AS IF caving were not dangerous enough, regular cavers are also exposed to
high levels of the radioactive gas, radon. Formed naturally by the decay of
uranium in granite, it can build up to hazardous levels in enclosed spaces.
Researchers from University College Northampton and Princess Margaret
Hospital in Swindon measured radon in a popular system of caves in the Mendip
Hills in Somerset. They found that cavers who spend just 40 hours a year
underground could receive a radiation dose of as much as 4
millisieverts—four times the annual safety limit for members of the public
recommended by…
