Occupational exposure and lung cancer risk in a coastal area of Northeastern Italy

Summary A case-control study of lung cancer and occupational exposure was conducted in a coastal area of Northeastern Italy where metallurgical and mechanical industries, docks and shipyards are located. Cases comprised 756 men who died of primary lung cancer in a 5-year period. Controls comprised 756 male subjects dying from other causes during the same period. Occupational exposures to lung carcinogens were assessed according to a job title-based approach, using two separate lists of industries/occupations recognized as being causally associated (list A) or suspected of being causally associated (list B) with lung cancer in humans. Exposure to asbestos was classified as absent, possible, or definite. After adjustment for cigarette smoking and place of residence, a significant association was found between lung cancer and occupations in both list A [relative risk (RR) = 2.25, 95% confidence interval (CI) = 1.68–3.03] and list B (RR = 1.33, 95% CI = 1.03–1.71). A significant excess risk was found for workers with definite exposure to asbestos as compared to those with no exposure to lung carcinogens (RR = 1.98, 95% CI = 1.42–2.75). Among occupations with recognized exposure to lung carcinogens other than asbestos, a significant excess risk for lung cancer was observed in iron and metalware workers. In occupational groups with definite exposure to asbestos, elevated risk estimates were found for shipyard workers, dockworkers, carpenters, and electricians. The combined effect of smoking and asbestos was found to be compatible with that expected under a multiplicative model. The overall population-attributable risk (ARp) for cigarette smoking was found to be 87.5%. The ARp estimate for occupations in list A was 16.0%. The estimate increased to 25.3% (95% CI = 16.2–34.4) when occupations in list B were included. The ARp estimate for possible or definite exposure to asbestos was 20.0% (95% CI = 11.5–28.5). With regard to the histologic types of lung cancer, significant associations were found between definite exposure to asbestos and squamous cell carcinoma (RR = 2.00, 95% CI = 1.28-–3.11), small cell carcinoma (RR = 2.11, 95% CI = 1.31–3.39), and adenocarcinoma (RR = 2.16, 95% CI = 1.32–3.53).     

Occupational lung cancer risk for men in Germany: results from a pooled case-control study

Occupational exposures such as crystalline silica, diesel engine exhaust, polycyclic aromatic hydrocarbons, and man-made mineral fibers are strongly suspected to increase lung cancer risk. Two case-control studies in Germany conducted between 1988 and 1996 were pooled for a joint analysis. A total of 3,498 male cases and 3,541 male population controls, frequency matched for age and region, were included in the study. The lifelong history of all jobs and industries was coded and occupational exposures were evaluated by expert rating. Odds ratios, crude and adjusted for smoking and asbestos exposure, were calculated by conditional logistic regression. Job-related evaluation showed a statistically significant increased odds ratio adjusted for smoking among farmers; forestry workers, fishermen, and livestock workers; miners and quarrymen; chemical processors; cabinet makers and related wood workers; metal producers and processors; bricklayers and carpenters; road construction workers, pipelayers and well diggers; plasterers, insulators, and upholsterers; painters and lacquerers; stationary engine and heavy equipment operators; transport workers and freight handlers; and service workers. With regard to specific occupational exposures, elevated odds ratios (OR) (95% confidence intervals (CI)) for lung cancer risk adjusted for smoking and asbestos exposure were observed for man-made mineral fibers (OR = 1.48, 95% CI 1.17, 1.88); crystalline silica (OR = 1.41, 95% CI 1.22, 1.62); diesel engine exhaust (OR = 1.43, 95% CI 1.23, 1.67); and polycyclic aromatic hydrocarbons (OR = 1.53, 95% CI 1.14, 2.04). The risk of asbestos exposure, adjusted for smoking was also increased (OR = 1.41, 95% CI 1.24, 1.60).     

Occupation and lung cancer risk in the province of Trieste: a case-control study]

To investigate the relationship between occupation and lung cancer, a case-control study was performed in the province of Trieste, Italy, where metallurgical and mechanical industries, dock activities and shipbuilding and ship repairing are predominant. Through the local Cancer Registry, pathology records of 938 men who died of primary lung cancer (ICD 162) in a five-year period were examined. Residential, smoking and occupational histories were obtained from interviews of next of kin of 756 cases and 756 age-matched male controls (+/- 2 years). Occupational exposures to lung carcinogens were assessed according to a job-title based approach, identifying industries/occupations with well-recognized lung carcinogen exposures (list A) and industries/occupations with suspected lung carcinogen exposures (list B). Exposure to asbestos was classified as absent, possible or definite. After adjustment for cigarette smoking (four levels) and residence (three levels), a significant association was found between lung cancer and occupations in list A (RR = 2.28, 95% CI = 1.70-3.07) and in list B (RR = 1.33, 95% CI = 1.04-1.71). A significant excess risk was found for workers with definite exposure to asbestos when compared to those with no exposure to lung carcinogens (RR = 1.99, 95% CI = 1.43-2.76). A very high relative risk was observed among heavy smokers with definite exposure to asbestos (RR = 42.8). A stratified analysis showed that the combined effect of asbestos and smoking was compatible with that expected under a multiplicative model. The overall attributable risk in the population (ARp) for cigarette smoking was found to be 87.6%. The ARp fraction for occupations with well-established exposures to lung carcinogens (list A) was 16.2%. The ARp fraction increased to 25.5% (85% CI = 1.4-34.6) when occupations with suspected exposure to lung carcinogens (list B) were included. The ARp fraction for possible or definite exposure to asbestos was 20.1% (95% CI = 11.6-28.6).     

Occupational exposure and lung cancer risk: a population-based case-referent study in Sweden

This case-referent study investigated the lung cancer risk from occupational exposure to diesel exhaust, mixed motor exhaust, other combustion products, asbestos, metals, oil mist, and welding fumes. All cases of lung cancer in males aged 40-75 years among stable residents of Stockholm County, Sweden, were identified from 1985 to 1990. Referents were selected as a stratified (age, inclusion year) random sample. Information on lifetime occupational history, residency, and tobacco smoking was obtained from the study subjects or from next of kin. Response rates of 87% and 85% resulted in 1,042 cases and 2,364 referents, respectively. Occupational exposures were assessed by an occupational hygienist who coded the intensity and probability of each exposure. Risk estimates were adjusted for tobacco smoking, other occupational exposures, residential radon, and environmental exposure to traffic-related air pollution. For the highest quartile of cumulative exposure versus no exposure, the relative risk was 1.63 (95% confidence interval (CI): 1.14, 2.33) for diesel exhaust, 1.60 (95% CI: 1.09, 2.34) for combustion products, and 1.68 (95% CI: 1.15, 2.46) for asbestos. Dose-response analyses indicated an increase in lung cancer risk of 14% per fiber-year/ml for asbestos exposure. No increased risk was found for the other exposure factors. An overall attributable proportion of 9.5% (95% CI: 5.5, 13.9) was estimated for lung cancer related to diesel exhaust, other combustion products, and asbestos.     

Lung cancer and exposure to diesel exhaust among bus garage workers.

Mortality and cancer incidence was investigated among the 695 bus garage workers employed as mechanics, servicemen, or hostlers for at least six months in five bus garages in Stockholm between 1945 and 1970. The exposure to diesel exhaust and asbestos was estimated by industrial hygienists. A small excess of lung cancer mortality was found in the cohort when occupationally active men in Stockholm were used as the reference group. A case-referent study was performed within the cohort, six referents being selected for each of the 20 lung cancer cases. The lung cancer risk increased with increasing cumulative exposure to diesel exhaust, but not with cumulative asbestos exposure. The relative risk for lung cancer among the highly exposed men was 2.4 (95% CI 1.3-4.5) as compared with those with low exposure. The study indicates that exposure to diesel exhaust increases the risk for lung cancer.     

Occupational exposure to diesel motor exhaust and risk of lung cancer by histological subtype: a population-based case–control study in Swedish men

We investigated occupational exposure to diesel motor exhaust (DME) and the risk of lung cancer by histological subtype among men, using elemental carbon (EC) as a marker of DME exposure. 993 cases and 2359 controls frequency-matched on age and year of study inclusion were analyzed by unconditional logistic regression in this Swedish case–control study. Work and smoking histories were collected by a questionnaire and telephone interviews. DME was assessed by a job-exposure matrix. We adjusted for age, year of study inclusion, smoking, occupational exposure to asbestos and combustion products (other than motor exhaust), residential exposure to radon and exposure to air pollution from road traffic. The OR for lung cancer for ever vs. never exposure to DME was 1.15 (95% CI 0.94–1.41). The risk was higher for squamous and large cell, anaplastic or mixed cell carcinoma than for alveolar cell cancer, adenocarcinoma and small cell carcinoma. The OR in the highest quartile of exposure duration (≥34 years) vs. never exposed was 1.66 (95% CI 1.08–2.56; p for trend over all quartiles: 0.027) for lung cancer overall, 1.73 (95% CI 1.00–3.00; p: 0.040) for squamous cell carcinoma and 2.89 (95% CI 1.37–6.11; p: 0.005) for the group of undifferentiated, large cell, anaplastic and mixed cell carcinomas. We found no convincing association between exposure intensity and lung cancer risk. Long-term DME exposure was associated with an increased risk of lung cancer, particularly to squamous cell carcinoma and the group of undifferentiated, large cell, anaplastic or mixed carcinomas.     

Occupational dust exposure and the risk of laryngeal cancer in Turkey

OBJECTIVES: A hospital-based case-referent study was conducted to identify occupational risk factors for laryngeal cancer. In a previous report an association was found between laryngeal cancer and occupations with potential dust exposure; a job-exposure matrix was developed to aid further evaluation of laryngeal cancer risks from five occupational dust exposures. METHODS: Among 7631 cancer cases from the Okmeydani Hospital, Istanbul, between 1979 and 1984, 958 larynx cancer cases were identified among men. After exclusions, 940 laryngeal cancer cases and 1519 referents were available. A standardized questionnaire was used to obtain basic information on the patients. Seven-digit standard occupational and industrial codes were created to classify the job and industrial titles. A job-exposure matrix was developed for occupational dusts, including silica, asbestos, wood, cotton, and grain, and age-, smoking-, and alcohol-adjusted odds ratios (OR) and 95% confidence intervals (95% CI) were calculated to evaluate risks of laryngeal cancer. RESULTS: An excess of laryngeal cancer occurred for workers potentially exposed to silica and cotton dust, particularly for supraglottic cancer (OR 1.8, 95% CI 1.3-2.3, for silica and OR 1.6, 95% CI 1.1-2.5, for cotton dust), and there was a significant dose-response relationship with silica exposure. No relationship was found between laryngeal cancer and asbestos, grain, or wood dust exposures. CONCLUSION: Laryngeal cancer, especially supraglottic tumors, is associated with silica and cotton dust exposures in Turkey.     

Low-dose exposure to asbestos and lung cancer: dose-response relations and interaction with smoking in a population-based case-referent study in Stockholm,Sweden

This population-based case-referent study investigated the lung cancer risk associated with occupational exposure to asbestos, focusing on dose-response relations and the interaction with tobacco smoking. Incident cases of lung cancer among males aged 40-75 years in Stockholm County, Sweden, were identified from 1985 to 1990. Referents were selected randomly within strata (age, inclusion year) of the study base. Questionnaires administered to subjects or their next of kin gave information on occupations, tobacco smoking habits, and residences. Response rates of 87% and 85% resulted in 1,038 cases and 2,359 referents, respectively. Occupational exposures were assessed by an industrial hygienist. Lung cancer risk increased almost linearly with cumulative dose of asbestos. The risk at a cumulative dose of 4 fiber-years was 1.90 (95% confidence interval (CI): 1.32, 2.74), higher than that predicted by downward linear extrapolation from highly exposed occupational cohorts. The relative risk (exp(beta)) for a transformed dose variable ln(fiber-years + 1) was 1.494 (95% CI: 1.193, 1.871) per unit of exposure. The joint effect of asbestos and smoking was estimated to be 1.15 (95% CI: 0.77, 1.72) times that predicted from the sum of their individual effects and 0.31 (95% CI: 0.11, 0.86) times that predicted from their product, indicating a joint effect between additivity and multiplicativity.     

Application of two job indices for general occupational demands in a pooled analysis of case–control studies on lung cancer

Objectives:We investigated general job demands as a risk factor for lung cancer as well as their role in the association between occupational prestige and lung cancer.Methods:In 13 case–control studies on lung cancer, as part of the international SYNERGY project, we applied indices for physical (PHI) and psychosocial (PSI) job demands – each with four categories (high to low). We estimated odds ratios (OR) and 95% confidence intervals (CI) for lung cancer by unconditional logistic regression, separately for men and women and adjusted for study centre, age, smoking behavior, and former employment in occupations with potential exposure to carcinogens. Further, we investigated, whether higher risks among men with low occupational prestige (Treiman’s Standard International Occupational Prestige Scale) were affected by adjustment for the job indices.Results:In 30 355 men and 7371 women, we found increased risks (OR) for lung cancer with high relative to low job demands in both men [PHI 1.74 (95% CI 1.56–1.93), PSI 1.33 (95% CI 1.17–1.51)] and women [PHI 1.62 (95% CI 1.24–2.11), PSI 1.31 (95% CI 1.09–1.56)]. OR for lung cancer among men with low occupational prestige were slightly reduced when adjusting for PHI [low versus high prestige OR from 1.44 (95% CI 1.32–1.58) to 1.30 (95% CI 1.17–1.45)], but not PSI.Conclusions:Higher physical job demands were associated with increased risks of lung cancer, while associations for higher psychosocial demands were less strong. In contrast to physical demands, psychosocial demands did not contribute to clarify the association of occupational prestige and lung cancer.     

Mortality from lung cancer and population risk attributable to asbestos in an asbestos cement manufacturing town in Italy

OBJECTIVE: To estimate mortality from lung cancer and the risk attributable to asbestos separately for asbestos cement workers and for the general (non-occupationally exposed) population in the town of Casale Monferrato, where the largest Italian asbestos cement factory had been in operation in 1907-86. According to cancer registry data, in the same town the incidence of malignant mesothelioma in the general population is about 10 times higher than in comparable Italian provinces. METHOD: Decedents from lung cancer in 1989-95 were nominally identified in the list of decedents kept at the Local Health Authority of Casale Monferrato. Workers in the asbestos cement factory have been identified with a search in the nominal list of workers and the same was done for the wives of asbestos cement workers. These lists have already been used in cohort studies. Sensitivity and specificity of the linkage procedure with occupational activity in asbestos cement production have been evaluated in a previous study. Population at risk was estimated on the basis of official figures and on the results of the cohort study of asbestos cement workers. RESULTS: 227 deaths from lung cancer were included (184 men and 43 women). Among the asbestos cement workers mortalities were 234.0 x 100,000 person-years among men and 35.5 among women. Corresponding figures in the general (non- occupationally exposed) population in Casale Monferrato were 80.6 and 18.7. The rates in the general population were not higher than in the rest of the region. Attributable risk (AR) among the asbestos cement workers (and wives) is 67.5% (95% confidence interval (95% CI) 56.8 to 78.2) for men and 51.3% (95% CI 14.9 to 87.8) among women. Population AR to occupational or paraoccupational exposure in the asbestos cement production is 18.3% (95% CI 11.1 to 25.6) among men and 10.1% (95% CI 0 to 24.6) among women. CONCLUSION: This work did not show an increase in mortality from lung cancer for the population not exposed occupationally, but a large excess was found among men and women occupationally exposed in asbestos cement production. The total burden of lung cancer due to occupational exposure to asbestos may be underestimated, as only occupational exposure in asbestos cement production was taken into consideration. Nevertheless even a single factory can be responsible for a considerable proportion of deaths from lung cancer in a population.

 

     

Occupation and the risk of laryngeal cancer in Turkey

OBJECTIVES: A hospital-based case-referent study was conducted in Turkey to provide further information on occupational risk factors and laryngeal cancer. METHODS: Among 7631 cancer cases seen at an oncology treatment center between 1979 and 1984, 958 laryngeal cancer cases were identified among men. Occupational history, tobacco and alcohol use, and demographic data were obtained from patients with a standardized questionnaire. Special 7-digit standard occupational and industrial codes were created to classify the job and industrial titles of the subjects. After exclusions, 940 laryngeal cancer cases and 1519 referents were available for study. Age-, smoking- and alcohol-adjusted odds ratios (OR) and 95% confidence intervals (95% CI) were calculated. RESULTS: Excess laryngeal cancer occurred among guards (OR 1.5, 95% CI 1.1-2.1), production supervisors (OR 1.8, 95% CI 1.1-3.1), textile workers (OR 1.9, 95% CI 1.2-3.3), drivers (OR 1.7, 95% CI 1.1-2.4), construction workers (OR 1.7, 95% Cl 1.2-2.6), and workers in grain mills (OR 3.1, 95% CI: 1.3-7.6), trade unions (OR 3.6, 95% CI: 1.1-11.7) and local government services (OR 4.7, 95% CI 1.7-12.5). Supraglottic cancer was excessive among the textile workers, construction workers, and local government laborers, all with potential dust exposure. The risks of the general managers, electricians, and workers from industries such as pharmaceutical production, industrial machinery production, electric utilities, and retail services were lower than expected. CONCLUSIONS: The risk of laryngeal cancer was associated with several occupations, and supraglottic larynx cancer appears to be more common among workers in dusty occupations and industries.     

Association between asbestos exposure,cigarette smoking,myeloperoxidase (MPO) genotypes,and lung cancer risk

BACKGROUND: As observed in tobacco-associated carcinogenesis, genetic factors such as the polymorphic metabolic/oxidative enzyme myeloperoxidase (MPO) could modulate individual susceptibility to asbestos-associated carcinogenesis. METHODS: RFLP-PCR analysis identified the MPO genotypes in 375 Caucasian lung cancer cases and 378 matched controls. An epidemiological interview elicited detailed information regarding smoking history and occupational history and exposures. RESULTS: Asbestos exposure was associated with a significantly elevated risk estimate (OR = 1.45; 95% CI 1.04-2.02). On stratified analysis, we found the MPO genotypes modified the effect of asbestos exposure on lung cancer risk. Specifically, G/G carriers who were exposed to asbestos had an odds ratio (OR) of 1.72 (95% CI; 1.09-2.66), while A-allele carriers (G/A + A/A) exposed to asbestos exhibited a reduced OR of 0.89 (95% CI; 0.56-1.44). The OR was further reduced to 0.73 (0.49-1.06) for A-allele carriers not exposed to asbestos. A similar trend was observed for the joint effects between the MPO genotypes and pack-years smoking. Next, all three risk factors (MPO genotypes, asbestos exposure, and smoking) were analyzed simultaneously for joint effects. Heavy smokers with the G/G genotype and a history of asbestos exposure demonstrated a statistically significant elevated risk estimate (OR = 2.19; 95% CI 1.16-4.11), while the A-allele carriers with the same exposure profile were at a lower risk for lung cancer (OR = 1.18; 95% CI 0.58-2.38). The A-allele genotypes demonstrated similar protective effects for the other three exposure profiles. CONCLUSIONS: For a similar level of exposure to established carcinogens, individuals with the MPO A-allele genotypes appear to have a reduced risk of lung cancer.     

Occupational exposure to carcinogens and risk of lung cancer: results from The Netherlands cohort study.

OBJECTIVES: To investigate risk of lung cancers associated with common established carcinogenic occupational exposures (asbestos, paint dust, polycyclic aromatic hydrocarbons, and welding fumes) in a prospective cohort study among the general population, and to estimate the proportion of lung cancer cases attributable to these occupational exposures. METHODS: A prospective cohort study on diet, other lifestyle factors, job history, and cancer risk that started in 1986 in The Netherlands on 58,279 men, aged 55-69 years. Based on information about job history obtained from a self-administered questionnaire, case by case expert assessment was carried out to assign to each study subject a cumulative probability of occupational exposure for each carcinogenic exposure. For analysis, a case-cohort approach was used, in which the person-years at risk were estimated from a randomly selected subcohort (n = 1688). After 4.3 years of follow up, 524 lung cancer cases with complete job history were available. RESULTS: After adjustment for age, each of the other occupational exposures, and for smoking habits and intake of vitamin C, beta-carotene, and retinol, significant associations were found between risk of lung cancer and cumulative probability of occupational exposure to asbestos (relative risk (RR) highest/no exposure = 3.49, 95% confidence interval (95% CI) 1.69 to 7.18, trend P < 0.01 or paint dust (RR highest/no exposure = 2.48, 95% CI 0.88 to 6.97, trend P < 0.01). The population attributable risks (PARs) for the four exposures based on the multivariately adjusted RRs for ever exposed versus never exposed workers were calculated. The PAR of lifetime occupational exposure to asbestos was calculated to be 11.6%. CONCLUSIONS: This prospective cohort study among the general population showed that occupational exposure to asbestos or paint dust is associated with higher RRs for lung cancer. This study shows that after adjustment for smoking and diet about 11.6% of the cases of lung cancer in men is attributable to lifetime occupational exposure to asbestos.     

Occupation and cancer of the oral cavity or oropharynx in Turin, Italy

In a population-based case-referent study, the occupational experience of 86 men with oral or oropharyngeal cancer and 373 referents was analyzed with respect to employment in 41 occupations and 40 industries, as well as to exposure to 16 chemicals, as estimated via a job-exposure matrix. Among the occupations and industries at higher risk were machinery operator (odds ratio [OR] 2.0; 95% confidence interval [95% CI] 1.0-4.0), plumber (OR 5.0, 95% CI 1.2-21.5), building industry (OR 2.5; 95% CI 1.3-4.5), textile industry (OR 2.5; 95% CI 0.6-4.6), and electricity production (OR 2.8; 95% CI 0.7-12.1). All the OR estimates were adjusted for age, education, area of birth, tobacco smoking, and alcohol consumption. An association between formaldehyde exposure and oral cancer was suggested (OR for any exposure 1.6, 95% CI 0.9-2.8; OR for probable or definite exposure 1.8, 95% CI 0.6-5.5). No other chemical included in the matrix showed any risk pattern. The evidence of an association between formaldehyde exposure and oral or oropharyngeal cancer is strengthened by the results of this study.     

Occupational risk factors for renal cell carcinoma: agent-specific results from a case-control study in Germany. MURC Study Group. Multicenter urothelial and renal cancer study

BACKGROUND: This case-control study was conducted to estimate the renal cell cancer (RCC) risk for exposure to occupation-related agents, besides other suspected risk factors. METHODS: In a population-based multicentre study, 935 incident RCC cases and 4298 controls matched for region, sex, and age were interviewed between 1991 and 1995 for their occupational history and lifestyle habits. Agent-specific exposure was expert-rated with two job-exposure matrices and a job task-exposure matrix. Conditional logistic regression was used to calculate smoking adjusted odds ratios (OR). RESULTS: Very long exposures in the chemical, rubber, and printing industries were associated with risk for RCC. Males considered as 'substantially exposed to organic solvents' showed a significant excess risk (OR = 1.6, 95% CI : 1.1-2.3). In females substantial exposure to solvents was also a significant risk factor (OR = 2.1, 95% CI : 1.0-4.4). Excess risks were shown for high exposure to cadmium (OR = 1.4, 95% CI : 1.1-1.8, in men, OR = 2.5, 95% CI : 1.2-5.3 in women), for substantial exposure to lead (OR = 1.5, 95% CI : 1.0-2.3, in men, OR = 2.6, 95% CI : 1.2-5.5, in women) and to solder fumes (OR = 1.5, 95% CI : 1.0-2.4, in men). In females, an excess risk for the task 'soldering, welding, milling' was found (OR = 3.0, 95% CI : 1.1-7.8). Exposure to paints, mineral oils, cutting fluids, benzene, polycyclic aromatic hydrocarbons, and asbestos showed an association with RCC development. CONCLUSIONS: Our results indicate that substantial exposure to metals and solvents may be nephrocarcinogenic. There is evidence for a gender-specific susceptibility of the kidneys.     

Incidence of cancer among anthophyllite asbestos miners in Finland.

A cohort of 736 male and 167 female workers of two anthophyllite mines in Finland was followed up through the Finnish Cancer Registry for cancer in 1953-91. Compared with the total cancer incidence of the east Finnish population, the men had a raised risk of total cancer (standardised incidence ratio (SIR) 1.7; 95% confidence interval (95% CI) 1.4-1.9), mainly attributable to an excess in lung cancer (SIR 2.8; 95% CI 2.2-3.6). The risk of lung cancer was somewhat higher among workers classified as heavily exposed (SIR 3.2; 95% CI 2.4-4.1) than among those moderately exposed (SIR 2.3; 95% CI 1.5-3.6) and the risk increased with increasing smoking and with increasing time of work with exposure. There were four cases of mesothelioma v 0.1 expected, all in men who smoked and had had a long and heavy asbestos exposure. Among women, a non-significant excess in total cancer (SIR 1.5; 95% CI 0.9-2.4) was found in the subgroup with heavy exposure to asbestos. Anthophyllite asbestos seems to have high potency in the carcinogenesis of lung cancer and low potency in carcinogenesis of mesothelioma in comparison with the other types of asbestos.     

Lung cancer risk of workers in shoe manufacture and repair

BACKGROUND: The occupational lung cancer risk in manufacturing and repair of shoes was studied by pooling of two major case-control studies from Germany. METHODS: Some 4184 incident hospital-based cases of primary lung cancer and 4253 population controls, matched for sex, age, and region of residence were intensively interviewed with respect to their occupational and smoking history. Based on the occupational coding and a free text search, all individuals who had ever worked in shoe manufacturing or repair for at least half a year were identified. Shoemaker-years were calculated as the cumulated duration of working in shoe manufacturing or repair. Odds ratios (OR) and 95% confidence intervals (CI) were calculated via conditional logistic regression. Additional adjustment for smoking and occupational asbestos exposure was used. RESULTS: Seventy-six cases and 42 controls who had ever worked in shoe manufacture or repair (OR = 1.89, 95% CI: 1.29-2.78). After adjustment for smoking, this risk was lowered to 1.69 (95% CI: 1.09-2.62). Further adjustment for asbestos exposure only slightly changed the risk estimates upwards. The smoking adjusted OR in males was 1.50 (95% CI: 0.93-2.41) and 2.91 (95% CI: 0.90-9.44) in females. Logistic regression modeling showed a positive dose-effect relationship between duration of exposure in shoe manufacture and repair and lung cancer risk. The odds ratio for 30 years of exposure varied between 1.98 and 2.24 depending on the model specified. CONCLUSIONS: The study demonstrates an increased lung cancer risk for shoemakers and workers in shoe manufacturing. The risk seems to double after being 30 years in these occupations.     

Asbestos exposure, manganese superoxide dismutase (MnSOD) genotype, and lung cancer risk

To assess whether differences in genetic susceptibility to oxidative stress modify asbestos-related lung cancer risk (caused by lung inflammation, free radical production), we examined possible interactions between manganese superoxide dismutase (MnSOD) genotypes and asbestos in a hospital-based case-control study of 811 white lung cancer cases and 957 friend/spouse controls. Cumulative lifetime asbestos exposure score (AES) was calculated from self-reported duration and intensity of occupational and nonoccupational exposures. A total of 13.5% of cases and 10% of controls had "high" AES (determined by a priori cut point). The homozygous variant MnSOD genotype was associated with increased lung cancer risk among individuals with zero or "low" AES (odds ratio [OR], 2.14; 95% confidence interval [CI], 1.52-3.01) and no association (OR = 1.00; 95% CI = 0.36-2.73) among the "high" AES group. We observed no statistically significant interaction between MnSOD genotype and asbestos exposure for lung cancer risk.     

Socioeconomic status and lung cancer incidence in men in The Netherlands: is there a role for occupational exposure?

STUDY OBJECTIVE: To evaluate the influence of occupational exposure to carcinogens in explaining the association between socioeconomic status and lung cancer. DESIGN: A prospective cohort study. Data on diet, other lifestyle factors, sociodemographic characteristics and job history were collected by means of a self administered questionnaire. Follow up for incident cancer was established by record linkage with a national pathology register and with regional cancer registries. SETTING: Population originating from 204 municipalities in The Netherlands. PARTICIPANTS: These comprised 58 279 men aged 55-69 years in September 1986. After 4.3 years of follow up there were 470 microscopically confirmed incident lung cancer cases with complete data on dietary habits and job history. MEASUREMENTS AND MAIN RESULTS: Estimation of occupational exposure to asbestos, paint dust, polycyclic aromatic hydrocarbons, and welding fumes was carried out by two experts, using information on job history from the baseline questionnaire. Socioeconomic status was measured by means of highest attained level of education and two indicators based on occupation. In the initial multivariate analyses of socioeconomic status and lung cancer, adjustment was made for age, smoking habits, intake of vitamin C, beta-carotene and retinol, and history of chronic obstructive pulmonary disease or asthma. Additional adjustment for occupational exposure to the four carcinogens mentioned above did not change the inverse association between the level of education and lung cancer risk (initial model: RR highest/lowest level of education = 0.53; 95% CI 0.34, 0.82; additional model: RR highest/lowest level of education = 0.53; 95% CI 0.34, 0.84). Nor was the association between the two occupation based indicators of socioeconomic status and lung cancer risk influenced by occupational exposure to carcinogens. The effect of occupational exposure on the association between the level of education and lung cancer risk did not differ between ex-smokers and current smokers. CONCLUSIONS: Occupational exposure to asbestos, paint dust, polycyclic aromatic hydrocarbons, and welding fumes could not explain the inverse association between socioeconomic status and lung cancer risk. More research which explicitly addresses possible explanations for the association between socioeconomic status and lung cancer risk is needed.