Radon concentration in caves is known to vary within an extremely wide range. Here the distribution of the average values of radon concentration is examined and a power law describing is identified, i.e. radon concentration has a fractal dimension D=1.26. This fact means that concentrations are not grouped around a mean value, a characteristic common to many other phenomena.
Cigna, Arrigo A..
The distribution of radon concentration in caves.
International Journal of Speleology,
Available at: http://scholarcommons.usf.edu/ijs/vol32/iss1/8