Abstract
To the Editor,
We read this article with interest. 1 We commend the authors for an interesting and thought-provoking paper as well as for providing a demonstration of the importance of maintaining our stoves for both optimal performance and safety.
Although the study was well designed overall, it was noted that there was not a consistent volume of water melted during each experiment but rather a consistent volume of snow at the start of each trial. The amount of water contained in snow can be highly variable and depends on multiple factors, including air temperature, amount of ice crystals versus supercooled water droplets in the clouds, and depth of the warm air layer contributing to the creation of the snow clouds.2,3 Given the potential for significant variability in water content within snow, the lack of a standardized water volume may have led to additional variables within the study.
While there are several studies that have examined carbon monoxide (CO) as it relates to a wilderness environment, there has been a considerable variance including pan diameter, flame size, and fuel type as well as different methods of CO generation (ie, cooking meals, boiling water, and melting snow). Although it is true that this level of variance does represent real-world applications, it also introduces variables that make it difficult to compare results between studies.4–7
To optimize reproducibility and generalizability, as well as to reduce the risk of introducing unintended variables, we would like to suggest a standardization for future studies that involve using a stove to generate CO. We would like to call attention to a paper published in this journal by Leigh-Smith et al 4 in 2004 that evaluated CO production while boiling water from either 1 L of ice or 1 L of liquid water.
Drawing from the paper by Leigh-Smith et al, 4 we would like to posit that the goal should be to obtain a specific final volume of water, such as 1 L. An alternative protocol could consider using 1 kg of snow or ice, but given the highly variable water content in snow, this may be less than ideal. Altitude and temperature will remain critical for comparison. Using a standard may help improve future research on CO, give users an understandable measure of exposure, and help us achieve our ultimate goal of improving the safety of people who spend time in the wilderness.
