Caving for “Pink Puffers” and “Blue Bloaters”

The terms “Pink Puffers” and “Blue Bloaters” have been around for many years. They are used in a colloquial sense by speleologists to describe how cavers react to an elevated concentration of carbon dioxide (CO2) and reduced oxygen (O2) in a cave’s “foul air” atmosphere. Foul air is only found in a small number of Australian caves and is defined as having a noticeable abnormal physiological effect on humans. Pink Puffers hyperventilate when exposed to foul air while Blue Bloaters are slow to react and run the risk of losing consciousness without warning. This paper compares these colloquial terms with the same terminology used by some doctors to describe patients with medical conditions related to Chronic Obstructive Airways Disease (COAD). Pink Puffers hyperventilate and have good colour, while Blue Bloaters do not hyperventilate and look bluish because they are starved of oxygen. This is where the similarity in definitions ends. In the caving fraternity the term refers to a speleologist’s respiratory reaction to one of three types of foul air in a cave whereas in medical terminology it refers to a COAD patient’s specific condition and how their body functions in good air. Also discussed are possible links between smokers and ex-smokers with early stages of COAD (not yet causing noticeable disability in good air) who go underground and when subjected to foul air become speleologist blue bloaters. Two possible scenarios are put forward for discussion, which could form the basis of a future research project for someone with access to lung function measurements equipment.