What is spelunkers?

Answer 1

Spelunkers lung, is a lung disease caused by cave exploration where bat excrement is present. The excrement may contain a fungus. This fungus' spores are inhaled into the lungs causeing inflammation. Also see: Acute Symptomatic Pulmonary Histoplasmosis.

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It's associated more with caves in tropical / sub-tropical regions, and holding very large bat colonies.

I have never seen the name "spelunkers' lung" in any serious report - it's always called simply 'Histoplasmosis'. "Spelunker" is an old-fashioned term concocted by two American cavers in the 1930s(?), and after a decade or so of normal use, though only in the US, it became a term of derision among American cavers themselves, and is now rarely if ever used in caving literature.

Answer 2

Spelunking is the exploration of caves for recreational purposes or just for fun. Spelunkers do not collect scientific data. Spelunkers are not trained in advanced cave exploration techniques. People who enter caves with the bare minimum of equipment are said to be spelunking. Spelunkers do not venture to depths beyond 300 meters, or lengths beyond 2 kilometers. Once a spelunker gains some experience and training, he is a "caver." And once a caver begins contributing to the cave science community by publishing articles, he is said to be a "speleologist."