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.     

Cancer incidence among European man-made vitreous fiber production workers.

OBJECTIVES: This study analyzed cancer incidence among man-made vitreous fiber workers. METHODS: A cancer incidence follow-up was conducted among 3685 rock-slag wool (RSW) and 2611 glass wool (GW) production workers employed for > or =1 year in Denmark, Finland, Norway, or Sweden, and the standardized incidence ratios (SIR) were calculated on the basis of national incidence rates. RESULTS: Overall cancer incidence was close to expectation. Lung cancer incidence was increased among the RSW [SIR 1.08, 95% confidence interval (95% CI) 0.85-1.36] and GW (SIR 1.28, 95% CI 0.91-1.74) workers. For both subcohorts, a trend was suggested for time since first employment (P-value for linear trend 0.1 and 0.2, respectively). Neither subcohort showed an association with employment during the early technological phase, when fiber exposure was high. The incidence of oral, pharyngeal, and laryngeal cancer was increased among the RSW (SIR 1.46, 95% CI 0.99-2.07) and the GW (SIR 1.41, 95% CI 0.80-2.28) subcohorts. Despite a trend in risk for these neoplasms among the GW workers with time since first employment, the lack of a positive relation with other indirect indicators of fiber exposure points against a causal interpretation. No association between RSW or GW exposure and the risk of other neoplasms was suggested. CONCLUSIONS: These lung cancer results are similar to those of a mortality study that included a larger number of factories. For other cancers there was no suggestion of an association with RSW or GW exposure.     

Incidence of cancer among the participants of the Finnish Asbestos Screening Campaign

OBJECTIVES: Cancer risk has been estimated for asbestos production workers or other heavily exposed asbestos workers in numerous studies. The bulk of the asbestos epidemic results come, however, from past intermittent exposures during asbestos product use. This study concentrated on estimating the risk of cancer in such a population. METHODS: Altogether 23285 men and 930 women invited to a nationwide screening campaign for benign asbestos-related diseases in 1990-1992 were followed for cancer through the Finnish Cancer Register up to 1998. Standardized incidence ratios (SIR) were calculated in comparison with the total Finnish population. RESULTS: Altogether 1392 cases of cancer were found among the men. The risk was slightly, but significantly elevated for lung cancer [SIR 1.14, 95% confidence interval (95% CI) 1.01-1.26), mesothelioma (SIR 2.77, 95% CI 1.66-4.31), and prostate cancer (SIR 1.21, 95% CI 1.09-1.34). The risk of lung cancer was slightly higher among the invited nonparticipants (SIR 1.48, 95% CI 1.20-1.79) than among the participants (SIR 1.02, 95% CI 0.88-1.17). About 98% of the lung cancers occurred in current or ex-smokers. CONCLUSIONS: In a population of long-term construction workers, the risk of lung cancer and mesothelioma was increased, but considerably lower than among insulators, asbestos sprayers, or patients with asbestosis. As it was not possible to follow most of the invited nonparticipants in the original screening study, selection bias by smoking or other life-style factors possibly correlated to the individual's decision to participate in the health screening cannot be excluded.     

Cancer incidence among members of the Norwegian trade union of insulation workers

Insulation work has been described as an occupation with high exposure to asbestos. A cohort of members of the Norwegian Trade Union of Insulation Workers (n = 1116), hired between 1930 and 1975, was established. During 2002, the cohort was linked to the Cancer Registry of Norway. The standardized incidence ratio (SIR) of pleural mesothelioma was 12.9 (95% confidence interval [CI] = 6.0-24.6). Two cases with peritoneal mesotheliomas were found (SIR, 14.8; 95% CI = 1.8-53.4). The SIR of lung cancer was 3.0 (95% CI = 2.3-3.8). Four cases of lung cancer were observed among cork workers without any exposure to asbestos, but to cork dust and tar smoke (SIR, 5.3; 95% CI = 1.5-13.6). Our study showed a high risk of mesothelioma and an elevated risk of lung cancer among members of the Trade Union of Insulation Workers.     

Age at exposure modifies the effects of low-level ionizing radiation on cancer mortality in an occupational cohort

In a cohort of 4,563 nuclear workers followed retrospectively from 1950 to 1994, we found that age at exposure modified the effects of external radiation dose on cancer mortality. Analyses involved application of conditional logistic regression to risk sets of age- and calendar time-matched cancer deaths, with covariates treated as time dependent and with cumulative radiation doses divided according to the age intervals in which exposure occurred. After adjustment for confounding factors, we found that workers exposed to external radiation after the age of 50 years experienced exposure-related elevations in mortality from cancer at any site [rate ratio (RR) = 1.98; 95% confidence interval (CI) = 0.63-6.26], radiosensitive solid cancer (RR = 3.29; 95% CI = 1.10-9.89), and lung cancer (RR = 3.89; 95% CI = 1.23-12.3) substantially greater (1.6- to 3.5-fold greater) than were seen in coworkers exposed at all earlier ages. In contrast, all of the radiation doses contributing to mortality from cancers of the blood and lymph system were received before age 50 (for age <50, RR = 2.73 and 95% CI = 1.46-5.10; for age > or =50, RR = 0.24 and 95% CI = 0.00-687). Our results for cancer of any site are consistent with the results of previous studies examining the effects of exposure age in nuclear workers. Thus, effects of low-level radiation doses may depend on exposure age, and furthermore, patterns of effect modification by age may differ by type of cancer.     

Reevaluation of lung cancer risk in the acrylonitrile cohort study of the National Cancer Institute and the National Institute for Occupational Safety and Health

OBJECTIVES: The present study provides additional analyses of data obtained earlier on lung cancer risk among workers with acrylonitrile exposure. METHODS: The original authors provided the data. For total mortality and the cancer sites of a priori interest (lung, stomach, brain, breast, prostate, and the lymphatic and hematopoietic systems), standardized mortality ratios (SMR) and 95% confidence intervals (95% CI) were computed, the total United States and surrounding counties being used as standard populations. Regional rate-based SMR values were also computed between lung cancer and cumulative acrylonitrile exposure. RESULTS: Except for lung cancer, the external comparisons corroborated the earlier internal comparisons (no increased cancer mortality risk). For lung cancer, the external comparisons revealed death deficits for the unexposed workers (SMR 0.68, 95% CI 0.5-0.9) and all categories of acrylonitrile-exposed workers. The SMR obtained using external rates and the most exposed group (SMR 0.92. 95% CI 0.6-1.4) differed from the corresponding relative risk (RR) of the internal rates (RR 1.5, 95% CI 0.9-2.4). CONCLUSIONS: The analysis of the present study provides little evidence that acrylonitrile exposure increases the mortality risk of cancers of a priori interest, including lung cancer. The lung cancer findings of the external comparison differed from the earlier findings of the internal comparisons. Selection bias (as the healthy worker effect) was probably not responsible. Additional follow-up and analyses, especially of the unexposed workers with low lung cancer rates, may help elucidate the internal and external comparison differences. Results from both comparisons should be presented when the relative risks differ markedly, as both have advantages and disadvantages.     

Exposure to nickel compounds and smoking in relation to incidence of lung and nasal cancer among nickel refinery workers.

OBJECTIVES: To investigate the relation between occupational hazards among nickel refinery workers and their exposure to different forms of nickel over time and the interaction between smoking and total exposure to nickel. METHODS: The cohort consisted of 379 workers with first employment 1916-40 and at least three years of employment and 4385 workers with at least one year of employment 1946-83. Data on smoking (ever or never) were available for almost 95% of the cohort. Two analyses were used, indirect standardisation from observed and expected numbers and Poisson regression. RESULTS: During the follow up 1953-93, 203 new cases of lung cancer were observed v 68 expected (standardised incidence ratio (SIR) 3.0, 95% confidence interval (95% CI) 2.6-3.4) and 32 cases of nasal cancer were observed v 1.8 expected (SIR 18.0, 95% CI 12-25). The Poisson regression analysis showed an excess risk of lung cancer in association with exposure to soluble forms of nickel, with a threefold increase in relative risk (RR) (P < 0.001) and a multiplicative effect of smoking and exposure to nickel. The RRs were 1.1 (95% CI 0.2-5.1) for exposed workers who had never smoked and 5.1 (95% CI 1.3-20.5) for exposed workers who smoked. CONCLUSION: It is not possible to state with certainty which specific nickel compounds are carcinogenic, but a significant excess risk was found for workers exposed to soluble nickel alone or in combination with other forms of nickel. The present study suggests a multiplicative effect of smoking and nickel exposure.     

Cancer mortality among European asphalt workers: an international epidemiological study. I. Results of the analysis based on job titles

BACKGROUND: Inhalation of bitumen fumes is potentially carcinogenic to humans. METHODS: We conducted a study of 29,820 male workers exposed to bitumen in road paving, asphalt mixing and roofing, 32,245 ground and building construction workers unexposed to bitumen, and 17,757 workers not classifiable as bitumen workers, from Denmark, Finland, France, Germany, Israel, the Netherlands, Norway, and Sweden, with mortality follow-up during 1953-2000. We calculated standardized mortality ratios (SMRs) and 95% confidence intervals (CIs) based on national mortality rates. Poisson regression analyses compared mortality of bitumen workers to that of building or ground construction workers. RESULTS: The overall mortality was below expectation in the total cohort (SMR 0.92, 95% CI 0.90-0.94) and in each group of workers. The SMR of lung cancer was higher among bitumen workers (1.17, 95% CI 1.04-1.30) than among workers in ground and building construction (SMR 1.01, 95% CI 0.89-1.15). In the internal comparison, the relative risk (RR) of lung cancer mortality among bitumen workers was 1.09 (95% CI 0.89-1.34). The results of cancer of the head and neck were similar to those of lung cancer, based on a smaller number of deaths. There was no suggestion of an association between employment in bitumen jobs and other cancers. CONCLUSIONS: European workers employed in road paving, asphalt mixing and other jobs entailing exposure to bitumen fume might have experienced a small increase in lung cancer mortality risk, compared to workers in ground and building construction. However, exposure assessment was limited and confounding from exposure to carcinogens in other industries, tobacco smoking, and other lifestyle factors cannot be ruled out.     

中国联苯胺作业工人职业性膀胱癌发病率和死亡率流行病学调查

本文研究了1972年至1977年在册的累计专业工龄一年以上天津、上海和吉林1972名联苯胺男工的膀胱癌发病率和死亡率。与上海市普通居民相比联苯胺工人膀胱癌的标化死亡比(SMR)为17.5(95%可信限:7.5～34.5)、标化发病比(SIR)为25.0(95%可信限:16.9～35.7)。联苯胺工人膀胱癌发病率增高25倍,与接触水平有关。低接触组SIR=4.8;中接触组SIR=36.2;高接触组SIR=158.4(X~2趋势检验P<0.01)。联苯胺生产工人SIR=45.7(95%可信限:20.9～86.8),联苯胺使用工人SIR=20.9(95%可信限:12.9～32.0)。联苯胺吸烟者危险度增加31倍(95%可信限:20.4～46.4),而非吸烟者仅11倍(95%可信限:3.6～25.8)。     

Occupational sunlight exposure and cancer incidence among Swedish construction workers

We studied sunlight exposure from outdoor work in relation to cancer, using data from 323,860 men participating in an occupational health service program of the Swedish construction industry. An experienced industrial hygienist assessed the exposure for 200 job tasks. We estimated relative risks (RRs) adjusted for age, smoking, and magnetic field exposure. There was an increased RR in the high-exposure group for myeloid leukemia [RR = 2.0, 95% confidence interval (95% CI) = 1.1-3.6] and lymphocytic leukemia (RR = 1.7, 95% CI = 0.9-3.2). For non-Hodgkin's lymphoma there was a 30% increase in risk in the high-exposure group (95% CI = 0.9-1.9). There was no increased risk of malignant melanoma, except for tumors of the head, face, and neck in the high-exposure group (RR = 2.0, 95% CI = 0.8-5.2), and we also found an increased risk for malignant melanoma of the eye in this group (RR = 3.4, 95% CI = 1.1-10.5). Outdoor workers had no increased risk of nonmelanoma skin cancer. Nevertheless, the RR for lip cancer (squamous cell carcinoma) among the high-exposure group was estimated at 1.8 (95% CI = 0.8-3.7). Among other sites, an increased risk of stomach cancer was suggested in this group (RR = 1.4, 95% CI = 1.0-1.9). The results for lymphoma, leukemia, and possibly also for stomach cancer might reflect a suppression of the immune system from ultraviolet light in outdoor workers.     

Cohort study of cancer risk among male and female shift workers

OBJECTIVES: Melatonin, a hormone that inhibits experimentally induced cancers, is suppressed by nighttime exposure to light so that nighttime shift workers may be at an increased risk of cancer. Previous studies of shift workers found an increased risk of breast cancer among women and suggested a possible increased risk of colon cancer among women and prostate cancer. The present study was conducted to see whether these previous findings could be confirmed and whether shift workers are at elevated risk for cancer at additional sites. METHODS: Altogether 2 102 126 male and 1 148 661 female workers were identified who worked in both 1960 and 1970. Their jobs were classified according to the percentage of shift workers, and they were followed from 1971 through 1989 or until they were diagnosed with cancer or died. Standardized incidence ratios (SIR) were used to compare the adjusted cancer incidence rates for shift workers with those for nonshift workers. RESULTS: Cancer rates were not elevated for the male shift workers [all sites combined: N=6524 cases among shift workers, SIR 1.02, 95% confidence interval (95% CI) 1.00-1.05; prostate: N=1319, SIR 1.04, 95% CI 0.99-1.10] or for the female shift workers (all sites combined: N=268, SIR 1.00, 95% CI 0.89-1.13; breast: N=70 cases, SIR 0.94, 95% CI 0.74-1.18). CONCLUSIONS: No evidence was found for an association between shift work and breast or prostate cancer, or all cancer sites combined among shift workers.     

Cancer incidence and mortality in a Swedish rubber tire manufacturing plant

BACKGROUND: A classification of 12 work categories was used to evaluate the cancer incidence and mortality among a cohort of Swedish rubber tire workers. METHODS: Cancer incidence and mortality in the cohort was compared with expected values from national rates. Standardized incidence and mortality ratios were calculated for the total cohort, for sub-cohorts and with the inclusion of a latency requirement. RESULTS: Among men, increased incidence and mortality risks were found for cancer in the larynx; SIR=2.10; 95% confidence intervals (95% CI): 1.05-3.76, SMR=2.08; 95% CI: 0.42-6.09. Increased risks were also seen for cancer in the trachea, bronchus, and lung; SIR=1.62; 95% CI: 1.28-2.02, SMR=1.54; 95% CI: 1.21-1.94, the incidence risk was highest among those with the longest exposure duration and among workers in compounding/mixing, milling, and maintenance. Decreased incidence risks were seen for cancer of the prostate (SIR=0.74; 95% CI: 059-0.92) and skin (SIR=0.57; 95% CI: 0.36-0.84). CONCLUSIONS: The finding of an excess of tumors in the respiratory system is in agreement with earlier findings in other studies on rubber tire workers. The results on other cancer types are compared to earlier findings and related to work processes and chemical exposures of possible causal importance.     

Cancer in the Norwegian printing industry

OBJECTIVES: The aim of this study was to investigate cancer risk among Norwegian workers in the printing industry, particularly lung and bladder cancer. METHODS: Cancer incidence was investigated from 1953 through 1998 in a cohort of 10 549 male members of a trade union in the printing industry in Oslo and nearby areas. Rates from the region, were used to calculate standardized incidence ratios (SIR) separately for the skilled and unskilled workers. Smoking data from a sample of the cohort were utilized for evaluating the risk estimates of smoking-related cancers. Specific exposure data were not available. RESULTS: Among the skilled workers, significantly elevated risks of cancer of the urinary bladder [standardized incidence ratio (SIR) 1.47, 95% confidence interval (95% CI) 1.19-1.79], liver (SIR 1.92, 95% CI 1.15-2.99), pancreas (SIR 1.46, 95% CI 1.07-1.94) and colon (SIR 1.27, 95% CI 1.05-1.55) were observed, whereas an increased risk of lung cancer in this group was confined to those born before 1910. Among the unskilled workers, there were significantly increased risks of cancer of the mouth, esophagus, stomach, larynx, lung, and all sites. CONCLUSIONS: The study showed that workers in the printing industry were at increased risk of several types of cancer. In particular the increased risk of bladder cancer among the skilled workers is suggestive of an occupational cause. However, no specific agent could be identified as an occupational carcinogen. The results did not support the hypothesis of a generally increased risk of lung cancer. The risk pattern for unskilled workers may reflect confounding by nonoccupational factors.     

Cancer incidence among workers in the asbestos-cement producing industry in Norway

OBJECTIVES: The incidence of cancer among employees of a Norwegian asbestos-cement factory was studied in relation to duration of exposure and time since first exposure. The factory was active in 1942-1968. Most of the asbestos in use was chrysotile, but for technical reasons 8% amphiboles was added. METHODS: For the identification of cancer cases, a cohort of 541 male workers was linked to the Cancer Registry of Norway. The analysis was based on the comparison between the observed and expected number of cancer cases. Standardized incidence ratios (SIR) and 95% confidence intervals (95% CI) were estimated. Period of first employment, duration of employment, and time since first employment were used as indicators of exposure. Poisson regression analysis was used for the internal comparisons. RESULTS: The standardized incidence ratio was 52.5 (95% CI 31.1-83.0) for pleural mesothelioma, on the basis of 18 cases. The highest standardized incidence ratio was found for workers first employed in the earliest production period (SIR 99.0, 95% CI 51.3-173). No peritoneal mesothelioma was found. The standardized incidence ratio for lung cancer was 3.1 (95% CI 2.14.3), but no dose-response effect was observed. The ratio of mesothelioma to lung cancer cases was 1:2. CONCLUSIONS: This study showed a high incidence of mesothelioma and a high ratio of mesothelioma to lung cancer among asbestos-cement workers. The high incidence of mesothelioma was probably due to the fact that a relatively high proportion of amphiboles was used in the production process.     

Mortality patterns among workers exposed to acrylamide: 1994 follow up

OBJECTIVE: To update the mortality experience of a cohort of 8508 workers with potential exposure to acrylamide at three plants in the United States from 1984-94. METHODS: Analyses of standardised mortality ratios (SMR) with national and local rates and relative risk (RR) regression modelling were performed to assess site specific cancer risks by demographic and work history factors, and exposure indicators for acrylamide and muriatic acid. RESULTS: For the 1925-94 study period, excess and deficit overall mortality risks were found for cancer sites of interest: brain and other central nervous system (CNS) (SMR 0.65, 95% confidence interval (95% CI) 0.36 to 1.09), thyroid gland (SMR 2.11, 95% CI 0.44 to 6.17), testis and other male genital organs (SMR 0.28, 95% CI 0.01 to 1.59), and cancer of the respiratory system (SMR 1.10, 95% CI 0.99 to 1.22); however, none was significant or associated with exposure to acrylamide. A previously reported excess mortality risk of cancer of the respiratory system at one plant remained increased among workers with potential exposure to muriatic acid (RR 1.50, 95% CI 0.86 to 2.59), but was only slightly increased among workers exposed or unexposed to acrylamide. In an exploratory exposure-response analysis of rectal, oesophageal, pancreatic, and kidney cancer, we found increased SMRs for some categories of exposure to acrylamide, but little evidence of an exposure-response relation. A significant 2.26-fold risk (95% CI 1.03 to 4.29) was found for pancreatic cancer among workers with cumulative exposure to acrylamide > 0.30 mg/m3.years; however, no consistent exposure-response relations were detected with the exposure measures considered when RR regression models were adjusted for time since first exposure to acrylamide. CONCLUSION: The contribution of 1115 additional deaths and nearly 60,000 person-years over the 11 year follow up period corroborate the original cohort study findings of little evidence for a causal relation between exposure to acrylamide and mortality from any cancer sites, including those of initial interest. This is the most definitive study of the human carcinogenic potential of exposure to acrylamide conducted to date.

 

     

Occupational risk factors for mortality from stomach and lung cancer among rubber workers: an analysis using internal controls and refined exposure assessment

OBJECTIVES: To determine occupational risk factors for stomach and lung cancer among workers in the German rubber industry. METHODS: A cohort of all male German rubber workers (n = 11,633) who had been employed for at least one year in one of five study plants and who were alive and actively employed or retired on 1 January 1981 was followed for mortality from 1 January 1981 through December 1991. A subcohort of n = 8,933 workers who were hired after 1 January 1950 was defined to focus on working conditions in the more recent rubber industry. Work histories were reconstructed using routinely documented 'cost centre codes' and classified into six work areas as well as subgroups of some work areas. The work areas are: 1. preparation of materials, 2. production of technical rubber goods, 3. production of tyres, 4. storage and dispatch, 5. maintenance, 6. others. Standardized mortality ratios (SMR) and Cox proportional hazards models were calculated for each of the work areas (>1 year of employment in the respective work area). Hazard rate ratios were adjusted for age (time marker) and stratified for year of hire (1950-1959, > or =1960) and years of employment in the respective work area (1-9 years, > or =10 years); years of employment were lagged 10 years to account for latency. RESULTS: Compared to the national reference population mortality from cancer of stomach (observed 44, SMR = 117; 95% CI: 85-157) and lung (observed 154, SMR = 123; 95% CI: 104-144) was slightly increased. Using internal controls we observed excess deaths from stomach cancer in work area 1 (relative risk [RR] = 2.3; 95% CI: 1.2-4.2) and from lung cancer in work areas 1 (RR = 1.7; 95% CI: 1.2-2.3), 2 (RR = 1.5; 95% CI: 1.1-2.1), and 3 (RR = 1.3; 95% CI: 0.9-1.8). On the basis of cumulative years of employment an exposure response relationship was observed for mortality from both cancer sites among a subcategory of work area 1: weighing and mixing. Increased risks were also seen for lung cancer among workers employed in production of technical rubber goods. CONCLUSION: Our results support an association between an excess mortality from stomach and lung cancer and employment in early production stages of rubber manufacturing, especially weighing and mixing. This may point to an aetiologic role of asbestos or carbon black. For stomach cancer additional risk factors, e.g. exposure to dust and talc, deserve further investigation. The results of the present study do not support a causal role of nitrosamines for stomach or lung cancer.     

Construction work and risk of occupational disability: a ten year follow up of 14,474 male workers

Aims: Most industrialised countries have public income maintenance programmes to protect workers in case of disability but studies addressing disability risk of specific professional groups are rare. The objective of this study was to establish a detailed pattern of the nature and extent of occupational disability among construction workers. Methods: A cohort study was set up including 14 474 male workers from the construction industry in Württemberg (Germany) aged 25–64 years who underwent occupational health exams between 1986 and 1992. The cohort was linked to the regional pension register of the manual workers'' pension insurance institution to identify workers who were granted a disability pension during the 10 year follow up. All-cause and cause specific standardised incidence ratios (SIR) and 95% confidence intervals (CI) were calculated using disability rates from the general workforce and from all blue collar workers in Germany as references. Results: In total, 2247 (16%) members of the cohort were granted a disability pension. Major causes of disability were musculoskeletal (45%) and cardiovascular diseases (19%). In comparison with the general workforce, construction workers experienced a higher risk of disability from cancer (SIR = 1.26; 95% CI 1.08 to 1.47), respiratory diseases (SIR = 1.27; 95% CI 1.03 to 1.55), musculoskeletal diseases (SIR = 2.16; 95% CI 2.03 to 2.30), injuries/poisoning (SIR = 2.52; 95% CI 2.06 to 3.05), and all causes combined (SIR = 1.47; 95% CI 1.41 to 1.53). When compared with the blue collar reference group, increased risks of disability among construction workers were found for musculoskeletal diseases (SIR = 1.53; 95% CI 1.44 to 1.63), injury/poisoning (SIR = 1.83; 95% CI 1.50 to 2.21), and all causes combined (SIR = 1.11; 95% CI 1.07 to 1.16). Conclusions: Musculoskeletal diseases and external causes are major factors limiting the work capability of construction workers and lead to an increased proportion of occupational disability.     

Mortality and incidence of bladder cancer in benzidine-exposed workers in China.

We examined bladder cancer mortality and incidence to 1981 in 1,972 workers employed in benzidine-exposed jobs in Tianjin, Shanghai, and Jilin, China, between 1972 and 1977, and in 1,974 unexposed workers employed during the same time period. In comparison to general population rates, in the benzidine-exposed group the ratio of observed to expected deaths (SMR) was 17.5 (95% C.I.: 7.5-34.5) and the ratio of observed to expected incident cases (SIR) was 25.0 (95% C.I.: 16.9-35.7). No excess was noted in the unexposed group. The 25-fold increase in bladder cancer incidence in the exposed group was related to level of exposure, with the SIR rising from 4.8 for low exposure to 36.2 for medium exposure, and 158.4 for high exposure. Risks were elevated both for producers of benzidine (SIR = 45.7; 95% C.I.: 20.9-86.8) and for users (SIR = 20.9; 95% C.I.: 12.9-32.0) of benzidine dyes. Benzidine-exposed workers who smoked tobacco had a 31-fold risk (95% C.I.: 20.4-46.4), while non-smoking workers had an 11-fold risk (95% C.I.: 3.6-25.8), suggestive of a multiplicative relationship between these two carcinogens.     

Mortality and cancer incidence in Swedish battery workers exposed to cadmium and nickel

OBJECTIVE: To follow up cancer incidence and mortality in a group of Swedish battery workers exposed to nickel hydroxide and cadmium oxide. METHODS: 869 workers, employed at least one year between the years 1940 and 1980 were followed up until 1992. Vital status and causes of death were obtained from the Swedish cause of death registry. Cancer morbidity was retrieved from the Swedish cancer registry. Regional reference rates were used to compute the expected numbers of deaths and cancers. RESULTS: Up to 31 December, 1992, a total of 315 deaths (292 in men and 23 in women) had occurred in the cohort. For men, the overall standardised mortality ratio (SMR) was 106 (95% confidence interval (95% CI) 93.7 to 118) and for women 83.8 (95% CI 53.1 to 126). The SMRs for total cancer mortality were 125 (95% CI 98.2 to 157) for men and 69.5 (95% CI 25.5 to 151) for women. The SMR for lung cancer in men was 176 (95% CI 101 to 287). No lung cancers were found among female workers. Up to 31 December, 1991, a total of 118 cancers had occurred in the cohort. A significantly increased standardised incidence ratio (SIR) was found for cancer of the nose and nasal sinuses in men, three cases v 0.36 expected, yielding an SIR of 832 (95% CI 172 to 2430). Applying a 10 year latency period in cohort members exposed to > or = 1000 micrograms cadmium/m3, the SIR was 1107 (95% CI 134 to 4000). Similarly, for cohort members exposed to 2000 micrograms nickel/m3, the SIR was 1080 (95% CI 131 to 3900). CONCLUSION: There was an increased overall risk for lung cancer, but no exposure-response relation between cumulative exposure to cadmium or nickel and risk of lung cancer. There was a highly significant increased risk of cancer of the nose and nasal sinuses, which may be caused by exposure to nickel or cadmium or a combination of both exposures.