Affiliation:
1. Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University in Prague, 272 01 Kladno, Czech Republic
Abstract
On average, one hundred people die each year under avalanche snow. Despite extensive global research on gas exchange in buried avalanche victims, it remains unclear how the diffusion of respiratory gases affects survival under avalanche snow. This study aims to determine how oxygen and carbon dioxide diffuse through snow, as well as through wet and dry perlite, which may serve as a surrogate for avalanche snow. A custom-made apparatus to study the diffusion of respiratory gases consisted of a plastic cylinder (1200 mm long, ID 300 mm) with 13 gas sampling needles evenly spaced along the axis of the cylinder filled with the tested material. Following 60 min of free diffusion, gas samples were analyzed using a vital signs monitor with a module for respiratory gas analysis (E-CAiOVX, Datex-Ohmeda, GE Healthcare, Chicago, IL, USA). A combination of 16% oxygen, 5% carbon dioxide, and 79% nitrogen was used. The rates of diffusion for both respiratory gases were comparable in snow and both forms of perlite. Oxygen propagated faster than carbon dioxide. Due to similar diffusion characteristics to snow, perlite possesses the potential to stand in as an effective substitute for soft snow for the study of respiratory dynamics, for conducting breathing experiments, and for testing avalanche safety equipment.
Funder
Czech Technical University in Prague
Subject
Fluid Flow and Transfer Processes,Computer Science Applications,Process Chemistry and Technology,General Engineering,Instrumentation,General Materials Science
Reference32 articles.
1. Avalanche fatalities in the European Alps: Long-term trends and statistics;Techel;Geogr. Helv.,2016
2. Statistics and reporting (2023, September 09). Colorado Avalanche Information Center. Available online: https://avalanche.state.co.us/accidents/statistics-and-reporting/.
3. Cause of death in avalanche fatalities;McIntosh;Wilderness Environ. Med.,2007
4. Effects of snow properties on humans breathing into an artificial air pocket–an experimental field study;Strapazzon;Sci. Rep.,2017
5. Diffusional flux of CO2 through snow: Spatial and temporal variability among alpine-subalpine sites;Sommerfeld;Glob. Biogeochem. Cycles,1996