A follow-up study of agricultural chemical production workers.

This retrospective follow-up study evaluated the mortality experience of 4,323 men employed at a plant in Alabama (AL) that manufactures agricultural and other chemicals. On average, there were 18 years of follow-up per subject during the study period of 1951 to 1987. The observed numbers of deaths among cohort members were compared with the numbers expected on the basis of United States (US) and AL general population mortality rates. The all causes standardized mortality ratio (SMR), computed using US rates as the referent, was 97 (233 observed/240 expected deaths) for whites and 68 (47/69) for blacks. White subjects had more than expected deaths from buccal cavity and pharynx (BCP) cancer [SMR = 388; 95% confidence interval (CI) = 125-905] and from esophageal cancer (SMR = 417; 112-1,067). Their lung cancer mortality rate was 50% higher than the rate of US white men and 14% higher than the rate of AL white men. Each of these three cancers has strong nonoccupational determinants, the roles of which were not assessed and which may have been responsible in whole or in part for the observed increases. The excesses of lung and esophageal cancer were concentrated among short-term employees, an observation which also argues against a causal link with occupational factors. Black men experienced no increased mortality from BCP, esophageal or lung cancer, but results for blacks were imprecise. For white and black subjects combined, there were 3 observed versus 0.62 expected deaths due to soft tissue sarcoma (p = 0.05). The job histories of subjects with this type of cancer did not suggest any shared occupational exposure.     

Mortality of professional chemists in England and Wales, 1965–1989

Several studies on the mortality of chemists have revealed a lower overall mortality but an excess of deaths from certain diseases, in particular, cancers. This study determined the causes of mortality of 4,012 chemists among 14,884 members of The Royal Society of Chemistry who were followed for a period of 25 years. The results demonstrated consistency with other studies. There was an overall low mortality rate, with fewer deaths than expected from cancers, but an excess mortality from lymphatic and hematopoietic cancers, in particular leukemias. There was an excess of deaths from certain gastrointestinal cancers. There was reduced mortality from respiratory diseases, including lung cancers, and from cardiovascular disease. New findings reported in this study are increased mortality from cancers of the duodenum and kidney, certain skin cancers, mental disorders, and diseases of the nervous system. © 1993 Wiley-Liss, Inc.     

Proportionate mortality among US shoeworkers, 1966–1977

Proportionate mortality for various causes was examined among 3,754 decedents (2,144 men, 1,610 women) who had worked in shoe manufacturing plants represented by either of two labor unions in the US. None of the shoeworker deaths were attributed to nasal cancer, whereas 2.2 were expected on the basis of general population data. Mortality from leukemia and cancer of the urinary bladder was not unusual in either sex or either union. However, deaths from cancers of the liver and gallbladder combined were significantly increased among male and female members of one union. Three deaths from mesothelioma were seen among members of this same union. Rectal cancer mortality was higher than expected among men and women in both unions. The findings are at variance with previous reports of high risks of certain cancer sites among shoeworkers. However, results for liver and gallbladder cancer and mesothelioma suggest the possibility that other previously unsuspected hazards may have been present in certain areas of the US shoe industry.     

Mortality among German vegetarians: first results after five years of follow-up

A prospective study of vegetarians recruited from all regions of the Federal Republic of Germany, including West Berlin, was started in 1978 after a preparatory phase of two years in which the cohort was established. The mortality of the 1,904 study participants was evaluated after a follow-up of five years, comparing observed deaths with expected rates based on the national mortality statistics. Of the 858 men and 1,046 women, 89% had followed their diet for at least five years at study entry, the majority of them as strict vegetarians (1,163). By the end of 1983, only 82 persons had died, whereas 219 deaths were expected. In both sexes, the mortality was lowest from cardiovascular diseases [standardized mortality ratio (SMR) for ischemic heart disease about 20] and from cancer (SMR 58 for men, 54 for women). Deaths from diseases of the respiratory and digestive system were also reduced. For individual cancer sites the observed numbers were extremely small, but the risk of dying from lung cancer was significantly reduced; however, deaths from cancers of the colon and rectum, prostate, and breast were rare or even absent. More deaths than expected were observed from stomach, pancreatic, testicular, and brain cancers. An internal comparison of mortality between strict and moderate vegetarians (741) suggests a higher mortality from all causes and malignant neoplasms among strict vegetarians in both sexes, although not statistically significant, and a lower mortality from circulatory system diseases for males. The possible influence of selection factors (e.g., "healthy participant effect," socioeconomic level, and body weight) on the findings of a decreased mortality is discussed together with the role of diet.     

Cancer mortality in a Texas county with prior uranium mining and milling activities, 1950-2001.

Uranium was discovered in Karnes County, Texas, in 1954 and the first uranium mill began operating in 1961 near Falls City. Uranium milling and surface and in situ mining continued in Karnes County until the early 1990s. Remediation of uranium tailings ponds was completed in the 1990s. There were three mills and over 40 mines operating in Karnes County over these years and potential exposure to the population was from possible environmental releases into the air and ground water. From time to time concerns have been raised in Karnes County about potential increased cancer risk from these uranium mining and milling activities. To evaluate the possibility of increased cancer deaths associated with these uranium operations, a mortality survey was conducted. The numbers and rates of cancer deaths were determined for Karnes County and for comparison for four 'control' counties in the same region with similar age, race, urbanisation and socioeconomic distributions reported in the 1990 US Census. Comparisons were also made with US and Texas general population rates. Following similar methods to those used by the National Cancer Institute, standardised mortality ratios (SMRs) were computed as the ratio of observed numbers of cancers in the study and control counties compared to the expected number derived from general population rates for the United States. Relative risks (RRs) were computed as the ratios of the SMRs for the study and the control counties. Overall, 1223 cancer deaths occurred in the population residing in Karnes County from 1950 to 2001 compared with 1392 expected based on general population rates for the US. There were 3857 cancer deaths in the four control counties during the same 52 year period compared with 4389 expected. There was no difference between the total cancer mortality rates in Karnes County and those in the control counties (RR = 1.0; 95% confidence interval 0.9-1.1). There were no significant increases in Karnes County for any cancer when comparisons were made with either the US population, the State of Texas or the control counties. In particular, deaths due to cancers of the lung, bone, liver and kidney were not more frequent in Karnes County than in the control counties. These are the cancers of a priori interest given that uranium might be expected to concentrate more in these tissues than in others. Further, any radium intake would deposit primarily in the bone and radon progeny primarily in the lung. Deaths from all cancers combined also were not increased in Karnes County and the RRs of cancer mortality in Karnes County before and in the early years of operations (1950-64), shortly after the uranium activities began (1965-79) and in two later time periods (1980-89, 1990-2001) were similar, 1.0, 0.9, 1.1 and 1.0, respectively. No unusual patterns of cancer mortality could be seen in Karnes County over a period of 50 years, suggesting that the uranium mining and milling operations had not increased cancer rates among residents.     

Cosmic radiation and mortality from cancer among male German airline pilots: extended cohort follow-up

Commercial airline pilots are exposed to cosmic radiation and other specific occupational factors, potentially leading to increased cancer mortality. This was analysed in a cohort of 6,000 German cockpit crew members. A mortality follow-up for the years 1960-2004 was performed and occupational and dosimetry data were collected for this period. 405 deaths, including 127 cancer deaths, occurred in the cohort. The mortality from all causes and all cancers was significantly lower than in the German population. Total mortality decreased with increasing radiation doses (rate ratio (RR) per 10 mSv: 0.85, 95 % CI: 0.79, 0.93), contrasting with a non-significant increase of cancer mortality (RR per 10 mSv: 1.05, 95 % CI: 0.91, 1.20), which was restricted to the group of cancers not categorized as radiogenic in categorical analyses. While the total and cancer mortality of cockpit crew is low, a positive trend of all cancer with radiation dose is observed. Incomplete adjustment for age, other exposures correlated with duration of employment and a healthy worker survivor effect may contribute to this finding. More information is expected from a pooled analysis of updated international aircrew studies.     

Cancer mortality of granite workers

A retrospective cohort study was undertaken to investigate the cancer mortality of granite workers. The study comprised 1,026 workers hired between 1940 and 1971. The number of person-years was 20,165, and the number of deaths 235. During the total follow-up 46 tumors were observed and 44.9 were expected. An excess mortality from tumors was observed for the workers followed for 20 years or more, the greatest excess occurring during the follow-up period of 25-29 years (observed 11, expected 5.2). Of the 46 tumors, 22 were lung cancers (expected 17.1) and 15 were gastrointestinal cancers (expected 9.7), nine of which were cancers of the stomach (expected 6.0). Mortality from lung cancer was excessive for workers with at least 15 years since entry into granite work (latency) (21 observed and 9.5 expected), being highest during the follow-up period of 25-29 years (observed 8, expected 2.1). The results indicate that granite exposure per se may be an etiologic factor in the initiation or promotion of malignant neoplasms.     

Proportionate cancer mortality among workers in the Belarussian tanning industry

BACKGROUND: The tanning industry involves many occupational exposures. This study evaluates proportionate cancer mortality among workers employed in the Belarussian tanning plant in Minsk. METHODS: A total of 768 workers with seniority of not less than 6 months who were hired after January 1, 1953 and died before December 31, 2000 was investigated. Proportionate mortality ratios (PMRs) were calculated using the population of Minsk to generate expected numbers. RESULTS: Among women employed in the tannery, there was a significant excess of pancreatic cancer, based on eight deaths (expected = 2.56, PMR = 3.13, 95% CI = 1.35-6.17). Six of the eight pancreatic cancer deaths occurred among women occupied in dyeing-stuffing workshops (expected = 1.64, PMR = 3.67, 95% CI = 1.34-7.97), all among workers hired between 1962 and 1984 (expected = 1.06, PMR = 6.54, 95% CI = 2.6-13.4). CONCLUSIONS: Women in this tanning industry cohort experienced excess mortality of cancer of the pancreas, with suggested increases of corpus and cervix uteri, melanoma, and kidney cancers. For men, an insignificant increase in PMR of oral cavity-pharynx and pancreatic cancers was seen. Further prospective follow-up of living members of this cohort, will allow more in-depth analysis of rare cancer sites, latency, and duration of employment, and is warranted.     

A study on cancer mortality in Tarapur-based atomic energy community.

Cancer mortality risks for individuals who were employed at nuclear facilities in Tarapur and for their respective family members with whom they lived were examined. Cancer deaths that occurred in this population between 1971 and 1988 were compared with death rates published by the Bombay City Cancer Registry. Risks were expressed as standardized mortality ratios (SMRs), which were computed by dividing the observed number of deaths by the expected number of deaths and multiplying this value times 100. There were 11 deaths from cancer among the employees, and this figure was too small to permit any trend analysis with respect to radiation exposures. The SMRs for all cancers and leukemia for male employees and for middle-aged male family members who were not exposed to any radiation were not statistically significant. A much larger database of person years at risk would be required to reach definite conclusions. The combined cancer risks for employees and families combined were similar to risks experienced by individuals in Bombay.     

Update of the follow-up of mortality and cancer incidence among European workers employed in the vinyl chloride industry.

Although vinyl chloride is an established cause of liver angiosarcoma, the evidence is inconclusive on whether it also causes other neoplastic and nonneoplastic chronic liver diseases as well as neoplasms in other organs. Furthermore, the shape of the dose-response relation for angiosarcoma is uncertain. We have extended for approximately 8 years the mortality and cancer incidence follow-up of 12,700 male workers in the vinyl chloride industry in four European countries. All-cause mortality was lower than expected, whereas cancer mortality was close to expected. A total of 53 deaths from primary liver cancer (standardized mortality ratio 2.40, 95% confidence interval = 1.80-3.14) and 18 incident cases of liver cancer were identified, including 37 angiosarcomas, 10 hepatocellular carcinomas, and 24 liver cancers of other and unknown histology. In Poisson regression analyses we observed a marked exposure response for all liver cancers, angiosarcoma, and hepatocellular carcinoma. The exposure-response trend estimated for liver cancer in analyses restricted to cohort members with cumulative exposures of <1,500 parts per million-years was close to that estimated for the full cohort (relative risk of 2.0 per logarithmic unit of cumulative dose). No strong relation was observed between cumulative vinyl chloride exposure and other cancers. Although cirrhosis mortality was decreased overall, there was a trend with cumulative exposure.     

Mortality among employees at a plastics and resins research and development facility.

OBJECTIVES--The study was undertaken to update a previous study of employees from a resins and plastics research and development facility and to further examine the mortality of these employees with particular emphasis on deaths due to pancreatic cancer. METHODS--This retrospective cohort study examined mortality from 1962 to 1992 for 257 men who were employed for at least one year during a 14 year period from 1962 to 1975 at a plastics and resins research and development facility. During the operative period, the primary activities involved applications and process development for polypropylene, polystyrene, epoxy resins, and to a lesser extent high density polyethylene. RESULTS--The cohort was young and was followed up for an average of 26 years. Although mortality for all causes among employees who worked at least one year at this facility was low (standardised mortality ratio (SMR) 0.74), the death rate from cancer was moderately higher than that of the general population (14 observed and 9.4 expected deaths). There were four observed and 0.5 expected deaths from pancreatic cancer among men who worked at this facility for at least one year, which resulted in a statistically increased SMR of 8.88 (95% confidence interval 2.42-22.74). All cases of pancreatic cancer had "laboratory" jobs, and their ages at death were relatively young compared with deaths in the general population from pancreatic cancer. Lung cancer mortality was high but not significant with seven observed and 3.5 expected deaths. There were no deaths due to non-malignant respiratory disease (1.9 expected). CONCLUSIONS--The increased cancer mortality was entirely due to excess deaths from pancreatic and lung cancers. No causative agent or process for these cases of pancreatic cancer has been identified. This study shows no increased colorectal cancer mortality as was found among another group of workers involved in the manufacture of polypropylene.     

Mortality among workers at the Pantex weapons facility

We compared total and cause-specific mortality for workers at the Pantex nuclear weapons assembly facility employed between 1951 and 31 December 1978 with expected mortality based on U.S. death rates. We observed significantly fewer deaths than expected from all causes of death, all cancers, digestive cancers, lung cancer, arteriosclerotic heart disease, and digestive diseases. There were no causes of death which occurred significantly more frequently than expected. Analyses of worker mortality by duration of employment, time since first employment, and radiation exposure greater than 1.00 rem produced similar results. We found no evidence that mortality from any cause of death was increased as a result of employment at Pantex.     

Mortality of nickel workers: experience of men working with metallic nickel.

The mortality of men employed in a plant manufacturing nickel alloys from metallic nickel and other metals has been examined. The plant has operated since May 1953, and 1925 men were identified who had been employed in the operating areas at the plant, other than as members of the staff, for a total of five or more years, excluding breaks. Analysis of samples of air obtained from personal samplers showed that since 1975 most of the men are likely to have been exposed to average concentrations of nickel of between 0.5 and 0.9 mg Ni/m3. All but 22 (1.1%) of the men were successfully traced to 1 April 1978 or until they died or emigrated. One hundred and seventeen had died. The numbers of deaths observed from cancers of respiratory and other sites, other respiratory disease, ischaemic heart disease, and other causes of death were compared with the numbers expected from national and local mortality rates. No evidence of the existence of any occupational hazard was obtained. The number of deaths from lung cancer (15) in men employed for five years or more is small. At 98% of the number expected at local rates it is statistically compatible with risks of between 0.5 and 2.2 times "normal."     

Mortality among a cohort of garment workers exposed to formaldehyde: an update

Aims: To evaluate the mortality experience of 11 039 workers exposed to formaldehyde for three months or more in three garment plants. The mean time weighted average formaldehyde exposure at the plants in the early 1980s was 0.15 ppm but past exposures may have been substantially higher.

Methods: Vital status was updated through 1998, and life table analyses were conducted.

Results: Mortality from all causes (2206 deaths, standardised mortality ratio (SMR) 0.92, 95% CI 0.88 to 0.96) and all cancers (SMR 0.89, 95% CI 0.82 to 0.97) was less than expected based on US mortality rates. A non-significant increase in mortality from myeloid leukaemia (15 deaths, SMR 1.44, 95% CI 0.80 to 2.37) was observed. Mortality from myeloid leukaemia was greatest among workers first exposed in the earliest years when exposures were presumably higher, among workers with 10 or more years of exposure, and among workers with 20 or more years since first exposure. No nasal or nasopharyngeal cancers were observed. Mortality from trachea, bronchus, and lung cancer (147 deaths, SMR 0.98, 95% CI 0.82 to 1.15) was not increased. Multiple cause mortality from leukaemia was increased almost twofold among workers with both 10 or more years of exposure and 20 years or more since first exposure (15 deaths, SMR 1.92, 95% CI 1.08 to 3.17). Multiple cause mortality from myeloid leukaemia among this group of workers was also significantly increased (8 deaths, SMR 2.55, 95% CI 1.10 to 5.03).

Conclusions: Results support a possible relation between formaldehyde exposure and myeloid leukaemia mortality. Previous epidemiological studies supporting a relation between formaldehyde exposure and leukaemia mortality have been primarily of formaldehyde exposed professional groups, not formaldehyde exposed industrial workers. Limitations include limited power to detect an excess for rare cancers such as nasal and nasopharyngeal cancers and lack of individual exposure estimates.

     

Mortality among workers exposed to cutting oil mist: update of previous reports

BACKGROUND: Earlier reports of the mortality experience of this cohort of automotive workers followed from 1938 to 1967 who were exposed to cutting oil mist noted an excess of gastrointestinal cancer. The present report describes the mortality experience of these workers followed for mortality through 1980. METHODS: Cause-specific standardized mortality ratios were calculated by comparing the observed number of deaths to the expected numbers based on rates for the U.S. male population. RESULTS: The SMRs for liver and biliary tract, and testicular cancers were significantly elevated. Among the subset of workers with heavy oil mist exposure, SMRs were significantly elevated for cancers of the lung and testis, and for Hodgkin's disease. The risk of death due to lung cancer was greatest among workers with heavy exposure to oil mist employed for 15 or more years. Mortality due to stomach cancer was in excess among workers with heavy exposure to oil mist who were employed for 5 or more years. There were significant excesses of deaths due to asthma and emphysema. CONCLUSIONS: Further studies with information on the presence of contaminants and additives in oil mists will help elucidate the relationship between oil mist exposure and cancer.     

Respiratory organs cancer mortality in New Jersey counties and the relationship with selected demographic and environmental variables

The state of New Jersey (N.J.) has been thought to have an unusually high overall cancer mortality rate; this assumption has been based on national 1950–1969 mortality data for N.J. counties. This study presents an analysis of more recent rates of respiratory cancer mortality in 21 N.J. counties during 1968–1977, a comparison with the 1950–1969 rates, and associations between current respiratory cancer mortality rates and selected demographic and environmental variables. Age-adjusted mortality rates for cancer of respiratory organs were calculated for the N.J. counties during the period 1968–1977 and compared with the period 1950–1969, with the Surveillance, Epidemiology, and End Results (SEER) survey, and with cancer mortality in the United States, 1973–1977. The county rates were also correlated with chemical toxic-waste disposal sites (CTWDS), annual per capita income, percentage of the population employed in chemical industries, the density of population, and the urbanization index of each of 21 N.J. counties. The lung, bronchus, trachea, and pleura cancer mortality rates among white and nonwhite males and females in N.J. were substantially higher than the national rates during the period 1950–1969. In more recent years, the increases in U.S. mortality rates for lung, bronchus, trachea, and pleura cancers were significantly greater (P < 0.01) than those found in most of the 21 N.J. counties. As a consequence, the national rates are now more comparable to N.J. rates. Although the gaps between N.J. and the United States in these rates have narrowed, the observed number of laryngeal and lung cancer deaths remained significantly higher (P < 0.01 to P < 0.0001) than expected cancer deaths, based on U.S. rates, among one or more subgroup populations (white and nonwhite males and females) in several N.J. counties. Among white men in Middlesex, Camden, Burlington, and Ocean counties, the observed number of deaths for lung cancer was found to be significantly (P < 0.0001) greater than the expected number of deaths. In Hudson county observed deaths from both laryngeal and lung cancer among white men were significantly greater than the expected number of deaths from these cancers (P < 0.0001). Statistically significant and positive correlations were found between laryngeal cancer mortality and CTWDS, urbanization index, and population density. Lung cancer mortality also correlated significantly with CTWDS in N.J. Both larynx and lung cancer mortality showed significant and consistent negative correlations with annual per capita-income in N.J. Some of the implications of the study findings are discussed and recommendations made for future investigations.     

Alcohol consumption and 17-year mortality in the Chicago Western Electric Company study

The association between baseline alcohol intake and mortality from all causes and specific causes based on 17 years of follow-up experience was analyzed for 1,832 white males originally age 40–55 from the Chicago Western Electric Company study. Alcohol consumption was expressed as number of drinks per day for all intake combined, including hard liquor, beer, and wine, based on the maximum intake reported on three questionnaires. With mortality rates adjusted only for age, total intake was associated with increased risk of death from all causes, the cardiovascular diseases, coronary heart disease, cancer, and other causes at the level of six or more drinks per day. There was no increase in mortality with increasing alcohol consumption below this level. Only the associations between alcohol intake and death from the cardiovascular diseases and coronary heart disease failed to persist after adjustment for other risk factors, such as smoking and blood pressure. When the deaths were divided into those occurring within the first 10 years of follow-up and those occurring more than 10 years after entry, the association between baseline alcohol intake and mortality was generally stronger for those deaths occurring more than 10 years after entry.     

Mortality among chemical workers at Texas City plant: 1940–2001

Objectives  To evaluate the mortality experience of workers at a major chemical manufacturing site and to examine brain and liver cancers excesses reported at this site in previous studies. Methods  This study included 9,730 employees at the Texas City location who worked between 1940 and 2001. Standardized mortality ratios and confidence intervals were calculated. Results  There was less than expected deaths due to all cause mortality and no increase in all cancer mortality. Brain tumor mortality, which did exceed expected rates in past years, was at expected levels in recent years. Liver cancer mortality was greater than expected. Conclusion  Brain tumor mortality was either due to chance in the early years or the cause of the brain tumors has been eliminated. Mortality due to liver cancer is higher than expected but only among men hired before 1950. Eugenio Salazar is deceased.     

Mortality of workers exposed to polychlorinated biphenyls--an update

A retrospective cohort mortality study of workers exposed to polychlorinated biphenyls (PCBs) in two plants manufacturing electrical capacitors was reported in 1981. The study was conducted primarily to examine the risk of cancer mortality associated with exposure to PCBs. Based on animal data, liver cancer was the disease of most interest. Due to the small number of deaths and a relatively short observation period, the study was considered inconclusive. This study has been updated by adding 7 yr of observation. The number of deaths in the study cohort has increased from 163 to 295. Mortality from all causes was found to be lower than expected (295 observed vs. 318 expected deaths) as well as mortality from all cancers (62 observed vs. 80 expected deaths). A statistically significant excess in deaths was observed in the disease category that includes cancer of the liver (primary and unspecified), gall bladder, and biliary tract (5 observed vs. 1.9 expected; p less than .05). Most of this excess was observed in women employed in one plant. Due to the small number of deaths and the variability of specific cause of death within this category, it remains difficult to interpret these findings in regard to PCB exposure.     

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.