  We have suggested a complexity measure based method for studying the
dependence of measured 222Rn concentration time series on indoor air
temperature and humidity. This method is based on the Kolmogorov complexity
(KL). We have introduced (i) the sequence of the KL, (ii) the Kolmogorov
complexity highest value in the sequence (KLM) and (iii) the KL of the product
of time series. The noticed loss of the KLM complexity of 222Rn concentration
time series can be attributed to the indoor air humidity that keeps the radon
daughters in air.
