Immunobiochemical profiles of workers differing in the degree of occupational exposure to vinyl chloride

The immunobiochemical studies were conducted in a group of 98 production workers engaged in polyvinyl chloride manufacture from ethylene (group A workers) and in a group of 59 vinyl chloride workers from a chemical plant employing classic production technology from acetylene (group B workers). Both groups of workers were matched by age (group A workers: 37.7 +/- 8.66 years; group B workers: 34.9 +/- 11.2 years) and average exposure length (group A workers: 8.6 +/- 3.0 years; group B workers: 10.7 +/- 8.4 years). All workers were examined for the serum concentrations of immunoglobulins IgG, IgA and IgM and acute reactants lysozyme (LYS), transferrin (TRF), ceruloplasmin (CPL), alpha-l-antitrypsin (AlAT), alpha-2-macroglobulin (A2M) and orosomucoid (ORO). The statistical analysis included calculations of means, standard deviations and 95% confidence intervals. Differences in means were evaluated by t-test, differences in the distribution pattern of values by F-test. Abnormality of values was assessed by comparisons to normal values valid in Czechoslovakia. Group A worked in conditions meeting the MAC 10 mg VC.m-3 comparing with group B workers had elevated levels of IgG (P less than 0.005), IgA and IgM (P less than 0.001 both). Group B workers differed from group A workers by exhibiting significantly elevated levels of AlAT, and CPL. (P less than 0.001). The differences in the frequency of abnormal values between group A and group B worked in substantially less favourable hygienic conditions were significant for immunoglobulins elevated in group A and for ORO (P less than 0.01) and CPL (P less than 0.001) elevated in group B. The possible relationship of these immunobiochemical findings with the degree of vinyl chloride exposure are critically analyzed.     

Immunological profiles in workers of a power plant burning coal rich in arsenic content

A group of 47 male adults working in a thermal power plant burning coal containing 900 to 1,500 g of arsenic per ton dry weight was examined on the blood serum immunoglobulins IgG, IgA and IgM content and levels of acute reactants alpha-1-antitrypsin (A1AT), alpha-2-macroglobulin (A2M), transferrin (TRF), orosomucoid (ORO) ceruloplasmin (CPL), and lysozyme (LYS). Investigations in the control group comprising 27 workers from another power plant in the same district where the coal content of arsenic was more than 10 times lower were analogous. The inter-group differences in means were evaluated by t-test, differences in the association of values by F-test, and the correlations with age and the length of exposure were assessed using the regression analysis method. The differences in mean IgG, IgA, IgM, LYS and A2M levels between the exposed and control groups of workers were insignificant or of borderline significance only. In contrast, differences in TRF, ORO and particularly CPL levels were statistically highly significant, in all instances P less than 0.001. In the control group, persons with abnormal values in at least two immunobiochemical tests used accounted for 3.7%, in the group of the exposed for 51% (P less than 0.002). All these findings, especially the rise in CPL concentration levels in the exposed group are discussed on the background of the rise in cancer mortality rates found previously in this group of power plant workers.     

Cytogenetic monitoring of hospital workers exposed to low-level ionizing radiation

In the present study the cytogenetic effects in hospital workers exposed to low-level radiation were evaluated. Samples of peripheral blood were collected from 63 subjects working in radiodiagnostics and from 30 subjects, working in the same hospitals, who were used as controls. A higher number of cells with chromosome-type aberrations (CA) was observed in the exposed workers vs. the controls and the difference was statistically significant (p less than 0.05). No correlation was, on the contrary, found between CA and years of exposure. A significant difference was observed in the incidence of cells with CA between smokers and non-smokers, but in the control group only. In contrast, in the workers exposed to ionizing radiation, the frequency of cells with CA was very similar in smokers and non-smokers.     

Immuno-biochemical findings in groups of individuals occupationally and non-occupationally exposed to emissions containing nickel and cobalt

Immune reactions elicited in the sera of individuals exposed to nickel and cobalt were assessed by changes in the concentration of serum immunoglobulins IgG, IgA and IgM and serum proteins alpha 2 macroglobulin (A2M), transferrin (TRF), alpha 1-antitrypsin (A1AT), ceruloplasmin (CPL) and lysozyme (LYS). Examinations were carried out in workers occupationally exposed to Ni (38 individuals) or Co (35 individuals) and in groups of non-occupationally exposed children living in areas with a different degree of air pollution from a nearby source of Ni and Co emissions (one group was made up of 54 exposed children, the other one of 64 "less exposed" children of the same age). Groups of non-exposed controls were represented by a group of 42 male adults matched by age and by a group of 48 children from a non-polluted area. Significantly increased average values were obtained for IgG, IgA and IgM in group of workers exposed to Ni, for IgA in workers exposed to Co and for A1AT, A2M, CPL and LYS in both groups of occupationally exposed adults (p less than 0.001 - p less than 0.005). Among non-occupationally exposed children the group of the most exposed had significantly elevated average values for A2M and A1AT which were higher than those recorded in groups of "less exposed" and control children (p less than 0.02 and p less than 0.05, respectively). The biomedical importance of these findings is discussed in detail.     

Analysis of chromosomal aberrations in men occupationally exposed to cement dust

Cement industry is considered as a major pollution problem on account of dust and particulate matter emitted at various steps of cement manufacture. Cement dust consists of many toxic constituents. The workers who are employed in cement industries are exposed to cement dust for long periods. Therefore, it is mandatory to evaluate the mutagenic effects of occupational exposure to cement dust in such workers. In the present study, we analyzed the samples of 124 male workers including 59 smokers and 65 non-smokers who were employed in cement industry for a period of 1–17 years. For comparison, 106 controls (including 47 smokers and 59 non-smokers) of the same age group and socio-economic status were also studied. Controls had no exposure to cement dust or any known physical or chemical agent. A significant increase in the incidence of chromosomal aberrations was observed in the exposed group when compared to the control group. The results were analyzed separately for non-smokers and smokers. The chromosomal damage was more pronounced in the smokers when compared with the non-smokers both in control and exposed groups. A significant increase in the frequency of chromosomal aberrations was also observed with increase in age in both control and exposed subjects.     

Analysis of chromosomal aberrations in men occupationally exposed to cement dust

Cement industry is considered as a major pollution problem on account of dust and particulate matter emitted at various steps of cement manufacture. Cement dust consists of many toxic constituents. The workers who are employed in cement industries are exposed to cement dust for long periods. Therefore, it is mandatory to evaluate the mutagenic effects of occupational exposure to cement dust in such workers. In the present study, we analyzed the samples of 124 male workers including 59 smokers and 65 non-smokers who were employed in cement industry for a period of 1-17 years. For comparison, 106 controls (including 47 smokers and 59 non-smokers) of the same age group and socio-economic status were also studied. Controls had no exposure to cement dust or any known physical or chemical agent. A significant increase in the incidence of chromosomal aberrations was observed in the exposed group when compared to the control group. The results were analyzed separately for non-smokers and smokers. The chromosomal damage was more pronounced in the smokers when compared with the non-smokers both in control and exposed groups. A significant increase in the frequency of chromosomal aberrations was also observed with increase in age in both control and exposed subjects.     

Salivary immunoglobulin classes in Nigerian smokers with periodontitis

AIM:To determine the levels of salivary immunoglobulin classes in Nigerian smokers and non-smokers with periodontitis.METHODS:Sixty-nine individuals were recruited into this study after obtaining informed consent.They were subdivided into three groups that consisted of 20(aged 46 ± 11 years) cigarette smokers with periodontitis(S+P);24(40 ± 12 years) smokers without periodontitis(S-P);and 25(53 ± 11 years) non-smokers with periodontitis(NS+P).An oral and maxillofacial surgeon used radiographs for periodontal probing for the diagnosis of periodontitis.The smokers included subjects who smoked at least six cigarettes per day and all the periodontitis patients were newly diagnosed.About 5 mL of unstimulated saliva was expectorated by each subject into plain sample bottles.Salivary immunoglobulin levels were estimated using enzyme linked immunosorbent assay.Student's t test was used to deter-mine significant differences between the means.Values of P 0.05 were regarded as significant.RESULTS:No significant differences were observed in the mean salivary levels of the immunoglobulin classes(IgG,IgA,IgM and IgE) when S+P was compared with S-P.Mean salivary levels of IgA(520.0 ± 155.1 ng/mL vs 670.0 ± 110 ng/mL,P = 0.000) and IgM(644.5 ± 160.0 ng/mL vs 791.4 ± 43.7 ng/mL,P = 0.000) were significantly lower in the S+P compared with NS+P group.Salivary IgA(570.4 ± 145.6 ng/mL vs 670.0 ± 110 ng/mL,P = 0.008) and IgM(703.1 ± 169.3 ng/mL vs 791.4 ± 43.7 ng/mL,P = 0.012) levels were significantly lower in the S-P compared with NS+P group.Only one(5%) periodontal patient had detectable levels of salivary IgE(0.20 IU/mL).Similarly,only one smoker(4.17%) had detectable levels of salivary IgE(0.04 IU/mL) and two non-smokers(9.52%) had detectable levels of IgE(0.24 IU/mL).CONCLUSION:Our study suggests that reduced salivary IgA and IgM levels in smokers with periodontitis could enhance increased susceptibility to periodontitis.     

Immunological profiles in workers occupationally exposed to inorganic mercury.

Forty-one male mercury-exposed workers were examined for the serum concentration levels of immunoglobulins (IgG, IgA, IgM), alpha-1-antitrypsin (A1AT), alpha-2-macroglobulin (A2M), ceruloplasmin (CPL) and orosomucoid (ORO). In the period preceding this investigation the mercury concentrations in workplace air ranged from 0.106 to 0.783 mg.m-3, the range of urinary mercury concentrations was from 0.029 to 0.545 mg.1(-1). All but two (IgG and A1AT) of the immune parameters tested were at the levels that were evidently higher than those found in a control group of 55 workers matched by age who lived in a relatively clean area. The percentage of individuals with no value out of the range of normal physiological limits was in the controls almost 80%, in the exposed 36.6% only. These findings confirm the literature data which show that an inhalation exposure to inorganic mercury may evidently have a stimulating effect on some serum proteins in humans.     

Changes in serum markers indicative of health effects in vineyard workers following exposure to the fungicide mancozeb: an Italian study

The aim of this study was to investigate the health effects induced by exposure to the fungicide mancozeb in Italian vineyard workers. Ninety-three Italian subjects entered the study - 48 vine-growers intermittently exposed to mancozeb and 45 healthy controls. The subjects were investigated three times: before the seasonal application of pesticides (T0), 30 days after the beginning of the application period (T30), and 45 days after T0 (T45). At T0 the comparison between agricultural workers and controls showed a higher prevalence of cold or flu symptoms, a statistically significant lower percentage of monocytes, higher absolute count of T lymphocytes, CD4 and natural killer cells, and lower plasma levels of IgA and IgM in workers. Such differences were not confirmed at T30 and T45. In fact at T30 in exposed workers, besides a significant increase of urinary ethylenethiourea, confirming mancozeb exposure, T lymphocytes, CD4 and natural killer cells, IgA and IgM returned to values comparable to those observed in controls. Moreover, no other differences in clinical signs, haematological, and immune parameters, such as the immune functional capability evaluated as a response to hepatitis B vaccination, was observed. Altogether the differences between exposed and controls were not consistently correlated to any clinical impairment and suggest that the seasonal application of mancozeb does not pose a significant health risk to exposed subjects.     

Assessment of DNA sensitivity in peripheral blood leukocytes after occupational exposure to microwave radiation: the alkaline comet assay and chromatid breakage assay

DNA sensitivity in peripheral blood leukocytes of radar-facility workers daily exposed to microwave radiation and an unexposed control subjects was investigated. The study was carried out on clinically healthy male workers employed on radar equipment and antenna system service within a microwave field of 10 μW/cm²–20 mW/cm² with frequency range of 1,250–1,350 MHz. The control group consisted of subjects of similar age. The evaluation of DNA damage and sensitivity was performed using alkaline comet assay and chromatid breakage assay (bleomycin-sensitivity assay). The levels of DNA damage in exposed subjects determined by alkaline comet assay were increased compared to control group and showed inter-individual variations. After short exposure of cultured lymphocytes to bleomycin cells of subjects occupationally exposed to microwave (MW) radiation responded with high numbers of chromatid breaks. Almost three times higher number of bleomycin-induced chromatid breaks in cultured peripheral blood lymphocytes were determined in comparison with control group. The difference in break per cell (b/c) values recorded between smokers and non-smokers was statistically significant in the exposed group. Regression analyses showed significant positive correlation between the results obtained with two different methods. Considering the correlation coefficients, the number of metaphase with breaks was a better predictor of the comet assay parameters compared to b/c ratio. The best correlation was found between tail moment and number of chromatid with breaks. Our results indicate that MW radiation represents a potential DNA-damaging hazard using the alkaline comet assay and chromatid breakage assay as sensitive biomarkers of individual cancer susceptibility.     

Frequencies of chromosomal aberrations in pesticide sprayers working in plastic green houses.

The frequency of chromosome aberrations was studied in peripheral blood lymphocytes of 29 workers occupationally exposed to a mixture of pesticides and in 14 age- and sex-matched healthy controls. There was a significant increase in chromosome aberrations in sprayers when compared to unexposed persons (2.39% compared to 0.54%). No positive correlation between the frequency of chromosome aberrations and the duration of exposure was observed. No significant difference between smokers and non-smokers was found.     

Seasonal changes in the relationship of blood calcium levels to immunoglobulins and some of the blood proteins in schoolchildren

Blood and saliva were collected in the autumn and spring from a group of schoolchildren (39 girls, 35 boys) with a mean age of 11.4 years. Serum immunoglobulin IgG, IgA, IgM and IgE, alpha 1-antitrypsin (A 1-AT), alpha 2 macroglobulin (A 2M), transferrin (TRF), ceruloplasmin (CPL), lysozyme (LYS) and pertussis (PE) antibody levels were determined. Calcium (Ca2+) and total serum protein levels were also determined. Secretory IgA (sIgA) and secretory lysozyme (sLYS) levels were assessed in the saliva. A highly significant drop in Ca2+ levels was found in the spring in boys, while in girls there was only a greater scatter of the values. Mean IgG, IgA and IgM values fell significantly in the spring in both sexes, but IgE levels fell significantly only in boys. PE levels rose significantly in the spring in girls. Among the other proteins, all the values rose in boys, except for TRF, whose levels fell. In girls, LYS and TRF levels rose, but all the other values fell. The coefficients of correlation between Ca2+ and the tested proteins showed a significant relationship only for A 2M and PE in girls and only for the total protein level in boys; in boys, the determination coefficient for sIgA and IgM was over 10%. The results do not testify to the existence of a close relationship between blood Ca2+ levels and Ig and other blood protein levels.     

Genetic monitoring of aluminum workers exposed to coal tar pitch volatiles

A group of 50 workers exposed to coal tar pitch volatiles (CTPV) in an aluminum reduction plant and a group of 50 non-exposed workers were selected to evaluate the genotoxic effects of CTPV exposure. A battery of tests was performed on 3 different body fluids; urine, blood and semen. Urine samples were evaluated for mutagenic constituents using the Ames/Salmonella assay. Cultured lymphocytes from blood samples were used to perform cytogenetic analysis. Semen samples were used to measure sperm count, percent abnormal sperm morphology and frequency of sperm carrying double fluorescent bodies (2-F). 14 of 28 (50%) exposed workers and 7 of 36 (19.4%) non-exposed workers had mutagenic urine. This difference was significant (p less than 0.01). Among the non-smokers a significantly higher percentage of workers who were exposed had positive urine (36%) compared to the non-exposed workers (5%) (p less than 0.05). Among the exposed group, more mechanics had mutagenic urine than did other types of workers. Overall chromosome aberration rates were similar in both exposed and non-exposed workers. Among exposed workers a significant inverse correlation (p less than 0.05) between age and chromatid aberration rate was observed. Results of semen analysis failed to detect differences between exposed and non-exposed workers. Results of these tests lend support to a battery approach to genetic monitoring and suggest a link between exposure to CTPV and genotoxic effects. Detection of exposure to mutagens at an early time offers an opportunity for disease prevention by the reduction of exposure.     

Nuclear anomalies in the buccal cells of calcite factory workers

The micronucleus (MN) assay on exfoliated buccal cells is a useful and minimally invasive method for monitoring genetic damage in humans. To determine the genotoxic effects of calcite dust that forms during processing, MN assay was carried out in exfoliated buccal cells of 50 (25 smokers and 25 non-smokers) calcite factory workers and 50 (25 smokers and 25 non-smokers) age- and sex-matched control subjects. Frequencies of nuclear abnormalities (NA) other than micronuclei, such as binucleates, karyorrhexis, karyolysis and 'broken eggs', were also evaluated. Micronuclei and the other aforementioned anomalies were analysed by two way analysis of covariance. The linear correlations between the types of micronucleus and nuclear abnormalities were determined by Spearman's Rho. There was a positive correlation between micronuclei and other types of nuclear abnormalities in accordance with the Spearman's Rho test. Results showed statistically significant difference between calcite fabric workers and control groups. MN and NA frequencies in calcite fabric workers were significantly higher than those in control groups (p < 0.05). The results of this study indicate that calcite fabric workers are under risk of significant cytogenetic damage.     

Results of cytogenetic testing of workers exposed to ethylene oxide

The present work was undertaken to test cytogenetically workers exposed to Ethylene oxide (EO) aiming at detecting possible adverse effects of this agent to man. In the period 1983-1984, female workers of the Laboratory of Toxicology and the Production laboratory of ethylene oxide production in a chemical plant, and female workers in a sterilization centers in a medical facilities, were repeatedly examined. In 1984, also workers in ethylene oxide production in a chemical plant were tested. For each exposed group a control group was simultaneously examined, using cytogenetic analysis of peripheral blood lymphocytes. General examination of the health condition of exposed workers were organized in the framework of preventive examinations. The exposure level to ethylene oxide in the working environment was simultaneously monitored. The results have revealed an increase in chromosomal aberrations in lymphocytes of persons exposed professionally to EO at the given exposure levels. Smoking was associated with increased frequency of chromosomal aberrations in exposed workers; the difference as compared to non-smokers was however insignificant. By contrast, difference in chromosomal aberration frequency between smokers and non-smokers was significant in the control group.     

Smoking-reIated DNA adducts and genetic polymorphism for metabolic enzymes in human lymphocytes

Smoking-related aromatic DNA adducts in lymphocytes were measured from smokers (n = 76), ex-smokers (n = 25) and non-smokers (n = 56) by the ³²P-postlabelling method, to clarify whether a genetic polymorphism for metabolic enzymes could explain the inter-individual variation of DNA adduct levels. Adduct levels were compared with respect to smoking status and polymorphic genotypes of cytochrome P4501A1 (CYP1A1) and glutathione S-transferase M1 (GTSM1). The mean adduct level (1.24 per 10⁸ nucleotides) in smokers was significantly higher than that (0.85 per 10⁸) in non-smokers. Although we expected higher adduct levels in the CYP1A1 variant or GSTM1 null subjects, the adduct level in 'GSN1 nulls' was significantly lower than that in 'GSTM1 presents' among smokers. DNA adduct levels had significant positive correlations with smoking indices such as number of cigarettes or smoking years in all subjects. In smokers only, however, no correlation was found, because there were negative correlations between adduct levels and smoking dose in GSTM1 null genotypes. CYP1A1 genotypes had no effects on adduct levels.     

Chromosomal Aberrations (CA), Sister Chromatid Exchanges (SCE), and High-Frequency Cells (HFC) Frequencies in Peripheral Blood Lymphocytes of Tunisian Gasoline Truck Loaders

Gasoline constitutes a mixture of chemicals that contain well-known genotoxicants. Thus, chronic occupational exposure to gasoline may be considered to possess genotoxic risk. In this study, the frequencies of total chromosomal aberrations (TCA), aberrant cells (Ab.c.), sister chromatid exchanges (SCE), high-frequency cells (HFC), and high-frequency cell individual (HFI) were investigated in peripheral blood lymphocytes from 17 gasoline-exposed workers (10 smokers and 7 non-smokers) and 22 unexposed reference subjects (12 smokers and 10 non-smokers). The exposed subjects were gasoline truck loaders at a gasoline company from Tunis City, north of Tunisia. The results indicate multiple CA, such as dicentrics (DIC), chromatid breaks (SB), and chromosome breaks (DB). A significant difference was observed in TCA and Ab.c. frequencies between exposed and unexposed groups (p < 0.01). A significant difference was found in frequencies of SCE (p < 0.01) and HFI (p < 0.05) between exposed and unexposed groups. SCE and TCA frequencies of smokers were found to be significantly higher than those of non-smokers in both groups. There was an interaction between gasoline exposure and smoking habit for TCA (p = 0.020), but not for SCE. Our findings indicate that gasoline truck loaders were under risk of significant cytogenetic damage that was enhanced by their smoking habit.     

Determination of urinary and salivary cotinine using gas and liquid chromatography and enzyme-linked immunosorbent assay

The objective of this study was to compare cotinine concentrations in urine and saliva using gas chromatography (GC), high-performance liquid chromatography (HPLC) and enzyme-linked immunosorbent assay (ELISA). Ninety-four subjects were selected (27 smokers and 67 non-smokers) and interviewed using questionnaire. Of the non-smokers, 39 had been exposed to environmental tobacco smoke (ETS) and 28 had not been exposed to ETS. Cotinine levels among smokers were highest using all three measurements, followed by ETS exposed subjects and non-smokers. Cotinine levels in urine, using HPLC, correlated significantly with levels measured using ELISA (r=0.92) and GC-nitrogen-phosphorus detection (NPD) (r=0.92). Salivary cotinine levels measured using ELISA did not correlate significantly with either HPLC (r=0.37) or GC-NPD (r=0.33) measurements. Multiple regression models were used to adjust for age, gender, drug use and health status, and it was found that cotinine levels in urine and saliva were significantly correlated with smoking pack-year. The authors conclude that urinary cotinine concentration is a more accurate biomarker for ETS than salivary cotinine concentration.     

Aromatic DNA adduct levels in coke oven workers: correlation with polymorphisms in genes GSTP1, GSTM1, GSTT1 and CYP1A1

The aim of this study was to use DNA adducts levels, detected by 32P-postlabelling, as a biomarker to assess human exposure to polycyclic aromatic hydrocarbons (PAHs) from a coke oven plant and explore the possible association between CYP1A1 MspI, GSTP1, GSTM1 and GSTT1 genotypes, and smoking status on bulky DNA adduct formation. A large amount of inter-individual variation in adduct level was observed among workers with the same job and the same smoking habits. No significant differences were observed in DNA adduct levels between the coke oven workers and control group. Smokers in the control group had significantly higher DNA adducts than the non-smokers in the same group (35.13+/-21.11 versus 11.18+/-8.00, per 10(8) nucleotides, P=0.003). In this group, the correlation between the level of DNA adducts and the cigarettes smoked was strongly significant (r=0.70, P<0.0005), but no correlation was found among the coke oven workers. Among non-smokers there was a significant difference between the control group and the coke oven workers (11.18+/-8.00 versus 24.62+/-15.20, per 10(8) nucleotides, P=0.03). These results suggests that tobacco smoke could behave as a confounding factor for evaluation of DNA adducts arising from occupational exposure. The levels of DNA adducts in smokers not occupationally exposed to PAHs is dependent on the polymorphisms CYP1A1 MspI in the 3' non-coding region (49.04+/-22.18 versus 25.85+/-15.87, per 10(8) nucleotides, P<0.05), but no effect was observed for the GST genotypes studied.     

Sister-chromatid exchanges in lymphocytes from styrene-exposed boat builders

Sister-chromatid exchanges (SCE) were measured in peripheral blood lymphocytes from 40 workers in the boat-building trade. Twenty of these workers were exposed to significant amounts of styrene. The mean air concentration of styrene in the breathing zone of the boat builders was 209 mg/m3 in the 7 exposed current smokers and 230 mg/m3 in the 13 exposed non-smokers. Urinary styrene metabolites were also measured and the mean mandelic acid/creatinine ratios in the exposed, smokers was 275 mg/g, and in the exposed, non-smokers 323 mg/g. The SCE frequency in lymphocytes from the styrene-exposed group did not differ from that in the controls, although smoking significantly induced SCE in these workers.