Bomb Disposal in the Tropics: A Cocktail of Metabolic and Environmental HeatIan B Stewart1*, Andrew Townshend1,2, Amanda M Rojek1 and Joseph T Costello1
- *Corresponding Author:
- Ian Stewart
Queensland University of Technology, 60 Musk Ave
Kelvin Grove, QLD 4059, Australia
Tel: 07 3138 6118
Fax: 07 3138 6030
E-mail: [email protected]
Received date: November 27, 2012; Accepted date: December 26, 2012; Published date: January 02, 2013
Citation: Stewart IB, Townshend A, Rojek AM, Costello JT (2013) Bomb Disposal in the Tropics: A Cocktail of Metabolic and Environmental Heat. J Ergonomics S2:001. doi:10.4172/2165-7556.S2-001
Copyright: © 2013 Stewart IB, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Bomb technicians perform their work while encapsulated in explosive ordnance disposal (EOD) suits. Designed primarily for safety, these suits have an unintended consequence of impairing the body’s natural mechanisms for heat dissipation.
Purpose: To quantify the heat strain encountered during an EOD operational scenario in the tropical north of Australia.
Methods: All active police male bomb technicians, located in a tropical region of Australia (n=4, experience 7 ± 2.1 yrs, age 34 ± 2 yrs, height 182.3 ± 5.4 cm, body mass 95 ± 4 kg, VO2max 46 ± 5.7 ml. kg-1.min-1) undertook an operational scenario wearing the Med-Eng EOD 9 suit and helmet (~32 kg). The climatic conditions ranged between 27.1–31.8°C ambient temperature, 66-88% relative humidity, and 30.7-34.3°C wet bulb globe temperature. The scenario involved searching a two story non air-conditioned building for a target; carrying and positioning equipment for taking an X-ray; carrying and positioning equipment to disrupt the target; and finally clearing the site. Core temperature and heart rate were continuously monitored, and were used to calculate a physiological strain index (PSI). Urine specific gravity (USG) assessed hydration status and heat associated symptomology were also recorded.
Results: The scenario was completed in 121 ± 22 mins (23.4 ± 0.4% work, 76.5 ± 0.4% rest/recovery). Maximum core temperature (38.4 ± 0.2°C), heart rate (173 ± 5.4 bpm, 94 ± 3.3% max), PSI (7.1 ± 0.4) and USG (1.031 ± 0.002) were all elevated after the simulated operation. Heat associated symptomology highlighted that moderate-severe levels of fatigue and thirst were universally experienced, muscle weakness and heat sensations experienced by 75%, and one bomb technician reported confusion and light-headedness.
Conclusion: All bomb technicians demonstrated moderate-high levels of heat strain, evidenced by elevated heart rate, core body temperature and PSI. Severe levels of dehydration and noteworthy heat-related symptoms further highlight the risks to health and safety faced by bomb technicians operating in tropical locations.