Carbon dioxide in cave atmospheres. New results in Belgium and comparison with some other countries.
Lab. Geomorphol. Geol. Quaternaire, Univ. Liege, Place du 20-Aout, 7, B-4000 Liege, Belgium
Earth Surface Processes and Landforms vol. 10, no. 2, pp. 173-187, 1985 ISSN 0197-9337
More than 600 measurements of the carbon dioxide content of cave air in Belgium lead up to the conclusion that the main factors of its distribution are: (1) a flow originating from the biomass and diffusing in the soil and the voids of bedrock; (2) a trend, discernible in very still air only, to go down by density; (3) in some caves, draughts caused, for instance, by a swift underground stream. Results in Belgium are compared with published and unpublished data from other countries, showing that CO sub(2) is often less abundant in cold climate caves and in caves of semi-arid regions (influence of the biomass). Special attention is paid to human contamination during analyses: the influence of people passing through the cave nearly the operator, but also the influence of the operator himself are discussed, and the use of special precautions (including a CO sub(2)-absorbing mask) in defined critical situations is stressed.