Rn discussion

["Mickhail V. Zhukovsky" <MICHAEL@ecko.rcupi.e-burg.su>]

Dear Radsafers

Over 1.5 months we carefully analyzed óohen's data received via Internet.
We didn't find the combination of factors explaining negative dose-effect.
Multiply linear regresslon analysis shows that the most significant factors
increased the lung cancer mortality are smoking, income per capita, the level
of unemployment and the percent of large industrial enterprises. Mortality
rate dependence from Rn stay negative.

Let step aside from LNT model. In this case óohen's data are well described
by U-shaped curve with minimum about 4-5 pCi/l. This U-shaped trend at
r>5 goes along with data on miners. We shall note that starting point of axis
of abscissas in cohort miners studies is not zero exposure, but zero
PROFESSIONAL exposure.

In the case of non-linear model the most significant survey info are the
parameters of distribution (geometric mean and geometric standart deviation).

I don't quite understand the total disregard of Tn (Rn-220) progeny exposure
in US. By our data in different Ural districts (counties) the Tn progeny at
average contribute from 4 to 50% of total Rn exposure.

In spite of convincing óohen's data the reason for termination of Rn survey
programmes does not exist. One of the main goal of such surveys is the
finding of the dwellings with high Rn concentration (above action level). In
Russia action level for existing dwellings is 400 Bq/m3 (over 10 pCi/l).
Under such levels the lifetime exposure is comparable to low dose range of
miners.

Michael Zhukovsky
Radiation Lab
Institute of Industrial Ecology
Ekaterinburg, Russia
E-mail: Michael@ecko.rcupi.e-burg.su