[Show abstract][Hide abstract] ABSTRACT: . In a French large population-based case-control study we investigated the dose-response relationship between lung cancer and occupational exposure to diesel motor exhaust (DME), taking into account asbestos exposure.
. Exposure to DME was assessed by questionnaire. Asbestos was taken into account through a global indicator of exposure to occupational carcinogens or by a specific JEM.
. We found a crude dose response relationship with most of the indicators of DME exposure, including with the cumulative exposure index. All results were affected by adjustment for asbestos exposure. The dose response relationships between DME and lung cancer were observed among subjects never exposed to asbestos.
. Exposure to DME and to asbestos is frequently found among the same subjects, which may explain why dose-response relationships in previous studies that adjusted for asbestos exposure were inconsistent.
Full-text · Article · Oct 2015 · Journal of Cancer Epidemiology
[Show abstract][Hide abstract] ABSTRACT: Objective:
The objective of the study was to investigate the joint effect of occupational exposure to asbestos, and tobacco and alcohol consumption, on the risk of laryngeal cancer among men.
We used data from a large population-based case-control study conducted in France. We estimated two-way and three-way interactions between asbestos exposure (never vs ever exposed), tobacco consumption (<20 vs ≥20 pack-years) and alcohol consumption (<5 vs ≥5 drinks per day). The interaction on an additive scale was assessed by estimating the relative excess risk due to interaction (RERI) and the attributable proportion due to interaction, and the interaction on a multiplicative scale was assessed by estimating the multiplicative interaction parameter (ψ). Multiplicative interactions were also assessed using fractional polynomials for alcohol drinking, tobacco smoking and asbestos exposure.
When compared with light-to-moderate smokers and drinkers never exposed to asbestos, the increase in laryngeal cancer risk was smallest among light-to-moderate drinkers and smokers exposed to asbestos (OR=2.23 (1.08 to 4.60)), and highest among heavy smokers and drinkers ever exposed to asbestos (OR=69.39 (35.54 to 135.5)). We found an additive joint effect between asbestos exposure and alcohol consumption (RERI=4.75 (-4.29 to 11.12)), whereas we observed a more than additive joint effect between asbestos exposure and tobacco consumption (RERI=8.50 (0.71 to 23.81)), as well as between asbestos exposure, and tobacco and alcohol consumption (RERI=26.57 (11.52 to 67.88)). However, our results did not suggest any interaction on a multiplicative scale.
Our results suggest that asbestos exposure, in combination with tobacco and alcohol exposure, accounted for a substantial number of laryngeal cancer cases. Our findings therefore highlight the need for prevention in activities, such as construction work, where exposure to asbestos-containing materials remains.
No preview · Article · Sep 2015 · Occupational and environmental medicine
[Show abstract][Hide abstract] ABSTRACT: We assessed whether maternal employment during pregnancy - overall and in selected occupational sectors - is associated with birth weight, small for gestational age (SGA), term low birth weight (LBW), length of gestation, and preterm delivery in a population-based birth cohort design.
We used data from >200 000 mother-child pairs enrolled in 13 European birth cohorts and compared employed versus non-employed women. Among employees, we defined groups of occupations representing the main sectors of employment for women where potential reproductive hazards are considered to be present. The comparison group comprised all other employed women not included in the occupational sector being assessed. We performed meta-analyses of cohort-specific estimates and explored heterogeneity.
Employees had a lower risk of preterm delivery than non-employees [adjusted odds ratio (OR adj) 0.86, 95% confidence interval (95% CI) 0.81-0.91]. Working in most of the occupational sectors studied was not associated with adverse birth outcomes. Being employed as a nurse was associated with lower risk SGA infants (OR adj0.91, 95% CI 0.84-0.99) whereas food industry workers had an increased risk of preterm delivery (OR adj1.50, 95% CI 1.12-2.02). There was little evidence for heterogeneity between cohorts.
This study suggests that, overall, employment during pregnancy is associated with a reduction in the risk of preterm birth and that work in certain occupations may affect pregnancy outcomes. This exploratory study provides an important platform on which to base further prospective studies focused on the potential consequences of maternal occupational exposures during pregnancy on child development.
Full-text · Article · May 2015 · Scandinavian Journal of Work, Environment & Health
[Show abstract][Hide abstract] ABSTRACT: Objectives We aimed to investigate the role of occupational exposure to chlorinated solvents in the aetiology of lung cancer.
Method ICARE is a multicenter population-based case-control study conducted in France between 2001 and 2006. Information on subjects lifelong work history was collected by face to face interviews using standardised questionnaires. Occupational exposures were assessed using job-exposure matrices (JEM) relative to five chlorinated solvents including trichloroethylene (TCE), methylene chloride, perchloroethylene (PER), chloroform and carbon tetrachloride. Solvents were studied separately and since overlapping among exposures analyses for combined solvents exposure were performed. In the questionnaire, subjects also had to report if they were exposed to TCE or other substances (PER was among them). Odds ratios (ORs) were computed using unconditional logistic regression models adjusted for classical risk factors.
Results A total of 2926 cases (2276 men and 650 women) and 3555 controls (2780 men and 775 women) were included. A statistically significant positive association for lung cancer risk was observed in both men (OR 1.47, 95% CI: 1.00–2.17) and in women (OR 3.86, 95% CI: 1.36 -11.01) exposed to PER combined with TCE and/or methylene chloride. In contrast, no statistically significant associations were found for TCE or other solvent combinations. Finally for subjects, who reported the exposure to PER, the ORs were 3.25 (95% CI: 1.23, 8.59) and 3.12 (95% CI: 0.50, 19.28) among men and women respectively.
Conclusions The results of this study suggest that PER alone or in combination with TCE and/or methylene chloride may increase the risk of lung cancer.
No preview · Article · Jun 2014 · Occupational and Environmental Medicine
[Show abstract][Hide abstract] ABSTRACT: To describe the performance of a lifelong task-based questionnaire (TBQ) in estimating exposures compared with other approaches in the context of a case-control study.
A sample of 93 subjects was randomly selected from a lung cancer case-control study corresponding to 497 jobs. For each job, exposure assessments for asbestos and polycyclic aromatic hydrocarbons (PAHs) were obtained by expertise (TBQ expertise) and by algorithm using the TBQ (TBQ algorithm) as well as by expert appraisals based on all available occupational data (REFERENCE expertise) considered to be the gold standard. Additionally, a Job Exposure Matrix (JEM)-based evaluation for asbestos was also obtained. On the 497 jobs, the various evaluations were contrasted using Cohen's κ coefficient of agreement. Additionally, on the total case-control population, the asbestos dose-response relationship based on the TBQ algorithm was compared with the JEM-based assessment.
Regarding asbestos, the TBQ-exposure estimates agreed well with the REFERENCE estimate (TBQ expertise: level-weighted κ (lwk)=0.68; TBQ algorithm: lwk=0.61) but less so with the JEM estimate (TBQ expertise: lwk=0.31; TBQ algorithm: lwk=0.26). Regarding PAHs, the agreements between REFERENCE expertise and TBQ were less good (TBQ expertise: lwk=0.43; TBQ algorithm: lwk=0.36). In the case-control study analysis, the dose-response relationship between lung cancer and cumulative asbestos based on the JEM is less steep than with the TBQ-algorithm exposure assessment and statistically non-significant.
Asbestos-exposure estimates based on the TBQ were consistent with the REFERENCE expertise and yielded a steeper dose-response relationship than the JEM. For PAHs, results were less clear.
No preview · Article · Sep 2013 · Occupational and environmental medicine
[Show abstract][Hide abstract] ABSTRACT: To investigate the associations between occupations and head and neck (HN) cancer risk in men.
ICARE is a French population-based case-control study on HN cancer. Analyses included 1833 cases and 2747 controls. Complete occupational history was collected. Odds ratios (ORs) were estimated for occupations and industries ever held and according to duration of employment.
Elevated ORs, increasing with duration of employment, were observed for several occupations, including cleaners (OR = 1.7; 95% confidence interval [CI], 1.0 to 2.8), launderers (OR = 6.8; CI, 1.3 to 34.4), firefighters (OR = 3.9; CI, 1.4 to 11.2), several agricultural occupations, welders (OR = 1.9; CI, 1.3 to 2.8), structural metal preparers and erectors (OR = 2.1; CI, 1.2 to 3.7), rubber workers (OR = 2.0; CI, 1.0 to 3.9), several construction occupations, and material-handling equipment operators (OR = 1.8; CI, 1.1 to 2.9). Analyses by industry corroborated these findings.
These results confirmed the role of occupational exposures in HN cancer.
Full-text · Article · Aug 2013 · Journal of occupational and environmental medicine / American College of Occupational and Environmental Medicine
[Show abstract][Hide abstract] ABSTRACT: In 2003, a cluster of renal cell carcinoma (RCC) cases was reported among men working at a French chemical plant using a proprietary process to produce vitamin A. The 10 index cases yielded a standardised incidence ratio of 13.1 for 1994-2002. Nine of these 10 cases were diagnosed by a plant-specific abdominal ultrasonography screening programme that targeted exposure to an intermediate chemical, 4-chloro-1,1-dimethoxy-3-methyl-2-butene, commonly named 'chloracetal C5', suspected as the cause by some experts. Epidemiological investigations sought to examine the relations between occupational exposures and RCC.
A retrospective cohort mortality study and a nested case-control study were conducted. The cohort study included all workers who had been employed at the plant for at least 6 months between 1960 and 2003. The case-control study included an extensive search within the region for other kidney cancer cases among the cohort members. Industrial hygienists assessed occupational exposure.
From 1968 to 2006, no significant excess mortality was observed for all causes of death or for all cancers. We found excess mortality for kidney cancer only among women. The nested case-control study showed a dose-response relation for cumulative exposure to chloracetal C5: the OR rose from 2.5 in the low-exposure category to 10.5 in the high-exposure group. Adjustment for screening attenuated this relation.
The results of the case-control study were consistent with the positive results of in vivo genotoxic tests and suggest that chloracetal C5 can have a causal role in RCC.
No preview · Article · Aug 2013 · Occupational and environmental medicine
[Show abstract][Hide abstract] ABSTRACT: To evaluate the potential association between occupational exposure to chlorinated and petroleum solvents and mycosis fungoides (MF).
A questionnaire on lifetime job history was administered to 100 patients diagnosed with MF and 2846 controls. Odds ratios (ORs) were calculated as the measure of the association between exposure to each specific solvent and MF.
In the total sample and in men, cases and controls did not differ in relation to exposure to any of the solvents studied. In women, an association with MF was seen for the highest level of estimated exposure to perchloroethylene (OR = 11.38; 95% confidence interval: 1.04 to 124.85) and for exposure less than the median to kerosene/fuel/gasoil (OR = 8.53; 95% confidence interval: 1.11 to 65.62).
These results do not provide conclusive evidence that exposure to solvents may increase risk of MF because they were not found in men.
Full-text · Article · Jul 2013 · Journal of occupational and environmental medicine / American College of Occupational and Environmental Medicine
[Show abstract][Hide abstract] ABSTRACT: To assess the risk of lung cancer associated with exposure to mineral wools (MWs), while taking into account smoking, asbestos, and crystalline silica exposures.
The analyses were restricted to men (1350 cases and 1912 controls). Lifelong occupational history was collected. MWs and asbestos exposures were assessed, using task-exposure matrices and silica exposure, a job-exposure matrix.
We observed consistent not-significant increased risks of lung cancer of the same order of magnitude among workers exposed to high levels of MWs (odds ratio, 1.4; 95% confidence interval: 0.9 to 2.2; for highest quartile of the Cumulative Exposure Index).
These results do not allow to draw firm conclusion about a carcinogenic effect of MWs on the lung, but they cannot exclude it. Given the high number of potentially exposed workers, it will be necessary to replicate them in a future further removed from the asbestos ban.
No preview · Article · Jun 2013 · Journal of occupational and environmental medicine / American College of Occupational and Environmental Medicine
[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.
[Show abstract][Hide abstract] ABSTRACT: RATIONALE: Occupational co-exposure to asbestos and other fibers or particles could modify the carcinogenicity of asbestos with regard to pleural mesothelioma. OBJECTIVES: To estimate associations between pleural mesothelioma and occupational mineral wool and silica exposure and to study the impact of occupational co-exposure on the risk of pleural mesothelioma. METHODS: 1,199 male cases and 2,379 controls were included in a French pooled case-control study. Complete job histories were collected and occupational exposure to asbestos, mineral wool (MW), and silica were assessed by three French job exposure matrices. Unconditional logistic regression models adjusted for age, birth date, and occupational asbestos exposure were used to estimate odds ratios (OR) and 95% confidence intervals. MEASUREMENTS AND MAIN RESULTS: A significant association between mesothelioma and MW exposure was observed after adjustment for occupational asbestos exposure. OR for subjects exposed to less than 0.01 f/ml-y was 1.6 (95% CI: 1.2-2.1) and increased to 2.5 (95% CI: 1.8-3.4) for subjects exposed to more than 0.32 f/ml-y. All ORs for silica exposure were around the null. Co-exposure to either asbestos and MW or asbestos and silica seemed to increase the risk of pleural mesothelioma. ORs were 17.6 (95% CI: 11.8-26.2) and 9.8 (95% CI: 4.2-23.2) for subjects exposed to both asbestos and MW and for subjects exposed to both asbestos and silica, respectively, compared to 4.3 (95% CI: 1.9-9.8) for occupational asbestos exposure alone. CONCLUSION: Our results are in favour of an increased risk of pleural mesothelioma for subjects exposed to both asbestos and MW or asbestos and silica.
Full-text · Article · Mar 2013 · American Journal of Respiratory and Critical Care Medicine
[Show abstract][Hide abstract] ABSTRACT: Night work involving disruption of circadian rhythm was suggested as a possible cause of breast cancer. We examined the role of night work in a large population-based case-control study carried out in France between 2005 and 2008. Lifetime occupational history including work schedules of each night work period was elicited in 1,232 cases of breast cancer and 1,317 population controls. Thirteen percent of the cases and 11% of the controls had ever worked on night shifts (OR = 1.27 [95% confidence interval = 0.99-1.64]). Odds ratios were 1.35 [1.01-1.80] in women who worked on overnight shifts, 1.40 [1.01-1.92] in women who had worked at night for 4.5 or more years, and 1.43 [1.01-2.03] in those who worked less than three nights per week on average. The odds ratio was 1.95 [1.13-3.35] in women employed in night work for >4 years before their first full-term pregnancy, a period where mammary gland cells are incompletely differentiated and possibly more susceptible to circadian disruption effects. Our results support the hypothesis that night work plays a role in breast cancer, particularly in women who started working at night before first full-term pregnancy.
Preview · Article · Feb 2013 · International Journal of Cancer
[Show abstract][Hide abstract] ABSTRACT: Objectives:
Trichloroethylene (TCE) is suspected of association with elevated risk of cervical cancer. A case-control study was performed in a geographical area in which occupational TCE exposure is high. The study objective was to analyze the correlation between occupational TCE exposure and cervical cancer (including precancerous conditions).
Case and control subjects were recruited by gynecologists. General and occupational data were collected by telephonic interviews. An industrial hygienist assessed occupational TCE exposure on a task-exposure matrix. Analysis focused on occupational TCE exposure at various levels and on cumulative dose. Multivariate analysis was performed to take account of the various risk factors.
In total, 67 case and 67 age-matched control subjects were included. Mean age was 36 years in both groups. Five of the possible general risk factors correlated significantly with cervical dysplasia or cancer: number of partners, history of genital or anal wart, interval between first period and first sexual relation, parity, and body mass index, the last three showing inverse correlation. Elevated risk was found in women who had had jobs as manual workers according to the PCS French classification (professions and socioprofessional categories), and production and related workers according to ISCO classification (International Standard Classification of Occupations), with odds ratios (ORs), adjusted on general and medical risk factors, of 7.68 [95% confidence interval (CI): 1.39-42.54] and 7.48 (1.30-43.24), respectively, among skilled service sector workers; the adjusted OR was close to significance, at 4.67 (95% CI: 0.92-23.67). No occupational sectors were significantly associated with elevated risk. In all, 17 (25.4%) case and 15 (22.4%) control subjects were exposed to TCE: raw OR = 1.17 (95% CI: 0.54-2.52), adjusted OR = 1.51 (95% CI: 0.42-5.41). There was no significant correlation between cumulative dose and exposure time.
The study found no significantly increased risk of cervical dysplasia or cancer associated with occupational TCE exposure.
Full-text · Article · Oct 2012 · Annals of Occupational Hygiene
[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.
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.
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).
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.