examination (N=923). In regression analyses, the child's current blood-mercury at age 7 (N=694) showed only weak associations with the neuropsychological test variables, but visuospatial memory revealed a significant negative association. Mutual adjustment caused decreases of the apparent effect of the prenatal exposure. However, such adjustment may lead to underestimations due to the presence of correlated, error-prone exposure variables. In structural equation models, all methylmercury exposure parameters were instead entered into a latent exposure variable that reflected the total methylmercury load. This latent exposure showed significant associations with neurodevelopmental deficits, with prenatal exposure providing the main information. However, postnatal methylmercury exposure appeared to contribute to neurotoxic effects, in particular in regard to visuospatial processing and memory. Thus, addition in the regression analysis of exposure information obtained at a different point in time was not informative and should be avoided. Further studies with better information on exposure profiles are needed to characterize the effects of postnatal methylmercury exposure.

Negative confounding by essential fatty acids in methylmercury neurotoxicity associations

BackgroundMethylmercury, a worldwide contaminant of fish and seafood, can cause adverse effects on the developing nervous system. However, long-chain n-3 polyunsaturated fatty acids in seafood provide beneficial effects on brain development. Negative confounding will likely result in underestimation of both mercury toxicity and nutrient benefits unless mutual adjustment is included in the analysis. MethodsWe examined these associations in 176 Faroese children, in whom prenatal methylmercury exposure was assessed from mercury concentrations in cord blood and maternal hair. The relative concentrations of fatty acids were determined in cord serum phospholipids. Neuropsychological performance in verbal, motor, attention, spatial, and memory functions was assessed at 7years of age. Multiple regression and structural equation models (SEMs) were carried out to determine the confounder-adjusted associations with methylmercury exposure. ResultsA short delay recall (in percent change) in the California Verbal Learning Test (CVLT) was associated with a doubling of cord blood methylmercury (−18.9, 95% confidence interval [CI]=−36.3, −1.51). The association became stronger after the inclusion of fatty acid concentrations in the analysis (−22.0, 95% confidence interval [CI]=−39.4, −4.62). In structural equation models, poorer memory function (corresponding to a lower score in the learning trials and short delay recall in CVLT) was associated with a doubling of prenatal exposure to methylmercury after the inclusion of fatty acid concentrations in the analysis (−1.94, 95% CI=−3.39, −0.49). ConclusionsAssociations between prenatal exposure to methylmercury and neurobehavioral deficits in memory function at school age were strengthened after fatty acid adjustment, thus suggesting that n-3 fatty acids need to be included in analysis of similar studies to avoid underestimation of the associations with methylmercury exposure.

Neurological abnormalities in a mercury exposed population among indigenous Wayana in Southeast Suriname.

The indigenous Wayana community of Puleowime (Apetina) in Suriname is susceptible to the effects of mercury because they consume large amounts of fish compared to mainstream communities. Small-scale and artisanal gold mining activities occur at numerous sites in eastern and southeastern Suriname placing the Wayana at risk from exposure to mercury released into the environment. A previous community-led risk assessment study showed that the Wayana were at a high lifetime risk of adverse effects from exposure to mercury. Subsequent to this earlier study, the residents of Puleowime requested assistance in a community-led follow-up research project to determine for themselves whether there were health impacts associated with exposure to mercury contamination. Neurotoxic effects consistent with methylmercury exposure were documented in an exposed population through a battery of neurological tests. Although the specific motor and cognitive batteries were not exactly the same, similar associations were observed between neurologic impairment and hair mercury concentrations compared to other studies in the Amazonia region where mean hair mercury levels were in the subacute range.

Hair mercury and urinary cadmium levels in Belgian children and their mothers within the framework of the COPHES/DEMOCOPHES projects

A harmonized human biomonitoring pilot study was set up within the frame of the European projects DEMOCOPHES and COPHES. In 17 European countries, biomarkers of some environmental pollutants, including urinary cadmium and hair mercury, were measured in children and their mothers in order to obtain European-wide comparison values on these chemicals. The Belgian participant population consisted in 129 school children (6–11years) and their mothers (≤45years) living in urban or rural areas of Belgium.The geometric mean levels for mercury in hair were 0.383μg/g and 0.204μg/g for respectively mothers and children. Cadmium in mother's and children's urine was detected at a geometric mean concentration of respectively 0.21 and 0.04μg/l. For both biomarkers, levels measured in the mothers and their child were correlated. While the urinary cadmium levels increased with age, no trend was found for hair mercury content, except the fact that mothers hold higher levels than children. The hair mercury content increased significantly with the number of dental amalgam fillings, explaining partially the higher levels in the mothers by their higher presence rate of these amalgams compared to children. Fish or seafood consumption was the other main parameter determining the mercury levels in hair. No relationship was found between smoking status and cadmium or mercury levels, but the studied population included very few smokers. Urinary cadmium levels were higher in both mothers and children living in urban areas, while for mercury this difference was only significant for children. Our small population showed urinary cadmium and hair mercury levels lower than the health based guidelines suggested by the WHO or the JECFA (Joint FAO/WHO Expert Committee on Food Additives). Only 1% had cadmium level slightly higher than the German HBM-I value (1μg/l for adults), and 9% exceeded the 1μg mercury/g hair suggested by the US EPA.

Hair mercury concentrations and associated factors in an electronic waste recycling area, Guiyu, China

ObjectiveToxic heavy metals are released to the environment constantly from unregulated electronic waste (e-waste) recycling in Guiyu, China, and thus may contribute to the elevation of mercury (Hg) and other heavy metals levels in human hair. We aimed to investigate concentrations of mercury in hair from Guiyu and potential risk factors and compared them with those from a control area where no e-waste processing occurs. MethodsA total of 285 human hair samples were collected from three villages (including Beilin, Xianma, and Huamei) of Guiyu (n=205) and the control area, Jinping district of Shantou city (n=80). All the volunteers were administered a questionnaire regarding socio-demographic characteristics and other possible factors contributed to hair mercury concentration. Hair mercury concentration was analyzed by hydride generation atomic fluorescence spectrometry (AFS). ResultsOur results suggested that hair mercury concentrations in volunteers of Guiyu (median, 0.99; range, 0.18–3.98μg/g) were significantly higher than those of Jinping (median, 0.59; range, 0.12–1.63μg/g). We also observed a higher over-limit ratio (>1μg/g according to USEPA) in Guiyu than in Jinping (48.29% vs. 11.25%, P<0.001). Logistic regression model showed that the variables of living house also served as an e-waste workshop, work related to e-waste, family income, time of residence in Guiyu, the distance between home and waste incineration, and fish intake were associated with hair mercury concentration. After multiple stepwise regression analysis, in the Guiyu samples, hair mercury concentration was found positively associated with the time residence in Guiyu (β=0.299, P<0.001), and frequency of shellfish intake (β=0.184, P=0.016); and negatively associated with the distance between home and waste incineration (β=−0.190, P=0.015) and whether house also served as e-waste workshop (β=−0.278, P=0.001). ConclusionsThis study investigated human mercury exposure and suggested elevated hair mercury concentrations in an e-waste recycling area, Guiyu, China. Living in Guiyu for a long time and work related to e-waste may primarily contribute to the high hair mercury concentrations.

Mercury in Scalp Hair Near the Mid-Atlantic Ridge (MAR) in Relation to High Fish Consumption

The aim of this study was to evaluate the potential risk of mercury contamination near the Mid-Atlantic Ridge relating total mercury (THg) concentrations in the human scalp hair (n = 110) and high fish consumption levels. THg was quantified in human scalp hair, and volunteers were questioned about age, gender, and smoking habits being subsequently grouped in categories based on the individual average intake of fish meals per week. THg concentrations ([THg]) in hair samples ranged from 0.05 to 2.24 μg g(-1), and significant differences were found according to age (p < 0.05) and also among volunteers presenting different fish consumption rates (p < 0.001) being the highest [THg] observed on the adult population and also on volunteers that indicated consuming five or more meals of fish per week. Results indicate a pattern of increased mercury accumulation with increasing fish consumption. Despite mercury availability and a potential mercury intake of up to seven times, the WHO provisional tolerable weekly intake of mercury value, in consequence of high fish consumption, mercury concentrations in scalp hair are comparatively low regarding recommended levels by WHO.

The Minamata Convention on Mercury: A First Step toward Protecting Future Generations

In July 1956, in a fishing village near the city of Minamata on Japan’s Shiranui Sea, a baby girl named Shinobu Sakamoto was born. Her parents soon realized something was wrong. At 3 months old, when healthy babies can hold up their heads, Sakamoto could not. She grew slowly and began crawling unusually late. At age 3 years, she drooled excessively and still couldn’t walk. Her parents sent her to live at a local hospital, where she spent four years in therapy to learn to walk, use her hands, and perform other basic functions. Early on, several physicians agreed on a diagnosis of cerebral palsy.