Abstract
Conventional sampling with pumps and sampling media can be used to determine whether exposures to air contaminants are excessive. Unfortunately, such results provide few insights into the reasons for the excessive exposures. However, Video Exposure Monitoring can be used to identify the sources causing these excessive exposures. Any movable instrument that has an analog or digital output can potentially be used for Video Exposure Monitoring. The instrument should be light enough to mount on a worker, be specific for the chemical interest, and have a short time constant. Although most existing direct-reading instruments do not simultaneously meet all these requirements, currently available instruments, such as aerosol photometers, photoionization detectors, and portable infrared analyzers have been used effectively. The analog or digital output from direct-reading instruments can be recorded by data-logging devices. The data-logging devices transfer the exposure data to a personal computer for storage and statistical analysis. In addition to statistical analysis of the data, the personal computer, outfitted with a video overlay system, can also be used to overlay the exposure data onto a video recording of worker activities. The worker's exposure is displayed as a moving bar proportional in height to the air contaminant concentration. The work activity video image with the overlaid exposure data can be recorded on a second video tape. By replaying the overlaid video recording, this technique shows how worker exposures are related to work activities, permitting industrial hygienists to make recommendations for control measures focusing on actual exposure sources. Furthermore, these video recordings can be used to train workers to avoid work practices that cause elevated air contaminant exposures. Gressel, M.G.; Heitbrink, W.A.; Jensen, P.A.: Video Exposure Monitoring—A Means of Studying Sources of Occupational Air Contaminant Exposure, Part 1—Video Exposure Monitoring Techniques. Appl. Occup. Environ. Hyg. 8(4):334-338; 1993.