Asbestos Cement Plant Research Articles

Полиморфизм генов репарации ДНК при бронхолегочной патологии у работников вредных и опасных отраслей промышленности

Introduction. Polymorphism of DNA repair genes is actively studied in the formation of the individual sensitivity of the genome to damaging mutagenic effects. Objective of the work. To study the distribution of frequencies of alleles and genotypes of DNA repair genes: XPD (rs13181, rs799793) and ERCC1 (rs11615) in workers of asbestos-cement plants and miners to identify risk markers for bronchopulmonary pathology. Material and methods. The study included workers of asbestos-cement plants and miners (n=214). Real-time polymerase chain reaction was used to determine genotypes of XPD (rs13181, rs799793) and ERCC1 (rs11615) genes. Results. The study determined alleles and genotypes associated with the risk of developing bronchopulmonary pathology: - in the population of workers of asbestos-cement plants: XPD*Asn/Asn (rs799793), (p<0.01; χ2=6.62; OR=2,20; 95 %CI: 1,75–2,77); - in the population of miners: XPD*C (rs13181), (p<0.02; χ2=4,99; OR=1,88; 95 %CI: 1,04–3,40); XPD*CC (rs13181), (p<0,003; χ2=8.61; OR=4,29; 95 %CI: 1,41–13,37). The study also detected allele XPD*A (rs13181), which in the population of miners proved to be a marker of resistance to bronchopulmonary pathology (p<0,02; χ2=4.99; OR=0,53; 95 %CI: 0,29–0,96). Conclusions. The study has identified alleles and genotypes associated with the risk of developing bronchopulmonary pathology in the population of workers in harmful and dangerous production facilities of Ukraine. The study has determined the genotype and allele that can be used as biomarkers of resistance to the pathology of the respiratory system. Key words: molecular-genetic markers, XPD and ERCC1, bronchopulmonary pathology.

Аллельный полиморфизм генов репарации ДНК и вероятность развития бронхолегочной патологии у шахтёров и работников асбестоцементных заводов Украины

Аллельный полиморфизм генов репарации ДНК и вероятность развития бронхолегочной патологии у шахтёров и работников асбестоцементных заводов Украины

SENTIERI-ReNaM Project: Malignant mesothelioma incidence in Italian Contaminated Sites

Introduction: One of the aims of the SENTIERI-ReNaM Project is to identify excess risks of malignant mesothelioma in National Priority Contaminated Sites and to discuss the results by means of data on individual case histories available from the Italian National Mesothelioma Register (ReNaM). Methods: Incident cases of mesothelioma and Standardized Incidence Ratios (SIRs), with corresponding 95% confidence intervals, have been estimated in 39 sites for both gender, in the period 2000-2011. Age-standardized rates of Italian geographical macro-areas (North-Eastern, North-Western, Centre, South-Islands) have been used to estimate expected cases. For each analyzed site the occupational and non-occupational asbestos exposure modalities are discussed. Results: An excess of mesothelioma incidence is confirmed in sites with a known past history of direct use of asbestos, such as Balangero (chrysotile mine) for men (SIR=197.11, 95% CI: 82.04-473.56), Casale Monferrato (asbestos-cement plant) for men and women (SIR=910.70, 95% CI: 816.45-1012.84 and SIR=1338.1, 95%CI: 1176.7-1515.4), Broni (asbestos-cement plant) for men and women (SIR=1288.52, 95%CI: 981.86-1690.97 and SIR=2006.7, 95%CI: 1488.3-2705.8), and in coastal areas (shipyards and harbours) (e.g. Trieste, La Spezia, Venice and Leghorn). A significant excess of mesothelioma has been observed in settings without documented direct use of asbestos, such as Cengio and Saliceto in the North, Falconara Marittima in the Centre, and the Litorale Domizio Flegreo and Agro Aversano in Southern Italy. Conclusion: The analysis of occupational risk in geographical studies with an ecological design is essential to attribute a weight to etiological factors. The evaluation of environmental risk for people living in polluted areas, considering also the risk for workers, and the assessment of a risk produced by industrial settlements, are feasible through the use of data available from surveillance systems of occupational tumors.

Pleural mesothelioma risk associated with environmental asbestos exposure in Casale Monferrato (Italy) area: a case control study

Introduction. The area of Casale Monferrato (north west Italy) is affected by high levels of environmental asbestos pollution from an Eternit asbestos cement (AC) plant active from 1906 to 1986. We...

Two cases of asbestosis and one case of rounded atelectasis due to non-occupational asbestos exposure

Asbestos is a well-known cause of several neoplastic (malignant mesothelioma, lung cancer) and non-neoplastic (asbestosis, pleuropathies) occupational diseases. Lower-level exposure in the general environment may induce pleural plaques and thickenings, and is associated with an increased mesothelioma risk. We present two patients (a 68-year-old man and a 72-year-old woman) who developed asbestosis (in association with pleural plaques and calcifications), and a 78-year-old man who developed rounded atelectasis (with pleural plaques and benign effusion), after living for several decades in the proximity of large Italian asbestos-cement plant. None of them had been exposed to asbestos occupationally. Besides living in a contaminated area, the woman used to clean the work clothes of her brother, who was employed in the local asbestos factory. The three cases indicate that non-neoplastic, long-latency asbestos-related diseases which are usually observed as a consequence of occupational exposures, may rarely develop in subjects living in contaminated geographical sites and buildings. These unusual environmental diseases raise the diagnostic problem of differentiating them from other, more common respiratory illnesses, and impose the duties of patient notification, assessment and follow-up, to assess the possibility of progression of disease and increased neoplastic risk.

Epidemiological patterns of asbestos exposure and spatial clusters of incident cases of malignant mesothelioma from the Italian national registry.

BackgroundPrevious ecological spatial studies of malignant mesothelioma cases, mostly based on mortality data, lack reliable data on individual exposure to asbestos, thus failing to assess the contribution of different occupational and environmental sources in the determination of risk excess in specific areas. This study aims to identify territorial clusters of malignant mesothelioma through a Bayesian spatial analysis and to characterize them by the integrated use of asbestos exposure information retrieved from the Italian national mesothelioma registry (ReNaM).MethodsIn the period 1993 to 2008, 15,322 incident cases of all-site malignant mesothelioma were recorded and 11,852 occupational, residential and familial histories were obtained by individual interviews. Observed cases were assigned to the municipality of residence at the time of diagnosis and compared to those expected based on the age-specific rates of the respective geographical area. A spatial cluster analysis was performed for each area applying a Bayesian hierarchical model. Information about modalities and economic sectors of asbestos exposure was analyzed for each cluster.ResultsThirty-two clusters of malignant mesothelioma were identified and characterized using the exposure data. Asbestos cement manufacturing industries and shipbuilding and repair facilities represented the main sources of asbestos exposure, but a major contribution to asbestos exposure was also provided by sectors with no direct use of asbestos, such as non-asbestos textile industries, metal engineering and construction. A high proportion of cases with environmental exposure was found in clusters where asbestos cement plants were located or a natural source of asbestos (or asbestos-like) fibers was identifiable. Differences in type and sources of exposure can also explain the varying percentage of cases occurring in women among clusters.ConclusionsOur study demonstrates shared exposure patterns in territorial clusters of malignant mesothelioma due to single or multiple industrial sources, with major implications for public health policies, health surveillance, compensation procedures and site remediation programs.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-015-1301-2) contains supplementary material, which is available to authorized users.

Continued Spirometry Changes After Cessation of Exposure in Asbestos-Cement Workers

To assess further progression of spirometry parameters among former asbestos-cement plant workers. The following parameters were assessed: forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and the ratio (FEV1/FVC) using a linear regression model with mixed effects. The analysis included 3005 individuals. Spirometrically defined restrictive ventilatory defects were registered in 21.6% of the patients, obstructive defects in 8.3%, whereas mixed changes in 7%. Current smokers had significantly lower levels of FEV1, FVC, and FEV1/FVC and a steeper decline compared with nonsmokers. More rapid progression was also observed along with increasing termination of exposure. Having higher exposure was associated with a slower decline in FEV1 and FEV1/FVC ratios. This report indicates that asbestos-cement workers with higher cumulative exposure still had lower mean levels of spirometric parameters, despite cessation of asbestos exposure many years ago.

Mesothelioma incidence in the neighbourhood of an asbestos-cement plant located in a national priority contaminated site.

An epidemic of asbestos-related disease is ongoing in most industrialized countries, mainly attributable to past occupational exposure but partly due to environmental exposure. In this perspective, the incidence of pleural mesothelioma close to a former asbestos-cement plant in a national contaminated site was estimated. The census-tracts interested by atmospheric dispersion of facilities in the contaminated site were identified. Two subareas with different estimated environmental asbestos impact were distinguished. An ecological study at micro-geographic level was performed. The standardized incidence ratios (SIR) for study area and the two subareas, in comparison with region and municipality were computed. The standardized incidence rate ratio (IRR) between the two subareas was computed. Mesothelioma incidence in the study area was increased: 46 cases were observed with respect to 22.23 expected (SIR: 2.02). The increase was confirmed in analysis considering only the subjects without an occupationally exposure to asbestos: 19 cases among men (SIR = 2.48; 95% CI: 1.49-3.88); 11 case among women (SIR = 1.34; 95% CI: 0.67-2.40). The IRR between the two subareas is less than one in overall population considering all age-classes and of 3 fold (IRR = 3.14, 95% CI: 0.65-9.17) in the age-classes below 55 years. The findings indicate an increased incidence of pleural mesothelioma in the neighbourhood of asbestos-cement plant, and a possible etiological contribution of asbestos environmental exposure in detected risks.

Assessment of airborne asbestos exposure at an asbestos cement sheet and pipe factory in Iran

Iran imports nearly 55,000 metric tons of asbestos per year, and asbestos cement (AC) plants contribute nearly 94% of the total national usage. In the present study, asbestos fiber concentrations during AC sheet and pipe manufacturing were measured by phase-contrast microscopy (PCM) and polarized light microscopy (PLM) in 98 personal air samples. The fiber type and its chemical composition were also evaluated by scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX). Personal monitoring of fiber levels indicated a range from 0.02 to 0.55 PCM f/ml (0.02–0.69 PLM f/ml). The AC workers’ geometric mean asbestos exposure was 0.09 PCM f/ml (0.11 PLM f/ml), with arithmetic mean of 0.13 PCM f/ml (0.16 PLM f/ml). The observed fiber concentrations in many processes were higher than the threshold limit value (TLV) proposed by the American Conference of Governmental Industrial Hygienists (ACGIH), which is 0.1 f/ml. Based on these findings, the PLM values were approximately 25% higher than PCM values. The SEM data demonstrate that fibrous particles contained chrysotile. The thinnest fiber recognized by SEM had a diameter of 0.2 μm. Mean exposure exceeded the TLV for asbestos in pipe molding and finishing (100%) as well as sheet molding and finishing (45.5–83.3%). In conclusion exposure control may be needed to be in compliance with the ACGIH TLV and other guidance levels. Also, with regard to PCM limitations for airborne fiber analysis, the use of microscopic methods other than PCM can be used to improve the techniques used presently.

Mortality study in an asbestos cement factory in Naples, Italy.

The objective of this paper is to investigate mortality among 1247 male asbestos-cement workers employed in an asbestos-cement plant located in Naples. The cohort included 1247 men hired between 1950 and 1986. The follow-up began on January 1st 1965. The vital status and causes of death were ascertained up to December 31 2005. Cause-specific mortality rates of the Campania Region population were used as reference. Relative risks were estimated using Standardized Mortality Ratios (SMRs), and the confidence intervals were calculated at a 95% level (95% CI). A significant increase in mortality was observed for respiratory disease (81 deaths; SMR = 187; 95% CI = 149- 233), particularly for pneumoconiosis (42 deaths; SMR = 13 313; 95% CI = 9595-17 996) of which 41 deaths for asbestosis (SMR = 43 385; 95% CI = 31 134-58 857), for pleural cancer (24 deaths; SMR = 2617; 95% CI = 1677-3893), for lung cancer (84 deaths; SMR=153; 95% CI = 122-189) and for peritoneal cancer (9 deaths; SMR = 1985; 95% CI = 908-3769). Non-significant increases were also observed for rectum cancer (6 deaths; SMR = 157; 95% CI = 58-342). In conclusion, consistently with other mortality studies on asbestos-cement workers performed in different countries, an increased mortality from asbestosis, lung cancer, pleural and peritoneal mesothelioma was detected in the present cohort.

Evaluation of exposure to the airborne asbestos in an asbestos cement sheet manufacturing industry in Iran

Iran imports nearly 55,000 tons of Chrysotile asbestos per year and asbestos cement (AC) plants contribute nearly 94% of the total national usage. In the present study, airborne asbestos concentrations during AC sheet manufacturing were measured. The fiber type and its chemical composition were also evaluated by scanning electron microscopy (SEM), with energy-dispersive X-ray analysis. Airborne total fiber concentrations of 45 personal samples were analyzed by phase contrast microscopy. The results have highlighted that 15.5% of samples exceed the threshold limit value (TLV) established the American Conference of Governmental Industrial Hygienists, which is 0.1 fiber per milliliter (f/ml). Personal monitoring of asbestos fiber levels indicated a ranged from 0.02 ± 0.01 to 0.16 ± 0.03 f/ml. The geometrical mean was 0.05 ± 1.36 f/ml, which is considerably lower than the TLV. SEM data demonstrate that the fibrous particles consisted, approximately, of Chrysotile (55.89%) and amphiboles (44.11%). We conclude that the industrial consumption of imported Chrysotile asbestos is responsible for the high airborne amphibole asbestos levels in the AC sheet industry. More research is needed to improve characterization of occupational exposures by fiber size and concentration in a variety of industries.

Asbestos fiber concentration in the area surrounding a former asbestos cement plant and excess mesothelioma deaths in residents

Many persons who had lived near a former asbestos cement plant (AC plant) died from mesothelioma in Amagasaki city, Japan. Asbestos fiber concentration in the area surrounding the AC plant was estimated so that the female mesothelioma death number predicted by a mathematical model was the same as the observed excess death number. We used the estimated asbestos fiber concentration to predict the excess mesothelioma deaths from 1970 to 2049. In a grid just south of the AC plant, the fiber concentration was estimated to be more than 3 f/ml for K(M) (asbestos potency factor for mesothelioma) of 7.75 x 10(-9). An uncertainty factor of five yields a K(M) range 1.55 x 10(-9) to 38.8 x 10(-9); these in turn correspond to fiber concentrations of 15 and 0.6 f/ml. For K(M) = 7.75 x 10(-9), grid units with higher fiber concentrations than 0.01 f/ml were estimated to extend 4.1 km (95% CI: 3.8-4.4 km) south-southwest of the plant. Over the 80-year study period (1970 to 2049), we predicted that the exposure under study will cause 346 excess mesothelioma deaths with range of 296 to 382 deaths. This prediction suggests that considerable medical resources will be needed through 2049 as a result of past asbestos exposure in this region.

Occupational characteristics of respiratory cancer patients exposed to asbestos in Lithuania

Objective: To assess characteristics of asbestos exposure in respiratory cancer patients in Lithuania. Methods. Information on occupational exposure to asbestos was collected by personal interviews and occupational characteristics were evaluated among 183 lung cancer and mesothelioma patients with cumulative asbestos exposure ⩾0.01 fibre years hospitalized at the Institute of Oncology, Vilnius. Additionally, some results of workplace air measurements were reviewed. Results. Cases with estimated cumulative exposure ⩾5 fibre years had worked mainly in the construction industry (49%), installation and maintenance (13%), foundry and metal products manufacturing (6%), heating trades and boilerhouses (6%) as fitters/maintenance technicians, construction workers, welders, electricians or foremen. Typical asbestos materials used by the patients were asbestos powder, asbestos cement sheets and pipes, asbestos cord, brake and clutch linings. Patients were exposed to asbestos when insulating boilers, furnaces, pipes in power stations, industrial facilities, ships, locomotives, buildings, while covering and repairing roofs, at the asbestos cement plant or unloading asbestos products. Most patients with estimated cumulative exposure of ⩾0.01-4.9 fibre years worked as lorry, bus or tractor drivers and motor vehicle mechanics. In 2002-2007 workplace air asbestos concentrations exceeded the limit value of 0.1 f/cm3 in 11 samples out of 208 measurements. Conclusion. The results of this study indicate that since the 1960s occupational exposure to chrysotile asbestos was extensive in Lithuania.

Mortality from Occupational Exposure to Relatively Pure Chrysotile: A 39-Year Study

Background: Asbestos exposure is related to serious adverse health effects. However, there is disagreement about the relationship between chrysotile exposure and mesothelioma or lung cancer. Objectives: Our aim was to investigate the mortality rate among workers exposed to relatively pure chrysotile in an asbestos cement factory. Patients and Methods: In an asbestos cement plant opened in 1968, we prospectively studied all 317 workers. A quantity of 2,000 tons of chrysotile, with minimal amphibole contamination, was used annually until 1 January 2005. Asbestos fiber concentration was measured regularly. Date and cause of death were recorded among active and retired workers. Results: Asbestos fiber concentration was always below permissible levels. Fifty-two workers died during the study. The cause was cancer in 28 subjects; lung cancer was diagnosed in 16 of them. No case of mesothelioma was reported. Death was attributed to cardiovascular diseases in 23 subjects and to liver cirrhosis in 1. Overall mortality rate was significantly lower than that of the Greek general population, standardized mortality ratio (SMR) was 0.71 (95% CI 0.53–0.93). Mortality due to cancer was increased (SMR 1.15, 95% CI 0.77–1.67), mainly due to lung cancer mortality (SMR 1.71, 95% CI 0.98–2.78), but not significantly. Conclusions: Occupational exposure to relatively pure chrysotile within permissible levels was not associated with a significant increase in lung cancer or with mesothelioma. Decreased overall mortality of workers indicates a healthy worker effect, which – together with the relatively small cohort size – could have prevented small risks to be detected.

The relationship between malignant mesothelioma and an asbestos cement plant environmental risk: a spatial case–control study in the city of Bari (Italy)

To estimate the mesothelioma risk and environmental asbestos exposure (EAE) due to an asbestos-cement plant. A spatial case-control study including 48 malignant mesothelioma (MM) cases occurred in the period 1993-2003 selected from the regional mesothelioma register (RMR) and 273 controls. The disease risk was estimated by means of a logistic-regression model, in which the probability of disease-occurrence is expressed as a function of the classes of distances. A non-parametric method was applied to estimate the full relative risk surface. Significant MM odds ratio of 5.29 (95 CI: 1.18-23.74) was found for people living within a range up to 500 m centered on the plant. The non-parametric estimation of relative risk surface unveiled a marked peak near the plant not paralleled by the spatial distribution of controls. Evidence of an association between mesothelioma risk and EAE is highlighted. The role played by the RMR in increasing the public health local authorities awareness is stressed.

Sensitivity analysis of the relationship between disease occurrence and distance from a putative source of pollution

The relation between disease risk and a point source of pollution is usually investigated using distance from the source as a proxy of exposure. The analysis may be based on case-control data or on aggregated data. The definition of the function relating risk of disease and distance is critical, both in a classical and in a Bayesian framework, because the likelihood is usually very flat, even with large amounts of data. In this paper we investigate how the specification of the function relating risk of disease with distance from the source and of the prior distributions on the parameters of the function affects the results when case-control data and Bayesian methods are used. We consider different popular parametric models for the risk distance function in a Bayesian approach, comparing estimates with those derived by maximum likelihood. As an example we have analyzed the relationship between a putative source of environmental pollution (an asbestos cement plant) and the occurrence of pleural malignant mesothelioma in the area of Casale Monferrato (Italy) in 1987-1993. Risk of pleural malignant mesothelioma turns out to be strongly related to distance from the asbestos cement plant. However, as the models appeared to be sensitive to modeling choices, we suggest that any analysis of disease risk around a putative source should be integrated with a careful sensitivity analysis and possibly with prior knowledge. The choice of prior distribution is extremely important and should be based on epidemiological considerations.

Lung function predicts survival in a cohort of asbestos cement workers

To study the predictive power of respiratory screening examinations a cohort of asbestos workers was followed from active work in an asbestos cement plant until death. From a cohort with data on individual exposure since first employment 309 workers who had a preventive medical examination in 1989/1990 were observed until death or the end of 2006. The impact of asbestos exposure (fibre years) and of smoking history on lung function was examined by linear regression, on specific causes of death and total mortality by Cox regression. The prognostic value of lung function, chest X-ray, and various clinical findings regarding total mortality was also examined by Cox regression. Lung function proved to be the best predictor of survival apart from current smoking. Depending on the lung function variable an impairment by the interquartile range resulted in a hazard ratio of 1.5-1.6 while for current smokers it was 2.3. An increase of 70 fibre years (interquartile range) led to a hazard ratio of only 1.1. Lung function was influenced by asbestos exposure, current (but not former) smoking, and by pathological X-ray findings. The risk for pleural mesothelioma was dominated by time since first exposure to crocydolite in the pipe factory while the risk for bronchial cancer increased with smoking and total fibre years. An unexpected finding was an increase of gastric cancer in asbestos cement workers. Lung function decrease predicts risk of premature death better than exposure history and regular spirometry should therefore be offered as primary screening to all former asbestos workers. In workers with a history of high cumulative exposure or rapid lung function decrease or radiological signs (diffuse pleural thickening or small irregular opacities) more sensitive techniques (high resolution computer tomography) need to be applied. All smokers with a history of asbestos exposure should be given free smoking cessation therapy to prevent premature death and lung cancer in particular.

Modeling Mesothelioma Risk Associated with Environmental Asbestos Exposure

BackgroundEnvironmental asbestos pollution can cause malignant mesothelioma, but few studies have involved dose–response analyses with detailed information on occupational, domestic, and environmental exposures.ObjectivesIn the present study, we examined the spatial variation of mesothelioma risk in an area with high levels of asbestos pollution from an industrial plant, adjusting for occupational and domestic exposures.MethodsThis population-based case–control study included 103 incident cases of mesothelioma and 272 controls in 1987–1993 in the area around Casale Monferrato, Italy, where an important asbestos cement plant had been active for decades. Information collected included lifelong occupational and residential histories. Mesothelioma risk was estimated through logistic regression and a mixed additive–multiplicative model in which an additive scale was assumed for the risk associated with both residential distance from the plant and occupational exposures. The adjusted excess risk gradient by residential distance was modeled as an exponential decay with a threshold.ResultsResidents at the location of the asbestos cement factory had a relative risk for mesothelioma of 10.5 [95% confidence interval (CI), 3.8–50.1), adjusted for occupational and domestic exposures. Risk decreased rapidly with increasing distance from the factory, but at 10-km the risk was still 60% of its value at the source. The relative risk for occupational exposure was 6.0 (95% CI, 2.9–13.0), but this increased to 27.5 (95% CI, 7.8–153.4) when adjusted for residential distance.ConclusionsThis study provides strong evidence that asbestos pollution from an industrial source greatly increases mesothelioma risk. Furthermore, relative risks from occupational exposure were underestimated and were markedly increased when adjusted for residential distance.

A Case Control Study of Lung Cancer and Exposure to Chrysotile and Amphibole at a Slovenian Asbestos-Cement Plant

A lung cancer case-control study was conducted in a Slovenian asbestos-cement factory for which unusually good records of asbestos exposures were available. The cohort consisted of all 6714 workers employed at the Salonit Anhovo factory after 31 December 1946 who worked there for at least one day between 1964 and 1994. Fifty-eight histologically confirmed cases of primary lung cancer and 290 controls were selected from the cohort. Working life exposure histories to amphibole and chrysotile forms of asbestos were estimated separately. Airborne asbestos concentrations were low. For example, the arithmetic mean exposure to all forms of asbestos in the highest exposure period (1947-1971) was 1.2 f/cm(3). Chrysotile asbestos made up about 90% of this exposure (mean 1.1 f/cm(3)), whereas amphibole accounted for 10% (0.1 f/cm(3)). Comparing those above and below the 90 percentile of cumulative exposure, the odds ratios for all asbestos, chrysotile and amphibole were 1.5, 1.6 and 2.0, respectively, but confidence intervals were wide. There are only a few asbestos-lung cancer studies with high-quality exposure data and exposures in this low range. Though imprecise, the findings are important to the ongoing debate about asbestos risks.

Genotoxic effects of asbestos in humans

Risks of carcinogenic and non-carcinogenic effects from asbestos continue owing to the persistence of the fibres in building materials and other products. For this reason, epidemiological and mechanistic research on the toxic effects of asbestos and mineral fibres is still needed. The present molecular epidemiological study was conducted in a former asbestos cement plant in Slovakia. Altogether 82 subjects were investigated, 61 exposed subjects (24 smokers and 37 non-smokers), and 21 factory controls (8 smokers and 13 non-smokers). Workers were exposed to asbestos for between 5 and 40 years. Though the exposure to asbestos during past 40 years was relatively high, at the time of sampling the concentrations of asbestos in the production hall exceeded the Slovak occupational limit (0.001 fibre/cm 3) by a factor of only 3–5. The office area levels were below this limit. Biomarkers of exposure, effect and individual susceptibility were measured, including DNA damage (strand breaks [SBs], base oxidation and alkylation, using the comet assay); cytogenetic parameters; and individual DNA repair capacity (incision at 8-oxoguanine measured using a modified comet assay). Oxidised pyrimidines were significantly higher in exposed men compared with non-exposed ( P = 0.04). There was also a positive association between SBs ( P = 0.04) and age, and alkylation damage to DNA ( P = 0.04) and age. Moreover, oxidised pyrimidines ( P = 0.01) and alkylated bases ( P = 0.001) strongly correlated with years of occupational exposure. Micronucleus frequency did not differ between exposed and control subjects. Repair capacity overall did not show any effect of exposure, though female controls had higher incision rates than did female exposed subjects. However, exposed asbestos workers had significantly higher numbers of chromosomal aberrations ( P = 0.01) compared with control group. This finding is consistent with the known association of chromosome aberrations with cancer-risk.