Crazy high radon in southern Tasmania

Earlier this year my children and I took my sister, who was visiting from Queensland, and her family to Hastings Caves (far south Tasmania) for an outing. I had never been to the caves before and was keen to take a geiger counter and see if the caves were hot. I should have gone alone to take my measurements. Hindsight

During our tour of the caves I had my GK-4 with LND-7317 pancake tube in the bottom of my backpack with the GM pancake facing down and a bluetooth link to my mobile phone from the GK-4 so I could keep an eye on things without drawing too much attention to myself...you know how it is...
As we toured the caves I kept a close eye on the BT terminal on my phone and noticed an expected increase from ~20-30 CPM (usual 5min range) to ~35-55 CPM - so nothing to worry about under the circumstances. right?

Well, when we all got back to my car and started to pile in, I reached my hand across the dash to get my sunnies and then my GK-Plus w/ SBT-10a pancake tube (that has a permanent place on the dash) starts flashing like crazy. There was a bit of swearing at this point.
A quick test of everyones hands revealed that a good dose was had by all. We all would have had lungs full of alphas. At that point I turned off all of the geiger counters.
A while after returning home I decided to test my hair - see picture below

This measurement was taken about 40 minutes after leaving the caves.

see the video here - http://vid288.photobucket.com/albums/ll177/eatliesndie/hotHair_HastingsCaves_zpsfkyjdjxy.mp4

These caves are a popular destination for tourists, and bus loads of school children from all over Tasmania

This is a call for HEPA masks for all cave exploring kids!

That would actually be a good experiment for anyone doing a cave tour. Measure the mask after a cave trip. To not appear alarmist, you could say "I have a virus and don't want to give it to anyone" (which incidentally is a very smart Chinese practice).

These make interesting reading

http://www.arpansa.gov.au/pubs/technicalreports/arl119tx.pdf

https://www.dhhs.tas.gov.au/__data/assets/pdf_file/0013/53005/AnnualReport04-05_000.pdf