An Environmental Stress Index (ESI) as a Substitute for the Wet Bulb Globe Temperature (WBGT)
Abstract
This report summarizes the development of a new environmental stress index (ESI) to asses heat stress. Two independent studies containing four different databases were analyzed in order to evaluate ESI and a small light sensor that measures global radiation. The purpose of the first study was to develop a new environmental stress index (ESI). Meteorological measurements were taken in three climatic zones (hot/wet, hot/dry, and extremely hot/dry) for 60 days, and a new stress index with the following algorithm was developed: ESI=0.63Ta-0,03RH+0,002SR+0.0054 (TaRH)-0.073(0.1+SR)-1 where Ta = ambient temperature, RH = relative humidity, and SR = solar radiation. The correlation coefficients between ESI and WBGT were very high (R2>0.981). Therefore, we concluded that ESI, based on fast response and accurate climatic microsensors (Ta, RH, SR) which can be combined in a portable device, has the potential to be a practical alternative to the WBGT. A second study evaluated a small (5mm) light (L) sensor in order to measure global radiation (GR) for use in heat stress assessment and in the ESI. Data were collected from three instruments: L, pyranometer (P) and black globe.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 2001
- Accession Number
- ADA387455
Entities
People
- Daniel S. Moran
- Kent B. Pandolf
- Richard R. Gonzalez
- William T. Matthew
Organizations
- United States Army Research Institute of Environmental Medicine