Chromosome Aberrations In Workers Research Articles

Arsenic and Protein Expression: It might help to know the mechanism of As toxicity

Arsenic and Protein Expression: It might help to know the mechanism of As toxicity

Does and duration of exposure time dependent regulation of proteins in the urinary bladder of hamsters exposed to sodium arsenite

Does and duration of exposure time dependent regulation of proteins in the urinary bladder of hamsters exposed to sodium arsenite

Regulation of transgelin and GST-pi proteins in the tissues of hamsters exposed to sodium arsenite

Regulation of transgelin and GST-pi proteins in the tissues of hamsters exposed to sodium arsenite

Polymorphism of TGF-β1, TР53, CHEK2, ATM genes аnd chromosomal aberrations in workers at coal thermal electric power station

Introduction. Working conditions at coal-fired power plants cause an increased risk of the formation of chromosomal damage in workers. The contribution of the variability of the structure of the genes controlling the cell cycle and apoptosis to the occurrence of cytogenetic disorders induced by such mutagens has been little studied. Material and methods. The polymorphic variants of the genes: TP53 (rs1042522), CHEK2 (rs555607708), ATM (rs1801516), TGF-β1 (rs1800469), and the level of chromosomal aberrations (CA) in the lymphocytes of the blood were studied. Three hundred twenty-six workers of coal-fired power plants and 267 individuals who did not work in industrial enterprises were examined. All individuals were Caucasians, residents of Kemerovo (Western Siberia, Russia). Results. The level of CA in blood lymphocytes in thermal power plant workers was established to be statistically significantly higher than that of residents of the same locality who never works in industrial enterprises (3.05 ± 0.09% versus 1.67 ± 0.07%, p = 0, 000001). The prevalence of the polymorphic variants of the TP53 (rs1042522), CHEK2 (rs555607708), ATM (rs1801516), TGF-β1 (rs1800469) genes in the group of workers was the same to those in the comparison group and corresponded to the global data obtained in Caucasians. In the group of workers with the TT genotype of the TGF-β1 gene, the frequency of metaphases with chromosome damage was statistically significantly higher than in individuals with the CC genotype (4.07 ± 0.41% versus 2.85 ± 0.10%, p = 0.006). Discussion. For the first time a significant contribution of polymorphic variants of TGF-β1 genes to the formation of chromosomal damage in working coal-fired power plants was revealed. This may be associated with an increased level of expression of the multifunctional cytokine TGF-β1 in owners of the TT genotype and its ability to influence proliferation, apoptosis, telomerase activity, and other critical cellular processes. Conclusion. The results of the study I, ndicate that not only the complex of industrial genotoxicants, but also individual genetic characteristics of the organism can influence on the formation of cytogenetic disorders in workers at thermal power plants.

Induced mutagenesis in workers in chrysotile production

Studied induced mutation in lymphocytes of peripheral blood and established chromosomal aberrations in workers of chrysotile industry in different aged and experienced groups do not have specific signs.

Chromosome aberrations in workers occupationally exposed to tritium

This paper reports the findings of an historical chromosome analysis for unstable aberrations, undertaken on 34 nuclear workers with monitored exposure to tritium. The mean recorded β-particle dose from tritium was 9.33 mGy (range 0.25–79.71 mGy) and the mean occupational dose from external, mainly γ-ray, irradiation was 1.94 mGy (range 0.00–7.71 mGy). The dicentric frequency of 1.91 ± 0.53 × 10−3 per cell was significantly raised, in comparison with that of 0.61 ± 0.30 × 10−3 per cell for a group of 66 comparable worker controls unexposed to occupational radiation. The frequency of total aberrations was also significantly higher in the tritium workers. Comparisons with in vitro studies indicate that at these dose levels an increase in aberration frequency is not expected. However, the available historical tritium dose records were produced for the purposes of radiological protection and based on a methodology that has since been updated, so tritium doses are subject to considerable uncertainty. It is therefore recommended that, if possible, tritium doses are reassessed using information on historical recording practices in combination with current dosimetry methodology, and that further chromosome studies are undertaken using modern FISH techniques to establish stable aberration frequencies, as these will provide information on a cumulative biological effect.

Role of Gene-Gene Interactions in the Chromosomal Instability in Workers at Coal Thermal Power Plants

The 23 polymorphic variants in genes encoding the enzymes of xenobiotics biotransformation (CYP1A1 (rs4646903), CYP1A2 (rs762551), GSTP1 (rs1138272, rs1695), GSTM1 (del), and GSTT1 (del)), DNA repair (XRCC1 (rs25489, rs25487), APEX1 (rs1130409), hOGG1 (rs1052133), ADPRT (rs1136410), XPD (rs13181), XPG (rs17655), XPC (rs2228001), ATM (rs1801516), NBS (rs1805794), XRCC2 (rs3218536), and XRCC3 (rs861539)), antioxidant system (MnSOD (rs4880) and GPx1 (rs1050450)), cell cycle control and apoptosis (TP53 (rs1042522)), DNA methylation (MTHFR (rs1801133) and MTR (rs1805087)), and chromosomal aberrations in lymphocytes in the workers at thermal power plants were analyzed. We found that allelic variants in the CYP1A1 (rs4646903), hOGG1 (rs1052133), XRCC1 (rs25487), and APEX1 (rs1130409) genes were associated with an increased level of chromosomal aberrations in workers. Informative models of gene-gene interactions including CYP1A1 (rs4646903, T>C), CYP1A2 (rs762551, C>A), GSTT1 (del); XRCC1 (rs25487, G>A), MTHFR (rs1801133, C>T), GSTT1 (del); XRCC1 (rs25487, G>A), APEX1 (rs1130409, T>G), TP53 (rs1042522, G>C) determining the formation of the increased frequency of chromosomal aberrations in the workers at coal thermal power plants were discovered.

Cytogenetic Analysis of Peripheral Blood Lymphocytes of Workers Occupationally Exposed to Benzene in A Fuel Station in Erbil City- Iraq

The objective of the present study was to evaluate genotoxic effects in petrol station workers, who were previously exposed occupationally to benzene in comparison with a selected control group, through inhalation and skin contamination, by using the cytokinesis- blocked micronucleus (CBMN) and chromosomal aberration tests carried on peripheral blood lymphocytes. The study included (35) male petrol station worker and 25 control subjects. Metaphase chromosome preparations were analyzed, chromosome aberrations in peripheral blood lymphocytes, were examined. The results showed that the frequency of cell with aberrations in exposed workers was significantly higher (P≤0.01) than that of control subjects. Most chromosome aberration found in exposed group was acentric fragment, chromosome break, dicentric. Furtheremore, also the frequency of micronucle( MN) was highly significant in benzyne exposed groups as compared with control person (P≤0.01). In conclusion significant excess of chromosomal aberrations in workers who exposed occupationally to benzene, where compare to the matched controls.

MFISH analysis of chromosome aberrations in workers occupationally exposed to mixed radiation

We performed a study on the presence of chromosome aberrations in a cohort of plutonium workers of the Mayak production association (PA) with a mean age of 73.3 ± 7.2 years to see whether by multi-color fluorescence in situ hybridization (mFISH) translocation analysis can discriminate individuals who underwent occupational exposure with internal and/or external exposure to ionizing radiation 40 years ago. All Mayak PA workers were occupationally exposed to chronic internal alpha-radiation due to incorporated plutonium-239 and/or to external gamma-rays. First, we obtained the translocation yield in control individuals by mFISH to chromosome spreads of age-matched individuals and obtained background values that are similar to previously published values of an international study (Sigurdson et al. in Mutat Res 652:112-121, 2008). Workers who had absorbed a total dose of >0.5 Gy external gamma-rays to the red bone marrow (RBM) displayed a significantly higher frequency of stable chromosome aberrations relative to a group of workers exposed to <0.5 Gy gamma-rays total absorbed RBM dose. Thus, the translocation frequency may be considered to be a biological marker of external radiation exposure even years after the exposure. In a group of workers who were internally exposed and had incorporated plutonium-239 at a body burden >1.48 kBq, mFISH revealed a considerable number of cells with complex chromosomal rearrangements. Linear associations were observed for translocation yield with the absorbed RBM dose from external gamma-rays as well as for complex chromosomal rearrangements with the plutonium-239 body burden.

Chromosome aberrations in workers of beach sand mineral industries

Beach Sand Mining (BSM) is a profitable industry earning a sizable income for the country by way of foreign exchange. The Indian coast is rich in rare earths such as ilmenite, rutile, leucoxene, zircon, garnet and sillimanite, and is invariably associated with radioactive monazite. Due to the nature of the separation processes involved and the manual handling, workers in these factories are continuously being exposed to suspended particles containing naturally occurring radioactive materials. An attempt was made to estimate DNA damage using a chromosome aberration assay to monitor radiation effects in workers of BSM industries in India. The study group comprised 27 BSM workers and 20 controls. Percentage yields of dicentrics, acentric fragments and chromatid breaks observed in the control group were 0.058 ± 0.017, 0.073 ± 0.03 and 0.22 ± 0.112, respectively. Percentage yields of dicentrics + centric rings, acentric fragments and chromatid breaks observed in the BSM group were 0.029 ± 0.01 (P value 0.19), 0.24 ± 0.06 (P value 0.006) and 0.455 ± 0.06 (P value 0.0004), respectively. Elevated levels of fragments and chromatid aberrations are suggestive of low-dose radiation effects and also chemically-induced DNA damage.

Chromosome aberrations in workers exposed to organic solvents: Influence of polymorphisms in xenobiotic-metabolism and DNA repair genes

Organic solvents are widely used as diluents or thinners for oil-paints, gasoline and other organic mixtures. We evaluated chromosome aberrations (CAs) in lymphocytes of 200 workers exposed to organic solvents and 200 referents and the influence of polymorphisms in xenobiotic-metabolism (CYP2E1, GSTM1 and GSTT1) and in DNA repair genes (XRCC1 194 Arg/Trp, XRCC1 280 Arg/His, XRCC1 399 Arg/Gln and XRCC3 241 Thr/Met). Polymorphisms were determined by PCR–RFLP. Poisson regression analysis indicates a significant CA frequency increase in exposed workers, representing a higher risk in relation to the matched referent (RR 2.15, 95% CI 1.21–1.53, p < 0.001). The CA frequency in exposed workers was influenced by the polymorphic genotypes: GSTM1 null (RR 1.33, 95% CI 1.31–1.69, p < 0.001), XRCC1 194 Arg/Trp, Trp/Trp (RR 1.23, 95% CI 1.08–1.40, p < 0.001) and by the wild genotypes CYP2E1 C1/C1 (RR 1.20, 95% CI 1.05–1.37, p < 0.001), GSTT1 positive (RR 1.49, 95% CI 1.31–1.69, p < 0.001), XRCC1 280 Arg/Arg (RR 1.44, 95% CI 1.26–1.64, p < 0.001) and XRCC1 241 Thr/Thr (RR 1.54, 95% CI 1.34–1.76, p = 0.001). We contribute to the follow-up predictive value of individual susceptibility biomarkers and their CA frequency influence during occupational organic solvent exposure. We provide tools for surveillance and prevention strategies to reduce potential health risks in countries with a large population of car painters not using protection devices and limited organic solvents use control.

Occupational and environmental risks in and around a smelter in northern Sweden. IV. Chromosomal aberrations in workers exposed to lead.

A significantly increased frequency of chromosomal aberrations was found among lead-exposed workers at the Ronnskar smelter in northern Sweden. The frequency of aberrations showed a correlation with lead exposure as measured by the blood levels of lead. Strong individual variations were found. No synergistic effect of smoking was observed. Correlations were found between (chromosome and chromatid) breaks and gaps, which lends further support to the notion that gaps may be useful as indicators of genotoxic agents.

Occupational and environmental risks in and around a smelter in northern Sweden. VIII. Three-year follow-up of chromosomal aberrations in workers exposed to lead.

Chromosomal aberrations were studied at three different occasions (1976, 1978 and 1979) in ten workers who started to work at a new lead-process (Lead-Kaldo) in 1976. The average blood level of lead showed a significant increase (from 17 to 35μg/100 ml) between 1976 and 1978, followed by a significant decrease (from 35 to 29 μg/ 100 ml) between 1978 and 1979. The frequencies of chromosomal aberrations were found to increase between 1976 and 1979, but the statistical significance of this increase was rather low. In comparison with a reference material of individuals without known occupational exposure to toxic agents, the lead-exposed workers showed a significant increase of chromosomal aberrations in 1979, but not in 1976. Confounding factors, as altered smoking habits and simultaneous exposure to other toxic agents, were discussed, and it was concluded that variations in the frequency of chromosomal aberrations can not with certainty be ascribed to changes in lead exposure.

Occupational and environmental risks in and around a smelter in northern Sweden. VII. Reanalysis and follow-up of chromosomal aberrations in workers exposed to arsenic.

A reanalysis of data on chromosomal aberrations among 33 copper smelter workers exposed to arsenic revealed no significant variations due to age, smoking habits or degree of arsenic exposure although the observed deviations were in the expected direction. The arsenic exposed workers showed, however, significantly increased frequencies of chromosomal aberrations when compared with referents without known occupational exposure to genotoxic agents. Eight workers were studied at three different occasions, viz. 1976, 1978 and 1979. The levels of urinary arsenic decreased significantly between 1976 and 1978. There was also a significant decrease of chromosomal aberrations between 1976 and 1978 when group data were analysed. Two individuals showed a significant decrease of breaks with time. One of them had changed from full time to half time work in 1977. Thus, in the follow-up study there is some evidence that decreased exposure leads to a lowered frequency of aberrations.

DETERMINaTION OF CHROMOSOME ABERRATIONS IN WORKERS IN A PETROLEUM REFINING FACTORY

Human exposure to benzene is derived occupationally from the petrochemical and petroleum refining industries. This study was performed to determine whether the frequencies of chromosome aberrations in workers exposed to low levels of benzene in a petroleum refining factory were elevated compared to an unexposed control group. The study population was comprised of 178 exposed workers and 36 unexposed workers. The frequencies of chromatid deletions and total chromosome aberrations in workers exposed to benzene were significantly higher compared to the unexposed control group. The frequency of total chromosome aberration was 4.20 per 500 metaphase cells in the exposed workers, whereas the frequency was 2.24 per 500 metaphase cells in the unexposed control group. The frequencies of total chromosome aberrations were significantly associated with benzene concentration after adjusting for confounding variables such as age, smoking status, and alcohol intake. The frequencies of chromosome aberrations were significantly increased in workers with low white blood cell counts (below 4000 cells/mm3) compared to those with high white blood cell counts (above 4000 cells/mm3). A reduced white blood cell count (below 4000/mm3) is suggestive of chronic exposure to benzene. In conclusion chronic benzene exposure and preclinical signs, such as reduced white blood cell counts, may be monitored by chromosome aberrations analysis.

Chromosomal aberrations in workers exposed to low levels of benzene: association with genetic polymorphisms.

Benzene and its metabolites damage human lymphocytes, resulting in chromosomal aberrations and aneuploidy. Polymorphisms in the genes for benzene-metabolizing enzymes have been implicated in benzene-associated haematotoxicity. In this study, we examined the specificity of benzene-induced aneuploidy and the influence of genetic polymorphisms (GSTM1, GSTT1, GSTP1, NAT2, NQO1 and CYP2E1) on chromosomal aberrations. In total, 82 benzene-exposed workers from a coke oven plant and 76 matched controls were examined. The benzene concentration in the work-place air ranged from 0.014-0.743 p.p.m. (geometric mean 0.557 p.p.m.). Benzene exposure was associated with significant increases in both monosomy and trisomy of chromosomes 8 and 21. Translocations between chromosomes 8 and 21 [t(8:21)] were eight-fold more frequent in the high-level exposure group compared to the control group. Multiple regression analysis indicated that the frequencies of chromosome aberrations were significantly associated with benzene exposure and polymorphisms in the metabolic enzyme genes. A particular subset of genotypes, which included the GSTM1-null and GSTT1-null genotypes, the slow acetylator type of NAT2, a variant of the NQO1 genotype and the CYP2E1 DraI and RsaI genotypes, were either separately, or in combination, associated with increased frequencies of aneuploidy among the benzene-exposed individuals after adjustments for age, alcohol consumption and smoking. These results suggest that polymorphisms in the genes for benzene-metabolizing enzymes influence the susceptibility of individuals to chromosomal aberrations in relation to benzene exposure.

Chromosome aberrations in workers of nuclear-power plants

The frequencies of chromosome aberrations in 135 workers from nuclear-power plants were compared with those in 135 age-matched controls. A total of 135,000 cells was scored. The frequencies of dicentric chromosome were 1.67 × 10 −3 in the exposed group and 0.49 × 10 −3 in the control group and those of chromosome-type deletion were 3.33 × 10 −3 and 1.10 × 10 −3, respectively. The frequencies of all types of chromosome aberrations in the exposed subjects were higher than those in the control group, but no significant trend of dose-dependent increase was observed when only the exposed group were considered. Poisson regression analysis, with both exposed and control included, showed that there was a significant association of chromosome aberration with radiation dose and the duration of work, but not with age, smoking habit and alcohol intake. It was also found that recent exposure to radiation, within the last 5 years, had contributed more to the observed chromosome aberration than earlier exposure.

No increase in chromosome aberrations in workers from an oil catalytic cracking plant

A study of structural chromosome aberration frequencies in blood lymphocytes was performed in a group of 20 oil catalytic cracking unit workers and in 26 subjects belonging to the office staff of an oil refining plant, as well as in 35 matched controls. Subjects in the latter group were of the same sex (males) and similar age as the exposed group, and had similar smoking habits. Benzo[ a]pyrene levels in workplace air samples were also determined. The cytogenetic analysis failed to show any differences between the exposed and control groups. A slight increase in benzo[ a]pyrene level above the Cuban national standard of 1 ng/m 3 was found during the air sample analysis in the oil catalytic cracking unit.

Enhanced frequency of chromosome aberrations in workers occupationally exposed to diagnostic X-rays

To estimate the level of radiation exposure of personnel handling diagnostic X-ray machines, the yield of chromosomal aberrations was analysed in peripheral blood lymphocyte cultures. These occupationally exposed individuals showed higher frequencies of dicentrics as well as acentrics than normal controls. Absorbed radiation doses calculated by extrapolating reference in vitro dose-response curve for dicentrics ranged between 0.13 and 0.17 Gy. This implies exposure beyond the permissible limit of 0.05 Gy/year for the whole body. However, no obvious trend of increased aberrations as a function of either duration of employment or age was noticed. The increase in the aberration yields in this personnel underscores the need of adopting measures to avoid or minimise such overexposure.

Analysis of chromosomal aberrations in workers exposed to low level benzene.

Metaphase chromosome preparations were analysed as part of a larger study from a population occupationally exposed to benzene and compared with a control group. Forty eight of the 66 exposed individuals and 29 of the 33 controls had samples in which metaphase spreads could be evaluated. The incidence of chromosomal aberrations (particularly chromatid deletions and gaps) in the exposed group were slightly increased compared with the control group. This increase was of borderline significance in parametric statistical tests but was significant using Fisher's exact test. No lifestyle factors had any consistent effect on the incidence of chromosome aberrations, although there was a small reduction in gaps with increasing cigarette smoking. Older individuals had a higher incidence of chromosome exchanges and "other" aberrations. Individuals who reported a recent viral illness had a higher incidence of aberrations particularly gaps. There was no evidence of any correlation in the incidence of chromosome aberrations with any of the other biological parameters previously reported. The increased incidence of aberrations seen in the group exposed to benzene may result from a history of exposure to benzene. Nevertheless, other explanations such as sampling, interindividual variability, and unintentional bias in the selection of two groups cannot be excluded.