Occupational risk factors have to be considered in the definition of high-risk lung cancer populations.

BACKGROUND: The aim of this study was to compute attributable fractions (AF) to occupational factors in an area in North-Eastern France with high lung cancer rates and a past of mining and steel industry. METHODS: A population-based case-control study among males aged 40-79 was conducted, including confirmed primary lung cancer cases from all hospitals of the study region. Controls were stratified by broad age-classes, district and socioeconomic classes. Detailed occupational and personal risk factors were obtained in face-to-face interviews. Cumulative occupational exposure indices were obtained from the questionnaires. Attributable fractions were computed from multiple unconditional logistic regression models. RESULTS: A total of 246 cases and 531 controls were included. The odds ratios (ORs) adjusted on cumulative smoking and family history of lung cancer increased significantly with the cumulative exposure indices to asbestos, polycyclic aromatic hydrocarbons and crystalline silica, and with exposure to diesel motor exhaust. The AF for occupational factors exceeded 50%, the most important contributor being crystalline silica and asbestos. CONCLUSION: These AFs are higher than most published figures. This can be because of the highly industrialised area or methods for exposure assessments. Occupational factors are important risk factors and should not be forgotten when defining high-risk lung cancer populations.

Under-estimation of self-reported occupational exposure by questionnaire in hospital workers.

OBJECTIVES: The aim of the study was to determine whether self-reported occupational exposure to cleaning/disinfecting agents in hospital workers is accurate, in comparison to expert assessment, taken to be the gold standard. METHODS: In the Epidemiological Study of the Genetics and Environment of Asthma (EGEA), participants were interviewed on occupation with a specific questionnaire for hospital workers regarding tasks and cleaning/disinfecting agents. Two estimates of exposure were available: self-report and expert assessment. The expert assessment involved a standardised procedure to estimate intensity, frequency and probability of exposure for each job. The present analysis focused on eight exposures: formaldehyde, glutaraldehyde, bleach/chlorine, alcohol, quaternary ammonium components, ammonia, sprays and latex gloves. Agreement and differences between self-reported and expert estimates were studied by kappa and phi coefficients and McNemar tests, respectively. RESULTS: In the survey of 1571 adults, 176 ever hospital workers (327 occupations) with both self-reported and expert exposure assessments were studied. An underestimation of self-reported exposure was observed especially for formaldehyde (26.5% vs 32.7%, p=0.01), ammonia (7.4% vs 18.8%, p<0.0001), alcohol (64.9% vs 93.0%, p<0.0001) and quaternary ammonium components (16.6% vs 70.9%, p<0.0001), compared to expert assessment. CONCLUSION: Occupational exposure to disinfecting/cleaning agents is common and high in hospitals. A large underestimation of self-reported exposure and a lack of knowledge of product components was observed. Our results show the relevance of expert assessment in epidemiological studies to limit measurement bias. This work underlines the need for health education programmes on the occupational risks induced by these types of products.

[Renal cell carcinoma and exposure to trichloroethylene: are the French limits of occupational exposure relevant?]. / Cancer du rein et expositions au trichloroéthylène: les valeurs limites d'exposition professionnelle françaises en vigueur sont-elles adaptées ?

BACKGROUND: Several studies have investigated the association between trichloroethylene (TCE) exposure and renal cell cancer (RCC) but findings were inconsistent. The analysis of a case control study has shown an increased risk of RCC among subjects exposed to high cumulative exposure. The aim of this complementary analysis is to assess the relevance of current exposure limits regarding a potential carcinogenic effect of TCE on kidney. METHODS: Eighty-six cases and 316 controls matched for age and gender were included in the study. Successive jobs and working circumstances were described using a detailed occupational questionnaire. An average level of exposure to TCE was attributed to each job-period in turn. The main occupational exposures described in the literature as increasing the risk of RCC were assessed as well as non-occupational factors. A conditional logistic regression was performed to test the association between TCE and RCC risk. Three exposure levels were studied (average exposure during the eight-hour shift): 35ppm, 50ppm and 75ppm. Potential confounding factors identified were taken into account at the threshold limit of 10% (p=0.10) (body mass index [BMI], tobacco smoking, occupational exposures to cutting fluids and to other oils). RESULTS: Adjusted for tobacco smoking and BMI, the odd-ratios associated with exposure to TCE were respectively 1.62 [0.77-3.42], 2.80 [1.12-7.03] and 2.92 [0.85-10.09] at the thresholds of 35ppm, 50ppm and 75ppm. Among subjects exposed to cutting fluids and TCE over 50ppm, the OR adjusted for BMI, tobacco smoking and exposure to other oils was 2.70 [1.02-7.17]. CONCLUSION: Results from the present study as well as those provided in the international literature suggest that current French occupational exposure limits for TCE are too high regarding a possible risk of RCC.

Cancer mortality in a synthetic spinning plant in Besançon, France.

OBJECTIVES: To assess the mortality of a cohort of workers in a synthetic textile spinning plant and to evaluate the relationship between mortality from lung, liver and bladder cancer and the processes or the products used. METHODS: The study population consisted of male workers present for at least 6 months in the plant from 1968 to 1984. The cohort was followed until 1999. Vital status and the causes of death were determined by consulting national registries. The population of the Franche-Comté region was used for comparison. In total, 17 groups of exposure were assessed by the industrial hygienist, based on the consensus of an expert group that determined the exposure levels of each job to selected occupational hazards. Each worker was assigned to one or several groups, according to his occupational history. Confounding factors could not be assessed. Standardised mortality ratios (SMR) and 95% bilateral confidence intervals were calculated based on an assumed Poisson distribution of the number of cases to compare the plant mortality and the population mortality. Internal analyses were performed with Cox models in order to assess the risks of death related to the various exposures. RESULTS: In the whole cohort, mortality from all malignant neoplasms was lower than expected, but this was not significant. All the estimated SMRs were lower than or close to 1. The "hot -line fitters" (RR = 2.13; n = 9; 1.06 to 4.29) and the "fibre-drawing workers" (RR = 1.83; n = 20;1.09 to 3.07) experienced a statistically significant excess in mortality from lung cancer. A slightly elevated but not significant risk of death related to lung cancer (RR = 1.5; n = 41; 0.8 to 2.7) was observed in the groups with the highest exposure to mineral fibres. A statistically significant increase in cancer deaths was observed for workers with high exposure to dust (higher intensity: RR = 1.42; n = 79; 1.06 to 1.89). CONCLUSION: Some findings, mainly of lung cancer, justify further exploration in other plants in this industry.

Occupational exposures and lung cancer in New Caledonia.

AIMS: To study the associations between occupational exposures and the risk of lung cancer in New Caledonia. METHODS: All cases diagnosed between January 1993 and December 1995 (228 lung cancers) and 305 population controls were included. Detailed information on lifetime job history, smoking, and other potential risk factors was collected by interview. Occupational exposures were assessed from the questionnaires by an industrial hygienist, without knowledge of case-control status. RESULTS: No significant association was found with exposures related to nickel mining and refining, the main industrial activity in the territory. Among men, an excess risk of lung cancer was found for bus and truck drivers. Increased risks were also observed in men with the highest level of cumulative exposure to cleaning products and inorganic fertilisers. Exposure to field dust was associated with lung cancer risk in both sexes, and risk increased with cumulative exposure level. In some areas tremolite asbestos derived from local outcroppings was used as a whitewash. The association between exposure to field dust and lung cancer was limited to men and women exposed to this whitewash-that is, living in areas where the soil may contain tremolite. CONCLUSION: This study shows several associations between occupational exposures and lung cancer. The findings suggest that exposure to tremolite fibres from cultivated fields may increase the risk of lung cancer in New Caledonia.

Occupational risk factors, ultraviolet radiation, and ocular melanoma: a case-control study in France.

BACKGROUND: Ultraviolet radiation has been suspected as a possible cause of ocular melanoma. Because this association is controversial, we examine the role of occupational exposure to ultraviolet radiation on the occurrence of this rare cancer. MATERIAL AND METHODS: A population-based case-control study was conducted in 10 French administrative areas (départements). Cases were 50 patients with uveal melanoma diagnosed in 1995-1996. Controls were selected at random from electoral rolls, after stratification for age, gender, and area. Among 630 selected persons, 479 (76%) were interviewed. Data on personal characteristics, occupational history, and detailed information on each job held were obtained from face-to-face interviews using a standardized questionnaire. Estimates of occupational exposure to solar and artificial ultraviolet light were made using a job exposure matrix. RESULTS: Results show elevated risks of ocular melanoma for people with light eye color, light skin color, and for subjects with several eye burns. The analysis based on the job exposure matrix showed a significantly increased risk of ocular melanoma in occupational groups exposed to artificial ultraviolet radiation, but not in outdoor occupational groups exposed to sunlight. An elevated risk of ocular melanoma was seen among welders (odds ratio = 7.3; 95% confidence interval = 2.6-20.1 for men), and a dose-response relationship with job duration was observed. The study also showed increased risk of ocular melanoma among male cooks, and among female metal workers and material handling operators. CONCLUSION: Following the present study, the existence of an excess risk of ocular melanoma in welders may now be considered as established. Exposure to ultraviolet light is a likely causal agent, but a possible role of other exposures in the welding processes should not be overlooked.

Risk of lung cancer in workers producing stainless steel and metallic alloys.

OBJECTIVES: The mortality of workers involved in the production of stainless and alloyed steel from 1968 to 1992 was studied, in order to investigate the risk of lung cancer due to exposure to metals, i.e. iron oxides, chromium and/or nickel compounds. METHODS: The study design was a historical cohort mortality study and a nested case-control study concerning lung cancer. Standardized mortality ratios (SMRs) were computed using regional mortality rates as an external reference for comparing observed and expected numbers of deaths, adjusting for age, sex and calendar time. Conditional logistic regression was used to estimate odds ratios (ORs). Occupational exposure was assessed through the complete job histories of cases and controls and a specific job-exposure matrix. RESULTS: The cohort comprised 4,288 male and 609 female workers. The observed overall mortality was significantly lower than expected [649 deaths; SMR = 0.91; 95% confidence interval (CI) 0.84-0.98]. No significant SMR was observed for mortality from lung cancer (54 deaths; SMR = 1.19; CI 0.88-1.55). The case-control study was based on 54 cases and 162 individually matched controls. Smoking habits were available for 71%. No lung cancer excess was observed for exposure to (1) metals and/or their compounds, i.e. iron (OR = 0.94, CI 0.48-1.86), chromium and/or nickel (OR = 1.18, CI 0.62-2.25), and cobalt (OR =0.64, CI 0.33-1.25), (2) acid mists (OR = 0.43, CI 0.17-1.10), and (3) asbestos (OR = 1.00, CI 0.54-1.86). With respect to exposure to polycyclic aromatic hydrocarbons (PAHs) and silica, which are often found together in workplaces, (1) high and statistically significant lung cancer excesses were observed, the ORs being 1.95 (CI 1.03-3.72) and 2.47 (CI 1.28-4.77) respectively, (2) quantitative exposure parameters revealed upward trends reaching statistical significance (P < 0.05), and (3) adjustments for tobacco consumption did not reveal any confounding factors from smoking. CONCLUSION: This study failed to detect any relationship between lung cancer and exposure to iron, chromium, nickel and/or their compounds. High and statistically significant relative risks, along with increasing trends, were observed for simultaneous exposure to PAHs and silica.

Environmental exposure to tremolite and respiratory cancer in New Caledonia: a case-control study.

A case-control study on respiratory cancers was conducted in New Caledonia (South Pacific), where a high incidence of malignant pleural mesothelioma had been observed. The disease pattern suggested an environmental exposure to asbestos. The first results showed that, in some areas, tremolite asbestos derived from local outcroppings was used as whitewash (locally named "pö"). All cases diagnosed between 1993 and 1995 (including 15 pleural mesotheliomas, 228 lung cancers, and 23 laryngeal cancers) and 305 controls were included in the study. Detailed information on past or present use of the whitewash, residential history, smoking, diet, and occupation was collected. The risk of mesothelioma was strongly associated with the use of the whitewash (odds ratio (OR) = 40.9; 95% confidence interval (CI): 5.15, 325). All Melanesian cases had been exposed. Among Melanesian women, exposure to the whitewash was associated with an increased risk of lung cancer (OR = 4.89; 95% CI: 1.13, 21.2), and smokers exposed to po had an approximately ninefold risk (OR = 9.26; 95% CI: 1.72, 49.7) compared with women who never smoked and had never used the whitewash. In contrast, no association was noted between exposure to pö and lung cancer risk among Melanesian men, probably because of lower exposure levels. Among non-Melanesians, the numbers of exposed subjects were too small to assess the effect of exposure to po. There was no indication of elevated risks for the other cancer sites.

Congenital malformation and maternal occupational exposure to glycol ethers. Occupational Exposure and Congenital Malformations Working Group.

Glycol ethers are found in a wide range of domestic and industrial products, many of which are used in women's work environments. Motivated by concern about their potential reproductive toxicity, we have evaluated the risk of congenital malformations related to glycol ether exposure during pregnancy as part of a multicenter case-control study, conducted in six regions in Europe. The study comprised 984 cases of major congenital malformations and 1,134 controls matched for place and date of birth. Interviews of the mothers provided information about occupation during pregnancy, sociodemographic variables, and other potential risk factors (medical history, tobacco, alcohol, drugs). A chemist specializing in glycol ethers evaluated exposure during pregnancy, using the job description given by the mother, without knowledge of case or control status. We classified malformations into 22 subgroups. The overall odds ratio (OR) of congenital malformation associated with glycol ether exposure was 1.44 [95% confidence interval (CI) = 1.10-1.90], after adjustment for several potential confounders. The association with exposure to glycol ethers appeared particularly strong in three subgroups: neural tube defects (OR = 1.94; 95% CI = 1.16-3.24), multiple anomalies (OR = 2.00; 95% CI = 1.24-3.23), and cleft lip (OR = 2.03; 95% CI = 1.11-3.73). In this last subgroup, risk, especially of an isolated defect, tended to increase with level of exposure.

[Occupational exposure and malignant hemopathies: a case-control study in Lyon (France)]. / Expositions professionnelles et hémopathies malignes: une enquête cas-témoins réalisée à Lyon (France).

A hospital based case-control study was carried out in Lyon with the aim of assessing the association between haematologic malignancies and occupational exposures to 320 compounds. Job histories were obtained by questionnaire for 118 cases (52 non Hodgkin lymphomas, 48 acute myeloid leukemia, 18 others leukaemias), and 118 controls with diseases other than cancer from the same general hospital; controls were matched for sex, age and nationality. Systematic coding of exposures based on a blind analysis of job histories, was done by a team of experts in chemistry and occupational health. Mantel-Haenszel analysis was performed. Significantly elevated odds-ratio were observed for non Hodgkin lymphomas and exposure to mineral oils (14.86; 2.76-80.0), excavation dusts (3.91; 0.94-15.95), alkali compounds (2.90; 1.09-7.68), inks (2.47; 1.09-5.17). For inks, a dose-response relation was observed. Elevated odds-ratios appeared for acute myeloid leukaemias and arsenic compounds (3.02; 0.90-10.13) and lead compounds (3.70; 1.09-13.44). When regarding industrial activities, two of them are more frequently found: food industries (14 cases/5 controls), public works (12 cases/0 control). When regarding jobs, winding (6 cases/0 control), glass workers (8 cases/1 control) and warehousemen (10 cases and 4 controls) are more often seen among cases.

Bladder cancer and occupational exposures.

OBJECTIVES: A hospital-based case-referent study was carried out in Lyon with the purpose of generating hypotheses about the role of occupational exposures to 320 compounds in bladder carcinogenesis. METHODS: Job histories were obtained by questionnaire for 116 cases and 232 reference patients with diseases other than cancer (one referent from the same hospital ward and one from another ward of the same hospital per case); the referents were matched for gender, hospital, age, and nationality. Systematic coding of exposures, with a blind analysis of job histories, was carried out by a team of experts in chemistry and occupational health. RESULTS: Significantly elevated odds ratios were observed for exposure to pyrolysis and combustion products [odds ratio (OR) 2.3, 95% confidence interval (95% CI) 1.0-4.0] when the general referents were used and for cutting fluids (OR 2.6, 95% CI 1.2-5.4) when tobacco consumption was adjusted for. The latter was highest among the category consisting of blue-collar and unskilled workers, supervisors, and agricultural workers (OR 4.6 95% CI 2.0-10.6), while the odds ratio for the other category was 0.8 (95% CI 0.3-2.7). An elevated odds ratio for exposure to inks was observed for the women (OR 14.0, 95% CI 1.8-106.5) on the basis of 14 exposed cases, but confounding factors could have been responsible for this result. Odds ratios for several other exposures (rubber: OR 5.7, nitrates: OR 8.2, coke dust: OR 3.5, meat additives: OR 3.8) were also elevated, but not significantly so when based on a small number of exposed cases. CONCLUSION: The observations of this investigation should be tested in future studies, in particular since exposures to agents such as cutting fluids or pyrolysis products are ubiquitous in industrial settings and may present an important public health hazard.