David,
Concern about radon gas is not new. Back in the 70s when I was working at Carlsbad Caverns, the level of radon in the public areas of the cave was tested daily. And they'd been doing that for several years by '76.Their statistics showed that the concentration of radon gas seemed to be proportional to the circulation of air in each section. The highest concentration was in the back of the Big Room at the overlook during the winter months. The lowest at the entrance area in the summer.
Crews were divided into three groups--entrance area, central area and Big Room. Wewere required to keep accurate figures on how many hours/shifts we spent in each of these areas.These figures were used to determine how long each person could stay in each section of the cave and when they needed to take a tour outside and do nature walks, talks at the entrance, etc. By the time you'dworked your way down to the requisite number of shifts in theBig Room, your crew was shifted outside for a period of time.
Of course that was 30 years ago. I don't know how they're doing it now.Louise
From:"David Locklear" dlocklea...@gmail.comTo:texascavers@texascavers.comSubject:[Texascavers] Speleo-calculusDate:Mon, 17 Sep 2007 23:02:22 -0500MIME-Version:1.0Received:from raistlin.wokka.org ([69.56.185.90]) by bay0-mc11-f11.bay0.hotmail.com with Microsoft SMTPSVC(6.0.3790.2668); Mon, 17 Sep 2007 21:02:51 -0700Received:(qmail 74453 invoked by uid 89); 18 Sep 2007 04:02:54 -Received:(qmail 7 invoked by uid 31338); 18 Sep 2007 04:02:53 -Just when you think you have learned everything aboutcaving, someone comes along and adds more to learn.In the most recent issue of the NSS Journal ( April 2007 ),there is an interesting article about the potential for cavers
to beexposed to radiation, which could lead to cancer.Part of the author's study is based on calculus.I can'trecall seeing calculus in previous articles before, but I usuallyonly get a chance to skim through the Journal.It appears that people who spend a lot of time undergroundsuch as guano miners, or cave tour guides need to findout if their cave has radiation in it.The author introduces a whole new sleugh of speleo-terminology,such as Risk of Morbidity, Risk of Mortality, and acronymslike LD50 - median lethal dose.He even defines what a recreational caver is - a person thatgoes caving approximately 50 hours a year.You may recall from your high-school chemistry class - theperiodic table listing all the elements.Remember the columnwith the gases to the far
right? Do you remember Radon?The author, Mr. Malcolm Field, focuses his study on Radon,specifically Radon-222.He believes that if the cave has this form of Radon in it, that itwill decay and produce alpha radiation.He calls this process -ionizing radiation.Apparently, ionizing radiation is all around us, especially in ourhomes.He mentions radiation test done on laboratory mice.I thinksomeone needs to collect bats and mice that are known to havespent a large part of their life cycle in a cave and see if theyhave cancer.If there were a high percentage of cancer, thatmight explain why we don't have any troglobitic mammals.I imagine guano miners died of histo long before they
caughtcancer.And most of them smoke heavily, so you wouldhave to find non-smoking guano miners.If I understood it correctly, the threat is from breathing the radiation,and the result is pulmonary diseases like lung cancer.He trys to explain that it is not the Radon that is dangerous becauseyou exhale some of it before it can damage you.Instead, it is the other elements associated with it, such as lead,polonium, etc.Although, the article was interesting, I got lost in all the stuffover my head like phagocytized and reticuloendothelial, and oh yeah,the calculus.David Locklear-Visit our website: http://texascavers.comTo unsubscribe, e-mail: texascavers-unsubscr...@texascavers.comFor additional commands, e-mail: texascavers-h...@texascavers.com
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