Argon used as dry suit insulation gas for cold-water diving

Extreme Physiology & Medicine

Robert A van Hulst²  Pieter-Jan AM van Ooij¹  Xavier CE Vrijdag³ 

[1] Diving Medical Center, Royal Netherlands Navy, Den Helder 1780 CA, The Netherlands;Laboratory of Experimental Intensive Care and Anesthesiology (L.E.I.C.A.), Department of Anaesthesiology, Academic Medical Center, University of Amsterdam, Amsterdam 1105 AZ, The Netherlands;Department of Hyperbaric Medicine, Academic Medical Center, University of Amsterdam, Amsterdam 1105 AZ, The Netherlands

关键词: Thermal insulation;    Hypothermia;    Inflation gas;    Dry suit;    Argon;    Cold effects;    Diving;   

Others  :  820160
DOI  :  10.1186/2046-7648-2-17

 received in 2012-01-24, accepted in 2013-03-15,  发布年份 2013

【 摘 要 】

Background

Cold-water diving requires good thermal insulation because hypothermia is a serious risk. Water conducts heat more efficiently compared to air. To stay warm during a dive, the choice of thermal protection should be based on physical activity, the temperature of the water, and the duration of exposure. A dry suit, a diving suit filled with gas, is the most common diving suit in cold water. Air is the traditional dry suit inflation gas, whereas the thermal conductivity of argon is approximately 32% lower compared to that of air. This study evaluates the benefits of argon, compared to air, as a thermal insulation gas for a dry suit during a 1-h cold-water dive by divers of the Royal Netherlands Navy.

Methods

Seven male Special Forces divers made (in total) 19 dives in a diving basin with water at 13°C at a depth of 3 m for 1 h in upright position. A rubber dry suit and woollen undergarment were used with either argon (n = 13) or air (n = 6) (blinded to the divers) as suit inflation gas. Core temperature was measured with a radio pill during the dive. Before, halfway, and after the dive, subjective thermal comfort was recorded using a thermal comfort score.

Results

No diver had to abort the test due to cold. No differences in core temperature and thermal comfort score were found between the two groups. Core temperature remained unchanged during the dives. Thermal comfort score showed a significant decrease in both groups after a 60-min dive compared to baseline.

Conclusions

In these tests the combination of the dry suit and undergarment was sufficient to maintain core temperature and thermal comfort for a dive of 1 h in water at 13°C. The use of argon as a suit inflation gas had no added value for thermal insulation compared to air for these dives.

【 授权许可】

   
2013 Vrijdag et al.; licensee BioMed Central Ltd.

【 图 表 】

Figure 1.

【 参考文献 】

• [1]Thalmann E, Weinberg R: Cold water exposure guidelines for passive thermal garments. Bethesda: NMRC Work Unit 639113N M009.01B-1004; 1990.
• [2]Mekjavic IB, Tipton MJ, Eiken O: Thermal considerations in diving. In Bennett and Elliott's Physiology and Medicine of Diving. 5th edition. Edited by Brubakk AO, Neuman TS. Collingwood: Saunders Book Company; 2003:115-152.
• [3]Richardson D, Shreeves J, Van Roekel G, Hornsby A: The Encyclopedia of Recreational Diving. Santa Ana: Professional Association of Diving Instructors; 1996.
• [4]Stinton RT: Survey of thermal protection strategies. In Proceedings of Advanced Scientific Diving Workshop: February 23-24 2006; Washington. Edited by Lang MA, Smith NE. Washington: Smithsonian Institution; 2006:74-85. February 23-24 2006
• [5]Weinberg R: Alternate dry suit inflation gas for improved thermal insulation. In Proceedings of the DCIEM diver thermal protection workshop; Toronto. Edited by Nishi R. Toronto: DCIEM; 1989:41-43.
• [6]Lippitt M, Nuckols M: Active diver thermal protection requirements for cold water diving. Aviat Space Envir Med 1983, 54:644-648.
• [7]Wattenberger J, Breckenridge J: Dry suit insulation characteristics under hyperbaric conditions. In Hyperbaric diving systems and thermal protection. Volume 6. Edited by Johnson C, Nuckols M, Clow P. NY: ASME OED; 1978:101-116.
• [8]Nuckols ML, Giblo J, Wood-Putnam JL: Thermal characteristics of diving garments when using argon as a suit inflation gas. In Proceedings of the Oceans:September 15–18 2008; Quebec. Piscataway: IEEE; 2008:1-7.
• [9]Jablonski J: Doing it right: The Fundamentals of Better Diving. High Springs: Global Underwater Explorers; 2000.
• [10]Risberg J, Hope A: Thermal insulation properties of argon used as a dry suit inflation gas. Undersea Hyperb Med 2001, 28:137-144.
• [11]Wendling J, Nome T, Elliott D, Barosa C: Medical Assessment of Working Divers Fitness to Dive Standards.. Hyperbaric Editions; 2004.
• [12]Respiratory protective devices – Compressed air for breathing apparatus. http://www.nen.nl/web/Normshop/Norm/NENEN-120211999-en.htm webcite
• [13]Pendergast DR, Lundgren CEG: The underwater environment: cardiopulmonary, thermal, and energetic demands. J Appl Physiol 2009, 106:276-283.
• [14]Wester TE, Cherry AD, Pollock NW, Freiberger JJ, Natoli MJ, Schinazi EA, Doar PO, Boso AE, Alford EL, Walker AJ: Effects of head and body cooling on hemodynamics during immersed prone exercise at 1 ATA. J Appl Physiol 2009, 106:691-700.
• [15]Holmér I, Bergh U: Metabolic and thermal response to swimming in water at varying temperatures. J Appl Physiol 1974, 37:702-705.
• [16]Shiraki K, Sagawa S, Konda N, Park Y, Komatsu T, Hong S: Energetics of wet-suit diving in Japanese male breath-hold divers. J Appl Physiol 1986, 61:1475-1480.
• [17]Arieli R, Kerem D, Gonen A, Goldenberg I, Shoshani O, Daskalovic Y, Shupak A: Thermal status of wet-suited divers using closed circuit O2 apparatus in sea water of 17–18.5 C. Eur J Appl Physiol 1997, 76:69-74.
• [18]Leffler CT: Effect of ambient temperature on the risk of decompression sickness in surface decompression divers. Aviat Space Envir Med 2001, 72:477-483.
• [19]Gerth WA, Ruterbusch VL, Long ET: The influence of thermal exposure on diver susceptibility to decompression sickness. Panama City Beach: NEDU TR 06–07 TA 03–09; 2007.
• [20]Toner CB, Ball R: The effect of temperature on decompression and decompression sickness risk: a critical review. Bethesda: NMRC Work Unit 63713 N M0099.01C-1610; 2004.