The influence of ethyl alcohol on the absorption of mercury vapour from the lungs in man

Assessment of Lead and Mercury Exposure Levels in the General Population of Korea Using Integrated National Biomonitoring Data

In Korea, the estimated values of blood lead (Pb) and mercury (Hg) levels differ between two national-level biomonitors, namely the Korean National Environmental Health Survey and the Korea National Health and Nutrition Examination Survey. The present study used integrated data from these surveys to estimate the representative values of the change in concentration and recent distribution characteristics. The yearly trend of age-standardized exposure levels in regular adults was identified, and the geometric mean (GM) adjusted according to demographic characteristics was presented. Age-standardized GM for blood Pb and Hg in the integrated data was 2.06 and 3.64 μg/L in 2008, respectively, which decreased to 1.55 and 2.92 μg/L, respectively, by 2017. Adjusted GMs from most recently conducted surveys (2015-2017) were 1.61 and 2.98 μg/L for blood Pb and Hg, respectively. In particular, the adjusted percentage of blood Hg exceeding the reference value of 5 μg/L was 20.79%. While the blood Pb and Hg exposure levels are decreasing in Korea, the levels remain high relative to those in other countries. The Hg levels exceeded the reference value in many individuals. Therefore, continued biomonitoring must be conducted, and a reduction plan and exposure management are needed for harmful metals, including Hg.

Environmental and Body Concentrations of Heavy Metals at Sites Near and Distant from Industrial Complexes in Ulsan, Korea

BACKGROUND

Industrial pollution may affect the heavy metal body burden of people living near industrial complexes. We determined the average concentrations of atmospheric heavy metals in areas close to and distant from industrial complexes in Korea, and the body concentrations of these heavy metals in residents living near and distant from these facilities.

METHODS

The atmospheric data of heavy metals (lead and cadmium) were from the Regional Air Monitoring Network in Ulsan. We recruited 1,148 participants, 872 who lived near an industrial complex ("exposed" group) and 276 who lived distant from industrial complexes ("non-exposed" group), and measured their concentrations of blood lead, urinary cadmium, and urinary total mercury.

RESULTS

The results showed that atmospheric and human concentrations of heavy metals were higher in areas near industrial complexes. In addition, residents living near industrial complexes had higher individual and combined concentrations (cadmium + lead + mercury) of heavy metals.

CONCLUSION

We conclude that residents living near industrial complexes are exposed to high concentrations of heavy metals, and should be carefully monitored.

Health Complaints Attributed to Dental Amalgam: A Retrospective Survey Exploring Perceived Health Changes Related to Amalgam Removal

BACKGROUND

Many patients have complex health complaints they attribute to dental amalgam. There is some evidence of symptom relief after removal of amalgam.

OBJECTIVE

The aims of this study were to assess the total symptom load in patients with all their amalgam fillings removed, and to investigate the self-reported improvement of health with regard to precautions taken under amalgam removal and time since removal.

METHODS

The survey was distributed to all members (n=999) of the Norwegian Dental patients association in 2011. The study participants returned the questionnaires anonymously by means of a pre-stamped envelope. The questionnaire asked for sociodemographic data, subjectively perceived health status, complaints persisting after amalgam removal and self-reported changes in symptoms after amalgam removal.

RESULTS

A total of 324 participants were included in the study. The majority of the participants reported improved health after amalgam removal, even though the mean degree of severity of complaints was still high. Exhaustion and musculoskeletal complaints were most severe, and reflects the fact that 38% of the participants reported poor to very poor current health. With regard to amalgam removal, associations between improved health, number of precautions applied, and time since removal were found.

CONCLUSION

Most of the participants in this study reported improvement of health after amalgam removal even though they still suffered a high complaint load. Since absolute symptom load is a robust predictor for general health outcome and socioeconomic burden for society, a possible intervention, which enables patients to further improve their health status is desirable.

Mercury toxicity and treatment: a review of the literature

Mercury is a toxic heavy metal which is widely dispersed in nature. Most human exposure results from fish consumption or dental amalgam. Mercury occurs in several chemical forms, with complex pharmacokinetics. Mercury is capable of inducing a wide range of clinical presentations. Diagnosis of mercury toxicity can be challenging but can be obtained with reasonable reliability. Effective therapies for clinical toxicity have been described.

The inhibition of mercury absorption by dietary ethanol in humans: cross-sectional and case-control studies

BACKGROUND

Since the inhibition of mercury absorption by ethanol was serendipitously discovered in 1965,(1) a limited number of small number studies with both animal and human subjects have reported results consistent with this finding.

AIMS

To investigate this phenomenon in a large scale human study with low level Hg exposed dentists.

METHODS

Data were collected for a sample of 1171 dentists, and both cross sectional and case-control methods were utilised to examine the data.

RESULTS

Abstainers (n = 345) had significantly higher urinary mercury concentrations (HgU) than drinkers (n = 826): 5.4 microg/l v 4.8 microg/l. Multiple linear regression showed a significant effect of ethanol dose on HgU after adjusting for potential confounders. A case-control analysis in which cases were defined as those individuals with urinary Hg concentrations of > or =15 microg/l (approximately top 5%), and controls as those with concentrations of <1.0 microg/l ( approximately bottom 5%), showed a clear protective dose-response relation; there was a decreasing risk of being a "case" (having an HgU > or =15 microg/l) with increasing ethanol consumption. The significance of the adjusted model is p<0.001, and the chi2 test for trend across ethanol consumption categories in the adjusted model is p<0.05, confirming the dose-response relation.

CONCLUSION

We believe that this straightforward investigation provides the first specific confirmation in a large scale human study of the inhibitory effect of ethanol on urinary mercury concentration, and by inference, on mercury absorption.

Proposed revision of the ICRP model for inhaled mercury vapor

A critical review of the literature on the biokinetics of inhaled mercury vapor was performed as part of an accident analysis for the Spallation Neutron Source to be built at Oak Ridge National Laboratory. It was concluded that current models for inhaled mercury vapor do not accurately describe the distribution or residence time of mercury deposited in the respiratory tract. This paper proposes a model that is more consistent with collective information on the fate of inhaled mercury vapor in laboratory animals and human subjects. Compared with the model currently recommended by the International Commission on Radiological Protection (ICRP), the proposed model predicts lower deposition in the bronchi and bronchioles, greater deposition in the alveolar-interstitial region, and a different pattern of absorption to blood. The proposed model yields substantially reduced estimates of lung dose and effective dose for most radioisotopes of mercury inhaled as mercury vapor.

Speciation of mercury excreted in feces from individuals with amalgam fillings

Investigators established methods for the analysis of total mercury (Hg-total), oxidized mercury and mercury bound to sulfhydryl groups (Hg-S), mercury vapor (Hg0), and mercury from amalgam particles (APs) in fecal samples. Two individuals consumed mercury as a mercury-cysteine complex mercury vapor, and mercury from amalgam particles, and the cumulative excretion of mercury in feces was followed. Investigators found that 80% of the mercury from amalgam particles and mercury bound to sulfhydryl groups was excreted, but only 40% of the mercury vapor was excreted. Speciation of mercury excreted in feces from 6 individuals with a moderate loading of amalgam fillings showed that most of the mercury originating from the fillings consisted of oxidized mercury, which was probably bound to sulfhydryl-containing compounds. The proportion of amalgam particles in fecal samples from these individuals was low, and it did not exceed 26% of the total amount of mercury excreted.

Toxic interactions among environmental pollutants: corroborating laboratory observations with human experience

Combined exposures to multiple chemicals may result in interactions leading to a significant increase or decrease in the overall toxicity of the mixture compared to the summation of the toxicity of the components. A large number of chemical interactions have been described in animal studies by administering high doses of chemicals by routes and scenarios often different from anticipated human exposures. Though limited, there is some evidence for the occurrence of several supra-additive (the combined effects are greater than the simple summation of the individual effects) and infra-additive (the combined effects are smaller than the simple summation of the individual effects) chemical interactions in humans. For example, toxicokinetic interactions between several solvents have been found to occur in the workplace, whereas those involving pesticides have been reported less frequently, especially during accidental exposures. Toxic interactions involving nutritionally important metals and metalloids appear to occur more frequently, since several of them have an important role in a variety of physiological and biochemical processes. On the contrary, there is not much evidence to confirm the occurrence of toxic interactions among the commonly encountered inorganic gaseous pollutants in humans. Overall, the majority of chemical interactions observed in animal studies have neither been investigated in humans nor been extrapolated to humans based on appropriate mechanistic considerations. Future research efforts in the chemical interactions arena should address these issues by focusing on the development of mechanistically and biologically based models that allow predictions of the extent of interactions likely to be observed in humans.

Residual neurobehavioural effects associated with chronic exposure to mercury vapour

To find the residual effects of long term exposure to mercury vapour, neurobehavioural tests were given to ex-mercury miners about 18 years after the end of mercury exposure. Seventy six male ex-mercury miners who had been exposed to high concentrations of mercury vapour (over 1.0 mg/m3) and with a history of mercury intoxication were compared with controls matched for age (within 3 years), sex, and education. Although the extent of the workers' symptoms caused by mercury poisoning, termed erethismus merculialis, decreased considerably after the end of exposure, matched paired comparison showed that performances of motor coordination, simple reaction time, and short term memory had deteriorated significantly in the exposed group. Multiple linear regression analysis of exposure variables with neurological examination measures showed positive correlations between poorer neurological performance and variables related to mercury exposure. Thus the duration of exposure correlated with poorer performance of hand-eye coordination, tapping, and a colour card reading test. Job categories classified by exposure to mercury also had a significant negative correlation with these performances. The period of years after the end of exposure had a significant correlation with better performance of reaction time and digit span. On the other hand, the history of intoxication itself had no significant correlation with any of the current neurobehavioural performances. These results suggest that there are slight but persistent effects on neurobehavioural function, especially on motor coordination, among mercury miners even more than 10 years after the end of exposure.

Combined toxicity of ethanol and methylmercury in rat

The hepatotoxic and nephrotoxic effects of methylmercury (CH3Hg) and ethanol (EtOH) are well known; however, their interaction in vivo is not clearly understood. In order to investigate the combined effects of these 2 substances, 4 groups of male Wistar rats with an initial weight of approximately 190 g were treated for 7 weeks. Each group consisting of 8 rats was gavaged as follows: Group 1 with 5.0 ml/kg body weight of double distilled water, Group 2 with 5.0 ml/kg body weight of 25% EtOH, Group 3 with 2.5 mg/kg of CH3Hg in water, and Group 4 with 2.5 mg/kg of CH3Hg in 25% EtOH. At the termination of the experiment the mean body weights of the rats in Group 3 (372.5 +/- 10.8 S.E.) and Group 4 (383.4 +/- 13.4) were significantly lower than that of Group 1 (433.0 +/- 7.8). Linear regression showed a positive feed conversion efficiency for Groups 1 and 2 (1.07 and 0.83, respectively), and a negative score for this parameter for Groups 3 and 4 (-1.43, -1.53). At necropsy, rat livers from Group 3 exhibited random multifocal tan spots. The relative liver weights were similar to those of controls. Semithin sections of liver revealed an increase in lipid droplets in Groups 2 and 3 compared to those in the other 2 groups while vacuolization was more striking in CH3Hg treated rats (Groups 3 and 4). Severe hepatolysis and portal canal edema were noted in the groups of rats exposed to either EtOH alone or in combination with mercury. The relative weight of left kidney in Group 3 (0.70 +/- 0.03) and Group 4 (0.51 +/- 0.04) rats was significantly greater than that of the control (0.39 +/- 0.03). In gross appearance the kidney was pale and the urine production was significantly higher (P less than 0.05) in Group 3 compared to that of Group 1. Group 4 rats had significantly more (P less than 0.05) Hg in the kidney than Group 3; however, the inorganic percentages in both groups were similar. Morphological examination of the kidney proximal tubules from CH3Hg treated rats (Groups 3 and 4) revealed an increase in lipid droplets, vacuoles, cell sloughing and tubular degeneration compared to Groups 1 and 2. These histological changes in the proximal tubules of Group 4 rats indicate an additive effect of EtOH on the kidney pathology caused by CH3Hg.(ABSTRACT TRUNCATED AT 400 WORDS)

Effects of ethanol on methyl mercury toxicity in rats

This study was designed to investigate the effect of different doses of ethanol on the morbidity, mortality, and distribution of mercury in the tissues of groups of rats treated orally once daily with methyl mercury chloride (MMC: 5 mg/kg . d) for 10 consecutive days. Ethanol potentiated the toxicity of methyl mercury in terms of neurological manifestations (hindleg crossings and abnormal gait) and mortality. The magnitude of effect depended on the concentration of ethanol administered. The concentration of mercury in the kidney and brain also increased with the dose of ethanol given. These findings indicate that epidemiologic studies designed to evaluate methyl mercury toxicity must take into account the multiple environmental burdens that can affect the population cumulatively and simultaneously.

[Comparative studies of 2 organic mercury compounds alone or in combination with ethanol following pre- or postnatal application in mice]

Studies on pre- and/or postnatal effects on mice were carried out with their identical exposure (2 mg Hg/kg body mass) to phenyl mercuric acetate or N,N'-bis-(dimethylmercury)-p-toluol-sulphonamide. Parameters of morphology, of residues, and behaviour teratology were taken into consideration. Potentiating combination effects were only observed with behaviour toxicological investigations after prenatal exposure to methylmercury. That concerned the breeding results of the P-generation and the capacity of the F1-generation to learn on the 30th and 31st day p.n. during a swimming test in a labyrinth. Synergistic effects were observed with both the mercury compounds in the swimming test on the 12th day p.n. after pre- as well as postnatal exposure.

The effect of dental amalgam restorations on blood mercury levels

Mercury levels in blood and in mouth air before and after chewing were measured in 47 persons with and 14 persons without dental amalgam restorations. Questionnaires relating to exogenous sources of mercury exposure were administered to both groups. Differences in the mouth air mercury levels before and after chewing were statistically significant in the group with amalgams, but not in the group without amalgams. Analysis of the data from the questionnaires indicated that little or no exogenous exposure to mercury occurred among the two groups. Blood mercury concentrations were positively correlated with the number and surface area of amalgam restorations and were significantly lower in the group without dental amalgams.

The interaction of ethyl alcohol and industrial chemicals

A serious, relatively unrecognized, occupational health problem involves the interaction of ethyl alcohol and chemical agents used in industry. Workers who drink alcohol and are exposed to certain chemical agents may experience adverse health effects such as nausea, dizziness, headache, and liver damage. This report reviews the synergistic interactions of ethanol with compounds such as the thiurams, amides, oximes, halogenated hydrocarbons, and metals. Also discussed is the effect of ethanol as a cofactor with vinyl chloride in the etiology of cancer.