Laboratory evaluation of three personal heat strain monitors in young and older wearers of protective. clothing.
Turner-N; Sinkule-E; Eschenbacher-W; Freeland-D
American Industrial Hygiene Conference and Exposition, May 20-25, 2000, Orlando, Florida. Fairfax, VA: American Industrial Hygiene Association, 2000 May; :33
NIOSH has recommended that worker-acceptable physiological monitoring may be an effective alternative to environmental monitoring in extreme environmental conditions. This study evaluated the accuracy of three commercial personal heat strain monitoring systems: 1) Metrosonics hs-3800; 2) MiniMitter Vital Sense; and 3) Questemp II. Seven young (25-40 years) and seven older (40-55 years) men wore two different protective clothing ensembles in similar environments: 1) single- layer cotton/polyester coverall at 35 degrees C WBGT (COTTON); and 2) vapor-impermeable Level A suit with SCBA at 29.5 degrees C WBGT (HAZMAT). Subjects walked on a treadmill at a low intensity until rectal temperature reached 38.5 degrees C or until volitional fatigue. Mean work times ranged from 41.9 min to 51.7 min. Sensitivity for the Metrosonics and Vital Sense was 0.00 and 0.00 for COTTON and 0.38 and 0.71 for HAZMAT, respectively. Specificity was 1.00 for the Metrosonics and Vital Sense for both conditions. When rectal temperature measured 38.5 degrees C, mean disk temperatures for the Metrosonics and Vital Sense were 38 degrees C and 37.5 degrees C for COTTON and 38.2 degrees C and 38.2 degrees C for HAZMAT, respectively. Questemp ear canal temperatures in the young subjects were 39.1 degrees C and 38.7 degrees C for COTTON and HAZMAT, respectively; in the older group, Questemp temperatures were 39.4 degrees C and 37.7 degrees C for COTTON and HAZMAT, respectively. Correlation coefficients between rectal temperature and Metrosonics, Vital Sense, and Questemp temperatures were 0.09, -0.04, and 0.10 for the COTTON condition and 0.79, 0.76, and 0.03 for the HAZMAT condition, respectively. The accuracy of Metrosonics and Vital Sense was poor for the COTTON condition. While significant correlations for both Metrosonics and Vital Sense and better sensitivity for Vital Sense were observed during the HAZMAT condition, there was an unacceptably high number of false negatives for both systems. The Questemp performed poorly for both groups and conditions.
Personal-protection; Personal-protective-equipment; Clothing; Heat-production; Heat-stress; Heat-exposure; Environmental-factors; Environmental-physiology; Physiological-measurements; Physiological-testing; Medical-monitoring; Laboratory-testing; Monitoring-systems; Monitors; Equipment-reliability; Men; Age-groups; Environmental-health-monitoring; Measurement-equipment; Temperature-measurement; Temperature-effects; Body-temperature; Cotton-fabrics; Sensitivity-testing
American Industrial Hygiene Conference and Exposition, May 20-25, 2000, Orlando, Florida