American Industrial Hygiene Conference and Exposition, May 8-13, 2004, Atlanta, Georgia. Fairfax, VA: American Industrial Hygiene Association, 2004 May; :87
In support of a case-control epidemiology study of leukemia and external ionizing radiation at five U.S. Department of Energy sites, historical chemical exposure strategies have been developed for worker solvent exposure, a potential confounding factor. The size of the Savannah River Site population (207 workers) allows for an extensive exploration of potential chemical solvent confounders during the study period of 1951 to 1996. An exposure assessment strategy was developed to determine the levels of confounding by chemical solvent exposures, concentrating on benzene and carbon tetrachloride. The 207 study subjects have 86 unique job titles with the most frequent being mechanic, operator, patrolman, and engineer. The initial step in the exposure assessment process looked at potential exposures linked by job title, work location, and the time period in which the exposure was generated taking into consideration changes in personal protective equipment use, engineering controls, and removal of chemicals from the workplace. In order to implement this assessment strategy, work histories for each study subject were compiled using available information from electronic images of medical, personnel, and health physics records. A job exposure matrix (JEM) detailing the exposures to chemical solvents was developed through a comprehensive review of process descriptions, chemical inventories, and industrial hygiene monitoring data for each combination of site, work location, job title, and time period for each individual study location. After finalizing the JEM, the job title histories have a 93% completion rate (3331 of 3594 person-years); the division descriptor has a 95% completion rate (3405 of 3594 person-years), and the location descriptor has a 64% completion rate (2296 of 3594 person-years ). Comparison of these three factors allowed imputation of missing values. Categories of exposures can be assigned with these different methods of examining chemical solvent use at the site.
American Industrial Hygiene Conference and Exposition, May 8-13, 2004, Atlanta, Georgia