Occupational exposure to mercury vapour on genotoxicity and DNA repair.

We have conducted a population study to investigate whether current occupational exposure to mercury can cause genotoxicity and can affect DNA repair efficiency. Blood samples from 25 exposed workers and 50 matched controls were investigated for the expression of genotoxicity. The data indicate that mercury exposure did not cause any significant differences between the workers and controls in the baseline levels of DNA strand breaks (as measured by the alkaline version of the single cell gel electrophoresis [SCGE] assay) or sister chromatid exchanges (SCE). However, the exposure produced elevated average DNA tails length in the SCGE assay and frequency of chromosome aberrations. In the studies, isolated lymphocytes were exposed to 6J/m2 UV-C light or 2 Gy dose of X-rays in a challenge assay and repair of the induced DNA damage was evaluated using the SCGE assay. Results from the UV-light challenge assay showed no difference between the workers and controls in the expression of DNA strand breaks after exposure followed by incubation in the absence or presence of the cellular mitogen (phytohemagglutinin, PHA). No difference in DNA strand breaks between the workers and controls was seen immediately after the X-ray challenge, either. However, significant differences were observed in cells that were incubated for 2h with and without phytohemagglutinin. Data from the X-rays challenge assay were further used to calculate indices that indicate DNA repair efficiency. Results show that the repair efficiencies for the workers (69.7% and 83.9% in un-stimulated and stimulated lymphocytes, respectively) were significantly lower than that of matched controls (85.7% and 90.4%, respectively). In addition, the repair efficiency showed a consistent and significant decrease with the duration of occupational exposure to mercury (from 75.7% for <10 years employment, to 65.1% for 11-20 years and to 64.1% for 21-35 years) associated with increase of cytogenetic damage. Our study suggests that the occupational exposure to mercury did not cause a direct genotoxicity but caused significant deficiency in DNA repair. Our observations are consistent with previous studies using the standard chromosome aberration assay to show that exposure to hazardous environmental agents can cause deficiency in DNA repair. Therefore, these affected individuals may have exposure-related increase of health risk from continued exposure and in combination with exposure to other genotoxic agents.

Immunological findings in cigarette smokers.

The aim of our study was to assess the effects of cigarette smoking on selected indices of immunity. The study comprised 116 men divided into three groups: 37 subjects smoking for not more than 10 yr, 39 subjects smoking for more than 10 yr, and control group consisting of 40 age-matched men who never used to smoke. The following parameters were studied: total number of lymphocytes, B-cells, T-cells subpopulations: (CD3+)T-, (CD4+)T-helper, (CD8+)T-cytotoxic and (CD16+)natural killer (NK)-cells and serum concentration of immunoglobulins A, D, G and M, C3c and C4 complement components, acute phase proteins: alpha(1)-acid glycoprotein, haptoglobin, ceruloplasmin and lysozyme. The (CD4+)/(CD8+) ratio was also calculated. The suppressive effect of tobacco smoke on human immunity was seen as decreased serum concentration of immunoglobulins and lysozyme, especially in men smoking for more than 10 yr, decreased (CD16+)NK-cells absolute number and elevated population of (CD8+)T-cytotoxic lymphocytes entailing a decrease in CD4+/CD8+ ratio.

The activity of erythrocyte enzymes and basic indices of peripheral blood erythrocytes from workers chronically exposed to mercury vapours.

The influence of occupational exposure to mercury vapours on the activity of the red cell enzymes [glucose-6-phosphate dehydrogenase (G-6PD), acetylcholinesterase (AChE), glutathione reductase (GR) and superoxide dismutase (SOD)], as well as on peripheral blood indices [erythrocyte number (RBC), HCT, Hb, MCHC] and on serum concentrations of iron, ferritin, transferrin and total iron binding capacity (TIBC), was assessed. Studies were carried out on 46 men aged between 21 and 56 years (X = 39 +/- 10.4) exposed to mercury vapours during their work from 7 months to 32 years (= 14.7 +/- 10.8). The control group consisted of 35 healthy workers aged between 20 and 54 years (X = 33.6 +/- 9.8) not exposed to chemical nor physical agents. In both groups studied, there were 50% and 34.3% smokers, respectively. The activity of studied red cell enzymes--G-6PD, AChE, GR and SOD--was estimated according to the colorimetric methods described by Beutler and expressed as international units per gram of hemoglobin (IU g Hb(-1)). Peripheral blood cell parameters were determined using an automatic cell counter. The concentration of serum iron and TIBC was determined using colorimetric methods (Beckman), while that of ferritin and transferrin by nephelometric methods. The time-weighted average (TWA) of mercury concentration in the air determined before the study was 0.0028 mg m(-3). Statistical analysis of the data was performed using either the Cochran and Cox C-test or the Student's t-test. The medium mercury concentration in the urine was 77.44 +/- 48.15 microg l(-1). In the group exposed to mercury vapours, a significant decrease was found in G-6PD activity (23.9%, P<0.001), GR (18.8%, P<0.001), and SOD (5%, P<0.001) with a concomitant increase in AChE activity (35.9%, P<0.001) was found. Moreover, a statistically significant increase occurred in HCT and RBC, and a decrease in MCV and MCHC as well as increases of ferritin (130.9%, P<0.001), transferrin (118.4%, P<0.001) and TIBC (11.2%, P<0.05). Our results indicate that long-term exposure to mercury vapours induces changes in the activity of red cell enzymes--G-6PD, AChE, GR and SOD--and may also influence other important hematological parameters of the peripheral blood.

[Rupture of the cardiac wall during the course of acute myocardial infarction. Personal observations]. / Pekniecia wolnej sciany serca w przebiegu swiezego zawalu miesnia sercowego. Obserwacje wlasne.

Out of 3673 patients with myocardial infarction treated between 1989 and 1998, 128 (54 males and 74 females) deceased due to left ventricle wall rupture (death rate: 18.5%). Thrombolytic therapy started to be used in 1992. It was administered in 36.0% patients with myocardial infarction in the years 1992-1998. Out of the patients deceased due to left ventricle wall rupture thrombolytic was carried out in 24.2%, predominantly in males (31.5%) as compared to females (18.8%). Left ventricle wall rupture during acute myocardial infarction occurred mainly in females (57.7%), in patients with first infarction (89.8%), in the case of anterior wall infarction (66.4%), hypertension (80.5%), in patients aged 61-80 and more (86.7%). Majority of the patients (83.6%) deceased because of this condition between 1 and 7 hospitalisation day, mainly during the first 48 hours (48.4%).

[Right ventricle myocardial infarction from personal observations]. / Zawal prawej komory serca w obserwacjach wlasnych.

In 2514 patients with myocardial infarction (1961 male and 823 female) hospitalized between 1991 and 1997 right ventricle myocardial infarction was diagnosed based on of V3R-V5R electrocardiographic leads tracing in 147 patients aged 35-86 (105 male and 42 female), which means 5.4% of treated patients. Only one case of isolated right ventricle infarction was observed. In other cases it coexisted with left ventricle infarction--most often with inferior myocardial infarction (118 cases, which means 10.7% cases with this localization). Streptokinase was administered to 64 patients with right ventricle infarction, which means 43.5% treated. 10 patients, including 5 female, deceased during the hospitalization, hospital mortality was 6.8%. Cardiogenic shock was the reason of death in all cases. The frequency of concomitant chronic diseases (hypertension, congestive heart failure, diabetes mellitus) and hyperlipidaemia (hypercholesterolaemia and/or hypertriglyceridaemia), as well as arrhythmia and conduction disturbances, in patients with right ventricle myocardial infarction did not differ from the ones estimated in people with left ventricle infarction. According to the analysis of our own material (the most numerous group of patients as juxtaposed to ones observed by other authors) inferior myocardial infarction is most commonly accompanied by right ventricle infarction. Low hospital mortality in these patients is connected with fibrinolytic therapy. The performance of V3R-V5R electrocardiographic leads tracing is indispensable in patients with acute myocardial infarction. The diagnosis of right ventricle infarction is highly important because of the specific treatment of these patients.

[Is polycystic kidney disease a risk factor for neoplasm formation?]. / Czy wielotorbielowate zwyrodnienie nerek stanowi czynnik ryzyka zachorowania na nowotwór?

Our study aimed to elicit possible association between molecular and cytogenetic damage detected in lymphocytes of three members of family with polycystic kidney disease (41 and 19 years old females and in 9 years of age boy) and predictability to develop cancer or their susceptibility to environmental exposure. The DNA damage detected by Comet assay, chromosome aberrations and sisster chromatid exchanges were tested in lymphocytes and p21ras protein level in blood plasma. Lymphocytes of two persons showed higher level of cytogenetic damages and higher in responses to 0.5 Gy dose of radiation. We think it might be associated to specific aberration present in cells of these persons. A final conclusions can be taken when an application of FISH technique would be completed.

[The effect of various occupational exposures to microwave radiation on the concentrations of immunoglobulins and T lymphocyte subsets]. / Wplyw promieniowania mikrofalowego na stezenie immunoglobulin i subpopulacje limfocytów T w róznych ekspozycjach zawodowych.

The immunoglobulins' concentrations and T lymphocyte subsets during occupational exposures to microwave radiation were assessed. In the workers of retransmission TV center and center of satellite communications on increased IgG and IgA concentration and decreased count of lymphocytes and T8 cells was found. However, in the radar operators IgM concentration was elevated and a decrease in the total T8 cell count was observed. The different behaviour of examined immunological parameters indicate that the effect of microwave radiation on immune system depends on character of an exposure. Disorders in the immunoglobulins' concentrations and in the T8 cell count did not cause any clinical consequences.

Immunological disorders in men exposed to metallic mercury vapour. A review.

The awareness of the effects of metallic mercury vapour on the human immune system has increased only in the last decade. The regulatory guidelines relating to testing for immunotoxicity of metals are not standardized so far. A full understanding of the relevance of the tests to man is still incomplete. Immunotoxicity investigation of metals in rodents, with subsequent extrapolation to man, forms the basis of human risk assessment. Human contact with mercury vapour is mainly in chloralkali plants and in factories producing controlling and measuring devices. When the immune system acts as a target of xenobiotic insults, the result can be a decreased resistance to infection, cancers, or immune disregulation that can induce the development of allergy, or autoimmunity (Fig. 1). This article reviews literature data and our studies concerning the immunotoxicity of metallic mercury vapour. A number of data shows that mercury exerts a suppressing effect but another data suggest stimulating effects on the human immune system. The results of immunological monitoring of individuals exposed to mercury vapour were either positive or negative as well as borderline and uncertain as to the influence of mercury vapour on human immune system. The positive data had no influence on the resistance of workers to infections and neoplasms. Skin and mucosa hypersensitivity to metallic mercury is rare. No positive report that mercury vapour could be carcinogenic in man has appeared up to now.

Monitoring of molecular and cytogenetic damage in lymphocytes from three persons with polycystic kidney disease.

BACKGROUND: Much interest has been generated in the studies that would help to understand whether there is a causal association between disease and various types of molecular or cytogenetic damage detected in human cells. MATERIALS AND METHODS: The aims of this study were to elicit the possible association between DNA and cytogenetic damage induced in lymphocytes of three members of a family with autosomal dominant polycystic kidney disease (ADPKD). The predictability to develop cancer or to sensitive response to environmental exposure of the young girl at the age of 19, her brother (9 years old) and a maternal aunt at the age of 41 were sought. Cytogenetic studies, analysis of DNA damage by single cell gel electrophoresis assay (SCGE known as a Comet assay), and analysis of p21ras protein level in blood plasma were carried out on their lymphocytes. RESULTS: The analysis for presence of chromosome aberrations in the first mitosis and sister chromatid exchanges in the second mitosis revealed elevated levels of cytogenetic biomarkers when compared to the mean values observed in the reference group in environmental biological monitoring studies. Results of sister chromatid exchanges (SCE) and percent of cells with elevated number of exchanges (high frequency cells) that were significantly higher in two probands had demonstrated susceptibility to or possibility of environmental exposure (pesticides, smoking). The results of this study show that the lymphocytes of two persons revealed increased sensitivity to 0.5 Gy dose of gamma radiation expressed in the increased, although statistically insignificant, damage detected on the molecular level after cell irradiation. CONCLUSIONS: The latter might be associated with a specific aberration present in the cells of these persons. But final conclusions can be arrived at when an application of FISH technique is completed.

[The effects of occupational exposure to nitrogen dioxide (NO2) on the immunological parameters in workers]. / Wplyw zawodowego narazenia na dwutlenek azotu (NO2) oraz tlenek azotu (NO) na parametry ukladu odpornosciowego pracowników.

The study of T-cell subpopulation: T CD3+, T CD4+, T CD8+; NK CD16+ and B CD19+ cells as well as of serum concentrations of immunoglobulins G, A, M, E, complement components C3c and C4, total circulating immune complexes (CIC), CRP, haptoglobin, ceruloplasmin and transferin, was carried out in 16 males, smokers and non-smokers. The control group of smokers and non-smokers comprised 36 males not exposed to any chemical compound. The study was performed also in two groups of non-smokers: 5 workers occupationally exposed and 7 non-exposed controls. For the determination of T-cells, NK- and B CD19+ cells populations monoclonal antibodies were used in indirect immunofluorescence tests. Passive sampling spectrophotometric method was employed to determine NO2 and NO concentrations in the work environment air. Their mean values were 0.0867 +/- 0,0585 mg x m-3 (from 0.0165 to 0.1960) and 0.0614 +/- 0.0263 mg x m-3 (from 0.0220 to 0.1090), respectively. The number of total leucocytes and lymphocytes in the group of 16 smokers and non-smokers exposed to NO2 and NO was increased. Stimulation T-cells line in the men exposed to NO2 and NO was evidenced by an increased number of T CD3+ cells, about two-fold increase in absolute number of T CD4+ cells (p < 0.001), an increased number of T CD8+ cells (p < 0.001) and by an enhanced value (by 24.7%) of the T CD4+/T CD8+ ratio. In the group of 16 persons exposed to NO2 and NO serum IgG concentration was elevated (p < 0.01), C3c C4 decreased (p < 0.001), and serum CIC enhanced by about two times (p < 0.001). Stimulation T-cells line in the groups of 5 non-smoking workers exposed to NO2 and NO was evidenced by an increased number of T CD3+ (p < 0.05), T CD4+ (p < 0.05) and T CD8+ cells but without any change in the value of the T CD4+/T CD8+ ratio. In addition, decreased serum C3c and C4 levels together with serum CIC elevated by 76.7% (p < 0.05) were evidenced in this group on non-smokers. Moreover, significant positive correlations between NO2 concentrations in the air and the numbers of total lymphocytes, T CD3+, TCD4+, T CD8+ cells or IgG: (magnitude of r in the range between 0.31 and 0.71), as well as significant negative correlations between NO2 concentrations in the air and C3c (r = 0.44) in the group of 16 smoking and non-smoking workers were calculated. In this group significant positive correlation between NO concentrations in the air of the workplace and counts of T CD3+, T CD8+, B CD19+ (magnitude of r in the range between 0.51 and 0.63), haptoglobin and ceruloplasmin (magnitude of r from 0.37 to 0.58), as well as significant negative correlation between NO concentrations in the air and serum levels of IgG, IgA and IgM (magnitude of r from -0.67 to -0.47) and CIC (magnitude of r = -0.39) were also observed. In the group of 5 exposed non-smoking workers, the values of correlation coefficients magnitude of r between NO2 and NO concentrations in the work environment air and immunological parameters were similar to those in the whole group. The results obtained suggest that during occupational exposure NO2 may play a more important role mainly in the process of inflammation but exogenous NO seems to act as modulating factor of this proinflammatory NO2 effect through a greater and exposure-dependent influence mainly on B CD19+ cells and other parameters of humoral immunity.

[Usefulness of determining urinary markers of early renal damage for monitoring nephrotoxicity during occupational exposure to mercury vapors]. / Przydatnosc oznaczania w moczu markerów wczesnego uszkodzenia nerek do monitorowania nefrotoksycznosci par rteci w trakcie zawodowego narazenia.

Using nephelometry, concentration of albumin, IgG, transferrin, retinol binding protein (RBP) alpha 1-microglobulin were determined in urine of 83 males with history of occupational exposure to metallic mercury vapours from 0.6 to 37 years, and in 30 non-exposed males. The weighted average of mercury air concentrations was 0.028 mg/m3. Duration of occupational exposure to mercury vapours did not elevate urine excretion of proteins. The urine concentration of proteins in question were higher (especially beta 2-m) in workers with urine mercury concentration between 51 and 150 microliter-1 and highest in workers with urine mercury concentrations above 150 micrograms l-1 and the differences were significant. In addition, a positive correlations between urine mercury concentrations and alpha 1-m (r = 0.33) as well as between urine mercury concentration and albumin (r = 0.31) were observed. In conclusion, the determination of proteins in urine as markers of early renal damage may be useful for monitoring occupational exposure to mercury vapours, especially in the group of workers with elevated values of urine mercury concentrations.

Immunological effects of occupational exposure to metallic mercury in the population of T-cells and NK-cells.

This paper presents a study of the counts of lymphocytes, (CD3+)T-cells, (CD4+)T-helper and (CD8+)T-suppressor and (CD16+)NK-cells in the peripheral blood of 101 males with a history of occupational exposure to metallic mercury vapours (Hg0) and in 36 males without this exposure. These workers were divided depending on the duration of exposure: 37 males with a short-term history of exposure to Hg0 (up to 10 years) and 64 males with a history of long-term exposure (10 to 37 years). For the determination of T-cell populations monoclonal antibodies were used in indirect immunofluorescence tests. The time weighted average of mercury concentrations in air was 0.028 mg m-3. Mercury concentration in the urine of the exposed subjects ranged from 20-260 micrograms dm-3, and in blood it was from 4 to 72 micrograms dm-3. Stimulation of the T-cell line was noted as evidenced by increased numbers of (CD3+)T-cells, (CD4+)T-helper and (CD8+)T-suppressor cells in the workers with < 10 or > 10 years' exposure to Hg0. Lower increase count of (CD3+)T-cells and (CD4+)T-helper cells than (CD8+)T-suppressor cells was the cause of decreased values in the (CD3+)T/(CD8+)T-suppressor ratio and (CD4+)T-helper/(CD8+)T-suppressor ratio in the workers with < 10 or > 10 years' of exposure. Moreover, no changes were observed in the T-cell populations between workers with < 10 and those with > 10 years' exposure. In addition, statistical analysis of the effects of age and duration of exposure to Hg0 on the studied immunological parameters indicates that exposure duration may affect some of the values. These quantitative changes of T-cell population as well as changes of the (CD3+)T/(CD8+)T-suppressor and (CD4+)T-helper/(CD8+)T-suppressor ratio have been proposed as immunological indicators of exposure to Hg0, which can be used for monitoring and to explain the origin of autoimmunity disorders induced by metallic mercury.

[Levels of immunoglobulin and subpopulations of T lymphocytes and NK cells in men occupationally exposed to microwave radiation in frequencies of 6-12 GHz]. / Stezenie immunoglobulin oraz subpopulacje limfocytów T i komórek NK u mezczyzn zawodowo narazonych na promieniowanie mikrofalowe o czestosci 6-12 GHz.

Immunoglobulin concentrations and T-lymphocyte subsets in workers of TV re-transmission and satellite communication centres were assessed. An increase in IgG and IgA concentrations, an increased count of lymphocytes and T8 lymphocytes, an decreased count of NK cells and a lower value of T-helper/T-suppressor ratio were found. Neither disorders in immunoglobulin concentrations nor in the count of T8 and NK cells had any clinical implications.

[Vertebral hemangiomas--two case reports]. / Naczyniaki kregoslupa--opis dwóch przypadków.

It was described two cases of vertebral haemangiomas. The first one at a 30-year old man was situation in the 5-th lumbal vertebra. The second of the 7-th thoracic vertebra at a 57-th year old man simultaneously connected with oesophagus cancer. It not settled with of neoplasmas was the first one. The reason of the "cancer disorder" and appear of oesophagus cancer is probably the result of long habitual smoking and improper high consumption of animal fats and a small quantity of vegetables and fruits.

[Coexistence of Baker's cysts with a 5th chromosome aberration--case report]. / Wspólistnienie torbieli Bakera z aberracja chromosomu 5--opis przypadku.

A case of bilateral ruptured Baker's cysts in a 27-year-old woman was described. Their cause was probably the inborn flexibility of articular capsules conditioned by the genetic aberration of the 5-th chromosome.

[Atrial septum aneurysm as a personal observation]. / Tetniak przegrody miedzyprzedsionkowej w obserwacjach wlasnych.

In the midst of echocardiographic examination, which has been performed in years 1993-1995, the presence of atrial septal aneurysm has been found in 18 patients (0.2% explorations) in age of 23-72 years, including 7 male and 11 female. There were hospitalized thirteen of them, and five were observed in cardiologic outpatient clinic. Transesophageal echocardiographic examinations has been performed in 16 persons, and 12 persons has been performed 24 hours electrocardiographic monitoring Holter's method. Our observations revealed, that atrial septal aneurysm has been found in persons with diverse heart diseases and different ages.

Mercury compounds and the immune system: a review.

This article reviews the literature data concerning the immunologic monitoring of animals and cell cultures exposed to mercury compounds. Mercury is present in nature as metallic mercury, mono- and bivalent inorganic compounds, and organic alkyl, aryl and alloxy-alkyl compounds. Methylmercury is most important in terms of environmental exposure while metallic mercury is the most common form to which workers are exposed. The database on immune function disturbances in human induced by mercury compounds is limited. Immunotoxicity assessment in animals, mainly in rodents, with subsequent extrapolation to man, is the basis of human risk assessment. The strength of in vitro immunotoxicity testing lies in studies aimed at unravelling mechanisms of immunotoxicity. These experimental investigations show clearly that mercury compounds can have immunomodulating activity. Mercuric chloride and methylmercury inhibit most of animal and human lymphocyte functions including proliferation, expression of cell activation markers on cell surface and cytokine production. These cells exhibit a greater sensitivity to the immunotoxic effects of methylmercury than to mercuric chloride. Repeated administration of mercuric chloride to rats, mice and rabbits can induce autoimmune response and a membranous nephropathy. In contrast, Lewis rats injected with mercuric chloride do not develop autoimmunity but exhibit immunosuppression. The immunosuppressive effects associated with exposure to chemical substances are often accompanied by increased susceptibility to challenge with infectious agents or tumour cells. Only few reports are available on animal studies of increased mortality connected with exposure to mercury compounds and challenge with infectious agents. It is difficult to establish a relationship between the observed immunomodulatory properties of mercury compounds and their possible carcinogenicity. In fact, the epidemiological studies performed so far failed to bring any conclusive evidence of carcinogenicity of mercury in animal experiments. The induction of renal tumours in male rodents by methylmercury was observed only.

The effect of cigarettes smoking on the blood counts of T and NK cells in subjects with occupational exposure to organic solvents.

The study was carried out in a population of 139 men, divided into two control groups: 40 non-smokers and 39 smokers not exposed to chemical compounds, and two groups exposed to them: 19 non-smokers and 41 cigarette smokers with occupational contact with organic solvents. The results of toxicological analyses of air and chromatographic analyses of solvents demonstrated the presence of benzene, toluene, xylene and their partly hydrogenated derivatives, paraffin hydrocarbons, oleins, naphthenes (components of painter's naphtha), monohydric and polyhydric alcohols (butanol, cyclohexanol, butylene glycol) esters (ethyleneglycol acetate, butyl acetate) and ketones (methylisobutyl ketone, cyclohexanone). In the time of the studies the TWA values for benzene were 0 to 38 mg x m-3 (0 to 12 ppm), with arithmetic mean averages of about 19 mg x m-3 (6 ppm) and for the level of benzene 0-351 mg x m-3 (0-110 ppm) with arithmetic mean annual averages of about 48 mg x m-3 (15 ppm). Mean phenol concentration in the urine of the workers in groups I, II, III and IV respectively was: 7.9 +/- 3.5; 10.0 +/- 5.8; 16.8 +/- 6.2 and 18.4 +/- 9.7 mg x l-1. Hippuric acid concentration in the urine of the workers in groups I to IV was: 496 +/- 326, 538 +/- 341, 982 +/- 420 and 1107 +/- 507 mg x l-1 respectively. The absolute counts were determined of T-cells (CD 3+), T-helper (CD 4+), T-suppressor (CD 8+) cells and natural killer (NK) cells (CD 16+) in the peripheral blood by indirect immunofluorescence. In the subjects with occupational exposure to organic solvents the counts of T-cells and NK-cells were reduced, and the number of T-suppressor cells was raised which resulted in a decrease of the T-helper/T-suppressor ratio. These changes were more pronounced in cigarette smokers. The assessment of the immunotoxic effect of organic solvents during occupational exposure should take into consideration the possibility of a synergistic action with tobacco and may be of practical use for monitoring the toxic effect of organic solvents on the lymphocyte system.

Effects of occupational exposure to mercury vapors on T-cell and NK-cell populations.

The counts of lymphocytes, (CD3+) T-cells, (CD4+) T-helper and (CD 8+) T-suppressor and (CD 16+) NK-cells were determined in the peripheral blood of 81 males with a history of occupational exposure to metallic mercury vapors and in 36 males without this exposure. For the determination of T-cell populations monoclonal antibodies were used in indirect immunofluorescence tests. The weighted mean of mercury concentrations in air was 0.028 mg x m-3. Mercury concentration in the urine of the exposed subjects ranged from 10-240 micrograms x l-1, and in blood it was from 4-30 micrograms x l-1. Stimulation of the T-cell line was noted as evidenced by increased number of T-cells by 35% in the workers with exposure to mercury vapors below or by 38% in the workers over 10-years, by increased number of T-helper cells by 42% (p < 0.001) in the workers with exposure below or by 60% (p < 0.001) in the workers over 10 years and by increased number of T-suppressor cells by 85% (p < 0.001) in the workers below or by 96% (p < 0.001) in the workers over 10 years exposure. Lower increase of T-helper cells population than T-suppressor cells population was the cause of decreased value of the T-helper/T-suppressor ratio by about 21% (p < 0.01) in the workers with exposure below and over 10 years. No changes were observed in the T-cell populations between workers with up to 10 and those with over 10 years exposure. The quantitative changes of T-helper cells and T-helper/T-suppressor ratio may represent an immunological indicator of exposure to mercury vapors. Presented changes in human T-lymphocytes population associated with occupational exposure to mercury vapors have been proposed to explain the origin of more frequent autoimmunity induced by mercury.