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L Stayner

Publications and source records attributed to L Stayner.

33 records · Page 2Linked to original sources
PubMed1993

Exposure-response analysis of cancer mortality in a cohort of workers exposed to ethylene oxide.

The authors previously reported results from the largest cohort mortality study of ethylene oxide-exposed workers that has been conducted to date. Here they extend their previous work by quantitatively examining the relation between cancer mortality and ethylene oxide exposure. This study included workers from 13 of the 14 geographically distinct facilities that were included in the previous investigation. These facilities began regularly using ethylene oxide to sterilize medical supplies or spices sometime between 1938 and 1969. Workers were followed from first exposure through December 31, 1987. Historical exposures to ethylene oxide were estimated using a regression model. Standard life-table analysis was used to examine cancer mortality in three categories of cumulative exposure to ethylene oxide. The Cox proportional hazards model was also used to examine cumulative and other measures of ethylene oxide exposure as predictors of cancer mortality. In both the life-table analysis and the Cox model, a positive trend was observed in all lymphatic and hematopoietic cancer mortality for cumulative ethylene oxide exposure. This trend was strengthened when ethylene oxide exposures 10 years prior to death were discounted (lagged) and when the analysis was restricted to neoplasms of lymphoid cell origin. Despite limitations discussed in this paper, the authors believe that these findings provide some support for the hypothesis that exposure to ethylene oxide increases the risk of mortality from lymphatic and hematopoietic neoplasms. The authors intend to continue follow-up of this relatively young cohort, which may allow more definitive conclusions to be drawn in the future.

Cohort Studies↗
PubMed1993

Lung cancer.

Explore the source record for details and available documents.

Cadmium↗
PubMed1992

A dose-response analysis and quantitative assessment of lung cancer risk and occupational cadmium exposure.

We performed a quantitative assessment of the risk of lung cancer from exposure to cadmium based on a retrospective cohort mortality study of cadmium-exposed workers. The study population consisted of white male workers who were employed for at least 6 months at a cadmium smelter between January 1, 1940, and December 31, 1969, and who were first employed at the facility on or after January 1, 1926. The study findings were analyzed using a modified life-table analysis to estimate standardized mortality ratios (SMRs), and various functional forms (i.e., exponential, power, additive relative rate, and linear) of Poisson and Cox proportional hazards models to examine the dose-response relationship. Estimates of working lifetime risk (45 years) were developed using an approach that corrects for competing causes of death. An excess in mortality from lung cancer was observed for the entire cohort (SMR = 149, 95% confidence interval (CI) = 95, 222). Mortality from lung cancer was greatest among non-Hispanic workers (SMR = 211, 95% CI = 131, 323), among workers in the highest cadmium exposure group (SMR = 272, 95% CI = 123, 513), and among workers with 20 or more years since the first exposure (SMR = 161, 95% CI = 100, 248). A statistically significant dose-response relationship was evident in nearly all of the regression models evaluated. Based on our analyses, the lifetime excess lung cancer risk at the current Occupational Safety and Health Administration standard for cadmium fumes of 100 micrograms/m3 is approximately 50 to 111 lung cancer deaths per 1000 workers exposed to cadmium for 45 years.

Adult↗
PubMed1992

A quantitative assessment of lung cancer risk and occupational cadmium exposure.

We have performed a quantitative assessment of the risk of lung cancer from exposure to cadmium based on a retrospective cohort mortality study of cadmium-exposed workers. The findings were analysed using a life-table analysis to estimate standardized mortality ratios (SMRs), and various functional forms of Poisson and Cox proportionate hazards models to examine dose-response relationships. An excess mortality from lung cancer was observed for the entire cohort (SMR = 149,95% CI = 95-222). Lung cancer mortality was significantly elevated among non-hispanic workers, among those in the highest cadmium-exposure group, and among workers with 20 or more years since first exposure. A statistically significant dose-response relationship was evident in nearly all of the regression analyses. Based on our analyses, the lifetime excess lung cancer risk at the current OSHA standard for cadmium fumes of 100 micrograms/m3 is approximately 50-111 lung cancer deaths per 1000 workers exposed to cadmium for 45 years.

Adult↗
PubMed1991

Mortality among workers exposed to ethylene oxide.

BACKGROUND: Ethylene oxide is a sterilant gas that causes leukemia and other cancers in animals. Studies in Sweden have shown an excess of leukemia and stomach cancer in humans exposed to ethylene oxide, but other studies have generally failed to confirm these findings. METHODS: We conducted a study of mortality in 18,254 U.S. workers exposed to ethylene oxide at 14 plants producing sterilized medical supplies and spices. The subjects averaged 4.9 years of exposure to the gas and 16 years of follow-up. The exposure levels in recent years averaged 4.3 ppm (eight-hour time-weighted adjusted exposure) for sterilizer operators and 2.0 ppm for other workers. The levels in earlier years are likely to have been several times higher. Mortality in this cohort was compared with that in the general U.S. population. RESULTS: Overall there was no significant increase in mortality from any cause in the study cohort. The standardized mortality ratios (SMRs) were 0.97 for leukemia (95 percent confidence interval, 0.52 to 1.67; 13 deaths observed), 1.06 for all hematopoietic cancers (95 percent confidence interval, 0.75 to 1.47; 36 deaths), and 0.94 for stomach cancer (95 percent confidence interval, 0.45 to 1.70; 11 deaths). Analyses according to job category and according to the duration of exposure showed no excess in cancers, as compared with the rate in the general population, but there was a significant trend toward increased mortality with increasing lengths of time since the first exposure for all hematopoietic cancers. The rate of death from hematopoietic cancer (especially non-Hodgkin's lymphoma) was significantly increased among men (SMR, 1.55; 27 deaths). Mortality from leukemia in recent years (1985 through 1987) was significantly increased among men (SMR, 3.45; 5 deaths). CONCLUSIONS: For the entire cohort, there was no increase in mortality from hematopoietic cancer. There was a slight but significant increase among men, however. Among men and women combined, there was a trend toward an increased risk of death from hematopoietic cancer with increasing lengths of time since the first exposure to ethylene oxide.

Cohort Studies↗
PubMed1991

The importance of employment status in occupational cohort mortality studies.

Person-years at risk in occupational cohort mortality studies may be defined as "active" (when a person is working) or "inactive" (after a person has left employment at the plant under study). To investigate the effects of employment status (active/inactive) both across studies and within them, we have analyzed ten large cohort studies conducted by the National Institute for Occupational Safety and Health in which no occupational risk had been observed. These ten data sets included 89,376 workers, 1,984,505 person-years, and 18,840 deaths. In these ten studies, the SMR for all causes was positively correlated with the percentage of inactive person-years in the study (r = 0.57, p = 0.08). Considering only inactive person-years, the all-causes SMR was 1.12 (approximately 1.25 before age 65, dropping to 1.00 after age 65). Stratification of inactive person-years by time-since-last-employment showed markedly increased mortality during the first year following employment. The all-causes SMR during active person-years was 0.40 and was fairly constant across age categories. With active and inactive person-years combined, a strong negative trend in SMRs with duration of employment was observed for all causes and for heart disease. These trends were not apparent when person-years were stratified by employment status. These results indicate that investigators should evaluate the effects of employment status when comparing SMRs between multiple cohorts or when interpreting trends in rate ratios within cohorts.

Cohort Studies↗
PubMed1990

New developments in the Life Table Analysis System of the National Institute for Occupational Safety and Health.

In the 1970s, the National Institute for Occupational Safety and Health developed a Life Table Analysis System to analyze occupational cohort studies. We have updated the original system by adding two new features: direct standardization with a test for linear trend, and analyses by lagged exposure (either duration of exposure or cumulative exposure). We have also updated US reference rates through 1989. The updated systems and documentation (version F) are available upon request. In collaboration with the National Cancer Institute, we have also developed multiple cause-of-death rate files, which consider contributory as well as underlying cause. These files (also available upon request) will enable investigators to derive the expected prevalence of diseases at death, which can then be compared with the observed prevalence in an exposed cohort. Work is currently underway to produce a personal computer version of the Life Table Analysis System.

Cause of Death↗
PubMed1987

Assessing the feasibility of retrospective cohort studies.

While most epidemiologic cohort studies are preceded by some sort of feasibility study, details of such prior investigations are rarely reported. Yet it is during such feasibility studies that critical decisions are made, such as site selection and definition of exposure. Here we present the details on one such feasibility study, conducted to determine the possibility of a cohort mortality study of workers exposed to ethylene oxide. Issues discussed include methods for estimating sample size and power, for estimating levels of exposure, and for assessing the adequacy of personnel records.

Data Collection↗
PubMed1985

Proportionate mortality study of workers in the garment industry exposed to formaldehyde.

In order to evaluate the human carcinogenicity of formaldehyde, we conducted a proportionate mortality study of garment workers engaged in the production of shirts from formaldehyde-treated cloth. This study included three plants, and was based upon 256 deaths identified from a death-benefit insurance fund. No deaths due to nasal cancer were observed, and the mortality from respiratory cancer (11 cases, PMR = 95) was slightly less than expected. Statistically significant (p less than .05) elevations in proportionate mortality were observed for malignant neoplasms of the "buccal cavity" (three cases, PMR = 750), for "biliary passages and liver" (four cases, PMR = 313) and for "other lymphatic and hematopoietic sites" (four cases, PMR = 400). A proportionate cancer mortality (PCMR) analysis also was conducted, and cancer of the "buccal cavity" (three cases, PCMR = 682), and other "lymphatic and hematopoietic sites" (four cases, PCMR = 342) were still significantly elevated. The observed excesses in cancer mortality were primarily experienced by white females, who made up the major portion of the workforce, and workers with more than 10 years of latency and duration of exposure, a criterion for inclusion for most workers in the study group. The neoplasms observed were not equally distributed among the three facilities included in the study. Because of the small number of deaths involved and the lack of consistency with other studies, we believe that these findings should be viewed cautiously, pending the outcome of more definitive studies.

Adolescent↗
PubMed1983

Nasal cancer in a worker exposed to formaldehyde.

Formaldehyde has not been established as a human carcinogen. Toxicological studies have, however, demonstrated that formaldehyde causes squamous cell carcinoma of the nasal cavity in rats. A case of squamous cell carcinoma of the nasal cavity occurred in a 57-year-old man who had 25 years of occupational exposure to low concentrations of formaldehyde in the textile-finishing industry.

Carcinoma, Squamous Cell↗