Urinary Mercury Concentration Research Articles

Inhalational mercury toxicity from artisanal gold extraction reported to the Oregon poison center, 2002–2015

Context: Mercury exposure has been described among small-scale gold mining communities in developing countries, but reports of inhalational mercury toxicity among home gold extractors in the US remain uncommon.Objective: We sought to identify inhalational mercury exposures and toxicity among artisanal gold extractors.Methods: This is an observational case series of a single Poison Center database from 2002–2015. We review all cases of “mercury” or “mercury inhalation” exposures, with detailed description of a recent representative case.Results: Nine cases were reported, with patients’ ages ranging 32–81 years. Eight (89%) patients were male. Seven of eight (88%) patients with acute exposures reported pulmonary symptoms consistent with mercury vapor inhalation such as dyspnea and cough; two (29%) patients had severe toxicity requiring intubation. Four of six (67%) patients had markedly elevated whole blood mercury concentrations up to 346 mcg/L; each received a different chelation regimen. Four (44%) patients used methamphetamines at the time of their exposure. The case report describes a patient with elevated mercury concentrations who required intubation for hypoxic respiratory failure. He received chelation therapy based on chelator availability, with decreasing 24-hour urine mercury concentrations. The house where he was exposed remains uninhabitable from elevated ambient mercury vapor concentrations.Conclusion: Artisanal gold extraction may be associated with inhalational mercury toxicity, including elevated blood mercury concentrations and acute hypoxic lung injury requiring intubation.

Dental amalgam exposure can elevate urinary mercury concentrations in children

Owing to its cost-effectiveness and operative convenience, dental amalgam remains in use as a restorative material for tooth caries in children in many countries. The aim of this study was to evaluate the relationship between dental amalgam exposure and urinary mercury (U-Hg) concentrations in children. In this longitudinal study, 463, 367 and 348 children, 8-11years of age, were evaluated at baseline, and at the first and second follow-up visits, respectively. The interval between each survey was 6months. For the oral examination and urine sample, the amalgam-filled tooth surface (TS), and U-Hg and creatinine concentrations of participants were determined, and the cumulative amalgam-filled TS and cumulative creatinine-adjusted U-Hg were calculated. To assess potential covariates, socio-demographic factors, oral health behaviour and dietary factors were surveyed by questionnaire. Data were analysed by the t-test, correlation analysis and mixed-model analysis. The statistical analyses were performed using SPSS 18.0. Children with more than one amalgam-filled TS exhibited significantly higher creatinine-adjusted U-Hg concentrations than those without, in all three survey periods (P<0.001). The results for the current and cumulative amalgam-filled TS significantly correlated with those for the current and cumulative creatinine-adjusted U-Hg concentration, respectively, in all surveys (P<0.001). In the repeated-measures mixed model analysis, current and cumulative amalgam-filled TS was significantly related to current and cumulative creatinine-adjusted U-Hg concentration, respectively (P<0.001). Amalgam-filled TS was significantly correlated with U-Hg concentrations in children. Therefore, dental amalgam exposure can affect the systemic mercury concentration in children.

The content of mercury in various types of cereals that were grown in the model conditions

The consumption of cereals in Slovakia but also worldwide is increasing by every year. From 30000 to 50000 tons of mercury circulates throught the biosphere that gets into the atmosphere degassing of the earth's crust and world oceans. Mercury affects CNS and causes its disorders. The high doses of mercury causes a lot of different changes of personality as well as increased agitation, memory lossorinsomnia. It can also affect other organ systems such as the kidney. The exposure level is reflected in the concentration of mercury in blood and urine. The aim of our work was the evaluation of transfer of mercury from sludge to edible part of chosen cereals. The objectives were achieved in simulated conditions of growing pot experiment. We used agricultural soil from the location of Výčapy - Opatovce for the realization of the experiment. The sludge, which was added atvarious doses, was taken from Central Spiš area from locality of Rudňany near the village where minedironore that contains mainly copperand mercury during last few decades was. We used three types of cereals: barley (Hordeum sativum L.) variety PRESTIGE, spring wheat (Triticum aestivum L.) variety ISJARISSA and oat (Avena sativa L.) variety TATRAN. The length of growing season was 90 days. From the obtained results of two years can be concluded that the accumulation of mercury by seed follows wheat ˂ barley ˂ oat. Even though that the oat is characterized by the highest accumulation of mercuryin the seeds, the content did not exceed the maximum level sspecified by The Codex Alimentarius of Slovak Republic. The results shows that the suitable cultivation of the cereals in localities, which are contaminated with heavy metals, especially by mercury, that the high content of mercury in soil do not pose a risk of accumulation of the metal into the cereal grain.

Effect of Mercury Exposure on Renal Function and Hematological Parameters among Artisanal and Small-scale Gold Miners at Sekotong, West Lombok, Indonesia.

Mercury is a toxic metal with effects on human health ranging from acute to chronic in a very short time of exposure. Artisanal and small-scale gold mining (ASGM) is the main source of direct human exposure to mercury. Human exposure to mercury (Hg) can occur through both direct inhalation of mercury vapor and consumption of material taken from contaminated areas. To protect the health of ASGM workers and surrounding communities, a health assessment of mercury exposure and its effects is urgently needed. However, analysis of hair and urine samples as a proof test for mercury toxicity is very expensive. Therefore other tests must be considered to identify the first symptoms of mercury toxicity in miners and the surrounding community. The present study aimed to determine the effects of mercury exposure on renal function along with the hematological parameters of gold miners and the community as a first indication of mercury exposure symptoms. The study was designed as a purposive field sampling study and was conducted in 3 main villages in Sekotong District, West Lombok Regency, West Nusa Tenggara Province, Indonesia. The 100 subjects were miners that have been exposed to mercury for at least 5 years and their wives and children (non-miners) who lived around the gold processing area. Blood and urine samples were then obtained from the subjects. The miners and non-miners were questioned about their mercury exposure over the previous 5 years, duration of exposure, and how mercury was handled in their daily life. Blood and urine samples were collected at the time of the study, around 10 ml of urine and 0.1 ml of blood (2 drops) were collected per subject. In order to determine the parallel results between the blood-urine and hair results, hair from the miners was collected at a different time for analysis. The results showed that the subjects had low proteinuria, hemoglobin and hematocrit concentrations as a consequence of chronic mercury intoxication. This finding was parallel with results of high mercury concentrations in urine (>7 - 273.3 μg/l) and miners' hair (>1 - 12.93 μg/g). Miners and non-miners in the exposure area were found to have proteinuria levels of more than 0.3 g/L. Proteinuria (≥0.3 g/L) was observed in 92.6% of miners and 72.4% of non-miners. The results of the present study suggest that urinalysis of proteinuria and hemoglobin values can be used as a screening test to detect renal impairment due to mercury intoxication.

The bioaccessibility of soil-based mercury as determined by physiological based extraction tests and human biomonitoring in children

Environmental contaminants associated with soil particles are generally less bioavailable than contaminants associated with other exposure media where chemicals are often found in more soluble forms. In vitro methods, such as Physiological Based Extraction Tests (PBET), can provide estimates of bioaccessibility for soil-based contaminants. The results of these tests can be used to predict exposure to contaminants from soil ingestion pathways within human health risk assessment (HHRA). In the current investigation, an HHRA was conducted to examine the risks associated with elevated concentrations of mercury in soils in the northern Canadian smelter community of Flin Flon, Manitoba. A PBET was completed for residential soils and indicated mean bioaccessibilities of 1.2% and 3.0% for total mercury using gastric phase and gastric+intestinal phase methodologies, respectively. However, as many regulators only allow for the consideration of in vitro results for lead and arsenic in the HHRA process, in vitro bioaccessibility results for mercury were not utilized in the current HHRA. Based on the need to assume 100% bioaccessibility for inorganic mercury in soil, results from the HHRA indicated the need for further assessment of exposure and risk. A biomonitoring study was undertaken for children between 2 and 15years of age in the community to examine urinary inorganic mercury concentrations. Overall, 375 children provided valid urine samples for analysis. Approximately 50% of urine samples had concentrations of urinary inorganic mercury below the limit of detection (0.1μg/L), with an average creatinine adjusted concentration of 0.11μg/g. Despite high variability in mercury soil concentrations within sub-communities, soil concentrations did not appear to influence urinary mercury concentrations. The results of the current investigation indicate that mercury bioaccessibility in residential soils in the Flin Flon area was likely limited and that HHRA estimates would have been better approximated through inclusion of the in vitro study results.

Assessment of mercury exposure among small-scale gold miners using mercury stable isotopes

Total mercury (Hg) concentrations in hair and urine are often used as biomarkers of exposure to fish-derived methylmercury (MeHg) and gaseous elemental Hg, respectively. We used Hg stable isotopes to assess the validity of these biomarkers among small-scale gold mining populations in Ghana and Indonesia. Urine from Ghanaian miners displayed similar Δ199Hg values to Hg derived from ore deposits (mean urine Δ199Hg=0.01‰, n=6). This suggests that urine total Hg concentrations accurately reflect exposure to inorganic Hg among this population. Hair samples from Ghanaian miners displayed low positive Δ199Hg values (0.23–0.55‰, n=6) and low percentages of total Hg as MeHg (7.6–29%, n=7). These data suggest that the majority of the Hg in these miners' hair samples is exogenously adsorbed inorganic Hg and not fish-derived MeHg. Hair samples from Indonesian gold miners who eat fish daily displayed a wider range of positive Δ199Hg values (0.21–1.32‰, n=5) and percentages of total Hg as MeHg (32–72%, n=4). This suggests that total Hg in the hair samples from Indonesian gold miners is likely a mixture of ingested fish MeHg and exogenously adsorbed inorganic Hg. Based on data from both populations, we suggest that total Hg concentrations in hair samples from small-scale gold miners likely overestimate exposure to MeHg from fish consumption.

Increased Mercury Levels in Patients with Celiac Disease following a Gluten-Free Regimen.

Background and Aim. Although mercury is involved in several immunological diseases, nothing is known about its implication in celiac disease. Our aim was to evaluate blood and urinary levels of mercury in celiac patients. Methods. We prospectively enrolled 30 celiac patients (20 treated with normal duodenal mucosa and 10 untreated with duodenal atrophy) and 20 healthy controls from the same geographic area. Blood and urinary mercury concentrations were measured by means of flow injection inductively coupled plasma mass spectrometry. Enrolled patients underwent dental chart for amalgam fillings and completed a food-frequency questionnaire to evaluate diet and fish intake. Results. Mercury blood/urinary levels were 2.4 ± 2.3/1.0 ± 1.4, 10.2 ± 6.7/2.2 ± 3.0 and 3.7 ± 2.7/1.3 ± 1.2 in untreated CD, treated CD, and healthy controls, respectively. Resulting mercury levels were significantly higher in celiac patients following a gluten-free diet. No differences were found regarding fish intake and number of amalgam fillings. No demographic or clinical data were significantly associated with mercury levels in biologic samples. Conclusion. Data demonstrate a fourfold increase of mercury blood levels in celiac patients following a gluten-free diet. Further studies are needed to clarify its role in celiac mechanism.

Early changes in renal injury parameters and their influencing factors in workers exposed to mercury

To investigate atmospheric mercury concentration in the workplace and urinary mercury concentration in workers exposed to mercury in a thermometer factory, and to determine the levels and influencing factors of urinary Β₂-microglobulin (Β₂-MG) and retinol-binding protein (RBP) in these workers. An occupational health survey of the workplace was completed according to relevant national occupational health standards. Questionnaire survey and occupational health examination were conducted in 178 workers exposed to mercury in the factory. Statistical analysis was accomplished using SPSS 19.0. In the workplace, atmospheric mercury concentration was out of limits at seven of eight detection points expressed by short-term exposure limit; it was out of limits at all the eight detection points shown by time-weighted average. Statistically significant difference in atmospheric mercury concentration was found among different detection points (F = 138.714, P < 0.001). The geometric mean of urinary mercury concentration measured in 154 workers was 171.607 µg/g. There were 127 workers with urinary mercury concentration exceeding the standard (82.5% over-standard rate). Significant difference in urinary mercury concentration was shown in the workers among different positions (χ² = 44.531, P < 0.01). Urinary mercury concentration was positively correlated with atmospheric mercury concentration (r = 0.624, P < 0.01). The mean urinary Β₂-MG level measured in 148 workers was 0.142 mg/L, and seven workers had urinary Β₂-MG levels greater than 0.3 mg/L (4.7% abnormal rate). The mean urinary RBP level measured in 153 workers was 0.485 mg/L, and 19 workers had urinary RBP levels greater than 0.7 mg/L (12.4% abnormal rate). Ordinal logistic regression showed that age >34 years (OR = 4.88, 95%CI: 2.24∼10.62) and length of service >15 years (OR = 2.50, 95%CI: 1.06-5.92) were risk factors for increased urinary Β₂-MG level. Age >45 years (OR = 7.52, 95%CI: 2.50∼22.65) was a risk factor for increased urinary RBP level. In the thermometer factory under study, atmospheric and urinary mercury concentrations both seriously exceeded the standards, which were harmful to the health of workers. High atmospheric mercury concentration, old age, and long length of service were risk factors for increased urinary Β₂-MG and RBP levels in workers exposed to mercury.

Systemic vasculitis in a child mimicking mercury poisoning

Results A 12 year-old girl was admitted to our hospital with complaints of weakness, weight loss (10 kg in the last month), excessive sweating, and abdominal and joint pains. Her complaints started 6 weeks prior to admittance when she began to suffer from intermittent fever, acrodynia and back and abdominal pain. Also she was found to have red painful hands, a blood pressure 170/120 mm Hg, and tachycardia. In laboratory examinations, acute phase reactants were very high while viral markers, ANA and ANCA were negative. Renal doppler ultrasound and MR angiography were normal. We found sensorial neuropathy in her legs. Her blood pressure was controlled with 2 different antihypertensive medicines. The patient’s symptoms were not controlled with steroid treatment, we continued our research. A blood mercury concentration of 12.4 Mcg/L (ref value 0,3 mcg/L )and spot urine mercury concentration of 18.8 Mcg/L (ref value 0.15 Mcg/L) were discovered. The girl was treated with metalcaptase 25 mg/kg three times daily for 5 days, then every 12 hours for another 2 weeks (total duration, 19 days).

Formal recycling of e-waste leads to increased exposure to toxic metals: An occupational exposure study from Sweden

Electrical and electronic waste (e-waste) contains multiple toxic metals. However, there is currently a lack of exposure data for metals on workers in formal recycling plants. The objective of this study was to evaluate workers' exposure to metals, using biomarkers of exposure in combination with monitoring of personal air exposure. We assessed exposure to 20 potentially toxic metals among 55 recycling workers and 10 office workers at three formal e-waste recycling plants in Sweden. Workers at two of the plants were followed-up after 6months. We collected the inhalable fraction and OFC (37-mm) fraction of particles, using personal samplers, as well as spot samples of blood and urine. We measured metal concentrations in whole blood, plasma, urine, and air filters using inductively coupled plasma-mass spectrometry following acid digestion. The air sampling indicated greater airborne exposure, 10 to 30 times higher, to most metals among the recycling workers handling e-waste than among the office workers. The exposure biomarkers showed significantly higher concentrations of chromium, cobalt, indium, lead, and mercury in blood, urine, and/or plasma of the recycling workers, compared with the office workers. Concentrations of antimony, indium, lead, mercury, and vanadium showed close to linear associations between the inhalable particle fraction and blood, plasma, or urine. In conclusion, our study of formal e-waste recycling shows that workers performing recycling tasks are exposed to multiple toxic metals.

Higher urinary heavy metal, arsenic, and phthalate concentrations in people with high blood pressure: US NHANES, 2009–2010

Background: A link between environmental chemicals and human health has emerged but not complete in risk factors. This work aimed to study the relationships of different sets of urinary environmental chemical concentrations and risk of high blood pressure (BP) in a national, population-based study. Methods: Data was retrieved from United States National Health and Nutrition Examination Surveys, 2009–2010, including demographics, BP readings and urinary environmental chemical concentrations. Analyses included t-test and survey-weighted logistic regression models. Results: Urinary mercury concentrations were not associated with high BP (OR = 1.19, 95% CI 0.97–1.48, p = 0.095). Urinary cobalt (OR = 1.35, 95% CI 1.01–1.81, p = 0.044), lead (OR = 1.77, 95% CI 1.31–2.38, p = 0.001), antimony (OR = 1.37, 95% CI 1.09–1.72, p = 0.010) and tungsten (OR = 1.52, 95% CI 1.27–1.81, p < 0.001) concentrations were observed to increase the risk of high BP. There are no clear associations between environmental parabens and high BP. The effect of environmental bisphenol A (OR = 1.14, 95% CI 1.00–1.30, p = 0.051) disappeared after additionally adjusting for subsample weighting (OR = 1.12, 95% CI 0.93–1.35, p = 0.225). People with higher urinary mono-2-ethyl-5-carboxypentyl phthalate (OR = 1.26, 95% CI 1.00–1.58, p = 0.051), mono-n-butyl phthalate (OR = 1.19, 95% CI 1.01–1.41, p = 0.042) and mono-n-methyl phthalate metabolites (OR = 1.16, 95% CI 1.03–1.32, p = 0.021) tended to have high BP. Moreover, urinary o-phenyl phenol concentrations (OR = 1.49, 95% CI 1.25–1.77, p < 0.001) and dimethylarsonic acid concentrations (OR = 1.35, 95% CI 1.06–1.73, p = 0.019) were also seen to be associated with high BP. Conclusions: Urinary environmental chemical concentrations were associated with risk of high BP, although the causal effect cannot be established. Elimination of environmental chemicals in humans would need to be continued.

0414 Cumulative mercury exposure and peripheral nerve function in a sample of U.S. dental professionals

ObjectivesTo calculate individual cumulative mercury exposures from a convenience sample of dental professionals and measure the effect on peripheral nerve function.MethodParticipants attended the American Dental Association’s (ADA) conventions held from...

Dental amalgam and urinary mercury concentrations: a descriptive study

BackgroundDental amalgam is a source of elemental and inorganic mercury. The safety of dental amalgam in individuals remains a controversial issue. Urinary mercury concentrations are used to assess chronic exposure to elemental mercury. At present, there are no indications of mercury-associated adverse effects at levels below 5 μg Hg/g creatinine (Cr) or 7 μg Hg/L (urine). The purpose of the present study is to determine the overall urinary mercury level in the Canadian general population in relation to the number of dental amalgam surfaces.MethodsData come from the 2007/09 Canadian Health Measures Survey, which measured urinary mercury concentrations in a nationally representative sample of 5,418 Canadians aged 6–79 years. Urinary mercury concentrations were stratified by sex, age, and number of dental amalgam surfaces.ResultsThe overall mean urinary mercury concentration varied between 0.12 μg Hg/L and 0.31 μg Hg/L or 0.13 μg Hg/g Cr and 0.40 μg Hg/g Cr. In general, females showed slightly higher mean urinary mercury levels than men. The overall 95th percentile was 2.95 μg Hg/L, the 99th percentile was 7.34E μg Hg/L, and the 99.9th percentile was 17.45 μg Hg/L. Expressed as μg Hg/g Cr, the overall 95th percentile was 2.57 μg Hg/g Cr, the 99th percentile was 5.65 μg Hg/g Cr, and the 99.9th percentiles was 12.14 μg Hg/g Cr. Overall, 98.2% of participants had urinary mercury levels below 7 μg Hg/L and 97.7% had urinary mercury levels below 5 μg Hg/g Cr. All data are estimates for the Canadian population. The estimates followed by the letter “E” should be interpreted with caution due to high sampling variability (coefficient of variation 16.6%-33.3%).ConclusionsThe mean urinary mercury concentrations in the general Canadian population are significantly lower than the values considered to pose any risks for health.

Intraperitoneal Elemental Mercury Exposure from a Mercury-Weighted Bougie

Significant exposure to elemental mercury can occur if a mercury-weighted medical device is damaged during use. We report a case of an elemental mercury spill into the peritoneum of a patient undergoing laparoscopic gastric bypass surgery. A 64-year-old man with multiple comorbidities underwent an elective Roux-en-Y gastric bypass procedure for the treatment of morbid obesity. A mercury-weighted esophageal bougie was inadvertently used during construction of the anastomosis. A suture placed through the distal tip of the device caused elemental mercury to leak into the peritoneum. Two days later, the patient underwent another surgical procedure for removal of the mercury. Intermittent air measurements taken from the laparoscope exhaust showed a peak intraperitoneal mercury concentration of 98,169 ng/m³. Blood mercury levels peaked at 146 μg/L on day 22 after the exposure, and urine mercury concentrations peaked on day 43 at 227 μg/L. The patient had no evidence of acute toxicity, but he was found to have proteinuria on follow-up evaluation. Patients can be exposed inadvertently to toxic amounts of elemental mercury when the integrity of medical devices is compromised. We encourage hospitals to discontinue the use of devices that contain mercury. Effective alternatives that do not pose exposure risks to patients or health care workers are readily available.

Relationship of estimated dietary intake of n-3 polyunsaturated fatty acids from fish with peripheral nerve function after adjusting for mercury exposure

BackgroundSome clinical studies have suggested that ingestion of n-3 polyunsaturated fatty acids (PUFA) has neuroprotective effects on peripheral nerve function. However, few epidemiological studies have examined the effect of dietary n-3 PUFA intake from fish consumption on peripheral nerve function, and none have controlled for co-occurrence of methylmercury exposure from fish consumption. ObjectivesWe evaluated the effect of estimated dietary n-3 PUFA intake on peripheral nerve function after adjusting for biomarkers of methylmercury and elemental mercury in a convenience sample of 515 dental professionals. MethodsWe measured sensory nerve conduction (peak latency and amplitude) of the median, ulnar and sural nerves and total mercury concentrations in hair and urine samples. We estimated daily intake (mg/day) of the total n-3 PUFA, n-3 docosahexaenoic acid (DHA), and n-3 eicosapentaenoic acid (EPA) based on a self-administrated fish consumption frequency questionnaire. We also collected information on mercury exposure, demographics and other covariates. ResultsThe estimated median intakes of total n-3 PUFA, n-3 EPA, and n-3 DHA were 447, 105, and 179mg/day, respectively. The mean mercury concentrations in urine (1.05μg/L) and hair (0.49μg/g) were not significantly different from the US general population. We found no consistent association between n-3 PUFA intake and sensory nerve conduction after adjusting for mercury concentrations in hair and urine although some positive associations were observed with the sural nerve. ConclusionsIn a convenience sample of dental professionals, we found little evidence suggesting that dietary intake of n-3 PUFAs from fish has any impact on peripheral nerve function after adjustment for methylmercury exposure from fish and elemental mercury exposure from dental amalgam.

German health-related environmental monitoring: Assessing time trends of the general population's exposure to heavy metals

The German system of a health-related environmental monitoring is based upon two instruments: The German Environmental Survey (GerES) and the Environmental Specimen Bank (ESB). The ESB is a tool to describe time trends of human exposure. Each year approx. 500 students from 4 sampling locations are analysed for their heavy metal contents in blood, blood plasma, and urine. GerES is a nationwide representative cross-sectional study that has been conducted four times up to now. Both instruments have been used to measure heavy metals over the last decades and thus provide complementary information. Both instruments are useful to describe time trends. However, combining the two has an added value, which is demonstrated for heavy metals for the first time in this paper. Major results and the changing importance of sources of exposure to heavy metals (Pb, Cd, Hg, Au, Pt, U and Ni) are shown. This leads to the following conclusion about the today's relevance of exposure in Germany. For the study participants of the city of Muenster, lead in whole blood decreased from about 70 μg/l in 1981 to levels below 15 μg/l in 2009. GerES data of young adults confirmed this time trend and GerES IV on children revealed the decreasing relevance of lead in outdoor air and in drinking water. The concentrations of mercury in urine decreased because in Germany it is no longer recommended to use amalgam fillings for children. However, GerES IV and ESB data also demonstrate that despite the decline of these heavy metals exposures to nickel and uranium originating from drinking water are still of importance.

국내 일부 지역주민의 혈액과 요중 중금속 농도에 관한 연구

The purpose of this study is to assess the effects of heavy metal concentrations in the blood and urine of the general population. This research had been conducted from April to December 2008, studying 545 residents of Daejeon and Chungcheong Province. Through the concentrations of heavy metals(Pb, Cd, Hg, As, Mn) in the biota samples and questionnaires, the residents heavy metal exposure level and the influential factors according to personal characteristics or lifestyle were evaluated. As to the heavy metal concentration in the blood and urine of the comparing region, were As and Mn statistically significant(p<0.01, p<0.05). Blood lead and urinary mercury concentrations were higher in males than females. The heavy metal concentration for each age group increased blood mercury. The concentration of all heavy metals were higher in the drinkers than in the non-drinkers. Blood lead and mercury concentrations were higher in the smokers than in the non-smokers, but the urinary cadmium, arsenic and blood manganese was higher in the non-smokers than in the smokers. As to the blood lead and urinary cadmium concentration according to the food preference fish showed high concentration. To clarify the factors affecting the heavy metal concentration in biota among subjects multiple regression analysis was conducted. As a results, it turned out that as to lead content in blood, sex, age and smoking have influence on the subjects with explanatory adequacy of 14.0 %. These results demonstrated that the factors affected the concentrations of heavy metals in blood and urine. The results of this study could be used as the foundational data for setting the health risk assessment.

Impact of amalgam removal on urinary mercury concentration in children: a pilot study

Copyright © 2013 by Journal of Korean Academy of Oral Health This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Objectives: This pilot study aimed to evaluate the effect of dental amalgam, a restorative material, on children by measuring the mercury concentration in the urine as well as the number of teeth filled with dental amalgam. Methods: Twenty children enrolled in grades 1-4 of two elementary schools in Daegu participated in this study. One trained dentist performed oral examinations and removed amalgam restorations from the teeth with a high and low speed handpiece. In order to measure the urinary mercury concentrations, urine samples were collected from all participants at baseline and immediately and 24 hours after removal of the dental amalgam restorations. Results: The mean number of teeth from which the amalgam restorations was removed was 9.8 while the mean urinary mercury concentrations at baseline, immediately, and 24 hours after removal of dental amalgam restorations were 2.66, 2.76, and 2.76 μg/g creatinine, respectively. The mean urinary mercury concentration increased consistently after amalgam restoration removal. For those participants whose removed amalgamated surfaces were more than 11, the mean urinary mercury concentration immediately after amalgam restoration removal and 24 hours after removal increased consistently but showed no significant difference. Conclusions: This study demonstrated that dental amalgam restoration was related to urinary mercury concentration, and these findings present a possibility of mercury accumulation in the body. Therefore, we suggest future longitudinal studies to ensure the safety of children exposed to mercury by establishing criteria for amalgam removal.

Polymorphisms in Genes Encoding Potential Mercury Transporters and Urine Mercury Concentrations in Populations Exposed to Mercury Vapor from Gold Mining

Background: Elemental mercury (Hg0) is widely used in small-scale gold mining. Persons working or living in mining areas have high urinary concentrations of Hg (U-Hg). Differences in genes encoding potential Hg-transporters may affect uptake and elimination of Hg.Objective: We aimed to identify single nucleotide polymorphisms (SNPs) in Hg-transporter genes that modify U-Hg.Methods: Men and women (1,017) from Indonesia, the Philippines, Tanzania, and Zimbabwe were classified either as controls (no Hg exposure from gold mining) or as having low (living in a gold-mining area) or high exposure (working as gold miners). U-Hg was analyzed by cold-vapor atomic absorption spectrometry. Eighteen SNPs in eight Hg-transporter genes were analyzed.Results: U-Hg concentrations were higher among ABCC2/MRP2 rs1885301 A–allele carriers than among GG homozygotes in all populations, though differences were not statistically significant in most cases. MRP2 SNPs showed particularly strong associations with U-Hg in the subgroup with highest exposure (miners in Zimbabwe), whereas rs1885301 A–allele carriers had higher U-Hg than GG homozygotes [geometric mean (GM): 36.4 µg/g creatinine vs. 21.9; p = 0.027], rs2273697 GG homozygotes had higher U-Hg than A–allele carriers (GM: 37.4 vs. 16.7; p = 0.001), and rs717620 A–allele carriers had higher U-Hg than GG homozygotes (GM: 83 vs. 28; p = 0.084). The SLC7A5/LAT1 rs33916661 GG genotype was associated with higher U-Hg in all populations (statistically significant for all Tanzanians combined). SNPs in SLC22A6/OAT1 (rs4149170) and SLC22A8/OAT3 (rs4149182) were associated with U-Hg mainly in the Tanzanian study groups.Conclusions: SNPs in putative Hg-transporter genes may influence U-Hg concentrations.

Left ventricular diastolic function in workers occupationally exposed to mercury vapour without clinical presentation of cardiac involvement

The aim of the study was to evaluate left ventricular diastolic function in workers occupationally exposed to mercury vapour without clinical presentation of cardiac involvement. The studies included 115 workers (92 men and 23 women) occupationally exposed to mercury vapour without clinical presentation of cardiac involvement (mean age: 47.83±8.29). Blood samples were taken to determine blood lipid profile, urine was collected to estimate mercury concentration (HgU) and echocardiographic examination was performed to evaluate diastolic function of the left ventricle. In the entire group of workers occupationally exposed to mercury vapour without clinical presentation of cardiac involvement, Spearman correlations analysis demonstrated the following significant linear relationships: between body mass index (BMI) and ratio of maximal early diastolic mitral flow velocity/early diastolic mitral annular velocity (E/E`) (r=0.32, p<0.05), between serum HDL concentration and E/E` (r=−0.22, p<0.05), between HgU and E/E` (r=0.35, p<0.05), between HgU and isovolumetric relaxation time (IVRT`) (r=0.41, p<0.05), between HgU and ratio of maximal early diastolic mitral flow velocity/maximal late diastolic mitral flow velocity (E/A) (r=−0.31, p<0.05) and between serum HDL concentration and E/A (r=0.43, p<0,05). In logistic regression analysis it as shown that independent factors of left ventricular diastolic dysfunction risk in the study group included a higher urine mercury concentration, a higher value of BMI and a lower serum HDL concentration (ORHgU=1.071, ORBMI=1.200, ORHDL=0.896, p<0.05). Summing up, occupational exposure to mercury vapour may be linked to impaired left ventricular diastolic function in workers without clinical presentation of cardiac involvement.