A Knowledge-Based Approach to Using Databases for Occupational Exposure Assessment

Abstract

The purpose of this study was to examine the feasibility of using knowledge-based systems (i.e., expert systems) for subjective exposure assessment of job tasks based on interviews of workers. The first phase of the study consisted of the development of a knowledge base to derive estimates of workers' exposures to occupational agents or stressors. A large aircraft maintenance facility was chosen as the subject for knowledge engineering. The resulting knowledge-based system links databases containing 25 major processes, 75 operations, 107 possible techniques, numerous hazardous materials (>2600 records total), and 665 agents to derive qualitative and semiquantitative exposure estimates. The qualitative exposure estimates were derived from the Chemical Abstracts Service numbers of material ingredients. The semiquantitative exposure estimates were based on a scoring system developed by occupational epidemiologists. The second phase of the study involved validation testing of the prototype system. A total of 82 workers who handled solvents and paints were interviewed. The system correctly identified 74 percent of the known agents, but also identified many more agents not listed in survey documents. The semiquantitative estimates were used to rank the various tasks. Those rankings were then compared with the rankings from air sampling data. Some tasks were correctly ranked, but the overall agreement in rankings was poor. However, several plausible explanations for the disparity in rankings were tested by modifying the knowledge base; the result was a relatively good fit of the data (Spearman rank correlation coefficient for methylene chloride exposures changed from −0.315 to 0.857). Although further testing is needed to validate the current system, the findings of this study support the feasibility of a knowledge-based approach to exposure assessment. The limitations, potential benefits, and recommendations were also discussed. Knechtges, P.L.: A Knowledge-Based Approach to Using Databases for Occupational Exposure Assessment. Appl. Occup. Environ. Hyg. 10(4):361–373; 1995.