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.     

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 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.     

Non-neoplastic mortality of European workers who produce man made vitreous fibres

OBJECTIVE: To study mortality from non-neoplastic diseases among European workers who produce man made vitreous fibres (MMVF). METHODS: 11,373 male workers were studied, who were employed for at least 1 year in the production of rock or slag wool (RSW), glass wool (GW), and continuous filament (CF) in 13 factories from seven European countries. Workers were followed up from the beginning of production, between 1933 and 1950 to 1990-2 and contributed 256,352 person-years of observation. Standardised mortality ratios (SMRs) were calculated with national mortalities for reference; an internal exposure-response analyses based on multivariate Poisson regression models was also conducted. RESULTS: Mortality from bronchitis, emphysema, and asthma was not increased (SMR 1.03, 95% confidence interval (95% CI) 0.82 to 1.28). In RSW workers, there was no overall increase in mortality from non-malignant renal diseases (SMR 0.97, 95% CI 0.36 to 2.11), although there was the suggestion of an increase in risk with duration of employment. Mortality from ischaemic heart disease was not increased overall (SMR 1.03, 95% CI 0.96 to 1.11), but RSW and CF workers with > or = 30 years since first employment had a higher risk. RSW and CF workers showed an increased mortality from external causes, mainly motor vehicle accidents and suicide, which was higher among workers with a short duration of employment. CONCLUSIONS: Mortality from most non-neoplastic diseases does not seem to be related to employment in the MMVF industry. The results on mortality from ischaemic heart disease and non- malignant renal diseases, however, warrant further investigations.

 

     

Lung cancer mortality among workers in the European production of man-made mineral fibers--a Poisson regression analysis.

One hundred and eighty-one lung cancer deaths among workers during 301,085 person-years in European man-made mineral fiber production between 1930-1955 and 1982 were analyzed according to Poisson regression models including age, calendar period, country, and exposure variables. Time since first employment was the variable most strongly associated with lung cancer risk in both the rock-slag wool and glass wool subcohorts. Workers in the early technological phase were at higher risk than those in other categories, particularly in rock-slag wool production. No clear trend with duration of employment was suggested. No major changes occurred in the interpretation of the results when workers with less than one year of employment or less than 20 years since first exposure were excluded. The original results, based on analyses for standardized mortality ratios, were confirmed, and workers with a short duration of employment or a short time since first employment did not need to be excluded from the analysis.     

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.     

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 risk among 43000 Norwegian nurses

OBJECTIVES: This study evaluated the influence of occupational exposure on cancer risk among female Norwegian nurses. METHODS: A historical prospective cohort study was performed. The cohort was established from the Norwegian Board of Health's registry of nurses and included women who graduated from a nursing school before 1985. The cohort (N=43 316) was linked to the Cancer Registry of Norway. The observed number of cases was compared with the expected number on the basis of national rates. Time since first employment, period of first employment, and duration of employment were used as indicators of exposure. Poisson regression analyses were used for internal comparisons, adjusting for age, period, and fertility. RESULTS: The nurses were followed over 1473931 person-years. During the follow-up (1953-2002), 6193 cancer cases were observed. The standardized incidence ratio (SIR) for all cancers combined was close to unity. Significantly lower risks were found for cancers with a known association with alcohol and tobacco consumption and sexual activity. A significantly increased risk was found for breast cancer (SIR 1.14, 95% confidence interval (95% CI) 1.09-1.19), ovarian cancer (SIR 1.14, 95% CI 1.04-1.25), malignant melanoma (SIR 1.15, 95% CI 1.04-1.28), and borderline significant risk appeared for other skin cancer (SIR 1.12, 95% CI 0.98-1.29). A positive trend for increasing time since first exposure was found for breast cancer and malignant melanoma. CONCLUSIONS: The results indicate an association between working as a nurse and an increased risk of breast cancer and malignant melanoma. Decreased risks, found for several cancers, indicate favorable lifestyle habits among nurses.     

Update of cancer incidence among workers at a copper/nickel smelter and nickel refinery

Objectives: To assess cancer risk among nickel-exposed workers. Methods: We updated cancer incidence among 1388 workers employed for at least 3 months at a copper/nickel smelter and nickel refinery in Harjavalta, Finland. There were 1155 workers exposed to nickel during the period 1960–1985 in the smelter (566 workers), repair shop (239 workers), or refinery (418 workers). Cancer incidence was followed through the files of the Finnish Cancer Registry up to 31 December 1995. For overall cancer and for a priori selected specific cancer types the ratio of observed to expected numbers of cases was computed as a standardized incidence ratio (SIR), controlled for age, gender, and calendar period and using the region-specific rates as a reference. Results: The overall cancer incidence among both nickel-exposed and unexposed subcohorts was at the expected level. A small increase in lung cancer incidence, which reached statistical significance among workers with a latency exceeding 20 years, was observed among the smelter workers exposed to insoluble nickel compounds. Among workers in the refinery, who were exposed primarily to nickel sulfate at levels below 0.5 mg/m³ as well as to low concentrations of other nickel compounds, there was an increased risk for nasal cancer (SIR 41.1, 95% CI 4.97–148), positively associated with latency and duration of employment, and an excess risk for stomach (SIR 4.98, 95% CI 1.62–11.6) and lung (SIR 2.61, 95% CI 0.96–5.67) cancers. Conclusions: Since elevated nasal and lung cancer risks were confined to the refinery, where the primary exposure was to nickel sulfate, it is likely that nickel sulfate is mainly responsible for the elevated respiratory cancer risk. We cannot rule out whether the excess stomach cancer risk is a chance finding, or related to the working environment. Received: 11 September 1997 / Accepted: 17 October 1997     

Mortality and cancer incidence among Lithuanian cement producing workers

Aims: To investigate mortality and cancer incidence of cement producing workers.

Methods: A total of 2498 cement workers who have been employed at Portland cement producing departments for at least one year from 1956 to 2000 were followed up from 1 January 1978 to 31 December 2000. The cohort contributed 43 490 person-years to the study. Standardised incidence ratios (SIR) and standardised mortality ratios (SMR) were calculated as ratios between observed and expected numbers of cancers and deaths. The expected numbers were based on sex specific incidence and mortality rates for the total Lithuanian population.

Results: Significantly increased SMRs were found for all malignant neoplasms (SMR 1.3, 95% CI 1.0 to 1.5) and for lung cancer (SMR 1.4, 95% CI 1.0 to 1.9) among male cement workers. SIR for all cancer sites was 1.2 (95% CI 1.0 to 1.4). Excess risk was found for cancer of the lung (SIR 1.5, 95% CI 1.1 to 2.1). The SIR for urinary bladder cancer was also increased (SIR 1.8, 95% CI 0.9 to 3.5). The overall cancer incidence was not increased among females (SIR 0.8, 95% CI 0.6 to 1.1). With increasing cumulated exposure to cement dust, there were indications of an increasing risk of lung and stomach cancers among males.

Conclusions: This study supported the hypothesis that exposure to cement dust may increase the lung and bladder cancer risk. A dose related risk was found for stomach cancer, but no support was found for an increased risk of colorectal cancer.

     

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.     

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 among Australian nuclear industry workers

To assess whether workers at Lucas Heights Science and Technology Centre (LHSTC) had different levels of cancer incidence from the New South Wales (NSW) population in Australia. A retrospective cohort study was undertaken at LHSTC. Data on 7,076 workers employed between 1957-98 were abstracted from personnel, dosimetry, and medical files. An inception cohort was defined which included 4,523 workers in employment between 1972-96 to examine cancer incidence. Cancer registrations in the inception cohort were identified to 1996 through electronic linkage of records with the NSW and the Australian national registers of cancer incidence. All-cancer incidence in workers at LHSTC was 15% below the NSW rates [SIR=0.85; 95% CI=(0.75, 0.95)]. Of 37 specific cancers and groups of cancers examined, statistically significant excesses relative to NSW rates were observed only for pleural cancer incidence [SIR=17.71; 95%=(7.96, 39.43)], and for incidence of cancer of the small intestine [SIR=4.34; 95% CI=(1.40, 13.46)]. This study gives little evidence of an increased risk of cancers associated with radiation exposure in a cohort of nuclear workers in Australia. The observed increase in the risk of cancer of the pleura was probably due to unmeasured exposures, given the lack of an established association with radiation exposure, and the strong link to asbestos exposure. Findings for cancers of the small intestine were based on small numbers and were likely to be due to chance.     

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.     

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.     

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 among rock and slag wool production workers

BACKGROUND: Previous cohort studies have found an elevated risk of lung cancer among rock and slag wool (RSW) production workers. The aim of the present study was to investigate the risk of lung cancer associated with exposure to RSW while controlling for other occupational exposures and tobacco smoking. METHODS: Since 1971, a total of 196 lung cancer cases occurred among men who worked in seven plants in Denmark, Norway, Sweden, and Germany, with start of production between 1937 and 1950. We obtained information on occupational history and extra-occupational factors from either the subject or the next of kin for 133 cases and 513 matched controls. We assessed occupational exposure on the basis of interview data combined with information from expert panels set up in each factory. RESULTS: For cumulative exposure to RSW assessed with a 15-year lag, the smoking-adjusted odds ratios in the second, third, and fourth quartiles of exposure were 1.3 (95% confidence interval [CI] = 0.7-2.3), 1.0 (CI = 0.5-1.9), and 0.7 (CI = 0.3-1.3). Similar results were obtained when we included only those workers employed for more than 1 year, when we included other indicators of RSW exposure, and after control for co-exposures. CONCLUSIONS: This study provides no evidence of a carcinogenic effect on the lung of rock and slag wool under exposure circumstances in the production industry during the last four to five decades.     

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.     

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.     

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.