Since direct measures of individual exposure seldom exist for the entire period of an occupational mortality study, retrospective exposure estimates are necessary. This is often done in a subjective manner involving a consensus of opinion from a panel of epidemiologists and industrial hygienists. An alternative method utilizing a statistical model provides a more objective procedure for retrospective exposure assessment. The development of a weighted multiple regression model is presented for estimation of exposure levels to ethylene oxide (ETO) for inclusion in a cohort mortality study of workers in the sterilization industry. Three steps in development of the model are described: (1) data acquisition and assessment, (2) model building, and (3) evaluation of the model. The final model explained a remarkable 85% of the variability in 205 average measurements of ETO levels. Exposure factors included in the model were exposure category, product type, size of the sterilization unit, selected engineering controls, days after sterilization, and calendar year. The model was evaluated in two ways: against a set of measurement data not used to develop the model and a panel of 11 industrial hygienists representing the sterilization industry. The model predicted ETO exposures within 1.1 ppm of the validation data set with a standard deviation of 3.7 ppm. The arithmetic and geometric means of the 46 measurements in the validation data set were 4.6 and 2.2 ppm, respectively. The model also outperformed the panel of industrial hygienists relative to the validation data in terms of both bias and precision.

This study illustrates how a union education center successfully integrated adult empowerment education principles into the teaching methods and curriculum of a health and safety training program. The 12-month follow-up phone survey involved 481 local union respondents each representing a separate plant site and a group of 50 manager trainees. The evaluation shows that the training manual continued to be used by more than 70% of respondents, more than 70% taught coworkers, more than 50% of union trainees went on to train their managers, and more than 90% identified problems at work and sought and obtained changes in programs, training, or equipment. More than 20% reported that major spills had occurred following training. The majority stated that the handling of the spills improved. More than 80% stated that the training better prepared them for their health and safety duties. The managers' data substantially supported union members' reports. The International Chemical Workers Union (ICWU) received one of the first of 11 national awards in 1987 from the National Institutes of Environmental Health Sciences to provide training for hazardous waste and emergency response workers. The Superfund Amendments and Reauthorization Act of 1986 mandated that the Occupational Safety and Health Administration develop a standard for training and regulation of health and safety conditions for workers at hazardous waste cleanup sites, at Resource Conservation and Recovery Act (RCRA)-regulated Treatment, Storage, and Disposal facilities, and at industrial plants where workers respond to substantial chemical releases.

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.

The study demonstrates that workers are more willing to attempt to change worksite conditions following training, and that their efficacy at making changes is substantially greater than before they were trained. The study confirms earlier work and strengthens these conclusions by using statistically tested comparisons of impact measures pre- and post-training.

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