Retrospective cohort mortality study of cancer among sewage plant workers

There is little known about the incidence of cancer among sewage workers. In this paper we examine findings from a retrospective cohort study of 487 white male sewer authority workers employed between January 1950 and October 1979. Vital status was ascertained for 93% of the cohort yielding a total of 6,886 person years. Total mortality from all causes was comparable to that of the general white male U.S. population (Standardized Mortality Ratio [SMR] = 0.91, 95% Confidence Interval [CI] = 0.77-1.07). The cohort was subdivided into those not exposed, and sewer workers who were exposed to sewage effluent, sludge, or wastewater containing chemicals including potential carcinogens. Among the nonexposed group, mortality from all causes was significantly low (SMR = 0.55, 95% CI = 0.33-0.88). Among the exposed sewer workers, mortality from all causes was not significantly different from that of the general white male U.S. population (SMR = 1.00, 95% CI = 0.84-1.19). Mortality from all cancers among exposed sewer workers was slightly higher than that of the general population (SMR = 1.19, 95% CI = 0.79-1.7). Statistically significant elevated mortality ratios were seen for cancer of the larynx (SMR = 7.93, 95% CI = 1.59-23.96), and cancer of the liver (SMR = 5.4, 95% CI = 1.10-16.05). Careful study of the medical and occupational histories of these cases suggested that larynx cancer was possibly work-related, while liver cancer was not. A group estimated to be the highest exposed, composed predominantly of operatives, had a higher directly adjusted death rate from all malignant neoplasms combined compared to all other workers (rate ratio = 1.64). These findings of increased risk of cancer among exposed sewage workers, especially operators, are based on small number of cases and should be interpreted with caution. Studies of larger cohorts are needed to clarify the risk of these cancers among sewage workers.     

Cancer mortality among workers in the German rubber industry: 1981-91.

OBJECTIVES: To determine the cancer specific mortality of active and retired workers of the German rubber industry with emphasis on cancer sites which have been associated with the rubber industry in previous studies. METHODS: A cohort of 11,663 German men was followed up for mortality from 1 January 1981 to 31 December 1991. Cohort members were active (n = 7536) or retired (n = 4127) at the beginning of the study, and had been employed for at least one year in one of five study plants producing types or general rubber goods. Vital status was ascertained for 99.7% of the cohort members, and cause of death found for 96.8% of the 2719 decedents. Age and calendar year adjusted standardised mortality ratios (SMR) and 95% confidence intervals (95% CI) were calculated overall from national reference rates and stratified by year of hire and by years since hire. RESULTS: Mortalities from all causes (SMR 108; 95% CI 104-112) and all cancers (SMR 111; 95% CI 103-119) were significantly increased in the study cohort. Significant excesses in the mortalities from lung cancer (SMR 130; 95% CI 115-147) and pleural cancer (SMR 401; 95% CI 234-642) were identified. SMRs higher than 100 were found for cancers of the pharynx (SMR 144; 95% CI 76-246), oesophagus (SMR 120; 95% CI 74-183), stomach (SMR 110; 95% CI 86-139), rectum (SMR 123; 95% CI 86-170), larynx (SMR 129; 95% CI 69-221), prostate (SMR 108; 95% CI 84-136), and bladder (SMR 124; 95% CI 86-172), as well as for leukaemia (SMR 148; 95% CI 99-213). Mortalities from liver cancer, brain cancer, and lymphoma were lower than expected. CONCLUSIONS: Mortalities from cancer of several sites previously associated with the rubber industry were also increased among workers of the German rubber industry. Results of the stratified analyses are consistent with a role of occupational exposure in the aetiology of some of these cancers.     

Occupational mortality in Hong Kong, 1979-1983

Occupational mortality among Hong Kong males aged 15 and above were examined for the period 1979-1983, using routine death registration and census data. Age-standardized mortality ratios (SMR) and relative SMR (RSMR) were calculated for each two-digit occupational group and elevated mortality from all and various causes were highlighted. Mortality from ischaemic heart disease was strikingly associated with professional and sales-managerial occupations whereas colorectal cancers were associated with predominantly clerical and sales workers. Mortality from cancer of the buccal cavity and pharynx was elevated in fishermen as well as in farmers, food, drink and tobacco workers, mechanical fitters, and others. Excesses of liver cancer were found in doctors, fishermen and construction workers. Lung cancer deaths were particularly excessive among fishermen, plumbers and welders, construction workers and transport equipment operators. Fishermen were at high risk of death from cancers of the buccal cavity and pharynx, stomach, liver and lung, cerebrovascular diseases and cirrhosis. Miners and quarrymen experienced high mortality from pulmonary tuberculosis and chronic obstructive airways disease whereas construction workers also experienced high mortality from pulmonary tuberculosis as well as cancers of the liver, lung and bladder and non-Hodgkin's lymphomas. Transport workers were at high risk of dying from cancers of the stomach and lung, cerebrovascular diseases and diabetes mellitus. These and other associations were generally in line with those found from other similar surveys or detailed studies. The limitations of such studies are many and discussed in the context of Hong Kong.(ABSTRACT TRUNCATED AT 250 WORDS)     

Extended mortality follow-up of a cohort of dry cleaners

PURPOSE: The mortality follow-up of a cohort of dry cleaners was extended to further evaluate cancers risks associated with organic solvents. METHODS: The underlying and contributing causes of death among 5,369 members of a dry cleaning union in St. Louis were determined through December 31, 1993. The mortality experience of the cohort was compared to that of the US population adjusted for age at entry, year of death, race and gender. RESULTS: The total mortality was about as expected (SMR = 1.0, N = 2351, 95% CI = 1.0-1.1). Excesses were observed for emphysema (SMR = 1.7, N = 21, 95% CI = 1.0-2.5), Hodgkin's disease (SMR = 2.0, N = 5, 95% CI = 0.6-4.6) and cancers of the esophagus (SMR = 2.2, N = 26, 95% CI = 1.5-3.3), larynx (SMR = 1.7, N = 6, 95% CI = 0.6-3.7), lung (SMR = 1.4, N = 125), 95% CI = 1.1-1.6), and cervix (SMR = 1.6, N = 27, 95% CI = 1.0-2.3). These excesses occurred among men and women and blacks and whites. Bladder cancer was elevated among white men and women and kidney cancer among black men and women, but not significantly so. None of these causes of death showed strong relationships with duration or estimated level of exposure to dry cleaning solvents, although relative risks for cancers of the larynx, lung and kidney were larger among subjects estimated to have higher levels of exposure and risks from bladder cancer and chronic nephritis were greater among persons who entered the union after 1960. CONCLUSION: The excesses observed are unlikely to be due to chance because most occurred in earlier as well as the recent follow-up. The specific factors contributing the excesses, however, are not clear. Socioeconomic, lifestyle, and occupational exposures are all possibilities. Lack of information on socioeconomic and lifestyle factors hampers evaluation.     

Mortality in the British printing industry: a historical cohort study of trade union members in Manchester.

A historical cohort study of the printing industry was established after an anecdotal report of a cluster of cases of bladder cancer in a newspaper factory in Manchester. The cohort comprised some 9500 men who were members of one or other of two trade unions (the NGA and NATSOPA) in the Manchester area between 1949 and 1963. During the follow up period (1949-83) 3482 deaths occurred among men born in 1890 or later; follow up was 97% complete. The results of the study do not support the hypothesis of an occupational risk of bladder cancer in the printing industry. The NGA have a standardised mortality ratio (SMR) of 63 (95% confidence interval (95% CI) 31-113) and NATSOPA an SMR of 113 (95% CI 67-178) based on 11 and 18 deaths from bladder cancer, respectively. Men involved in newspaper letterpress printing have a high mortality from lung cancer (SMR = 179, 95% CI 144-218) that is consistent with the findings of previous studies. Increased mortality from cancer of the buccal cavity and pharynx was found for NATSOPA workers in the newspaper industry; editorial workers had an SMR of 1053 (95% CI 128-3803) and clerical workers had an SMR of 638 (95% CI 132-1864). This is consistent with a review of published studies, which strongly suggest that workers in the printing industry have an increased risk of mortality from cancers of the buccal cavity and pharynx. Socioeconomic differences in union composition, rather than occupational factors, may account for the lower mortality in the NGA compared with NATSOPA. The NGA, a craft union, had an all causes SMR of 92 (95% CI 88-97), whereas NATSOPA covered a broader span of occupations and skill levels, and had an all causes SMR of 112 (95% CI 106-117); the NATSOPA and NGA all causes rate ratio was 1.21 (95% CI 1.13-1,29).     

Cancer and other causes of death among a cohort of dry cleaners

Mortality among 5365 members of a dry cleaning union in St. Louis, Missouri, was less than expected for all causes combined (SMR = 0.9) but slightly raised for cancer (SMR = 1.2). Among the cancers, statistically significant excesses occurred for oesophagus (SMR = 2.1) and cervix (SMR = 1.7) and non-significant excesses for larynx (SMR = 1.6), lung (SMR = 1.3), bladder (SMR = 1.7), thyroid (SMR = 3.3), lymphosarcoma and reticulosarcoma (SMR = 1.7), and Hodgkin's disease (SMR = 2.1). Mortality from emphysema was also significantly raised (SMR = 2.0). Eleven of the 13 deaths from oesophageal cancer occurred among black men. The risk of this cancer showed a significant association with estimated cumulative exposure to dry cleaning solvents (rising to 2.8-fold in the highest category) but not with level or duration of exposure. Mortality from kidney cancer was not excessive as reported in other studies. Excesses for emphysema and cancers of the larynx, lung, oesophagus, bladder, and cervix may be related to socioeconomic status, tobacco, or alcohol use. Although the number of deaths was small, the greatest risk for cancers of the lymphatic and haematopoietic system (fourfold) occurred among workers likely to have held jobs where exposures were the heaviest. Small numbers and limited information on exposure to specific substances complicates interpretation of this association but is unlikely to be due to confounding by tobacco use. It was not possible to identify workers exposed to specific dry cleaning solvents but mortality among those entering the union after 1960, when use of perchloroethylene was predominant, was similar to those entering before 1960.     

Cancer and other causes of death among a cohort of dry cleaners.

Mortality among 5365 members of a dry cleaning union in St. Louis, Missouri, was less than expected for all causes combined (SMR = 0.9) but slightly raised for cancer (SMR = 1.2). Among the cancers, statistically significant excesses occurred for oesophagus (SMR = 2.1) and cervix (SMR = 1.7) and non-significant excesses for larynx (SMR = 1.6), lung (SMR = 1.3), bladder (SMR = 1.7), thyroid (SMR = 3.3), lymphosarcoma and reticulosarcoma (SMR = 1.7), and Hodgkin's disease (SMR = 2.1). Mortality from emphysema was also significantly raised (SMR = 2.0). Eleven of the 13 deaths from oesophageal cancer occurred among black men. The risk of this cancer showed a significant association with estimated cumulative exposure to dry cleaning solvents (rising to 2.8-fold in the highest category) but not with level or duration of exposure. Mortality from kidney cancer was not excessive as reported in other studies. Excesses for emphysema and cancers of the larynx, lung, oesophagus, bladder, and cervix may be related to socioeconomic status, tobacco, or alcohol use. Although the number of deaths was small, the greatest risk for cancers of the lymphatic and haematopoietic system (fourfold) occurred among workers likely to have held jobs where exposures were the heaviest. Small numbers and limited information on exposure to specific substances complicates interpretation of this association but is unlikely to be due to confounding by tobacco use. It was not possible to identify workers exposed to specific dry cleaning solvents but mortality among those entering the union after 1960, when use of perchloroethylene was predominant, was similar to those entering before 1960.     

Lung cancer mortality in the German chromate industry, 1958 to 1998

OBJECTIVES: We conducted a mortality study of two German chromate production facilities and evaluated possible dose-response relationships between hexavalent chromium exposure and lung cancer. METHODS: Mortality was followed-up through 1998 and limited to those employed since each plant converted to a no-lime production process. More than 12,000 urinalysis results of chromium levels were available, as was smoking information. RESULTS: All-cause mortality indicated a healthy worker effect (standardized mortality ratio [SMR] = 0.80, 95% confidence interval [CI] = 0.67-0.96); however, lung cancers appeared to be increased (SMR = 1.48, 95% CI = 0.93-2.25). No clear dose-response was found in stratified analyses by duration of employment and time since hire. On the basis of urinary chromium data, lung cancer risk was elevated only in the highest exposure group (SMR = 2.09, 95% CI = 1.08-3.65). CONCLUSIONS: These data suggest a possible threshold effect of occupational hexavalent chromium exposure on lung cancer.     

Mortality among workers at a talc mining and milling facility

BACKGROUND: This study evaluated mortality among workers at a talc mining and milling facility. METHODS: Subjects were white men actively employed between 1948 and 1989 and known to have been alive in or after 1950. Analyses assessed cancer mortality during the period 1950-89 (809 subjects) and non-cancer mortality during 1960-89 (782 subjects). RESULTS: Comparisons with regional general population death rates for 1960-89 indicated that the workers had more than expected deaths from all causes combined [209 observed/160 expected, standardized mortality ratio (SMR) = 131, 95% confidence interval (CI) = 114-150], due mainly to increased mortality from lung cancer (31/13, SMR = 232, CI = 157-329) and non-malignant respiratory disease (NMRD) (28/13, SMR = 221, CI = 147-320). The lung cancer excess was concentrated in miners (18/4.6, SMR = 394, CI = 233-622); millers had only a small increase (7/5.5, SMR = 128, CI = 51-263). An excess of NMRD occurred both in miners (10/4.2, SMR = 241, CI = 116-444) and in millers (11/4.8, SMR = 227, CI = 113-407). The median estimated exposure to respirable dust was 511 mg/m(3)-days for all exposed employees, 739 mg/m(3)-days for mine workers and 683 mg/m(3)-days for mill workers. Employees with high, compared with low, estimated exposure to dust had a rate ratio of 0.5 (CI = 0.2-1.3) for lung cancer and of 11.8 (CI = 3.1-44.9) for pulmonary fibrosis. CONCLUSIONS: Exposure to talc ore dust may not have been responsible for the lung cancer excess among these workers but probably contributed to the elevated rate of NMRD, particularly pulmonary fibrosis.     

Mortality from lung cancer in workers exposed to sulfur dioxide in the pulp and paper industry

Our objective in this study was to evaluate the mortality of workers exposed to sulfur dioxide in the pulp and paper industry. The cohort included 57,613 workers employed for at least 1 year in the pulp and paper industry in 12 countries. We assessed exposure to SO(2) at the level of mill and department, using industrial hygiene measurement data and information from company questionnaires; 40,704 workers were classified as exposed to SO(2). We conducted a standardized mortality ratio (SMR) analysis based on age-specific and calendar period-specific national mortality rates. We also conducted a Poisson regression analysis to determine the dose-response relations between SO(2) exposure and cancer mortality risks and to explore the effect of potential confounding factors. The SMR analysis showed a moderate deficit of all causes of death [SMR = 0.89; 95% confidence interval (CI), 0.87-0.96] among exposed workers. Lung cancer mortality was marginally increased among exposed workers (SMR = 1.08; 95% CI, 0.98-1.18). After adjustment for occupational coexposures, the lung cancer risk was increased compared with unexposed workers (rate ratio = 1.49; 95% CI, 1.14-1.96). There was a suggestion of a positive relationship between weighted cumulative SO(2) exposure and lung cancer mortality (p-value of test for linear trend = 0.009 among all exposed workers; p = 0.3 among workers with high exposure). Neither duration of exposure nor time since first exposure was associated with lung cancer mortality. Mortality from non-Hodgkin lymphoma and from leukemia was increased among workers with high SO(2) exposure; a dose-response relationship with cumulative SO(2) exposure was suggested for non-Hodgkin lymphoma. For the other causes of death, there was no evidence of increased mortality associated with exposure to SO(2). Although residual confounding may have occurred, our results suggest that occupational exposure to SO(2) in the pulp and paper industry may be associated with an increased risk of lung cancer.     

The Drake Health Registry Study: cause-specific mortality experience of workers potentially exposed to beta-naphthylamine

OBJECTIVE: To examine the cause-specific mortality experience of an occupational cohort with probable past exposure to beta-naphythylamine (BNA). METHODS: Subjects were 374 male and 26 female workers employed at a Pennsylvania chemical plant that produced or used beta-naphthylamine (BNA) between 1940 and 1981. Vital status through 1998 was determined for 97.5% of the cohort and cause of death for 100% of 79 deaths. Limited industrial hygiene data and reports from former employees were used to categorize workers as high, medium, or low risk for BNA exposure. Statistical analyses included US and local county-based standardized mortality ratios (SMRs). RESULTS: We observed statistically significantly elevated county rate-based SMRs for all causes combined (SMR = 1.98, 95% confidence interval (CI) = 1.56-2.49), all malignant neoplasms combined (28 deaths, SMR = 3.08, 95% CI = 2.05-4.46), respiratory system cancer (12 deaths, SMR = 3.91, 95% CI = 2.02-6.83), and bladder cancer (four deaths, SMR = 16.83, 95% CI = 4.59-43.1). Three bladder cancer cases were classified as high risk (SMR = 26.79, 95% CI = 5.53-78.29). Mortality risks were also elevated for most other malignant and non-malignant cause of death categories examined. CONCLUSIONS: Bladder cancer risk remains highly elevated among Drake/Kilsdonk workers and appears to be causally related to past BNA exposure. While lifestyle and behavioral risk factors may explain some of the mortality excesses for non-urological cancers, the possibility remains that BNA exposure may have also played a role in these and other observed cancer excesses.     

Mortality of aluminium reduction plant workers in France

The mortality between 1950 and 1976 of 6455 French aluminium plant workers was analysed in order to assess occupational risks (especially lung cancer) associated with electrolysis, particularly with the S?derberg process. Mortality from all causes (SMR = 0.85), was lower in this cohort than in the French male population ('healthy worker effect'), and cancer mortality (SMR = 1.09) was only slightly higher. There was an excess of mortality from accidents (mainly non-occupational) in electrolysis workers (SMR = 1.38) and from cirrhosis of the liver in maintenance workers (SMR = 1.63). Among electrolysis workers, only those who had worked less than 10 years had a relative excess mortality from lung cancer (SMR = 1.94), but this did not seem to be associated with a particular electrolysis process. However a substantial underlying risk of lung cancer in S?derberg workers could not be excluded, although such a risk appeared unlikely for prebake workers.     

Cancer incidence among foundry workers in Denmark

Cancer incidence was studied among 6,144 male foundry workers who were invited to participate in either of two Danish national silicosis surveys conducted during 1967-1969 and 1972-1974. Cancer incidence was followed through to the end of 1985 by computerized linkage to the Danish Cancer Registry, and Standardized Morbidity Ratios (SMRs) were calculated based on incidence rates for the Danish population. For the entire cohort, significantly elevated SMRs were seen for all cancers (SMR, 1.09; 95% CI, 1.01-1.18) and lung cancer (SMR, 1.30; 95% CI, 1.12-1.51), and SMRs were at the borderline of statistical significance for bladder cancer (SMR, 1.24; 95% CI, 0.97-1.59). Excess lung and bladder cancer risk were confined to workers who had worked in foundries for at least 20 y. There was a positive correlation between silicosis prevalence in employees at the foundries at the time of the x-ray examinations and lung cancer incidence during the follow-up period. Squamous cell carcinomas, anaplastic carcinomas, and other lung cancers accounted for the excess lung cancer risk, whereas there was not excess risk among the foundry workers for adenocarcinomas of the lung.     

Mortality among pilots and cabin crew in Greece, 1960-1997

BACKGROUND: Specific health hazards, among them radiation of cosmic origin, have caused some concern among aircrew in civil aviation in recent years. Several cohort studies in Northern countries have investigated mortality and cancer incidence among aircrew. Our goal was to study the pattern of mortality among Greek commercial airline cockpit and cabin crew. METHODS: We performed a retrospective cohort study including 843 Olympic Airways cockpit crew and 1835 cabin attendants. Standardized mortality ratios (SMR) were calculated based on death rates of the Greek population. Duration of employment as a proxy for occupational exposure was used to stratify the cohort. RESULTS: For cockpit crew, the overall SMR was 0.7 (n = 65, 95% CI: 0.5-0.9). The SMR for all cancers was also significantly decreased (n = 17; SMR = 0.6; 95% CI: 0.3-0.9). Most of this reduction was due to a large deficit in lung cancer deaths (SMR = 0.1; 95% CI: 0.0-0.5). Slight but non-significant increases were noted for brain and liver cancer. The SMR for cardiovascular death was close to unity. Among female cabin attendants the SMR for all causes was 0.8 (95% CI: 0.4-1.3). The SMR for all cancers was 0.8 (95% CI: 0.3-1.7). Mortality from breast cancer was not increased. Among male cabin crew, SMR for all causes was 0.5 (95% CI: 0.3-0.9). Analyses according to duration of employment showed no pattern. CONCLUSIONS: In this first-ever occupational cohort study in Greece, Greek aircrew had a low overall and cancer mortality. Due to the small number of events, the strength of our study is limited. The Greek data will be included in a pooled analysis of European studies.     

Mortality among taxi drivers in Rome: A cohort study

The mortality pattern of taxi drivers in Rome as possibly exposed mainly to gasoline engine exhausts was evaluated by means of a historical cohort study. A total of 2,311 male subjects registered as taxi drivers between 1950 and 1975 was followed from 1965 through 1988. The overall mortality was lower than expected on the basis of regional (Latium) reference rates (692 deaths, standardized mortality ratio [SMR] = 0.89, 95% confidence interval [CI] 0.82–0.96), whereas the number of recorded deaths for malignant neoplasms was about the expected (205 deaths, SMR = 0.99, 95% CI 0.86–1.13). Mortality from circulatory and respiratory diseases was lower than expected. Diabetes was significantly increased (42 deaths, SMR = 1.73, 95% CI = 1.25–2.34). An increased SMR appeared for respiratory cancer (SMR = 1.23, 95% CI = 0.98–1.50), mainly due to lung cancer (observed [O] = 76, SMR = 1.23, 95% CI = 0.97–1.54); two pleural cancers were also recorded. The excess of lung cancer deaths was present only among those enrolled in the most recent period (1965–1975) (45 deaths, SMR = 1.40, 95% CI = 1.02–1.87), especially among those of younger age (<65 years) (SMR = 1.86); there was no relation between lung cancer mortality and latency since first enrollment in the cooperatives or duration of membership. There are difficulties in interpreting the excess of lung cancer on the basis of occupational exposures; however, the increased risk observed among workers employed in more recent calendar periods may be due to heavier exposure in the last decades; further follow-up of the cohort may elucidate whether there is an increasing lung cancer risk among taxi drivers. © 1994 Wiley-Liss, Inc.     

Mortality study in an asbestos cement factory in Naples, Italy

The objective of this paper is to investigate mortality among 1247 male asbestos-cement workers employed in an asbestos-cement plant located in Naples. The cohort included 1247 men hired between 1950 and 1986. The follow-up began on January 1st 1965. The vital status and causes of death were ascertained up to December 31 2005. Cause-specific mortality rates of the Campania Region population were used as reference. Relative risks were estimated using Standardized Mortality Ratios (SMRs), and the confidence intervals were calculated at a 95% level (95% CI). A significant increase in mortality was observed for respiratory disease (81 deaths; SMR = 187; 95% CI = 149- 233), particularly for pneumoconiosis (42 deaths; SMR = 13 313; 95% CI = 9595-17 996) of which 41 deaths for asbestosis (SMR = 43 385; 95% CI = 31 134-58 857), for pleural cancer (24 deaths; SMR = 2617; 95% CI = 1677-3893), for lung cancer (84 deaths; SMR=153; 95% CI = 122-189) and for peritoneal cancer (9 deaths; SMR = 1985; 95% CI = 908-3769). Non-significant increases were also observed for rectum cancer (6 deaths; SMR = 157; 95% CI = 58-342). In conclusion, consistently with other mortality studies on asbestos-cement workers performed in different countries, an increased mortality from asbestosis, lung cancer, pleural and peritoneal mesothelioma was detected in the present cohort.     

Mortality among hourly motor vehicle manufacturing workers

We evaluated mortality among 198,245 motor vehicle industry workers during the period of 1973 to 1995. Workers' mortality rates were lower than expected overall (40,131 observed/43,859 expected deaths, standardized mortality ratio [SMR] = 92, CI = 91-92) and for all major cause of death categories except cancer (SMR = 100, CI = 98-102). Mortality rates were higher than expected for lung cancer overall (SMR = 110, CI = 107-113) and among employees in transmission/gear manufacturing (SMR = 121, CI = 112-130), casting operations (SMR = 122, CI = 110-135), engine manufacturing (SMR = 111, CI = 101-123), and vehicle assembly (SMR = 111, CI = 105-117); for stomach cancer in engine manufacturing (SMR = 147, CI = 110-192); and for prostate cancer in casting operations (SMR = 128, CI = 102-158). Excesses of lung cancer in transmission, vehicle assembly, and casting operations and of stomach cancer in engine manufacturing have been observed in other investigations. Further information on employees' occupational exposures and personal attributes is required to clarify the interpretation of these results.     

Mortality of butchers and cooks identified from the 1961 census of England and Wales.

OBJECTIVES--To explore a suspected hazard of lung cancer in butchers and cooks. METHODS--4018 male butchers and 2062 male cooks were identified from the 1961 census of England and Wales. 4857 (79.9%) of these men were traced through the National Health Service Central Register, and 3518 deaths were recorded during follow up to the end of 1992. Mortality from lung cancer and other causes was compared with that of the general population by the person-years method. RESULTS--Mortality from all causes was significantly below that of the national population in both butchers (standardized mortality ratio (SMR) 0.94, 95% confidence interval (95% CI) 0.90-0.98) and cooks (SMR 0.89, 95% CI 0.84-0.95). When allowance was made for a latency of 20 years from entry to follow up, the deficit in butchers was reduced, but that in cooks persisted, and was largely explained by a shortfall of deaths from cancer and circulatory disease. Mortality from lung cancer was close to expectation in the butchers (SMR 1.01, 95% CI 0.90-1.13) and below expectation in the cooks (SMR 0.93, 95% CI 0.75-1.13). Cooks had increased mortality from cancers of the oral cavity (SMR 5.57) and pharynx (SMR 2.66). CONCLUSIONS--The findings provide no support for an occupational hazard of lung cancer in either butchers or cooks. The possibility of excess risk in sub-groups of these occupations cannot be discounted. The high rates of oral and pharyngeal cancer in cooks are probably a consequence of high alcohol consumption.     

Cohort study of art glass workers in Tuscany, Italy: mortality from non-malignant diseases

This investigation studies cause-specific mortality of art glass workers employed in 17 industrial facilities in Tuscany, Italy. A cohort of 3,390 workers employed for at least 1 year was enumerated from company payrolls. Follow-up was between the start of employment in each factory and 31 December 1993. The cause-specific expected mortality was computed relative to Tuscany rates and specified for gender, 5-year age groups and calendar year. Separate analyses were carried out for the jobs of makers and formers and for batch mixers. Among males (3, 180 individuals) observed mortality for non-cancer causes was higher than expected for hypertensive disease [standardized mortality ratio (SMR) = 178, 90% confidence interval (90% CI) = 96-301], pneumoconiosis (SMR = 200, 90% CI = 94-376) and diseases of the genitourinary system (SMR = 169, 90% CI = 95-279). Increases for the above causes were shown also among makers and formers: hypertensive disease (SMR = 182, 90% CI = 85-341), pneumoconiosis (SMR = 250, 90% CI = 109-493) and diseases of the genitourinary system (SMR = 224, 90% CI = 121-380). For batch mixers an increase was present for cerebrovascular disease. The observed mortality for cancer causes was above the expected for cancers of the larynx, lung, stomach and brain. This study points to the existence for Tuscan glass workers of health effects in addition to cancer; previously observed carcinogenic effects were also confirmed.     

Mortality among maintenance employees potentially exposed to asbestos in a refinery and petrochemical plant

This paper reports the mortality experience from 1948 to 1989 of 2,504 maintenance employees who had a minimum of one year of employment in jobs with potential exposure to asbestos at a Texas refinery and petrochemical plant. For the purposes of this study, “potential exposure” is equated with those jobs or crafts having the greatest direct potential proximity to, or which worked directly with, asbestos-containing materials, especially asbestos-containing thermal insulation. Approximately one-half of the study population had 10 years or longer potential exposure, and 80% had their first potential exposure before 1970. The total population exhibited significantly lower mortality for all causes, the standardized mortality ratio (SMR = 77); and for all cancer (SMR = 85), as compared to residents in the surrounding communities. Statistically significant deficits in mortality were also observed in a number of noncancerous diseases such as heart disease (SMR = 78; 95% CI = 69-88), nonmalignant respiratory disease (SMR = 70; 95% CI = 50-95), and cirrhosis of the liver (SMR = 44; 95% CI = 22-79). Mortality among employees who had 20 years or longer since their first potential exposure was also examined; the pattern of mortality was similar to that exhibited by the total cohort, with a slight increase in the SMR for most of the causes. The only statistically significant excess of mortality found was a fourfold increase in mesothelioma (5 observed and 1.2 expected deaths); the SMR was 428 (95% CI = 139-996) for the total cohort and was 469 (95% CI = 152-1093) for those who had 20 years or more since first potential exposure. In contrast to asbestos industry worker studies, mortality for lung cancer was substantially lower than the general population (SMR = 81; 95% CI = 63-103). The observed number of deaths for cancer of the larynx was virtually the same as expected (3 observed vs. 2.8 expected). This study also showed decreased mortality for cancers of gastrointestinal organs such as the esophagus (SMR = 78), stomach (SMR = 63), large intestine (SMR = 91), rectum (SMR = 55), or pancreas (SMR = 90)—cancers that have been reported to be elevated in studies of various industry workers directly exposed to asbestos. © 1996 Wiley-Liss, Inc.