Search PubMed⌕ Search

Biomedical subjects

E Delzell

Publications and source records attributed to E Delzell.

At least 37 records · Page 2Linked to original sources
PubMed1998

Mortality from cancer and other causes of death among synthetic rubber workers.

OBJECTIVES: This study evaluated the mortality experience of workers from the styrene-butadiene rubber industry. Concerns about a possible association of 1,3-butadiene and styrene with lymphohaematopoietic, gastrointestinal, and lung cancers prompted the investigation. METHODS: A retrospective follow up study was conducted of 15,649 men employed for at least one year at any of eight North American styrene-butadiene rubber plants. Analyses used standardised mortality ratios (SMRs) to compare styrene-butadiene rubber workers' cause specific mortalities (1943-91) with those of the United States and Ontario general populations. RESULTS: On average, there were 25 years of follow up per subject. The standardised mortality ratio (SMR) was 87 (95% confidence interval (95% CI) 85 to 90) for all causes of death combined and was 93 (95% CI 87 to 99) for all cancers. There was an excess of leukaemia (SMR 131, 95% CI 97 to 174), restricted to hourly workers (SMR 143, 95% CI 104 to 191). For causes of death other than leukaemia, SMRs were close to or below the null value of 100. Results by work area (process group) were unremarkable for non-Hodgkin's lymphoma, multiple myeloma, and stomach cancer. Maintenance workers had a slight increase in deaths from lung cancer, and certain subgroups of workers had more than expected deaths from cancer of the large intestine and the larynx. CONCLUSION: This study found an excess of leukaemia that is likely to be due to exposure to butadiene or to butadiene plus other chemicals. Deaths from non-Hodgkin's lymphoma, multiple myeloma, and stomach cancer did not seem to be related to occupational exposure. The excess deaths from lung cancer among maintenance workers may be due in part to confounding by smoking, which was not controlled for, and in part to an unidentified occupational exposure other than butadiene or styrene. Increases in cancer of the large intestine and larynx were based on small numbers, did not seem to be due to exposure to butadiene or styrene, and may be chance observations.

Butadienes↗
PubMed1998

A safety assessment of fixed combinations of acetaminophen and acetylsalicylic acid, coformulated with caffeine.

Overuse and abuse of phenacetin-containing mixed analgesics has contributed to end-stage renal disease. Combination analgesics, especially those coformulated with caffeine, have been implicated as imparting a greater risk of analgesic-associated nephropathy (AAN) than single or coformulated analgesics without caffeine. This has led to a recommendation that the sale of "two plus caffeine" analgesic mixtures be reclassified from over-the-counter to prescription only availability. There is a rational basis for coformulating acetylsalicylic acid (ASA) and acetaminophen (paracetamol) as this reduces the dose of each, without altering efficacy. The coformulation of caffeine with these analgesics has a significant adjuvant effect and increases analgesic efficacy 1.4-1.6-fold. Currently available animal and human data do not support the notion that the nephrotoxic risk from coformulated ASA and acetaminophen is higher than the risk from either ASA or acetaminophen alone, in equivalent analgesic doses. There are no epidemiological data that implicate caffeine in AAN, and only limited evidence that links excessive acetaminophen usage to renal disease. There is no evidence that caffeine increases analgesics papillotoxicity directly. The presence of caffeine in mixtures of analgesics are no more addictive than other sources of caffeine. There is no evidence to suggest that adding caffeine to analgesic mixtures enhances the potential for promoting analgesic misuse in the general population. Thus distinct therapeutic benefits of ASA, acetaminophen and caffeine appear to outweigh any known risk. It is doubtful if preventing the availability of these products will significantly affect the role of analgesic abuse/overuse in end-stage renal disease. Better risk management would come from a focused educational program, developed in a close collaboration between industry, healthcare professionals and consumer organizations, such a program must warn against the potential dangers of analgesic and non-steroidal anti-inflammatory drug misuse.

Acetaminophen↗
PubMed1997

A case-control study of lung cancer at a foundry and two engine plants.

A nested case-control study of lung cancer was conducted among workers at an iron foundry and two engine manufacturing plants whose lung cancer mortality rates were slightly higher than expected. The study included 231 lung cancer cases and 408 controls for whom complete work histories were obtained. There was no association between usual plant of employment and lung cancer mortality. The odds ratio for persons employed for 20 or more years in the foundry compared with persons employed in the engine plants was 0.90 (95% confidence interval: 0.55, 1.5). Long-term employment as an engine plant worker was associated with odds ratios slightly, but not statistically significantly, below unity. In the foundry, only usual employment in the material handling departmental group and any employment in the quality control departmental group were statistically significantly directly related to lung cancer risk. However, the number of subjects so employed was small and there was no dose-response relation between length of employment in these departmental groups and lung cancer risk. Cases were less frequently employed than were controls in engine plant machining and assembly jobs and departments. It is concluded that employment in this facility was either unrelated, or only weakly related, to lung cancer risk.

Carcinogens↗
PubMed1997

A review of epidemiologic studies of triazine herbicides and cancer.

We evaluated epidemiologic evidence pertaining to the human carcinogenic potential of triazine herbicides in general and of atrazine, the most common triazine. Cancers for which data are available included non-Hodgkin's lymphoma, Hodgkin's disease, leukemia, multiple myeloma, soft tissue sarcoma, colon cancer, and ovarian cancer. The investigations had methodologic limitations, including lack of in-depth exposure measurements and small numbers of subjects with heavy exposure and/or with many years since starting exposure, possibly required for the induction of cancer. The relation between triazines and non-Hodgkin's lymphoma has been assessed in four independent population-based case-control studies, reporting odds ratios ranging from 1.2 to 2.5. However, chance and/or confounding by other agricultural exposures may have produced these weak statistical associations. Furthermore, a pooled analysis of three of the case-control studies and the combined analysis of two retrospective follow-up studies did not demonstrate the types of dose-response or induction time patterns that would be expected if triazines were causal factors. The epidemiologic data pertaining to Hodgkin's disease, leukemia, multiple myeloma, soft tissue sarcoma, colon cancer, and ovarian cancer were inadequate for determining whether associations with atrazine or triazines exist in humans. For each of these cancers, only one or two studies evaluating the relationship were available, and the results of the studies typically were imprecise.

Carcinogens↗
PubMed1997

Epidemiologic evidence on the relationship between mists containing sulfuric acid and respiratory tract cancer.

This review identified and evaluated 25 epidemiologic studies pertaining to the carcinogenicity of mists containing sulfuric acid (MSA). Few studies were designed with acid mists as the principal exposure under investigation, and in all studies exposure assessment was limited. The results of the follow-up studies from industries with high or moderate exposure potential and the case-control studies indicate, in aggregate, a moderate association between MSA and larynx cancer. The data suggest a dose-response relationship. However, many of the results from individual studies are imprecise, and confounding by smoking, alcohol, and other occupational agents is not adequately adjusted for. The biologic plausibility and the possible carcinogenic mechanism remain uncertain. There is little evidence in support of a causal relationship between exposure to MSA and lung cancer. Information is inadequate for drawing any meaningful inference about the association between exposure to MSA and nasal cancer.

Aerosols↗
PubMed1996

A follow-up study of synthetic rubber workers.

Although 1,3-butadiene (BD) has been classified as an animal carcinogen, epidemiologic research has reported inconsistent results on the relationship between BD and lymphopoietic and other cancers in humans. This study evaluated the mortality experience of 15649 men employed for at least 1 year at any of eight North American styrene-butadiene rubber (SBR) plants. About 75% of the subjects were exposed to BD; 83% were exposed to styrene (STY). During 1943-1991, the cohort had a total of 386172 and an average of 25 person-years of follow-up, with 3976 deaths observed compared to 4553 deaths expected based on general population mortality rates (standardized mortality ratio (SMR) = 87, 95% confidence interval (CI) = 85-90). More than expected leukemia deaths occurred in the overall cohort (48 observed/37 expected, SMR = 131, CI = 97-174) and among ever hourly subjects (45/32, SMR = 143, CI = 104-191). The excess was concentrated among ever hourly subjects with 10+ years worked and 20+ years since hire (28/13, SMR = 224, CI = 149-323) and among subjects in polymerization (15/6.0, SMR = 251, CI = 140-414), maintenance labor (13/4.9, SMR = 265, CI = 141-453) and laboratories (10/2.3, SMR = 431, CI = 207-793), three areas with potential for relatively high exposure to BD or STY monomers. Some cohort sub-groups had slight increases in deaths from lymphopoietic cancers other than leukemia, but mortality patterns by race, years worked and process group within the SBR industry did not indicate a causal association with occupational exposures. These results indicate that exposures in the SBR industry cause leukemia.

Butadienes↗
PubMed1996

Leukemia and cumulative exposure to butadiene, styrene and benzene among workers in the synthetic rubber industry.

Retrospective, quantitative estimates of exposure to 1,3-butadiene, styrene and benzene were developed for a follow-up study of leukemia mortality among 16610 subjects employed at six North American styrene-butadiene rubber manufacturing plants (418846 person-years, 58 leukemia deaths). The estimation procedure entailed identifying work areas within each manufacturing process, historical changes in exposure potential and specific tasks involving exposure, and using mathematical models to calculate job- and time-period-specific average exposures. The resulting estimates were linked with the subjects' work histories to obtain cumulative exposure estimates, which were employed in stratified and Poisson regression analyses of mortality rates. Mantel-Haenszel rate ratios adjusted by race, age, and cumulative styrene exposure increase with cumulative butadiene exposure from 1 in the nonexposed category to 4.5 in the category of 80 ppm-years or more (P = 0.01). The risk pattern is less clear and statistically nonsignificant for styrene exposure. A trend of increasing risk with butadiene exposure is still present after exclusion of the nonexposed category (P = 0.03). A parsimonious interpretation of the findings presented here, in light of previous epidemiologic studies, is that exposure to butadiene in the synthetic rubber industry produces a dose-related increase in the occurrence of leukemia.

Benzene↗
PubMed1996

Mortality among workers at two triazine herbicide manufacturing plants.

Triazine herbicides, used extensively in the United States, have not been assessed adequately for carcinogenicity in humans. This study evaluated the mortality experience during the period 1960-1986 of 2,683 men with definite or probable manufacturing exposure to triazine herbicides and 2,234 men with possible exposure to triazines. Standardized mortality ratios (SMRs) were computed as the observed numbers of deaths among study subjects divided by the numbers expected on the basis of general population mortality rates. Subjects with definite or probable exposure to triazines had a favorable mortality experience, compared with U.S. men [all causes, SMR = 72, 95% confidence interval (CI) = 58-89; all cancer, SMR = 85, CI = 46-142]. This group had an increase in deaths from non-Hodgkin's lymphoma (NHL) (3 observed/0.78 expected, SMR = 385, CI = 79-1,124). Two of the decedents with NHL had worked for less than 1 year in triazine-related jobs. Among the 2,234 subjects with possible triazine-related work, the mortality rate for all causes combined was similar to the rates of U.S. men. There was only one confirmed death from NHL. On balance, the results were consistent with previous investigations, which have found no convincing evidence of a causal link between triazines and cancer. However, the exposed cohorts were relatively young and had, on average, only 18 years of follow-up. In particular, results were imprecise for subjects having both a long duration of exposure and long potential induction periods.

Adult↗
PubMed1996

Beyond social class.

Explore the source record for details and available documents.

Epidemiologic Methods↗
PubMed1996

Brain tumors among electronics industry workers.

We evaluated the relation between work experience in the United States operations of an electronics company and brain tumor mortality, focusing on video display terminal (VDT) development jobs. Subjects were 149 brain tumor cases and 591 matched controls selected from a company registry of all employees dying between 1975 and 1989. Company databases and interviews with company personnel constituted the basis for work histories, including information on whether subjects had held VDT development jobs. Subjects who worked at plants with hardware or VDT development operations had slightly but imprecisely elevated odds ratios (OR). The study found no meaningful association between VDT development work and brain tumor mortality. Other results included an elevated OR for 10 or more years of employment in engineering/technical jobs [OR = 1.7; 95% confidence interval (CI) = 1.0-3.0] or in programming jobs (OR = 2.8; 95% CI = 1.1-7.0). The OR for glioma for all subjects who had accrued 5 years of programming work 10 years before the case's death was 3.9 (95% CI = 1.2-12.4). These associations were limited in large part to one of four division groups. Also, only male programmers experienced an elevated OR. These patterns indicate that the associations may be due to chance, although unidentified causal exposures present in a subset of engineering/technical and programming jobs cannot be ruled out.

Adult↗
PubMed1995

Mortality patterns among women in the motor vehicle manufacturing industry.

This retrospective follow-up study evaluated the mortality experience of 11,271 women employed in a large motor vehicle manufacturing company in 1973. Company computerized personnel records were used to identify subjects and to obtain their employment histories. Follow-up through December 31, 1985, was conducted using company, state, and national data sources. The mortality rates of the cohort were compared with the rates of the U.S. general population of white or black women, adjusting for age and calendar time and using the standardized mortality ratio (SMR) as the measure of association. The overall mortality rate of the cohort was lower than the U.S. rate by 15% among whites (SMR = 85, 95% confidence interval (CI) = 78-93) and by 40% among blacks (SMR = 59, CI = 49-70). Among whites, the low mortality rate was due primarily to deficits of noncancer deaths, although a 32% deficit also was observed for breast cancer (SMR = 68, CI = 48-92). Black female workers had 40% fewer deaths than expected overall, and their all cancer SMR also was below expectation (SMR = 82, CI = 60-109). Despite evidence of a strong healthy worker effect among women in the motor vehicle manufacturing industry, the study found excesses of lung cancer among white women in assembly jobs (SMR = 158, CI = 107-226) and of pancreatic cancer among white assembly workers in upholstery and trim operations (SMR = 302, CI = 97-704).

Adult↗
PubMed1995

Epidemiologic perspectives on myelodysplastic syndromes and leukemia.

The ICD classification of the myelodysplastic syndromes (MDS), and the four main features of the descriptive epidemiology of the condition are discussed. MDS is: (1) a rare disease; which may be, (2) on the increase; (3) which primarily affects the elderly; and (4) which predominantly affects men. We reviewed four causal models pertaining to the relationship between MDS and leukemia. These models may be described as: (1) non-biological correlates; (2) biological correlates; (3) early phase; and (4) interactive cause. Each model is described and the evidence in support of or against each is presented.

Humans↗
PubMed1995

An updated study of mortality among workers at a petroleum manufacturing plant.

This study evaluated mortality among 9796 white male workers at a petroleum-manufacturing plant. The main purpose was to examine recent patterns in leukemia mortality, for which an increase had been reported in an earlier investigation. Compared to U.S. white men, the cohort had an excess of leukemia in 1940-1979 (38 observed/23 expected; standardized mortality ratio = 168; 95% confidence interval = 119-230). In the 1980s, there was a deficit of leukemia (8 observed/14 expected; standardized mortality ratio = 55; 95% confidence interval = 24-108). However, this was balanced by an excess of myelofibrosis and myelodysplasia (4 observed, < 1 expected). These results indicate that any occupational leukemogenic exposures at the plant have been reduced to a point at which they are insufficient to cause leukemia. Hourly workers also had an excess of deaths from mesothelioma in the 1980s (8 observed, about 2.5 expected), possibly because of exposure to asbestos in the past.

Adult↗
PubMed1995

Mortality among workers at a pesticide manufacturing plant.

This study evaluated the mortality experience of 2384 workers at a plant in Colorado that produced aldrin, azodrin, vapona, and other pesticides. Subjects were followed up for a median of 29 years, from 1952 through 1990. Comparisons of the cohort's mortality rates with those of the Colorado population indicated that observed and expected numbers of deaths were similar for all causes (465 observed/473 expected) and for all cancers (113/106). Standardized mortality ratios were elevated for hepatobiliary cancer (5/2.0; standardized mortality ratio, 249, 95% confidence interval, 81 to 581), due to an excess of biliary duct/gall bladder cancer, and for pneumonia (20/13; standardized mortality ratio, 150, 95% confidence interval, 92 to 232). These increases were limited to white men in hourly jobs but were not limited to any particular production unit and did not display duration-response trends. It is unlikely that these excesses are due to occupational exposures at the plant.

Adult↗
PubMed1995

A case-control study of leukemia among petroleum workers.

This case-control study evaluates the relationship between leukemia and the work histories of active and retired employees of a large petroleum company. The study includes 69 cases with leukemia and 284 matched controls. Employment in production-related work in the oil and gas division was associated with myelogenous leukemia (odds ratio [OR] = 2.0, 95% confidence interval [CI] = .97 to 4.2) and particularly with acute myelogenous leukemia (OR = 2.8, 95% CI = 1.1 to 7.3). The association with acute myelogenous leukemia was strongest for subjects in the highest tertile (32+ years) of duration of employment in oil- and gas production-related work (OR = 8.7, 95% CI = 2.0 to 37), and there was a consistent trend of increasing ORs with increasing duration of employment (P = .01). No clear association was observed for refining division work and leukemia. This is the first epidemiologic study reporting a positive association between oil and gas field work and acute myelogenous leukemia.

Adult↗
PubMed1994

Cancer mortality among women employed in motor vehicle manufacturing.

This article summarizes published data on employment and cancer patterns in the motor vehicle manufacturing (MVM) industry and presents results from a new study of female MVM workers. Historically, female MVM employees worked primarily in aerospace; electric and electronic equipment manufacturing; and paint, plastic, and trim operations. Women are now moving into vehicle assembly and metal parts production. Investigations of cancer have focused on men and reported excesses of lung cancer in foundry operations, of gastrointestinal cancer in metal processing operations involving exposure to machining fluids, and of colorectal cancer in wood pattern making. Numbers of women were insufficient for a meaningful evaluation of their cancer patterns. A recent study found that white women employed at a MVM company, compared to the female general US population, had small excesses of lung cancer (standardized mortality ratio (SMR) = 1.26; 95% confidence interval (CI) = 0.96-1.63) and of colorectal cancer (SMR = 1.27, 95% CI = 0.87-1.78) and a deficit of breast cancer (SMR = 0.68, 95% CI = 0.48-0.92). The lung cancer increase was concentrated among women in assembly jobs (SMR = 1.58, 95% CI = 1.07-2.26); the colorectal cancer increase, among women in nonproduction jobs (SMR = 1.78, 95% CI = 0.97-2.98); and the breast cancer deficit, among women in production-related jobs (SMR = 0.60, 95% CI = 0.37-0.91). Further investigation is needed to determine if these patterns are due to the occupational environment and to clarify causes of cancer among women in the MVM industry.

Automobiles↗
PubMed1993

Use of organic solvents and potential worker exposure in the motor vehicle manufacturing industry.

This survey was designed to assist with planning epidemiologic studies of the effects of solvent exposure among motor vehicle manufacturing workers. The objectives were to identify subgroups of workers with solvent exposure, and to evaluate the availability of data for a job-exposure matrix (JEM). Of 65 plants selected, 31 (48%) participated. Participant plants represent all production activities initially included in the survey, and employ 97,655 hourly workers. About 14% of these workers use organic solvents (direct exposure), and 19% work in the proximity of solvent-using operations (indirect exposure). However, only 3% have direct exposure, and 6% have indirect exposure to large-volume (> or = 100 gallons/month)/high-frequency (hourly)-use solvents. The highest solvent exposure prevalence occurs in plants manufacturing engines and power train components and in metal degreasing/cleaning and painting tasks, and entails exposure to petroleum fractions, aromatic hydrocarbons, alcohols, and ketones. A JEM can be developed using plant records on job titles, work histories, production scheduling, and plant engineering, and using the corporate computerized personnel and industrial hygiene databases. However, information on solvent use and on exposure is adequate only for recent time periods.

Automobiles↗