A mortality study of workers at seven beryllium processing plants.

The International Agency for Research on Cancer (IARC) has found that the evidence for the carcinogenicity of beryllium is sufficient based on animal data but "limited" based on human data. This analysis reports on a retrospective cohort mortality study among 9,225 male workers employed at seven beryllium processing facilities for at least 2 days between January 1, 1940, and December 31, 1969. Vital status was ascertained through December 31, 1988. The standardized mortality ratio (SMR) for lung cancer in the total cohort was 1.26 (95% confidence interval [CI] = 1.12-1.42); significant SMRs for lung cancer were observed for two of the oldest plants located in Lorain, Ohio (SMR = 1.69; 95% CI = 1.28-2.19) and Reading, Pennsylvania (SMR = 1.24; 95% CI = 1.03-1.48). For the overall cohort, significantly elevated SMRs were found for "all deaths" (SMR = 1.05; 95% CI = 1.01-1.08), "ischemic heart disease" (SMR = 1.08; 95% CI = 1.01-1.14), "pneumoconiosis and other respiratory diseases" (SMR = 1.48; 95% CI = 1.21-1.80), and "chronic and unspecified nephritis, renal failure, and other renal sclerosis" (SMR = 1.49; 95% CI = 1.00-2.12). Lung cancer SMRs did not increase with longer duration of employment, but did increase with longer latency (time since first exposure). Lung cancer was particularly elevated (SMR = 3.33; 95% CI = 1.66-5.95) among workers at the Lorain plant with a history of (primarily) acute beryllium disease, which is associated with very high beryllium exposure. The lung cancer excess was not restricted to plants operating in the 1940s, when beryllium exposures were known to be extraordinarily high. Elevated lung cancer SMRs were also observed for four of the five plants operating in the 1950s for workers hired during that decade. Neither smoking nor geographic location fully explains the increased lung cancer risk. Occupational exposure to beryllium compounds is the most plausible explanation for the increased risk of lung cancer observed in this study. Continued mortality follow-up of this cohort will provide a more definitive assessment of lung cancer risk at the newer plants and among cohort members hired in the 1950s or later at the older plants. Further clarification of the potential for specific beryllium compounds to induce lung cancer in humans, and the possible contribution of other exposures in specific processes at these plants, would require a nested case-control study. We are currently assessing whether available industrial hygiene data would support such an analysis.     

Updated mortality study of workers at a petroleum refinery in Torrance, California, 1959 to 1997.

The updated cohort consisted of 3328 workers who were employed at the Mobil (now ExxonMobil) Torrance, California, refinery for at least 1 year between 1959 and 1997. The vital status of the cohort was determined through a variety of sources, including company employment or retirement records, the Social Security Administration's Death Master File, and the National Death Index. The updated study covered an observation period of 38 years from 1960 to 1997, with a total of 60,612 person-years of observation. A total of 705 (21.2%) cohort members were identified as having died. Mortality data were analyzed in terms of cause-specific standardized mortality ratios (SMRs) and 95% confidence intervals (95% CIs), with expected deaths based on US national cause-, gender-, race-, year-, and age-specific mortality rates. The overall mortality of the cohort was significantly lower than expected when compared with the US general population (SMR, 81.9; 95% CI, 76.0 to 88.2). Overall cancer mortality was also lower than expected (SMR, 79.8; 95% CI, 67.9 to 93.1). For specific cancer sites, significant mortality deficits were observed for cancer of the digestive system (SMR, 70.9; 95% CI, 49.4 to 98.6) and cancer of the respiratory system (SMR, 74.1; 95% CI, 55.5 to 97.0). No significant increase was reported for any site-specific cancer. For nonmalignant diseases, no significant increase was observed for any cause. In particular, significant mortality deficits were reported for ischemic heart disease (SMR, 87.7; 95% CI, 77.2 to 99.3), chronic endocardial disease and other myocardial insufficiencies (SMR, 8.3; 95% CI, 0.2 to 46.0), all other heart disease (SMR, 64.2; 95% CI, 43.0 to 92.2), and influenza and pneumonia (SMR, 59.2; 95% CI, 33.1 to 97.6). Detailed analysis by length of employment did not reveal any significant mortality excess or upward trend. Analyses of male employees by job classification (process and maintenance) were conducted. Among maintenance workers, mortality from cirrhosis of the liver (SMR, 190.1; 95% CI, 101.2 to 325.1) and suicide (SMR, 208.6; 95% CI, 111.1 to 356.7) were significantly elevated. However, these mortality excesses did not seem to be related to employment at the refinery. No other causes of death showed significant increase among maintenance workers. A similar separate analysis was conducted for process workers, and no significant excess was detected for any cause. The findings from the present study are discussed in conjunction with results from previous investigations of employees at the Torrance refinery and with results from other refinery studies. Potential limitations of the study are also discussed.     

Cause-specific mortality in the unionized U.S. trucking industry

BACKGROUND: Occupational and population-based studies have related exposure to fine particulate air pollution, and specifically particulate matter from vehicle exhausts, to cardiovascular diseases and lung cancer. OBJECTIVES: We have established a large retrospective cohort to assess mortality in the unionized U.S. trucking industry. To provide insight into mortality patterns associated with job-specific exposures, we examined rates of cause-specific mortality compared with the general U.S. population. METHODS: We used records from four national trucking companies to identify 54,319 male employees employed in 1985. Cause-specific mortality was assessed through 2000 using the National Death Index. Expected numbers of all and cause-specific deaths were calculated stratifying by race, 10-year age group, and calendar period using U.S. national reference rates. Standardized mortality ratios (SMRs) and 95% confidence intervals (CIs) were calculated for the entire cohort and by job title. RESULTS: As expected in a working population, we found a deficit in overall and all-cancer mortality, likely due to the healthy worker effect. In contrast, compared with the general U.S. population, we observed elevated rates for lung cancer, ischemic heart disease, and transport-related accidents. Lung cancer rates were elevated among all drivers (SMR = 1.10; 95% CI, 1.02-1.19) and dockworkers (SMR = 1.10; 95% CI, 0.94-1.30); ischemic heart disease was also elevated among these groups of workers [drivers, SMR = 1.49 (95% CI, 1.40-1.59); dockworkers, SMR = 1.32 (95% CI, 1.15-1.52)], as well as among shop workers (SMR = 1.34; 95% CI, 1.05-1.72). CONCLUSIONS: In this detailed assessment of specific job categories in the U.S. trucking industry, we found an excess of mortality due to lung cancer and ischemic heart disease, particularly among drivers.     

Mortality among Catholic nuns certified as radiologic technologists

BACKGROUND: Several studies have shown that Catholic nuns have a different mortality experience than women of similar age in the general population. We had a unique opportunity to evaluate mortality patterns of nuns identified in an occupational study of nearly 145,000 radiologic technologists (73% female). METHODS: A total of 1,103 women were classified as nuns based on their titles of "Sister" or "SR". Their mortality experience was compared to other female radiologic technologists and to U.S. white females. RESULTS: Five hundred eighty-three nuns (53%) were deceased as of January 1, 1995. Compared to other technologists, nuns were at significantly increased risk of dying from all causes (Standardized mortality ratio (SMR)=1.1; 95% Confidence interval (CI)=1.0-1.2, stomach cancer (SMR=2.7; 95% CI=1.2-5.4), diabetes (SMR=2.2; 95% CI=1.0-4.1), ischemic heart disease (SMR=1.2; 95% CI=1.1-1.4), all digestive diseases (SMR=2.0; 95% CI=1.3-3.0), and gastric and duodenal ulcers (SMR=8.3; 95% CI=2.3-21.3). In contrast, we observed a significant deficit in lung cancer (SMR=0.5; 95% CI=0.2-0.9), no deaths from cervical cancer, and a breast cancer risk 10% lower than expected (SMR=0.9; 95% CI=0.6-1.3). When compared to U.S. females, nuns experienced significantly reduced mortality from all causes (SMR=0.8; 95% CI=0.7-0.9), cervical cancer (SMR=0.0; 95% CI=0.0-0.7), all endocrine, metabolic and nutritional diseases (SMR=0.5; 95% CI=0.3-0.9), all circulatory diseases (SMR=0.7; 95% CI=0.7-0.8) including ischemic heart disease and cerebrovascular disease, and all respiratory diseases (SMR=0.5; 95% CI=0.3-0.8), and a nearly significant deficit of diabetes (SMR=0.6; 95% CI=0.3-1.0). In contrast, nuns had an almost 3-fold greater risk of tuberculosis (SMR=2.9; 95% CI=1.4-5.3) and a 20% excess of breast cancer (SMR=1. 2; 95% CI=0.8-1.7). The breast cancer excess was concentrated among nuns first certified before 1940 (SMR=2.0; CI=1.3-3.0), when radiation doses were possibly the highest, but the risk did not increase with increasing length of certification. CONCLUSIONS: Compared with the general population, the mortality experience of nuns was favorable and reflected the "healthy worker effect" commonly seen in occupational studies. Patterns observed for breast and cervical cancer possibly indicate differences in reproductive and sexual activities associated with belonging to a religious order. The possibility of a radiation-related excess for breast cancer among nuns certified before 1940 cannot be completely discounted, although there was no dose-response relationship with a surrogate measure of exposure (number of years certified). When their mortality experience was compared with other radiologic technologists, the influence of lifestyle factors was not apparent. Am. J. Ind. Med. 37:339-348, 2000. Published 2000 Wiley-Liss, Inc. dagger     

Mortality and cancer morbidity in workers exposed to low levels of vinyl chloride monomer at a polyvinyl chloride processing plant

To study whether exposure to low levels of vinyl chloride monomer (VCM) causes increased risk for cancer morbidity and death from ischemic heart disease, a cohort study was performed among 2,031 male workers at a polyvinyl chloride (PVC) processing plant who had been employed for at least 3 months during the period 1945-1980. An almost significantly increased total mortality (SMR = 116, 95% CI 99-136) was found. Deaths caused by violence or intoxication were significantly increased (SMR = 153, 95% CI 109-213), but not deaths from ischemic heart disease (SMR = 100, 95% CI 73-135). A significant increase in total cancer morbidity was observed (SMR = 128, 95% CI 101-161). Respiratory cancers were significantly increased (SMR = 213, 95% CI 127-346). Furthermore, six brain tumors (vs. 2.6 expected) were observed. This increase, however, was not significant (SMR = 229, 95% CI 84-498). No liver hemangiosarcoma was observed. Applying a latency period of greater than or equal to 10 years from start of employment did not change the risk patterns. There were no significant exposure-response associations between exposure estimates for VCM, asbestos, and plasticizers and cancer morbidity.     

Drinking water arsenic in Utah: A cohort mortality study

The association of drinking water arsenic and mortality outcome was investigated in a cohort of residents from Millard County, Utah. Median drinking water arsenic concentrations for selected study towns ranged from 14 to 166 ppb and were from public and private samples collected and analyzed under the auspices of the State of Utah Department of Environmental Quality, Division of Drinking Water. Cohort members were assembled using historical documents of the Church of Jesus Christ of Latter-day Saints. Standard mortality ratios (SMRs) were calculated. Using residence history and median drinking water arsenic concentration, a matrix for cumulative arsenic exposure was created. Without regard to specific exposure levels, statistically significant findings include increased mortality from hypertensive heart disease [SMR = 2.20; 95% confidence interval (CI), 1.36-3.36], nephritis and nephrosis (SMR = 1.72; CI, 1.13-2.50), and prostate cancer (SMR = 1.45; CI, 1.07-1. 91) among cohort males. Among cohort females, statistically significant increased mortality was found for hypertensive heart disease (SMR = 1.73; CI, 1.11-2.58) and for the category of all other heart disease, which includes pulmonary heart disease, pericarditis, and other diseases of the pericardium (SMR = 1.43; CI, 1.11-1.80). SMR analysis by low, medium, and high arsenic exposure groups hinted at a dose relationship for prostate cancer. Although the SMRs by exposure category were elevated for hypertensive heart disease for both males and females, the increases were not sequential from low to high groups. Because the relationship between health effects and exposure to drinking water arsenic is not well established in U.S. populations, further evaluation of effects in low-exposure populations is warranted.     

An updated mortality study of workers at a petroleum refinery in Beaumont, Texas, 1945 to 1996

The present investigation represents an update of a previous cohort mortality study of 7543 workers who were employed at a petroleum refinery in Beaumont, Texas, for at least 1 year between 1945 and 1996. The updated study covered an observation period of 51 years, from 1946 to 1996, with a total of 208,627 person-years of observation. A total of 3020 (40.0%) cohort members were known to have died. The mortality data were analyzed in terms of cause-specific standardized mortality ratios (SMRs) and 95% confidence intervals (95% CIs). The overall mortality of the cohort was significantly lower than expected when compared with that of the general US population (SMR, 95.7; 95% CI, 92.3 to 99.2). Overall cancer mortality was also lower than expected (SMR, 85.8; 95% CI, 79.4 to 92.5). For specific cancer sites, significant mortality deficits were observed for the following: buccal cavity and pharynx, esophagus, large intestine, rectum, larynx, lung, and bladder and other urinary organs. No significant increase was reported for any site-specific cancer. A non-significant increase in acute myeloid leukemia was observed among male employees (SMR, 147.2; 95% CI, 76.1 to 257.2). Detailed analyses indicated that the excess was restricted to workers hired before 1950. No increase was detected for other leukemia cell-types, non-Hodgkin's lymphoma, or multiple myeloma. For non-malignant diseases, the majority of SMRs were below 100, and no significant increase was observed for any cause. In particular, significant mortality deficits were reported for ischemic heart disease (SMR, 91.0; 95% CI, 85.4 to 96.9), non-malignant respiratory disease (SMR, 61.5; 95% CI, 52.2 to 72.0), pulmonary fibrosis (SMR, 51.0; 95% CI, 22.0 to 100.4), cirrhosis of the liver (SMR, 47.2; 95% CI, 30.6 to 69.7), and accidents (SMR, 81.7; 95% CI, 66.3 to 99.6). Separate analyses of male workers by job classification (process and maintenance) were conducted. Mortality from acute myeloid leukemia was elevated among employees in maintenance jobs (8 observed deaths vs 4.31 expected; SMR, 185.5; 95% CI, 80.1 to 365.6). However, no upward trend by length of service was found. A detailed analysis indicated that the acute myeloid leukemia mortality excess was limited to maintenance workers who were hired before 1950. No other significant excess was detected for any cause among maintenance or process workers. These findings from the present study were discussed in conjunction with results from previous investigations of employees at the Beaumont refinery and with results from other refinery studies. Potential limitations of the study were also discussed.     

Mortality and incidence of cancer in a cohort of Swedish chimney sweeps: an extended follow up study.

Despite 200 years of efforts to regulate safety in this occupation, chimney sweeps have increased mortality from cancer, ischaemic heart disease, and respiratory disease. Mortality and incidence of cancer were examined in a cohort of 5542 Swedish chimney sweeps employed through their national trade union at any time between 1918 and 1980. Previous studies of this cohort found increased risks of ischaemic heart disease, respiratory disease, accidental deaths, and various neoplasms. By increasing follow up, we sought to increase the power of the study and examine disease time trends. Mortality analysis was extended 7.5 years to cover the period 1951-90; cancer incidence analysis was extended six years to cover the period 1958-87. New findings include increased incidence and mortality of prostate cancer (SMR 169, 95% CI 106-256, 22 observed) and increased incidence of total haematolymphatic cancers (SIR 151, 95% CI 106-209, 36 observed). When only the most recent follow up period was analysed, previously observed risks persisted for total lung cancer (SIR 178, 95% CI 99-293), oat cell lung cancer (SIR 240, 95% CI 103-472), bladder cancer (SIR 247, 95% CI 131-422), and oesophageal cancer (Obs/Exp = 2/1.1). Mortality from ischaemic heart disease (SMR 98, 95% CI 76-123) and respiratory disease (SMR 111, 95% CI 56-199) declined during recent follow up, although significant excess mortality remained during analysis of the entire study period (ischaemic heart disease SMR 128, 95% CI 112-145; respiratory disease SMR 159, 95% CI 115-213). In analyses of the entire study period, risks of ischaemic heart disease and lung, bladder, and oesophageal cancer were adjusted for smoking; oesophageal cancer was also adjusted for use of alcohol. All risks remained significantly raised. Exposure-response analyses showed significant positive associations between duration of employment and risks for mortality from lung, oesophageal, and total cancer. Chimney sweeps remain at increased risk for cancers of the lung, oesophagus, and bladder. Our study supports a casual role for exposure to chimney soot, which contains carcinogens including polycyclic aromatic hydrocarbons. Extended follow up of this cohort now shows increased risks of prostate and haematolymphatic cancers.     

Mortality in a historical cohort of bus drivers

In an attempt to address previously reported excesses of ischaemic heart disease (IHD), lung cancer and bladder cancer among professional drivers, the mortality (SMR) of 2134 Montreal city bus drivers employed for at least five years as of January 1962 and followed until 31 December 1985 was compared with that of the male population of greater Montreal. The vital status of 94% of the cohort was ascertained. The number of deaths observed was 804. The overall mortality was somewhat lower than expected (SMR = 97). A small, non-significant excess mortality was found for ischaemic heart disease (IHD) (O/E = 313/295, SMR = 106, 95% CI: 95-118) and circulatory system diseases (O/E = 441/405, SMR = 109, 95% CI: 99-119). However, no excesses were observed for lung cancer (O/E = 78/84.4, SMR = 92, 95% CI: 73-114) or bladder cancer (O/E = 4/7.4, SMR = 54, 95% CI: 15-138). These results are compatible with other studies which have found a small risk of IHD for bus drivers.     

Mortality among firefighters from three northwestern United States cities.

To explore whether exposure among firefighters to fire smoke could lead to an increased risk of cancer, lung disease, and heart disease, the mortality of 4546 firefighters who were employed by the cities of Seattle and Tacoma, WA and Portland, OR for at least one year between 1944 and 1979 were compared with United States national mortalities and with mortality of police officers from the same cities. Between 1945 and 1989, 1169 deaths occurred in the study population and 1162 death certificates (99%) were collected. Mortality due to all causes, ischaemic heart disease, and most other non-malignant diseases was less than expected based upon United States rates for white men. There was no excess risk of overall mortality from cancer but excesses of brain tumours (standardised mortality ratio (SMR) = 2.09, 95% confidence interval (95% CI) 1.3-3.2) and lymphatic and haematopoietic cancers (SMR = 1.31, 95% CI = 0.9-1.8) were found. Younger firefighters (< 40 years of age) appeared to have an excess risk of cancer (SMR = 1.45, 95% CI 0.8-2.39), primarily due to brain cancer (SMR = 3.75, 95% CI 1.2-8.7). The risk of lymphatic and haematopoietic cancers was greatest for men with at least 30 years of exposed employment (SMR = 2.05, 95% CI 1.1-3.6), especially for leukaemia (SMR = 2.60, 95% CI 1.0-5.4).     

Mortality among firefighters from three northwestern United States cities.

To explore whether exposure among firefighters to fire smoke could lead to an increased risk of cancer, lung disease, and heart disease, the mortality of 4546 firefighters who were employed by the cities of Seattle and Tacoma, WA and Portland, OR for at least one year between 1944 and 1979 were compared with United States national mortalities and with mortality of police officers from the same cities. Between 1945 and 1989, 1169 deaths occurred in the study population and 1162 death certificates (99%) were collected. Mortality due to all causes, ischaemic heart disease, and most other non-malignant diseases was less than expected based upon United States rates for white men. There was no excess risk of overall mortality from cancer but excesses of brain tumours (standardised mortality ratio (SMR) = 2.09, 95% confidence interval (95% CI) 1.3-3.2) and lymphatic and haematopoietic cancers (SMR = 1.31, 95% CI = 0.9-1.8) were found. Younger firefighters (< 40 years of age) appeared to have an excess risk of cancer (SMR = 1.45, 95% CI 0.8-2.39), primarily due to brain cancer (SMR = 3.75, 95% CI 1.2-8.7). The risk of lymphatic and haematopoietic cancers was greatest for men with at least 30 years of exposed employment (SMR = 2.05, 95% CI 1.1-3.6), especially for leukaemia (SMR = 2.60, 95% CI 1.0-5.4).     

Mortality study of chemical workers exposed to dioxins: follow-up 23 years after chemical plant closure

Objectives To examine the long-term effects of dioxin-exposure, particularly with regard to cancer mortality, in a follow-up 23 years after closure of the chemical plant (Hamburg, Germany). Methods The study comprised all persons (1191 men/398 women) employed in the plant on a full-time basis for a minimum of 3 months between 1952 and 1984 when the plant was closed down. Mortality follow-up was performed for the period from 1952 up to the reference date of 31 December 2007. Subjects entered the cohort at the date of their first employment in the plant. We calculated standardised mortality ratios (SMRs) using the population of Hamburg as reference. Results The vital status could be determined for 96.5% of the study group (1145 men and 389 women). For men, there was an increase in overall mortality (ICD-9 1-999) (SMR=1.14, 95% CI 1.06 to 1.23), all-cancer mortality (SMR=1.37, 95% CI 1.21 to 1.56) and specific mortality from respiratory cancer (ICD-9 161, 162, 163) (SMR=1.64, 95% CI 1.32 to 2.03), oesophageal cancer (ICD-9 150) (SMR=2.56, 95% CI 1.27 to 4.57), rectum cancer (ICD-9 154) (SMR=1.96, 95% CI 0.98 to 3.51), as well as diseases of the circulatory system (ICD-9 390-459) (SMR=1.16, 95% CI 1.02 to 1.31). For women, there was an increase in breast cancer mortality (ICD-9 174) (SMR=1.86, 95% CI 1.12 to 2.91). Conclusions The results of this extended follow-up are consistent with those of previous analyses of the cohort and with those of other cohorts. Our findings support the carcinogenic effect of dioxin compounds.     

Cancer mortality among magazine printing workers.

OBJECTIVE: After an inquiry from the employees of an offset printing plant, a historical cohort study was conducted to investigate cancer mortality among these workers. METHODS: The cohort comprised 262 men, who contributed 2771 person-years of observation. 16 deaths were identified during the follow up period (1980-91). Expected numbers of deaths were derived from age specific regional rates. Standardised mortality ratios (SMR) and 95% confidence intervals (95% CIs) were calculated. RESULTS: An increased cancer mortality was found after 10 years of employment (SMR 213, 95% CI 98 to 405, based on nine deaths), mainly due to a high mortality from lung cancer (SMR 381, 95% CI 104 to 975, four deaths), and from oesophageal cancer (SMR 1049, 95% CI 216 to 3065, three deaths). For workers with at least 20 years since the start of employment, the SMR was 262 (95% CI 105 to 540) for all cancer sites, 447 (95% CI 92 to 1306) for lung cancer, and 1094 (95% CI 132 to 3952) for oesophageal cancer. The increased cancer mortality was concentrated among pressmen. CONCLUSION: Although based on small numbers, the findings suggest an increased risk of cancer among these workers, which should be further investigated.     

An update of mortality from all causes among white uranium miners from the Colorado plateau study group

To place previously recognized mortality risks into the context of the total mortality from all causes, an updated retrospective cohort mortality study was conducted on 3,238 white males from the US Public Health Service cohort of Colorado Plateau uranium miners. Vital status was followed from 1960 through 1990. Life-table analyses used combined New Mexico, Arizona, Utah, and Colorado mortality rates for external comparison and mortality risks within the lowest radon-exposure or duration-employed category for internal comparison. Significantly elevated SMRs were found for pneumoconioses (SMR = 24.1, 95% CI 16.0–33.7), lung cancer (SMR = 5.8, 95% CI 5.2–6.4), tuberculosis (SMR = 3.7, 95% CI 1.9–6.2), chronic obstructive respiratory diseases (SMR = 2.8, 95% CI 2.2–3.5), emphysema (SMR = 2.5, 95% CI 1.9–3.2), benign and unspecified tumors (SMR = 2.4, 95% CI 1.0–4.6), and diseases of the blood and blood-forming organs (SMR = 2.4, 95% CI 1.0–5.0). No significantly lowered SMRs were found for any disease. For lung cancer and pneumoconioses, standardized rate ratios increased with increasing exposure to radon progeny or duration of employment. Most findings from this update are consistent with previous studies. Not observed were previously elevated SMRs for chronic nephritis and for acute alcoholism. New findings observed were elevated SMRs for benign and unspecified tumors and for diseases of the blood and blood-forming organs. The most important long-term mortality risks for the white uranium-miners continue to be lung cancer and pneumoconioses, for which SMRs remain significantly elevated after a mean period of 22.4 years since last uranium mining. Am. J. Ind. Med. 31:211–222, 1997. © 1997 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 urban policemen in Rome

A total of 3,868 urban policemen in Rome were investigated through a historical cohort study with emphasis on mortality from cardiovascular disease and cancer. Overall mortality from cardiovascular disease, respiratory conditions, digestive and genitourinary diseases, and accidents was lower than expected. An excess risk of ischemic heart disease was observed among subjects aged less than 50 years [14 deaths, standardized mortality ratio (SMR = 1.63), 95% CI = 0.89–2.73], corresponding to workers with a short duration of employment and a short latency since first employment. Overall cancer mortality was as expected and no excess was found for lung cancer (82 deaths, SMR = 1.05). Increased mortality was observed from colon cancer (16 deaths, SMR = 1.47), melanoma (four deaths, SMR = 2.34), bladder cancer (13 deaths, SMR = 1.27), renal cancer (seven deaths, SMR = 1.39), and non-Hodgkin's lymphoma (six deaths, SMR = 1.51), although none of the excesses were statistically significant. Two deaths from male breast cancer (SMR = 14.36) and three from cancer of endocrine glands were found (SMR = 3.44). Nested case-control studies were conducted to evaluate cancer mortality risk by job category. Bladder cancer was significantly increased among car drivers (OR = 4.17); for kidney cancer, an increased odds ratio (OR = 2.27) was found among motorcyclists; non-Hodgkin's lymphoma clustered among motorcyclists (OR = 5.14). In summary, excess risk for specific cancer sites (colon, male breast, and endocrine glands) might be linked to occupational exposures; professional drivers seem to be at higher risk of bladder cancer, kidney cancer, and non-Hodgkin's lymphoma.     

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.     

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.     

Mortality in a cohort of sugar refinery workers in Arezzo Province, Italy

BACKGROUND AND OBJECTIVES: The aim of this study was to investigate mortality of a cohort of 1,767 male workers employed in a sugar refinery plant located in the Province of Arezzo, Italy, where asbestos had been used from the 1960's for the insulation of thermohydraulic systems and for furnaces. In 1987-88 workers removed the asbestos-cement insulation from the plant. METHODS: The cohort was composed by male workers who were employed in the plant between 1 March 1962 and 1 February 1996, and had worked for at least 2 months. Follow-up started on 1 March 1962, and ended on 31 May, 2003. The population mortality for Tuscany Region was used as the reference. The relative risk was estimated by Standardized Mortality Ratio (SMR) and the confidence intervals were calculated at a 95% level (95% CI). RESULTS: The majority of workers were employed during the summer only. Significant decreases in mortality were observed for overall mortality (SMR = 78; 95% CI = 69-88), all cancers (SMR = 80; 95% CI = 65-97), cardiovascular diseases (SMR = 64; 95% CI = 50-81), lung cancer (SMR = 66; 95% CI = 43-98), and gastrointestinal diseases (SMR = 53; 95% CI = 26-98). Non-significant increases were observed for kidney cancer (SMR = 229; 95% CI = 92-472), and diseases of the nervous system (SMR = 155; 95% CI = 71-294). Kidney cancer mortality for workers employed for > = 5 years was significantly higher (SMR = 508; 95% CI = 105-1485). CONCLUSIONS: Mortality for asbestos-related diseases did not show any increase. The higher kidney cancer mortality for workers employed for > = 5 years could be due to exposures to various carcinogens, that occurred not only in the sugar refinery plant, given that the workers were seasonal and did other jobs during the rest of the year. Asbestos-related deaths could occur in the future among some workers who in 1987-88 were employed on the removal of asbestos-cement insulation from the plant.     

Cohort mortality study of Swedish pulp and paper mill workers-nonmalignant diseases

OBJECTIVES: The aim of this study was to determine mortality among pulp and paper mill workers according to the main mill pulping process, department, and gender, particular reference being given to diseases of the circulatory and respiratory systems. METHODS: The cohort of 18 163 men and 2 291 women employed between 1939 and 1999 and with >1 year of employment was followed for mortality from 1952 to 2001 (acute myocardial infarction from 1969). Standardized mortality ratios (SMR) with 95% confidence intervals (95% CI) were estimated by comparing the observed number of deaths with the expected number for the entire Swedish population. Exposure was assessed from personnel files in the mills. Data from an exposure measurement database are also presented. RESULTS: There were 5898 deaths in the cohort. Total mortality had an SMR of 1.02 (95% CI 0.98-1.06) for the men in the sulfate mills and an SMR of 0.93 (95% CI 0.90-0.97) for the men in the sulfite mills. Mortality from acute myocardial infarction was increased among the men in both the sulfate and sulfite mills [SMR 1.22 (95% CI 1.12-1.32) and SMR 1.11 (95% CI 1.02-1.21), respectively] and by department in sulfate pulping (SMR 1.29, 95% CI 1.07-1.54), paper production (SMR 1.26, 95% CI 1.06-1.49), and maintenance (SMR 1.16, 95% CI 1.02-1.30). Mortality from cerebrovascular disease, diabetes mellitus, and nonmalignant respiratory diseases was not increased. CONCLUSIONS: Death from acute myocardial infarction, but not cerebrovascular diseases, was increased in this cohort and was probably related to a combination of different occupational exposures (eg, dust, sulfur compounds, shift work, and noise).