Heat Exposure Control Using Non-refrigerated Water in Brazilian Steel Factory Workers

Abstract

To test an economically reasonable method to reduce thermal stress, we performed an alternated intervention-control study on 2 groups of 8 male steel workers performing the same jobs, using 2 l of water at ambient temperature (23.5°C ± 1.4), poured on the head and hands. Each group participated for 2 d as control and 2 d as intervention during 4 consecutive summer days in Brazil, 5 h per shift per day. Testing was done by: 1) recording of temperature by thermistors placed on the external ear canal through earplug, skin (chest, upper arm, inner thigh, outer calf) and clothes; 2) recording of heart rate; and 3) Wet Bulb Globe Temperature recording. The intervention was held hourly, when body weight and water intake were evaluated. Symptoms and subjective sensations were evaluated in the beginning and at the end of each shift. No differences were observed in external ear canal and skin temperatures. Subjective thermal sensation (p=0.018), sweat perception (p=0.043), and tiredness (p=0.028) presented positive statistically significant results when comparing intervention to control measurements. In conclusion, our results could not provide evidence that the proposed method cools the analyzed temperatures, although the subjective evaluation suggests a decrease in the head skin temperature, which could be a useful comfort measure.

Health Impacts of Workplace Heat Exposure: An Epidemiological Review

“…Usually, physiological responses and subjective symptoms of industrial workers exposed to heat include elevated blood pressure and urine gravity, increased recovery heart rates and body temperature, and increased fatigue symptoms 25 , 34 , 36 , 47 , 48 , 51 , 54 , 58 ) . However, if effective prevention measures are taken in the workplace, risk of heat-related illness and injury can be significantly reduced 20 , 24 , 57 , 59 ) .…”

“…Increased hot days due to climate change may worsen the extent of heat stress for individuals working around heat generating sources. Hence, many epidemiological studies have focused on the impacts of workplace-generated heat on factory workers in steel plants 13 , 59 ) , foundries 42 ) , automobile industries 43 , 44 ) , and glass manufacturing units 41 ) .…”

Cooling intervention studies among outdoor occupational groups: A review of the literature

“…In Brazil, eight steel workers exposed to WBGT of 26–29°C at the worksite poured 2 L of water at 23.5°C on their head and hands over 1‐min 10 times during the work shift 40 . The steel workers participated in a 4‐day trial and were randomized to one of the two groups.…”

“…In Brazil, eight steel workers exposed to WBGT of 26-29°C at the worksite poured 2 L of water at 23.5°C on their head and hands over 1-min 10 times during the work shift. 40 The steel workers participated in a 4-day trial and were randomized to one of the two groups. The first group participated in the control (usual work practices) for two consecutive days followed by 2 days of pouring water on their hands and head at scheduled times.…”

Effects of heat on behavioral and physiological mechanisms of the human thermoregulatory system during rest, exercise, and work

“…Calculator downloaded from www.ClimateCHIP.org. 181 This calculator uses the recommended method of Liljegren to calculate the outdoor WBGT from meteorological data, 182,183 as well as information from the official UTCI webpage 184 to estimate the UTCI.…”