Mortality of factory workers in east London 1933-80

The mortality of 3000 male factory workers, 1400 laggers, and 700 women factory workers in east London has been studied. The men were first employed between 1933 and 1964, the women between 1936 and 1942. Textiles were produced until the late 1950s as well as other asbestos products. Laggers were employed on contract in increasing numbers in later years. Crocidolite asbestos was used until the late 1950s as well as asmosite and chrysotile. Exposure of workers was graded according to the job into two categories, low/moderate and severe, and subdivided by duration of employment up to two years or longer. Mesothelial tumours accounted for 7.5% of the total mortality in men, and 9% in women with their longer follow up period. Lung cancer accounted for 20% of deaths in men and 14% in women. Both mesothelial tumours and lung cancer showed a dose response relationship. Histopathological examination of a series of predominantly postmortem specimens showed 22% of adenocarcinomas of lung among men and 21% in women. There was an excess of gastrointestinal tumours but no dose response relationship could be shown. Among severely exposed male factory workers there was an excess of deaths from cancer of the larynx and among severely exposed women of carcinoma of the breast and ovary. Twenty four deaths (2%) were due to asbestosis. There is an indication that the incidence of mesothelial tumours is declining but a further period of observation is required for confirmation.     

Mortality of factory workers in east London 1933-80.

The mortality of 3000 male factory workers, 1400 laggers, and 700 women factory workers in east London has been studied. The men were first employed between 1933 and 1964, the women between 1936 and 1942. Textiles were produced until the late 1950s as well as other asbestos products. Laggers were employed on contract in increasing numbers in later years. Crocidolite asbestos was used until the late 1950s as well as asmosite and chrysotile. Exposure of workers was graded according to the job into two categories, low/moderate and severe, and subdivided by duration of employment up to two years or longer. Mesothelial tumours accounted for 7.5% of the total mortality in men, and 9% in women with their longer follow up period. Lung cancer accounted for 20% of deaths in men and 14% in women. Both mesothelial tumours and lung cancer showed a dose response relationship. Histopathological examination of a series of predominantly postmortem specimens showed 22% of adenocarcinomas of lung among men and 21% in women. There was an excess of gastrointestinal tumours but no dose response relationship could be shown. Among severely exposed male factory workers there was an excess of deaths from cancer of the larynx and among severely exposed women of carcinoma of the breast and ovary. Twenty four deaths (2%) were due to asbestosis. There is an indication that the incidence of mesothelial tumours is declining but a further period of observation is required for confirmation.     

Exposures and mortality among chrysotile asbestos workers. Part II: mortality

A retrospective cohort mortality study was conducted among a cohort of 1,261 white males employed one or more months in chrysotile asbestos textile operations and followed between 1940 and 1975. Statistically significant excess mortality was observed for all causes combined (standardized mortality ratio [SMR] = 150), lung cancer (SMR = 135), diseases of the circulatory system (SMR = 125), nonmalignant respiratory diseases (SMR = 294), and accidents (SMR = 134). Using estimated fiber exposure levels in conjunction with detailed worker job histories, exposure-response relationships were investigated. Strong exposure-response relationships for lung cancer and asbestos related non-malignant respiratory diseases were observed. Compared with data for chrysotile miners and millers, chrysotile textile workers were found to experience significantly greater lung cancer mortality at lower lifetime cumulative exposure levels. Factors such as differences in airborne fiber characteristics may partially account for the large differences in exposure response between textile workers and miners and millers.     

Mortality among employees of an Ontario factory manufacturing insulation materials from amosite asbestos

The mortality of workers from an Ontario factory manufacturing amosite asbestos insulation materials under poorly controlled environmental conditions is reported here. Seven (58%) of 12 deaths among exposed workers 10 or more years after first exposure were due to malignancies; four (25%) were from lung cancer, and there were two deaths from peritoneal mesothelioma. Those dying from mesothelioma were 47 and 49 years of age. Three (25%) of 12 deaths were from respiratory disease, two were attributed to asbestosis (in men 42 and 53 years of ages), and one to pneumonia in a 54-year-old male.     

Correlation between fibre content of the lung and disease in east London asbestos factory workers

The lungs from 36 past workers at an east London asbestos factory who had died from asbestos related disease were compared with lung tissue from 56 matched control patients being operated on in east London for carcinoma of the lung, correlating the severity of asbestosis and the presence of pulmonary carcinoma or mesothelioma of the pleura or peritoneum with an asbestos exposure index and type and amount of mineral fibre in the lungs. Asbestosis was associated with far heavier fibre burdens than mesothelioma. There was also a striking difference in the degree of asbestosis between the subjects with mesothelioma and those with carcinoma of the lung, the asbestosis being more severe in the latter. A further finding was that crocidolite and amosite were strongly associated with asbestosis, carcinoma of the lung complicating asbestosis, and mesothelioma, whereas no such correlation was evident with chrysotile or mullite. It is suggested that more emphasis should be placed on the biological differences between amphibole and serpentine asbestos fibre.     

Mortality of workers in a French asbestos cement factory 1940-82

The mortality of a complete cohort of 1506 French asbestos cement workers employed for at least five years is related to the time elapsed since first exposure. The mortality from all causes (analysed by the "man-years method") has been found to be above normal only in those subjects employed for more than 20 years, with more than 35 years of follow up. Standardised mortality ratios for cancers of all sites (ICD 140-209) and pulmonary cancer (ICD 162-163.0) have been assessed in subjects whose first exposure dates go back more than 20 years. Mortalities from cancer of all sites and from pulmonary cancer have been detected in excess in workers employed for more than 20 years and originally hired when aged 25 or under.     

Influence of age at death on accuracy of death certificate disease diagnosis: findings in 475 consecutive deaths of mesothelioma among asbestos insulation workers and asbestos factory workers.

Age at death had no appreciable influence on accuracy of death certificate diagnoses of 475 consecutive deaths of mesothelioma among asbestos insulation and asbestos factory workers, until age 75 or older.     

Mortality of workers in a French asbestos cement factory 1940-82.

The mortality of a complete cohort of 1506 French asbestos cement workers employed for at least five years is related to the time elapsed since first exposure. The mortality from all causes (analysed by the "man-years method") has been found to be above normal only in those subjects employed for more than 20 years, with more than 35 years of follow up. Standardised mortality ratios for cancers of all sites (ICD 140-209) and pulmonary cancer (ICD 162-163.0) have been assessed in subjects whose first exposure dates go back more than 20 years. Mortalities from cancer of all sites and from pulmonary cancer have been detected in excess in workers employed for more than 20 years and originally hired when aged 25 or under.     

Correlation between fibre content of the lung and disease in east London asbestos factory workers.

The lungs from 36 past workers at an east London asbestos factory who had died from asbestos related disease were compared with lung tissue from 56 matched control patients being operated on in east London for carcinoma of the lung, correlating the severity of asbestosis and the presence of pulmonary carcinoma or mesothelioma of the pleura or peritoneum with an asbestos exposure index and type and amount of mineral fibre in the lungs. Asbestosis was associated with far heavier fibre burdens than mesothelioma. There was also a striking difference in the degree of asbestosis between the subjects with mesothelioma and those with carcinoma of the lung, the asbestosis being more severe in the latter. A further finding was that crocidolite and amosite were strongly associated with asbestosis, carcinoma of the lung complicating asbestosis, and mesothelioma, whereas no such correlation was evident with chrysotile or mullite. It is suggested that more emphasis should be placed on the biological differences between amphibole and serpentine asbestos fibre.     

Mortality from a Chinese asbestos plant: Overall cancer mortality

The cancer mortality in a Chinese asbestos plant using only chrysotile was studied. Opened in the 1950s, all workers with at least 1 year of employment by 1972 were followed through 1994. Most workers were female. Excess cancer mortality, compared to local city data, was found for lung cancer, including many cases among nonsmoking women, and stomach cancer. Plant asbestos levels have been high in the past but have consistently come down over the decades. Am. J. Ind. Med. 32:442–444, 1997. © 1997 Wiley-Liss, Inc.     

Colorectal cancer in asbestos cement workers in Denmark

Recent data on the risk of colorectal cancer following exposure to chrysotile are conflicting. We report on colorectal cancer morbidity in a large cohort of asbestos cement workers from Denmark mainly exposed to chrysotile. The total cohort had an SIR of 1.23 (95%CI 1.01–1.48). With a latency period of 15 years, men employed in the early (1928–1950) production period had an SIR of 1.47 (95%CI 1.05–2.01). With the observation of excess risks of colorectal cancer morbidity among chrysotile exposed asbestos cement workers in both Sweden and Denmark the question on the role of chrysotile in the etiology of colorectal cancer remains open. © 1996 Wiley-Liss. Inc.     

Mortality study of asbestos cement workers

The present study describes cause-specific mortality of asbestos cement workers in the Emilia Romagna region of Italy. The cohort included workers in ten factories, most of which started operating between 1955 and 1965. Asbestos, mainly chrysotile, constituted 10%–20% of the dry component of the mixture. Crocidolite range between 5% and 50% of total asbestos. Asbestos concentrations up to 44 ff/cc were reported prior to 1975, while in recent years they have usually been below 0–1 ff/cc. The cohort included 3341 workers who had at some time been employed in the ten factories under study. Their mortality experience was compared with that of the population resident in Emilia Romagna. Vital status was ascertained at 1989. Seventy-three subjects were lost to followup (2.2%). Mortality from all causes and from all types of cancer was increased in the cohort. Malignant neoplasms of the respiratory tract showed a significant increase (SMR: 134; 90% confidence interval: 101–175; 40 observed) due to lung cancer (SMR: 124; 90% confidence interval: 91–166; 33 observed) and neoplasms of the pleura, mediastinum, and other parts of the respiratory tract (SMR: 602; 90% confidence interval 237–1267; 5 observed). The discrepancy between observed and expected mortality mainly concerned subjects with at least 20 years of employment in the factories. Five more cases of histologically confirmed mesothelioma occurred after the end of follow-up.     

Mortality from cancers of major sites in female radium dial workers

The female radium dial workers have now experienced significant mortality from cancers other than the bone sarcomas and head carcinomas long known to be radium induced. The relationships of radium exposure to mortality from cancers of the stomach, pancreas, colon, rectum, liver, lung, breast, cervix, and corpus uteri, and from leukemia were studied in 1,285 pre-1930 dial workers. Mortality was compared with that expected from rates for US white females, with and without adjustment for local area mortality rates, and with mortality in dial workers exposed from 1930 to 1949. For the 693 cases whose body content of radium has been measured since 1955, dose-response relationships of cancer to systemic intake of radium and duration of employment were examined. Liver, pancreatic, cervical, and uterine cancers were clearly unrelated to radium exposure. Other cancers of the digestive tract appeared to be indirectly, if at all, associated with work in radium facilities. Lung cancer requires further investigation; inhalation exposures of the dial workers were reviewed. Analyses of the breast cancer data uncovered several observations inconsistent with the previously suggested causal association with radium exposure. Multiple myeloma was also reviewed. A threefold excess risk of death due to multiple myeloma has occurred, but is more closely correlated with duration of employment (a surrogate for external gamma radiation) than with radium intake.     

Cancer in ex‐asbestos cement workers in Israel, 1953–1992

A cohort of 3,057 male workers employed in an asbestos‐cement plant using 90% chrysotile‐10% crocidolite, located in Northern Israel, was followed from 1953–1992 for incidence and mortality from cancer. In the years 1978–1992, the cohort had an elevated risk for all malignant neoplasms combined (n > 153, SIR > 117, ns), lung cancer (n > 28, SIR > 135, ns), mesothelioma (n > 21; SIR >5000, p > .0001), unspecified pleural cancer (n > 5; SIR > 278 , P > .0001), and liver cancer (n > 7, SIR 290, ns). Risks for colo‐rectal (n > 19; SIR > 79, ns), bladder (n = 12, SIR 69) and renal cancers (n > 5, SIR 104) were less than expected. Risk for mesothelioma showed a sharp risk gradient with duration of exposure, increasing from 1 per 625 for those employed less than 2 years to 1 per 4.5 workers employed over 30 years. The ratio of mesothelioma to excess lung cancer cases was 2.9 to 1, or 3.6 to 1, if pleural cases of unspecified origin were included; the pleura to peritoneum ratio of verified mesothelioma cases was 20 to 1. This atypically high ratio of mesothelioma to excess lung cancer cases is suggested to be the combined result of high past asbestos exposures in the workers and their low prior risk for lung cancer, and possibly, relatively early smoking cessation in relation to asbestos exposure. Am. J. Ind. Med. 35:1–8, 1999. © 1999 Wiley‐Liss, Inc.