[show abstract][hide abstract] ABSTRACT: Studies suggest that ambient sunlight plays an important role in the pathogenesis of non-melanoma skin cancers (NMSC). However, there is ongoing controversy regarding the relevance of occupational exposure to natural and artificial ultraviolet radiation (UV) radiation.
We investigated potential associations between natural and artificial UV radiation exposure at work with NMSC in a case-control study conducted in Hungary, Romania, and Slovakia.
Occupational exposures were classified by expert assessment for 527 controls and 618 NMSC cases (515 basal cell carcinoma, BCC). Covariate information was collected via interview and multiple logistic regression models were used to assess associations between UV exposure and NMSC.
Lifetime prevalence of occupational exposure in the participants was 13% for natural UV radiation and 7% for artificial UV radiation. Significant negative associations between occupational exposure to natural UV radiation and NMSC were detected for all who had ever been exposed (odds ratio (OR) 0.47, 95% confidence interval (CI) 0.27-0.80); similar results were detected using a semi-quantitative metric of cumulative exposure. The effects were modified by skin complexion, with significantly decreased risks of BCC among participants with light skin complexion. No associations were observed in relation to occupational artificial UV radiation exposure.
The protective effect of occupational exposure to natural UV radiation was unexpected, but limited to light-skinned people, suggesting adequate sun-protection behaviors. Further investigations focusing on variations in the individual genetic susceptibility and potential interactions with environmental and other relevant factors are planned.
PLoS ONE 01/2013; 8(4):e62359. · 3.73 Impact Factor
[show abstract][hide abstract] ABSTRACT: OBJECTIVES: We describe the elaboration and sensitivity analyses of a quantitative job-exposure matrix (SYN-JEM) for respirable crystalline silica (RCS). The aim was to gain insight into the robustness of the SYN-JEM RCS estimates based on critical decisions taken in the elaboration process. METHODS: SYN-JEM for RCS exposure consists of three axes (job, region, and year) based on estimates derived from a previously developed statistical model. To elaborate SYN-JEM, several decisions were taken: i.e. the application of (i) a single time trend; (ii) region-specific adjustments in RCS exposure; and (iii) a prior job-specific exposure level (by the semi-quantitative DOM-JEM), with an override of 0 mg/m (3) for jobs a priori defined as non-exposed. Furthermore, we assumed that exposure levels reached a ceiling in 1960 and remained constant prior to this date. We applied SYN-JEM to the occupational histories of subjects from a large international pooled community-based case-control study. Cumulative exposure levels derived with SYN-JEM were compared with those from alternative models, described by Pearson correlation ( (Rp) ) and differences in unit of exposure (mg/m (3) -year). Alternative models concerned changes in application of job- and region-specific estimates and exposure ceiling, and omitting the a priori exposure ranking. RESULTS: Cumulative exposure levels for the study subjects ranged from 0.01 to 60 mg/m (3) -years, with a median of 1.76 mg/m (3) -years. Exposure levels derived from SYN-JEM and alternative models were overall highly correlated (R (p) > 0.90), although somewhat lower when omitting the region estimate ( (Rp) = 0.80) or not taking into account the assigned semi-quantitative exposure level (R (p) = 0.65). Modification of the time trend (i.e. exposure ceiling at 1950 or 1970, or assuming a decline before 1960) caused the largest changes in absolute exposure levels (26-33% difference), but without changing the relative ranking ( (Rp) = 0.99). CONCLUSIONS: Exposure estimates derived from SYN-JEM appeared to be plausible compared with (historical) levels described in the literature. Decisions taken in the development of SYN-JEM did not critically change the cumulative exposure levels. The influence of region-specific estimates needs to be explored in future risk analyses.
Annals of Occupational Hygiene 07/2012; · 2.16 Impact Factor
[show abstract][hide abstract] ABSTRACT: Occupation as a welder has been associated with a 25%-40% increase in lung cancer risk. This study aims to elucidate to what extent confounding by smoking and asbestos drives this association and to evaluate the role of welding-related exposures such as chromium. The study included 2,197 male incident lung cancer cases and 2,295 controls from Romania, Hungary, Poland, Russia, Slovakia, the Czech Republic, and the United Kingdom from 1998 to 2001. Information on risk factors was collected through face-to-face interviews. Experts assessed exposure to 70 agents, and risk estimates were adjusted for smoking and occupational exposures. Occupation as a welder/flame cutter (prevalence controls: 3.7%) was associated with an odds ratio of 1.36 (95% confidence interval (CI): 1.00, 1.86) after adjustment for smoking and occupational exposures including asbestos. An odds ratio of 1.18 (95% CI: 1.01, 1.38) was found for welding fumes (prevalence controls: 22.8%), increasing to 1.38 for more than 25 exposure years (95% CI: 1.09, 1.75). A duration-response association was also observed for mild steel welding without chromium exposure. In this population, occupational exposure to welding fumes accounted for approximately 4% of lung cancer cases, to which both stainless and mild steel welding contributed equally. Given that welding remains a common task for many workers, exposure to welding fumes represents an important risk factor for lung cancer.
American journal of epidemiology 02/2012; 175(7):706-14. · 5.59 Impact Factor
[show abstract][hide abstract] ABSTRACT: SYNERGY is a large pooled analysis of case-control studies on the joint effects of occupational carcinogens and smoking in the development of lung cancer. A quantitative job-exposure matrix (JEM) will be developed to assign exposures to five major lung carcinogens [asbestos, chromium, nickel, polycyclic aromatic hydrocarbons (PAH), and respirable crystalline silica (RCS)]. We assembled an exposure database, called ExpoSYN, to enable such a quantitative exposure assessment.
Existing exposure databases were identified and European and Canadian research institutes were approached to identify pertinent exposure measurement data. Results of individual air measurements were entered anonymized according to a standardized protocol.
The ExpoSYN database currently includes 356 551 measurements from 19 countries. In total, 140 666 personal and 215 885 stationary data points were available. Measurements were distributed over the five agents as follows: RCS (42%), asbestos (20%), chromium (16%), nickel (15%), and PAH (7%). The measurement data cover the time period from 1951 to present. However, only a small portion of measurements (1.4%) were performed prior to 1975. The major contributing countries for personal measurements were Germany (32%), UK (22%), France (14%), and Norway and Canada (both 11%).
ExpoSYN is a unique occupational exposure database with measurements from 18 European countries and Canada covering a time period of >50 years. This database will be used to develop a country-, job-, and time period-specific quantitative JEM. This JEM will enable data-driven quantitative exposure assessment in a multinational pooled analysis of community-based lung cancer case-control studies.
Annals of Occupational Hygiene 01/2012; 56(1):70-9. · 2.16 Impact Factor
[show abstract][hide abstract] ABSTRACT: To estimate the lung cancer risk attributable to occupational lung carcinogens.
Information was collected through interviews from 2624 newly diagnosed lung cancer cases and 2690 frequency-matched controls in Central and Eastern Europe. Industrial hygiene experts evaluated exposure to 70 occupational agents. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using unconditional logistic regression and attributable fractions (AF) by Miettinen's formula.
Exposure to at least one occupational lung carcinogen resulted in an AF of 7.9% in men and 1.4% in women. Metals and silica contributed the most to the AF. The AF was highest for squamous cell carcinoma among men (11.4%) and for small cell carcinoma among women (7.1%); the effect of occupational lung carcinogens was stronger overall among current smokers.
This estimation of the AF of occupational lung carcinogens is comparable to that estimated in other European studies, and cannot alone explain the high lung cancer rates in Central and Eastern Europe.
Journal of occupational and environmental medicine / American College of Occupational and Environmental Medicine 11/2011; 53(11):1262-7. · 1.88 Impact Factor
[show abstract][hide abstract] ABSTRACT: We describe an empirical model for exposure to respirable crystalline silica (RCS) to create a quantitative job-exposure matrix (JEM) for community-based studies. Personal measurements of exposure to RCS from Europe and Canada were obtained for exposure modelling. A mixed-effects model was elaborated, with region/country and job titles as random effect terms. The fixed effect terms included year of measurement, measurement strategy (representative or worst-case), sampling duration (minutes) and a priori exposure intensity rating for each job from an independently developed JEM (none, low, high). 23,640 personal RCS exposure measurements, covering a time period from 1976 to 2009, were available for modelling. The model indicated an overall downward time trend in RCS exposure levels of -6% per year. Exposure levels were higher in the UK and Canada, and lower in Northern Europe and Germany. Worst-case sampling was associated with higher reported exposure levels and an increase in sampling duration was associated with lower reported exposure levels. Highest predicted RCS exposure levels in the reference year (1998) were for chimney bricklayers (geometric mean 0.11 mg m(-3)), monument carvers and other stone cutters and carvers (0.10 mg m(-3)). The resulting model enables us to predict time-, job-, and region/country-specific exposure levels of RCS. These predictions will be used in the SYNERGY study, an ongoing pooled multinational community-based case-control study on lung cancer.
Journal of Environmental Monitoring 11/2011; 13(11):3262-8. · 2.09 Impact Factor
[show abstract][hide abstract] ABSTRACT: To study the association between occupational exposure to metals including chromium, cadmium, nickel, and arsenic compounds, within a population-based study design, while adjusting for confounding factors.
A population-based lung cancer case-control study in Central/Eastern Europe and UK was conducted in 1998-2003, including 2,853 cases and 3,104 controls. Exposure to 70 occupational agents was assessed by local expert-teams for all subjects. Odds ratios (OR) for exposure to dust and fumes/mist of chromium, nickel, cadmium, arsenic, as well as inorganic pigment dust and inorganic acid mist, were adjusting for smoking, age, center, sex, and exposure to other occupational agents including the metals under study.
Exposure to arsenic (prevalence = 1.4%) was associated with an increased lung cancer risk ((OR) 1.65, 95% confidence interval (95% CI):1.05-2.58). For chromium dust (prevalence = 4.8%, OR: 1.25, 95% CI: 0.95-1.65), a linear upward trend for duration and cumulative exposure was observed. A weak association was observed for exposure to cadmium fumes (prevalence = 1.8%, OR: 1.19, 95% CI: 0.77-1.82), which was strongest for the highest category of cumulative exposure (OR: 2.04, 95% CI: 1.07-3.90). No increased risk was observed for inorganic acid mist, inorganic pigment dust, or nickel, after adjustment for other metals. An independent effect of nickel cannot be excluded, due to its collinearity with chromium exposure.
Occupational exposure to metals is an important risk factor for lung cancer. Although the strongest risk was observed for arsenic, exposure to chromium dust was most important in terms of attributable risk due to its high prevalence.
Cancer Causes and Control 09/2011; 22(12):1669-80. · 3.20 Impact Factor
[show abstract][hide abstract] ABSTRACT: In New Zealand, there is a need for a comprehensive and accessible database with national occupational exposure information, such as a general population job-exposure matrix (GPJEM). However, few New Zealand-specific exposure data exist that could be used to construct such a GPJEM. Here, we present the methods used to develop a GPJEM for New Zealand (NZJEM), by combining GPJEMs from other countries with New Zealand-specific exposure information, using wood dust as an example to illustrate this process. The assessments of GPJEMs from other countries were made available to a New Zealand expert in occupational wood dust exposure, who then provided a preliminary NZJEM assessment (including the percentage exposed and the level of exposure for each occupation). Where possible, this assessment was based on New Zealand exposure measurements. In the next step, information from a nationwide workplace exposure survey of 3000 members of the New Zealand workforce was used to finalize the NZJEM assessments. The final NZJEM listed 104 of the 956 New Zealand occupational codes as exposed to wood dust. The percentage of workers exposed within an occupation ranged from 5% (e.g. boiler attendants) to 100% (e.g. cabinet makers). The level of exposure ranged from 0.05 mg m(-3) (e.g. electricians) to 3 mg m(-3) (e.g. carpenters). Of these assessments, 23% were mainly based on New Zealand exposure data, 37% on overseas GPJEMs and exposure data, and for 40% the national survey data served as the main source of information for the expert assessment. Combining the NZJEM assessments with national employment statistics indicated that 5.6% of the New Zealand workforce is occupationally exposed to wood dust, corresponding to a total of 97 000 workers (86% male and 14% female). Construction-related occupations included the largest number of exposed workers.
Annals of Occupational Hygiene 07/2011; 55(8):879-85. · 2.16 Impact Factor
[show abstract][hide abstract] ABSTRACT: Lung cancer incidence in Central and Eastern Europe (CEE) is among the highest in the world, and the role of occupational exposures has not been adequately studied in these countries.
To investigate the contribution of occupational exposure to polycyclic aromatic hydrocarbons (PAH) to lung cancer in CEE.
A case-control study was conducted in the Czech Republic, Hungary, Poland, Romania, Russia and Slovakia, as well as the United Kingdom (UK) between 1998 and 2002. Occupational and socio-demographic information was collected through interviews from 2861 newly diagnosed lung cancer cases and 2936 population or hospital controls. Industrial hygiene experts in each country evaluated exposure to 70 occupational agents, whereof 15 mixtures containing PAH. ORs of lung cancer were calculated after adjusting for other occupational exposures and tobacco smoking.
The OR for ever exposure to PAH in the CEE countries was 0.93 (95% CI 0.77 to 1.14). The ORs for the highest category of cumulative exposure, duration of exposure and intensity of exposure were 1.13 (95% CI 0.80 to 1.58), 1.02 (95% CI 0.66 to 1.57) and 1.11 (95% CI 0.60 to 2.05), respectively. The OR for ever PAH exposure in the UK was 1.97 (95% CI 1.16 to 3.35).
Occupational PAH exposure does not appear to substantially contribute to the burden of lung cancer in CEE. The apparently stronger effect observed in the UK may be due to high exposure levels and a joint effect with asbestos.
Occupational and environmental medicine 09/2009; 67(2):98-103. · 3.64 Impact Factor
[show abstract][hide abstract] ABSTRACT: We sought to evaluate the role of occupation and industry in lung carcinogenesis in six countries in Central and Eastern Europe.
This multi-center case-control study included 2,056 male and 576 female lung cancer incidence cases diagnosed from 1998 to 2001 and 2,144 male and 727 female controls frequency-matched for sex and age. Unconditional regression models were applied to calculate the odds ratios after controlling for potential confounders including age (5-year groups), study center (15 centers), and tobacco pack-years.
Elevated odds ratios (ORs) were found for men employed as production workers (OR 1.45, 95% CI 1.22-1.72), bookkeepers and cashiers (1.81, 1.03-3.24), general farmers (1.67, 1.08-2.60), livestock workers (2.54, 1.09-5.88), miners (2.17, 1.47-3.23), toolmakers and metal patternmakers (2.56, 1.34-4.94), glass formers (2.55, 1.18-5.50), dockworkers, and freight handlers (1.49, 1.04-2.12). Industries with elevated risk among men included mining (1.75, 1.20-2.57), manufacture of cement, lime, or plaster (3.62, 1.11-12.00), casting of metals (2.00, 1.17-3.45), manufacture of electric motors (2.18, 1.24-3.86). For women, elevated ORs were found for medical, dental, veterinary doctors (2.54, 1.01-6.31), librarians and curators (7.03, 1.80-27.80), sewers 3.63 (1.12-10.23).
This study identifies new areas for further, explanatory analyses, especially in production work, and indicates new possible sources of exposure to cancer risk for women.
Cancer Causes and Control 09/2007; 18(6):645-54. · 3.20 Impact Factor
[show abstract][hide abstract] ABSTRACT: To investigate the contribution of occupational exposure to asbestos and man-made vitreous fibres (MMVF) to lung cancer in high-risk populations in Europe.
A multicentre case-control study was conducted in six Central and Eastern European countries and the UK, during the period 1998-2002. Comprehensive occupational and sociodemographic information was collected from 2205 newly diagnosed male lung cancer cases and 2305 frequency matched controls. Odds ratios (OR) of lung cancer were calculated after adjusting for other relevant occupational exposures and tobacco smoking.
The OR for asbestos exposure was 0.92 (95% CI 0.73 to 1.15) in Central and Eastern Europe and 1.85 (95% CI 1.07 to 3.21) in the UK. Similar ORs were found for exposure to amphibole asbestos. The OR for MMVF exposure was 1.23 (95% CI 0.88 to 1.71) with no evidence of heterogeneity by country. No synergistic effect either between asbestos and MMVF or between any of them and smoking was found.
In this large community-based study occupational exposure to asbestos and MMVF does not appear to contribute to the lung cancer burden in men in Central and Eastern Europe. In contrast, in the UK the authors found an increased risk of lung cancer following exposure to asbestos. Differences in fibre type and circumstances of exposure may explain these results.
Occupational and environmental medicine 09/2007; 64(8):502-8. · 3.64 Impact Factor
[show abstract][hide abstract] ABSTRACT: The role of crystalline silica dust as a possible cause of lung cancer has been controversial. Relatively few large community-based studies have been conducted to investigate the lung cancer risk from exposure to silica at low levels, taking into account potential confounding factors.
Detailed lifestyle and occupational information were collected from 2852 newly diagnosed cases of lung cancer and 3104 controls between 1998 and 2002 in 7 European countries. For each job held, local experts assessed the probability, intensity, and duration of silica exposure.
Occupational exposure to crystalline silica was associated with an increased risk of lung cancer (odds ratio = 1.37; 95% confidence interval = 1.14-1.65). This risk was most apparent for the upper tertile of cumulative exposure (OR = 2.08; 95% CI = 1.49-2.90; P for trend <0.0001), duration of exposure (1.73; 1.26-2.39; P for trend = 0.0001) and weighted duration of exposure (1.88; 1.35-2.61; P for trend <0.0001). We did not observe any interaction beyond a multiplicative model between tobacco smoking and silica exposure.
Our results support the hypothesis that silica is an important risk factor for lung cancer. This risk could not be explained by exposure to other occupational carcinogens or smoking, and it was present for the main histologic types of lung cancer, different sources of silica exposure, and different industrial settings.
[show abstract][hide abstract] ABSTRACT: Tobacco smoking is the main cause for lung cancer worldwide, making it difficult to examine the carcinogenic role of other risk factors because of possible confounding by smoking. Therefore, the present study aimed to investigate the association between lung cancer and occupation independent of smoking.
A case-control study of lung cancer was carried out between March 1998 and January 2002 in 16 centers from 7 European countries, including 223 never-smoking cases and 1039 controls. Information on lifestyle and occupation was obtained through detailed questionnaires. Job and industries were classified as entailing exposure to known or suspected carcinogens; in addition, expert assessment provided exposure estimates to specific agents.
The odds ratio of lung cancer among women employed for more than 12 years in suspected high-risk occupations was 1.75 (95% confidence interval = 0.63-4.85). A comparable increase in risk was not detected for employment in established high-risk occupations or among men. Increased risk of lung cancer was suggested among individuals exposed to nonferrous metal dust and fumes, crystalline silica, and organic solvents.
Occupations were found to play a limited role in lung cancer risk among never-smokers. Jobs entailing exposure to suspected lung carcinogens should receive priority in future studies among women. Nonferrous metal dust and fumes and silica may exert a carcinogenic effect independently from smoking.
[show abstract][hide abstract] ABSTRACT: An increased risk of lung cancer has been reported for butchers and meat workers in several cohort studies, although confounding from tobacco smoking could not be ruled out in any of these studies. These exposures, as well as a potential risk associated with contact with live animals, are addressed here in a large case-control study with full adjustment for smoking. More than 5,900 subjects were included in a case-control study conducted in 7 European countries. For each job they employed local experts who assessed the exposure to a number of occupational agents, including (i) meat aerosols and (ii) live animals, on the basis of detailed occupational questionnaires. Information on tobacco consumption and other risk factors was also collected. A small increased risk of lung cancer was observed with exposure to meat aerosols, after adjusting for smoking, (odds ratio (OR)=1.27, 95% confidence interval (CI): 0.92, 1.75), which was most apparent for the upper tertile of cumulative exposure (OR=1.73, 95% CI: 1.03, 2.92). A similar overall effect was observed for exposure to live animals, with an increased risk observed for a high frequency of exposure, (OR=1.69, 95% CI: 1.21, 2.36) and a high intensity of exposure, (OR=1.85, 95% CI: 1.16, 2.94), with significant trends for increasing frequency (p=0.012), intensity (p=0.015) and cumulative exposure (p=0.024). In conclusion, this study provides evidence for an association between exposure to meat aerosols and lung cancer apparent in the highest tertile of exposure. The authors identified a more consistent association with exposure to live animals.
International Journal of Cancer 06/2006; 118(10):2543-7. · 6.20 Impact Factor
[show abstract][hide abstract] ABSTRACT: Occupational X-ray examination programs have been conducted in many countries to screen for occupational and nonoccupational respiratory diseases, resulting in widespread exposure to X-radiation. We conducted a multicentre case-control study of lung cancer in the Czech Republic, Hungary, Poland, Romania, Russia and Slovakia, including 2,589 cases and 2,859 controls enrolled during 1998-2002. We collected detailed information on occupational X-ray examinations, occupations and tobacco smoking. We calculated odds ratios of lung cancer via multiple logistic regression after adjustment for age, sex, center and tobacco smoking. Among controls 24.9% reported no X-ray examination, 62.9% reported 1-30 examinations and 12.2% reported more than 30 examinations. When we chose individuals with no examination as the reference group, the odds ratios of lung cancer were 1.21 (95% confidence interval [CI] 0.99-1.48), 1.33 (95% CI 1.08-1.64), 1.49 (95% CI 1.18-1.87), 1.52 (95% CI 1.17-1.99) and 2.15 (95% CI 1.50-3.08) for 1-10, 11-20, 21-30, 31-40 and more than 40 examinations, respectively (p-value of test for linear trend <0.0001). The association between X-ray examinations and lung cancer risk was strong in countries with low prevalence of exposure and absent in countries with high prevalence of exposure. Odds ratios for X-ray examinations were lower among smokers than among nonsmokers. The magnitude of the increased risk observed is higher than expected on the basis of other studies of radiation-exposed populations. Although the association we detected between X-ray examinations and lung cancer risk may reflect a carcinogenic effect of repeated exposure to low-level ionizing radiation, reporting bias and particularly uncontrolled confounding by occupational exposure to carcinogens are also likely explanations of the results.
International Journal of Cancer 07/2005; 115(2):263-7. · 6.20 Impact Factor
[show abstract][hide abstract] ABSTRACT: Several industry-based cohort studies have addressed the risk of lung cancer following exposure to vinyl chloride, acrylonitrile and styrene, with inconsistent results and usually without smoking adjustment. These exposures are addressed here in a large case-control study with full adjustment for smoking. Almost 6000 subjects were included in a case-control study conducted in seven European countries. For each job they held, local experts assessed the exposure to a number of occupational agents, including vinyl chloride, acrylonitrile and styrene, on the basis of detailed occupational questionnaires. Information on tobacco consumption and other risk factors was also collected. The odds ratio (OR) for ever exposure to vinyl chloride was 1.05 (95% confidence interval, CI: 0.68-1.62) and a modest, non-significant increase in the risk of lung cancer was found in the highest exposed subgroup. The OR for ever exposure to acrylonitrile was 2.20 (95% CI: 1.11-4.36) with a positive dose-response relationship between estimated cumulative exposure and lung cancer risk. No association between exposure to styrene and lung cancer risk was found. In conclusion, we cannot exclude a weak association between occupational exposure to vinyl chloride and lung cancer risk. Exposure to acrylonitrile was associated in our study with risk of lung cancer. Exposure to styrene does not seem to increase lung cancer risk.
Cancer Causes and Control 07/2004; 15(5):445-52. · 3.20 Impact Factor
[show abstract][hide abstract] ABSTRACT: In a multicenter case-control study of lung cancer in central and eastern Europe and in Liverpool, exposure to occupational agents was assessed by teams of local experts. We performed an interteam agreement study to estimate the levels of exposure misclassification and the expected attenuation of the risk estimate.
Eight teams of experts and a reference rater assessed exposure to 70 putative lung carcinogens for 19 jobs. Agreement among teams was calculated through Cohen's kappa, sensitivity, and specificity.
Each team showed an overall fair to good agreement with the reference (kappa between 0.53 and 0.64). The agreement among teams in the presence of exposure was excellent for 9 agents, fair to good for 16, and poor for 29. For all agents the specificity was high (average 0.94), although sensitivity varied considerably.
This study of expert exposure assessment showed a small range in reliability among teams of experts, but large differences among agents. This paper presents the range in levels of misclassification that can be expected using experts for assessing occupational exposure to different agents, and the attenuation of the odds ratio that can be expected to result from this misclassification.