Cancer mortality and incidence of mesothelioma in a cohort of wives of asbestos workers in Casale Monferrato, Italy

BACKGROUND: Family members of asbestos workers are at increased risk of malignant mesothelioma (MM). Although the hazard is established, the magnitude of the risk is uncertain, and it is unclear whether risk is also increased for other cancers. Few cohort studies have been reported. OBJECTIVE: The "Eternit" factory of Casale Monferrato (Italy), active from 1907 to 1986, was among the most important Italian plants producing asbestos-cement (AC) goods. In this article we present updated results on mortality and MM incidence in the wives of workers at the factory. METHODS: We studied a cohort of 1,780 women, each married to an AC worker during his employment at the factory but not personally occupationally exposed to asbestos. Cohort membership was defined starting from the marital status of each worker, which was ascertained in 1988 from the Registrar's Office in the town where workers lived. At the end of follow-up (April 2003), 67% of women were alive, 32.3% dead, and 0.7% lost to follow-up. Duration of exposure was computed from the husband's period of employment. Latency was the interval from first exposure to the end of follow-up. RESULTS: The standardized mortality ratio (SMR) for pleural cancer [21 observed vs. 1.2 expected; SMR = 18.00; 95% confidence interval (CI), 11.14-27.52] was significantly increased. Mortality for lung cancer was not increased (12 observed vs. 10.3 expected; SMR = 1.17; 95% CI, 0.60-2.04). Eleven incident cases of pleural MM were observed (standardized incidence ratio = 25.19; 95% CI, 12.57-45.07). CONCLUSIONS: Household exposure, as experienced by these AC workers' wives, increases risk for pleural MM but not for lung cancer.     

Cancer mortality and morbidity among Lithuanian asbestos-cement producing workers

OBJECTIVES: This study investigated the incidence of cancer and cause-specific mortality among workers in the two Lithuanian asbestos-cement factories. METHODS: The study included 1887 asbestos-cement workers, 1285 men and 602 women, and 37000 person-years. The two factories were active from 1956 (A) and 1963 (B), and the workers were observed from 1978 to 2000. The analysis was based on a comparison between the observed and expected numbers of cancer and causes of death. The observed numbers of cancer were obtained through linkage with the national cancer registry. The date and causes of death were obtained from two different sources. The expected numbers were calculated on the basis of gender- and age-specific incidence and mortality rates in 5-year periods from the whole country. Standardized incidence ratios (SIR) and standardized mortality ratios (SMR) and 95% confidence intervals (95% CI) were calculated. Duration of employment and time since first exposure were used as indicators of exposure. RESULTS: During the follow-up, 1978-2000. 473 deaths were observed versus 489 expected. There was no excess risk of deaths from nonmalignant respiratory diseases, except for an elevated risk of mortality in relation to the digestive organs other than cancer, 18 observed versus 12.2 expected (95% CI 0.9-2.3). There was no excess risk for any types of cancer, except for colorectal cancer in men, 17 observed cases (SIR 1.6, 95% CI 1.6-2.6) and one case of mesothelioma in a woman. CONCLUSIONS: This study on asbestos-exposed workers did not show any excess risk of respiratory cancer or deaths of pneumoconiosis.     

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.     

Cancer incidence and mortality among Finnish asbestos sprayers and in asbestosis and silicosis patients

Cohorts of Finnish asbestos sprayers and of asbestosis and silicosis patients were followed for cancer with the aid of the Finnish Cancer Registry in the period 1967–1994. Compared with the cancer incidence of the total Finnish population, asbestos sprayers had an increased risk for total cancer (standardized incidence ratio [SIR] 6.7, 95% confidence interval [95% CI] 4.2–10); lung cancer (SIR 17, 95% CI 8.2–31); and mesothelioma (SIR 263, 95% CI 85–614). The SIR of the asbestosis patients was 3.7 (95% CI 2.8–5.0) for all sites, 10 (95% CI 6.9–14) for lung cancer, and 65 (95% CI 13–188) for mesothelioma. The silicosis patients also had significantly high SIR values for all sites (1.5, 95% CI 1.0–2.1) and lung cancer (2.7, 95% CI 1.5–4.5). The values for the SIR and the standardized mortality ratio for all sites and lung cancer were very similar, and therefore it seems that both are reliable indicators of the occurrence of occupational cancer. It was concluded that pneumoconioses patients and asbestos-exposed workers have a markedly elevated risk for cancer. Asbestos-induced occupational cancers are not only diseases of the elderly, since the relative risk is high also for middle-aged people. Am. J. Ind. Med. 31:693–698, 1997. © 1997 Wiley-Liss, Inc.     

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.     

Lung cancer and mesothelioma in the pleura and peritoneum among Swedish insulation workers

OBJECTIVES: To estimate the risk of cancer and death in Swedish insulation workers some years after their exposure to asbestos had stopped. One hypothesis was that the risk of lung cancer would tend to decrease some years after the exposure had ended. METHODS: In a cohort study the cancer morbidity and cause of death was investigated in 248 insulation workers and compared with the corresponding morbidity and mortality in the general population. Due to stringent regulations, exposure to asbestos of all types had almost ended in Sweden in the mid- 1970s. Through a questionnaire, surviving insulation workers were asked about their exposure to asbestos and their smoking habits. RESULTS: Between 1970 and 1994 there were 86 deaths compared with the 46.0 expected (standardised incidence ratio (SIR) 1.9; 95% confidence interval (95% CI) 1.5 to 2.3), the increase was mainly due to an increased cancer mortality. The morbidity was increased for lung cancer (11 cases v 2.5 expected (SIR 4.4; 95% CI 2.2 to 7.9)), peritoneal mesothelioma (seven cases; no expected incidence could be calculated as the occurrence is too rare in the general population), cancer in pancreas (five cases v 0.7 expected (SIR 7.1; 95% CI 2.3 to 16.7)). No cases of pleural mesothelioma were found. The risk of lung cancer did not tend to approach that of the general population after the exposure to asbestos decreased. CONCLUSIONS: In the 1980s and the early 1990s, Swedish insulation workers still have a highly increased risk of diseases related to asbestos. The attributable risk for death and cancer was about 50%. The study also confirms the previous finding that mesothelioma in insulation workers seems to be situated in the peritoneum more often than in the pleura.     

Different measures of asbestos exposure in estimating risk of lung cancer and mesothelioma among construction workers

To analyze occupation, expert-evaluated cumulative exposure, and radiographic abnormalities as indicators of asbestos-related cancer risk we followed 16,696 male construction workers for cancer in 1990-2000. We calculated standardized incidence ratios (SIR) in comparison to the Finnish population and relative risks (RR) in a multivariate analysis in comparison to the internal low-exposure category of each indicator. Overall, the risk was increased for mesothelioma (SIR 2.0, 95% CI = 1.0-3.3), but not for lung cancer (SIR 1.1, 95% CI = 0.9-1.2). Radiographic lung fibrosis indicated a 2-fold and a high value of the exposure index a 3-fold RR of lung cancer, while there was no risk among those with pleural plaques. The risk of lung cancer was the highest in insulators (RR 3.7, 95% CI = 1.4-9.9). Occupation, expert-evaluated cumulative exposure, and lung fibrosis are useful indicators of lung cancer risk among construction workers.     

Wood dust exposure and cancer incidence: a retrospective cohort study of furniture workers in Estonia

BACKGROUND: Occupational wood dust exposure is associated with increased risk of sinonasal cancer in men. However, little is known whether it is associated with sinonasal cancer in women or with malignancies of other sites. METHODS: In a retrospective cohort study of furniture workers, cancer incidence in 3723 men and 3063 women between 1968 and 1995 was compared to the incidence in the general population of Estonia. Cancer risks were analyzed by employment duration and occupation. RESULTS: The standardized incidence ratio (SIR) for all cancers did not differ significantly from one. Two men and one woman had sinonasal cancer (expected 1.07 and 0.53, respectively). Significantly increased risk of colon cancer was seen in the cohort (SIR 1.65, 95% confidence interval (CI) 1.22-2.17). Subjects employed for 10 years and over had significant excess of colon cancer (SIR 2.29, 95% CI 1.28-3.77) and rectal cancer (SIR 2.10, 95% CI 1.05-3.76) in the analysis by employment duration using exposure with a latency of 20 years. The nonsignificant excess of pharyngeal cancer in men (SIR 1.82) and lung cancer in women (SIR 1.43) was restricted to short-term workers. CONCLUSIONS: This study found an excess of colon and rectal cancer in furniture workers. There was no increase in total cancer risk.     

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 incidence among Swedish pulp and paper mill workers: a cohort study of sulphate and sulphite mills

Purpose

Associations between various malignancies and work in the pulp and paper industry have been reported but mostly in analyses of mortality rather than incidence. We aimed to study cancer incidence by main mill pulping process, department and gender in a Swedish cohort of pulp and paper mill workers.

Methods

The cohort (18,113 males and 2,292 females, enrolled from 1939 to 1999 with >1 year of employment) was followed up for cancer incidence from 1958 to 2001. Information on the workers’ department and employment was obtained from the mills’ personnel files, and standardized incidence ratios (SIRs) were calculated using the Swedish population as reference.

Results

Overall cancer incidence, in total 2,488 cases, was not increased by work in any department. However, risks of pleural mesothelioma were increased among males employed in sulphate pulping (SIR, 8.38; 95 % CI, 3.37–17) and maintenance (SIR, 6.35; 95 % CI, 3.47–11), with no corresponding increase of lung cancer. Testicular cancer risks were increased among males employed in sulphate pulping (SIR, 4.14; 95 % CI, 1.99–7.61) and sulphite pulping (SIR, 2.59; 95 % CI, 0.95–5.64). Female paper production workers showed increased risk of skin tumours other than malignant melanoma (SIR, 2.92; 95 % CI, 1.18–6.02).

Conclusions

Incidence of pleural mesothelioma was increased in the cohort, showing that asbestos exposure still has severe health consequences, and highlighting the exigency of strict asbestos regulations and elimination. Testicular cancer was increased among pulping department workers. Shift work and endocrine disruptors could be of interest in this context.     

Mortality and cancer incidence in Ontario glass fiber workers

BACKGROUND: In a previous cohort study of glass fiber manufacturing, we found a significant increase in lung cancer. This study extends the follow-up period. METHODS: We conducted a historical prospective study of 2557 men employed in producing glass wool. We obtained work histories, causes and dates of death, and date and site of cancer diagnoses. We computed standardized mortality and incidence ratios (SMR, SIR). RESULTS: The overall SMR for lung cancer was 163 (95% CI = 118-221). The SMR did not vary consistently by duration of employment and time since first employment. However, plant workers with >20 years' employment and >40 years since first exposure had an SMR for lung cancer of 282 (95% CI = 113-582). The SMR dropped with later date of first exposure, but the trend was non-significant. There was an unexpected overall increase in kidney cancer incidence. DISCUSSION: The increase in lung cancer is greater than in other cohorts of glass fiber workers. Since exposure data are lacking from the early years of the plant, we cannot state if the excess was due to glass fibers, other work exposures or other reasons.     

Cancer incidence among male Norwegian asphalt workers

BACKGROUND: The main objective of the present study was to investigate whether exposure to bitumen fumes could enhance the risk of cancer in asphalt workers. METHODS: A historical prospective cohort study was performed including 8,763 male asphalt workers from all main asphalt companies in Norway. Name, date of birth, and unique personal identification number, address, job type, and start and stop of employment in specific jobs was obtained for the workers. Information was complied from payroll and personnel records in the companies. The cohort was then linked to the Cancer Registry of Norway, which has complete records of individual cases of cancer in the Norwegian population since 1953. Follow-up was from 1 January 1970 to 31 December 1997. The 5-year age and period adjusted general male population in Norway served as reference population. RESULTS: Lung cancer was found elevated with standardized incidence ratio (SIR) = 1.3 (95% confidence intervals (CI) = 1.1, 1.7) in the overall analysis. Lung cancer was found more elevated in workers first exposed in the 1950s and 1960s and in mastic asphalt workers (SIR = 4.2, 95% CI = 1.2, 10, based on four cases) and pavers (SIR = 1.4, 95% CI = 1.0, 1.9). There was a deficiency in the incidence of malignant melanoma with 13 cases versus 26 expected. CONCLUSIONS: Risk of lung cancer was found enhanced among the asphalt workers. Some of the enhanced risk could probably be explained by the smoking habits of the workers. Exposure to coal tar may also have contributed to the enhanced risk.     

Evaluation of mortality and cancer incidence among alachlor manufacturing workers.

Alachlor is the active ingredient in a family of preemergence herbicides. We assessed mortality rates from 1968 to 1993 and cancer incidence rates from 1969 to 1993 for manufacturing workers with potential alachlor exposure. For workers judged to have high alachlor exposure, mortality from all causes combined was lower than expected [23 observed, standardized mortality ratio (SMR) = 0.7, 95% CI, 0.4-1.0], cancer mortality was similar to expected (6 observed, SMR = 0.7, 95% CI, 0.3-1.6), and there were no cancer deaths among workers with 5 or more years high exposure and 15 or more years since first exposure (2.3 expected, SMR = 0, 95% CI, 0-1.6). Cancer incidence for workers with high exposure potential was similar to the state rate [18 observed, standardized incidence ratio (SIR) = 1.2, 95% CI, 0.7-2.0], especially for workers exposed for 5 or more years and with at least 15 years since first exposure (4 observed, SIR = 1.0, 95% CI, 0.3-2.7). The most common cancer for these latter workers was colorectal cancer (2 observed, SIR 3.9, 95% CI, 0.5-14.2 among workers). Despite the limitations of this study with respect to small size and exposure estimating, the findings are useful for evaluating potential alachlor-related health risks because past manufacturing exposures greatly exceeded those characteristic of agricultural operations. These findings suggest no appreciable effect of alachlor exposure on worker mortality or cancer incidence rates during the study period.     

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 pulp and paper workers exposed to organic chlorinated compounds formed during chlorine pulp bleaching

The risk of cancer of 152 male workers exposed to organic chlorine compounds formed during chlorine pulp bleaching was assessed in a retrospective cohort study. The men had worked continuously for at least one year in selected job categories between 1 January 1945 and 31 December 1961. The cohort was followed for death and cancer incidence until 31 December 1987 with the use of the data of the National Population Register and the Finnish Cancer Registry. There were 12 observed cancers against 8.1 expected [standardized incidence ratio (SIR) 1.5, 95% confidence interval (95% CI) 0.8-2.6]. Among the stock preparation workers (N = 53), a significantly elevated risk of lung cancer was found (6 observed, 1.0 expected, SIR 6.3, 95% CI 2.3-14) that was especially prominent after a latency (time since first employment) of at least 15 years and in the age group of 35 to 59 years. Although all of the cases involved smokers, a part of the increased incidence may be associated with the workplace exposure to organic chlorinated compounds.     

Cancer incidence of workers in the Finnish pulp and paper industry

The cancer incidence of 3,545 workers in the Finnish pulp and paper industry was assessed in a retrospective cohort study. The cohort included workers with continuous employment of at least one year between 1 January 1945 and 31 December 1961 and was followed until 31 December 1980. Six subcohorts were formed (sulfite mill, sulfate mill, paper mill, board mill, maintenance department, and power plant). Separate analyses were made for the 2,597 workers hired after 1 January 1945. The smoking habits were surveyed. Among the men, 196 cases of primary cancer were detected versus 203.8 expected [standardized incidence ratio (SIR) 96, 95% confidence interval (95% CI) 82-114], and there were 47 cancer cases among the women versus 57.9 expected (SIR 91, 95% CI 60-108). Lung cancer occurred in 78 men (62.6 expected, SIR 125, 95% CI 98-155), and the excess was the most prominent for the male board mill workers (40 observed, 81.1 expected, SIR 222, 95% CI 158-302), particularly after 20 year's latency (25 observed, 7.8 expected, SIR 323, 95% CI 209-476). Analogous excesses of lung cancer occurred among the men (especially the male board mill workers) who began work after 1 January 1945. The findings were not explained by smoking habits.     

Cancer morbidity in workers at aluminum foundries and secondary aluminum smelters

In a Swedish cohort of workers (n = 6,454) from seven aluminum foundries and three secondary aluminum (scrap) smelters there was no overall excess risk of cancer among male or female workers less than 85 years of age (males: 325 observed cases, standardized incidence ratio (SIR) 1.02, 95% confidence interval (CI) 0.91–1.13; females: 22 cases, SIR = 0.95, 95% CI = 0.60–1.44). In male workers, however, significantly elevated risk estimates were observed for cancer of the lung (51 cases; SIR = 1.49, 95%CI = 1.11–1.96), anorectal cancer (33 cases; SIR 2.13, 95%CI = 1.47–2.99), and sinonasal cancer (4 cases; SIR = 4.70, 95%CI = 1.28–12.01). There was no increase of urinary bladder or liver cancer. Lung cancer risks were highest in workers with a short duration of employment (<5 years) suggesting determinants of risk related to socioeconomic factors rather than the occupational environment under study, but there were also indications of a lung cancer hazard from sand casting of aluminum for 10 years or more (SIR = 2.10, 95%CI = 1.01–3.87). The increase in anorectal cancer could not be etiologically related to occupational determinants of risk. Sand casting of aluminum aside, the cancer risk in secondary aluminum smelting seems to be lower than in primary aluminum smelting and in iron and steel founding, respectively. Am. J. Ind. Med. 32:467–477, 1997. © 1997 Wiley-Liss, Inc.     

Epidemiological investigation on the health status of employees in two factories manufacturing and repairing railway rolling stock: a historical perspective study of mortality

BACKGROUND: Epidemiological studies of cancer risk due to occupational exposure to asbestos in production and repair of railway rolling stock has so far given consistent results for mesothelioma, but conflicting evidence for lung cancer. OBJECTIVES: The main purpose of this study was to investigate risk for mesothelioma and lung cancer in relation to estimated patterns of exposure in the occupational environment of railway rolling stock manufacture and repair. METHODS: A historical prospective study approach was adopted. The mortality experience of the study population was compared to that of the population of the Veneto Region. Two historical cohorts of workers employed in two plants manufacturing and repairing railway coaches were followed up for mortality. A total of 1,621 workers were enrolled in the study from the first factory, and 1,190 from the second. RESULTS: An elevation of both pleural mesothelioma and lung cancer was reported in the two factories with SMRs of 21.52 (CI 95%=1.64-32.29) and 6.46 (CI 95%=1.33-18.88), and 1.26 (CI 95%=1.01-1.54) and 1.18 (CI 95%=0.81-1.66) respectively. The two excesses however showed different patterns in relation to historical exposure estimates, which appear to correlate with mesotheliomas but not with lung cancer. An elevation of mortality for non-neoplastic respiratory diseases was associated with employment during periods when it was estimated that exposure was at higher levels in one of the two firms. CONCLUSIONS: The results confirm the high carcinogenic risk deriving from asbestos exposure, although inconsistencies were found between target organs in relation to exposure estimates, and the existence of time periods in production in which cancer risk was different.     

Cancer incidence of Nordic asphalt workers

OBJECTIVES: The aim of the study was to investigate cancer risk following employment in the asphalt industry. METHODS :Cancer incidence was studied among 22 362 male asphalt workers employed for more than one season in jobs entailing exposure to bitumen (mainly road pavers) in Denmark, Finland, Norway, and Sweden. These workers are part of a European cohort of asphalt workers, for which results on mortality have been reported. The follow-up was almost complete, and reference rates were obtained from national cancer registries. RESULTS: The incidence of cancer was reduced in all four countries [overall standardized incidence ratio (SIR) 0.89, 95% confidence interval (95% CI) 0.86-0.94]. Lung cancer incidence was increased in all four countries, yielding an overall SIR of 1.21 (95% CI 1.07-1.36), but no trend was detected according to time since first employment. No overall increased incidence of bladder cancer was observed, but there was a suggestion of a tendency towards higher risk with longer time since first employment, with a relative risk of 1.85 (95% CI 0.90-3.78) for more than 30 years versus 1-14 years (P-value for trend 0.1). The incidence of lip and stomach cancer was nonsignificantly increased, and the excess was present mainly in Denmark. No increased incidence was detected for other neoplasms, notably malignant melanoma, nonmelanoma skin cancer, and kidney cancer. CONCLUSIONS: The results of this study confirm the pattern of cancer risk detected in the mortality analysis of the European cohort; in addition, they provide suggestive evidence of an excess risk of bladder cancer among asphalt workers.