Estimating Occupational Heat Exposure From Personal Sampling of Public Works Employees in Birmingham, Alabama.

Abstract

This study investigated whether using thermometers clipped on workers' shoes would result in different heat exposure estimation and work-rest schedules compared with using area-level meteorological data alone. Alabama workers (n = 51) were individually monitored using thermometers on shoes. Wet bulb globe temperature (WBGT) was estimated using thermometer temperatures (WBGT [personal]) or nearby weather station temperatures (WBGT [WS]). Work-rest schedules were determined from WBGT, clothing, and hourly metabolic rates estimated from self-reported tasks and bodyweight. The percent of hours exceeding the threshold limit value (TLV, ACGIH, Cincinnati, OH) were estimated at 47.8% using WBGT (personal) versus 42.1% using WBGT (WS). For work-rest recommendations, more hours fell into the most protective schedule (0 to 15 min work/45 to 60 min rest) using WBGT (personal) versus WBGT (WS) (17.4% vs 14.4%). Temperatures from wearable thermometers, together with meteorological data, can serve as an additional method to identify occupational heat stress exposure and recommend work-rest schedules.