Cancer mortality among a cohort of chromium pigment workers

A study of mortality among 1,879 male workers employed in a New Jersey chromium pigment factory was carried out, with follow-up from 1940 to 1982. Vital status of 1,737 (92%) of the eligible cohort members was determined. For all malignant neoplasms, 101 deaths were observed while 108.8 were expected, SMR = 93 (standardized mortality ratio; n.s.). For the entire study group, no significant excess was observed for respiratory cancer or cancer at other sites. However, the total number of years of employment in the factory and the total number of years of exposure to chromate dusts were both statistically significantly (p less than .05, for trend) associated with an increased risk for lung cancer. The excess risk for lung cancer associated with duration of exposure to chromate dusts was, however, only clearly apparent for subjects followed for 30 years or more after initial employment. For this group, the SMRs were 81, 139, 201, and 321 for the subjects with 0 years, less than 1 year, 1-9 years, and 10+ years of exposure to chromate dusts (p less than .01, for trend), respectively. The risk for digestive cancer was only weakly associated with exposure to chromate dusts.     

Cancer mortality in German carbon black workers 1976-98

Background

Few studies have investigated cancer risks in carbon black workers and the findings were inconclusive.

Methods

The current study explores the mortality of a cohort of 1535 male German blue‐collar workers employed at a carbon black manufacturing plant for at least one year between 1960 and 1998. Vital status and causes of death were assessed for the period 1976–98. Occupational histories and information on smoking were abstracted from company records. Standardised mortality ratios (SMR) and Poisson regression models were calculated.

Results

The SMRs for all cause mortality (observed deaths (obs) 332, SMR 120, 95% CI 108 to 134), and mortality from lung cancer (obs 50, SMR 218, 95% CI 161 to 287) were increased using national rates as reference. Comparisons to regional rates from the federal state gave SMRs of 120 (95% CI 107 to 133) and 183 (95% CI 136 to 241), respectively. However, there was no apparent dose response relationship between lung cancer mortality and several indicators of occupational exposure, including years of employment and carbon black exposure.

Conclusions

The mortality from lung cancer among German carbon black workers was increased. The high lung cancer SMR can not fully be explained by selection, smoking, or other occupational risk factors, but the results also provide little evidence for an effect of carbon black exposure.     

A cohort mortality study of foundry workers

Since the 1970s, hygienic improvements have led to a reduction in the level of airborne pollutants in Danish foundries. This mortality study reflects the exposure situation prior to 1970, and the findings may be used as a baseline for future evaluations of the preventive impact of reduced exposure. Mortality data were derived from a historical cohort study in which 3,056 foundry workers were compared with 43,024 workers employed in other industries. The foundry workers' life-long risk of dying from pneumoconioses averaged 2% and the corresponding standardized mortality ratio (SMR) equaled 7,368 (95% confidence interval (95% CI): 4,029–12,363). Excess mortality was also seen for chronic bronchitis and emphysema (SMR = 132, 95% CI: 98–185). Nonsignificant increases were seen for buccal cancer, stomach cancer, colon cancer, and urothelial cancer. In conclusion, Danish foundry workers exposed prior to 1970 seem to suffer an excess risk of devastating lung disease of occupational origin. Am. J. Ind. Med. 32:223-233, 1997. © 1997 Wiley-Liss, Inc.     

A cohort mortality study of construction workers

This report presents a mortality study among the 17,344 members of the Construction Workers' Health Insurance Society of Mie Prefecture in Japan. The study period was between 1973 and 1993. During this period, 480 members died. Age-specific mortality rates of Mie Prefecture were used as comparison standards. Significantly elevated standardized mortality ratio (SMR) and proportionate mortality ratio (PMR) were observed for “accidents and adverse effects.” In addition, the PMRs of all cancers and “cancers of trachea, bronchus and lung” were also significantly elevated. The job classifications were reorganized into three groups, according to the frequency of asbestos exposure the workers experienced on the construction sites. The asbestos exposure was based on job classifications among 7,411 workers who had completed a self-administered survey questionnaire. In the frequent-exposure group, the PMR was significantly elevated for all cancers. In the medium-exposure group, the SMRs were significantly elevated for all cancers and “cancer of trachea, bronchus and lung.” The PMR was significantly elevated for “cancer of trachea, bronchus and lung.” In the less-exposure group, the PMR was significantly elevated for “accidents and adverse effects.” This study provided support for the hypothesis that working in the construction industry might be associated with high risks for asbestos-associated cancers and accidental deaths. Am. J. Ind. Med. 32:35-41, 1997. © 1997 Wiley-Liss, Inc.     

General mortality and respiratory cancer among a cohort of male chemical workers in California.

Cohort mortality and nested case-control studies were conducted involving 2,901 men employed 1 year or more between 1940 and 1986 at any of four California facilities of a major chemical company. Employees experienced fewer deaths from each of the major causes than were expected based on U.S., California, and local county mortality rates. Respiratory cancer was significantly elevated in one socioeconomic category comprised of operators (SMR = 157, 95% CI = 109-220). The 34 cases who died from respiratory cancer and 136 matched controls, all of whom were operators, were included in a nested case-control study. Departments in which subjects had worked were grouped into 13 work assignment or product categories by an industrial hygienist without knowledge of case-control status. Smoking habits and other occupational exposures were ascertained by telephone interview from subjects or surrogate-responders. As expected, current cigarette smoking was strongly related to respiratory cancer. After adjustment for smoking, cases were significantly more likely than controls to have ever worked in one of the 13 work areas (supervision, services, and business support). However, no dose-response relationship was evident with duration of employment in this work area and the departments involved were associated with plant security and not chemical production. Results were similar when a 15-year latency period was assumed. These findings suggest that the excess of respiratory cancer mortality among operators was most likely due to differences in cigarette smoking or other factors not ascertained, rather than to a specific occupational exposure.     

Cancer incidence and mortality in workers employed at a transformer manufacturing plant: update to a cohort study

BACKGROUND: This study is an extension of a previously published analysis of cancer mortality in a transformer manufacturing plant where there had been extensive use of mineral oil transformer fluid. The objectives of the present study were to update the mortality analysis and include deaths for the past 6 years as well as to do an analysis of cancer incidence of the cohort. METHODS: A cohort of 2,222 males working at a transformer manufacturing plant between 1946 and 1975 was constructed. Using a classical historical cohort study design, cancer incidence and mortality were determined through record linkage with Canadian provincial and national registries. The rates of cancer incidence and mortality experienced by this cohort were compared to that of the Canadian male population. RESULTS: A statistically significant increased risk of developing and dying of pancreatic cancer was found but not an increase in overall cancer mortality. This was consistent with the previous report from this group. Interestingly, the cohort demonstrated a statistically significant risk of overall cancer incidence and specific increased incidence of gallbladder cancer. CONCLUSIONS: This study contributes further evidence to the growing body of literature indicating the carcinogenic properties of mineral oils used in occupational settings, in particular those used prior to 1970s.     

Retrospective follow-up study of foundry and engine plant workers

A retrospective follow-up study of 21,013 workers employed at a foundry and two engine manufacturing plants was conducted to determine if these workers had an unusual mortality experience. A total of 2,235 deaths occurred during the follow-up period of 1970–1987. Mortality from all causes was lower than expected. Men experienced a 6–13% excess of lung cancer deaths, depending on the choice of the comparison group. The data displayed evidence of a positive trend between lung cancer mortality and increasing duration of employment (p = 0.008). White men experienced a statistically significant excess of deaths from stomach cancer (standardized mortality ratio [SMR] = 158; 95% confidence interval [CI] = 101–234). Black men had increased mortality from pancreatic cancer, especially among engine plant workers (SMR = 303; CI = 121–624), and an excess of prostate cancer, concentrated among foundry workers (SMR = 234; CI = 112–430). © 1993 Wiley-Liss, Inc.     

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.     

A cohort mortality study among cobalt and sodium workers in an electrochemical plant

We have studied the mortality between 1950 and 1980 of a cohort of 1,143 workers in an electrochemical plant producing cobalt and sodium. The mortality of the whole cohort is significantly lower than in the French population for all causes of death (SMR = 0.77), and especially for deaths from circulatory system diseases (SMR = 0.59). However, among cobalt production workers, there is a relative over-mortality, especially from lung cancers (SMR = 4.66, 4 cases). The relationship between cobalt production and lung cancer mortality was supported by a case-control study nested in the cohort study. The authenticity of the occupational origin of this risk could not be established due to the low number of cases and because the role of tobacco consumption could not be taken into account. Other studies should be carried out in plants producing or using cobalt.     

Industry-wide study of mortality of pulp and paper mill workers

A study of pulp and paper mill workers indicated low risks of death from all causes (standardized mortality ratio (SMR) = 0.74) and all cancers (SMR = 0.81) compared with U.S. rates. The leukemia death rate in workers was not higher than the U.S. rate but was higher than the rate in county populations surrounding mills. Workers whose last jobs were in the finishing areas of the mills had an elevated SMR for liver cancer. An internal comparison of occupational characteristics indicated that workers employed in mills using other chemical pulping operations had significantly elevated mortality from all causes, all cancers, heart disease, lymphomas, and brain cancers. Lung cancer mortality was elevated in mills using kraft pulping. The internal comparisons confirmed the association between work in finishing and the risk of liver cancer. This study was designed to investigate whether pulp and paper mill workers have any risks that would indicate the need for studies detailing exposures. Am. J. Ind. Med. 33:354–365, 1998. © 1998 Wiley-Liss, Inc.     

Nonrespiratory mortality and cancer incidence in a cohort of Canadian nickel workers

Mortality and cancer incidence were examined for an updated cohort of nonsinter nickel workers in Sudbury and Port Colborne, Ontario, Canada. Abstract results are provided for those with ≥ 15 years since first exposure. For circulatory disease mortality, significant elevations were observed overall in many Sudbury work areas and in Port Colborne staff. Underground miners, with first exposure before 1960, displayed significant elevations for pneumoconiosis, as well as silicosis and anthrasilicosis, likely due to crystalline silica. Significant elevations in colorectal cancer incidence were observed in Sudbury underground mining, mining maintenance, and maintenance work areas. Given a case-control study is not practical, the next cohort update should include more detailed occupational exposure assessment, including dust exposure, diesel engine emissions, solvents, various metals, silica, and sulphur dioxide.     

Underlying and multiple cause mortality in a cohort of workers exposed to aromatic amines

Background The National Institute for Occupational Safety and Health (NIOSH) has previously conducted studies of bladder cancer incidence and mortality at a synthetic dye plant that manufactured beta-naphthylamine from 1940 through 1979. This report extends the period of mortality follow-up 13 years and analyzes both underlying and nonunderlying causes of death. Methods The vital status of each cohort member, as of December 31, 1992, was determined by using the National Death Index and information from the Internal Revenue Service and the U.S. Postal Service. The NIOSH life table analysis system (LTAS) was used to generate person-years-at-risk and the expected numbers of death for 92 categories of death, using several referent rates (U.S. underlying, Georgia underlying, U.S. multiple cause). Results There were three bladder cancer deaths listed as underlying cause, yielding a standardized mortality ratio (SMR) based on U.S. rates of 2.4 (95% confidence interval (CI) = 0.5, 7.0) and a total of eight bladder cancers listed anywhere on the death certificates (SMR based on multiple cause referent rates = 5.6; 95% CI = 2.4, 11.1). Mortality from esophageal cancer, which had been significantly elevated in the previous study, was no longer significantly elevated (SMR = 2.0; 95% CI = 0.8,4.1). Mortality from all causes was significantly higher than expected (SMR = 1.5; 95% CI = 1.3, 1.6). Conclusions The elevated bladder cancer risk in this cohort was detected by the multiple cause, but not the underlying cause, analysis. Elevated mortality from other causes of death, especially among short-term workers, may be related to regional and lifestyle factors. Am. J. Ind. Med. 34:506–511, 1998. © 1998 Wiley-Liss, Inc.     

1817名铸造厂工人缺血性心脏病的队列研究

目的研究铸造作业工人缺血性心脏病发病风险及其与铸造作业、矽尘累积接触量之间的剂量-反应关系,并对缺血性心脏病的发病风险进行预测。方法采用队列研究方法,选择某铸造厂1980年1月1日-1996年12月31日在册一年以上的铸造作业工人建立研究队列,观察终止日期为2009年12月31日。以浇注、配砂、清理、熔炼、天车、造型和制芯等工种工人作为铸造组,电工、钳工和检查工等辅助工作为对照组。使用SPSS软件Cox回归模型分析缺血性心脏病发病风险及其与铸造作业、矽尘累积接触量之间的剂量-反应关系,并使用logistic回归建立缺血性心脏病发病风险的预测模型。结果本研究共随访30年,1817人,45 553.05人年,缺血性心脏病156例,人-年发病率为342.46/10万,平均发病年龄51.46岁,发病工龄21.61年。男性、吸烟、饮酒、年龄和工龄分别都是缺血性心脏病发病的危险因素。缺血性心脏病发病风险与矽尘累积接触量呈正相关,调整吸烟的影响后,工人矽尘年累积接触量每增加1mg/m3,缺血性心脏病发病风险增加75.8%(RR=1.758,95%CI1.221～2.532)。铸造组工人缺血性心脏病发病风险显著增加,调整吸烟的影响后,与对照组工人相比,配砂工、清理工、熔炼工、造型工、制芯工分别增加1.048倍、1.395倍、70.4%、97.0%和1.270倍。根据预测模型,工人缺血性心脏病发病概率随日接触矽尘浓度的增加、接尘工龄的延长而增加。结论铸造作业工人面临较大的缺血性心脏病发病风险。不同工种工人缺血性心脏病发病风险不同,其中,配砂、清理、熔炼、造型、制芯工人较高。铸造作业、矽尘累积接触量是缺血性心脏病的独立危险因素。缺血性心脏病预测模型表明,发病概率与日接触矽尘浓度和接尘工龄呈明显的剂量-反应关系。     

Injury mortality in a cohort of mining,smelting, and refining workers in Ontario

Injury mortality was followed up from 1950 to 2000 in a cohort of 56,576 nickel workers. Injury fatalities were elevated throughout the cohort of never sinter plant workers (SMR = 134, 95% CI [129, 140]). Elevations were also observed in injury mortality subcategories of road, rail, and air (SMR = 137, 95% CI [127, 147]); boating and swimming (SMR = 150, 95% CI [128, 176]); suicide and possible suicide (SMR = 124, 95% CI [114, 135]); and possibly job-related accidents (SMR = 160, 95% CI [145, 175]). The results were largely attributed to underground miners, with 61.4% of all injury mortality (SMR = 162; 95% CI [153, 171]). Occupational etiology could not be ascertained; however, compiled workplace injury fatalities are presented separately. Recommendations include delivery of injury prevention and wellness programs in partnership with the local health unit and other stakeholders.     

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.     

A historical cohort mortality study among shipyard workers in Genoa, Italy

BACKGROUND: A historical cohort mortality study was conducted among 3984 shipyard workers assigned to ship repair, refitting, and construction in the harbor of Genoa, Italy, between 1960 and 1981. These workers were exposed to asbestos fibers, welding fumes and gases, silica dust, polycyclic aromatic hydrocarbons, and solvents. METHODS: Workers were classified in 20 different job-titles depending upon the type of activity. Standardized mortality ratios (SMRs) were computed using male residents of the Province of Genoa as the referent population. RESULTS AND CONCLUSIONS: For the whole cohort significantly increased SMRs were detected for all causes, all cancers, liver, larynx, lung, pleural and bladder cancers, respiratory tract diseases, and cirrhosis of the liver. The analysis by job-title showed increased SMRs not only for pleural cancer, but also for lung, laryngeal cancers and respiratory tract diseases in occupations entailing heavy asbestos exposure. Bladder and liver cancers and liver cirrhosis mortality also appeared to be related to occupational exposure.     

The mortality of coke workers in Britain

Two studies of coke workers in Britain, comprising 6,767 men, gave similar results. The proportion of lung cancer deaths was about 20% higher than in manual workers generally. The excess occurred primarily among younger men. The ratio of lung cancers to all other cancers was also higher than expected, with limited data showing no evidence of excessive tobacco consumption. Death rates from other causes were generally favorable. Overall the lung cancer death rates in oven workers were similar to those in non-oven men, but in both studies some indications of a job-specific excess were noted. These findings are compared with results from earlier studies in the United States and Canada where a much higher excess lung cancer mortality was found in oven men, particularly those with longer exposure times. We discuss possible reasons for the differences, and conclude that the results reported now contribute further evidence that exposure to coal carbonization fumes can cause lung cancer.     

An historical prospective study of mortality within a cohort of gas distribution workers

An historical prospective study of mortality within a cohort of 1,410 gas distribution workers was conducted. This cohort was followed for ten years (1971-1980) and data on 118 deaths were obtained. Five-year (1973-1977) averages of both St. Louis and United States age-specific mortality figures were used to create "expected" mortality rates for comparison with the observed deaths in the cohort. Analyses of the cohort were done according to: 1) person-years contributed during the study period (the "age-attained" method) and 2) the number of years from commencement of work in the company until the end of the study period (1980) or death (the "latency" methods of analysis, Standardized Mortality Ratios (SMRs) were calculated for all causes of death, all malignant neoplasms, and for cardiovascular disease and malignant neoplasms of the respiratory and digestive systems. In no case was the SMR found to be beyond the range of what would be expected in the "standard" populations. While the present study does not contradict the negative findings of the one previous investigation of mortality of gas distribution workers, the limitations of small cohort size, reliance on death certificates and non-industrial comparison populations make any conclusions at best provisional.