NOIRS 1997 Abstracts of the National Occupational Injury Research Symposium 1997. Washington, DC: National Institute for Occupational Safety and Health, 1997 Oct; :32-33
Waste abatement workers, due to the nature of their job, require a high level of protection and must therefore commonly wear personal protective equipment such as a self-contained breathing apparatus (SCBA) and encapsulating suits. Wearing this type of personal protective equipment while working adds a weight burden, impedes heat exchange and can lead to physiological strain and increased energy expenditure. This strain and increased energy expenditure can in turn lead to exhaustion in a period of time much shorter than would be experienced without this equipment. The goal of this study was to analyze the energy expenditure of hazardous waste abatement workers while performing tasks common to their jobs. Nine asbestos workers aged 27 to 40 performed six typical hazardous waste abatement tasks in a laboratory setting. Subjects carried an SCBA and wore a Mine Safety Appliances Company (MSA) BlueMaxTM totally encapsulating suit. This level of protection is designated "Level A" and is utilized by workers who require the ultimate possible protection during waste site cleaning operations. Although all subjects were in a safe laboratory environment, they were required to wear this complete protection in order to approximate work site energy expenditures. However, since no activity in a toxic environment was involved, subjects were allowed to keep the garment open and the SCBA disconnected. All tests were conducted in a neutral environment (20°Centigrade, 60% relative humidity). Heart rate, respiratory frequency, and oxygen consumption were measured every 30 seconds during the performance of the various activities. Six different tasks were selected for simulation through an agreement with hazardous waste abatement union experts. The activities simulated typical tasks performed daily on hazardous waste sites. These typical tasks included: walking from one place to another, carrying equipment, decontamination of soiled surfaces, shoveling toxic dirt into drums, digging to uncover barrels, and crawling in confined spaces. These tasks were simulated with the following activities: walking on a treadmill at 1.5 miles an hour, carrying a 20-pound bucket at the same speed, mopping the floor at 60 strokes per minute, shoveling sand from ground level into a drum, digging at ten shovels per minute, and crawling on the treadmill at 0.3 miles an hour. In all, each tested activity lasted ten minutes, including a five minute warm-up that allowed each subjects' heart rate to reach a plateau. Oxygen uptake data obtained during the last five minutes of each test are used to measure the energy expenditure. The data collected is being analyzed in graphical form. The risk of impending heat stress increases not only with the ambient temperature, but also with a work load. Results of this study will be useful in determining the workers' average energy expenditure when they perform a given task, and thus to assist with decision-making wether an appropriate micro cooling system is required.
Workers; Personal-protective-equipment; Self-contained-breathing-apparatus; Worker-health; Hazardous-waste-cleanup; Laboratory-testing; Demographic-characteristics; Age-factors; Work-environment; Work-clothing; Workplace-monitoring; Occupational-health; Occupational-exposure; Risk-factors; Risk-analysis; Heart-rate; Heat-exhaustion; Heat-exposure; Heat-stress