Environmental Engineering Reference
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in terms of measurements and health effect, including humans. Unfortunately, similar data for
nanoparticles are not available right now.
So, the question arises why we did not have the quantitative assessment of the correlation between
measured radon and its progeny and health effect.
From my point of view there are two reasons:
1. In the majority of the radon and its progeny—effect studies not the dose itself, but its surro-
gate physical value was measured. Moreover, no relationship between this surrogate value
and real dose as a main factor was established.
2. In some cases the neglect of elementary rules of metrology took place, especially in terms
of uncertainty of assessment of the measurements and calculations.
I will try to illustrate this with the results of two mega-studies conducted by the National Research
Council (1999) and Darby et al. (2004).
It should be mentioned that in BEIR VI a great work was accomplished; the distribution of radon
and its progeny concentrations in the mines of 11 different countries were presented and analyzed
together with the data on lung cancer mortality among miners.
In Darby et al., the similar very important data on radon concentrations in different countries
in Europe were collected and analyzed. Again, the authors did a very good job in collecting and
analyzing information on distribution of radon concentration in Europe.
Unfortunately they try to connect radon concentration itself with lung cancer mortality of gen-
eral population, despite the fact that practically in this case only the radon progeny, not a radon
itself, is responsible for biological effect. Experimental and theoretical studies suggested that only
radon progeny, not the radon, deposited in the lung produces harmful effect. So, it is a classical
case where a dose is not a cause of the effect, but rather the surrogate of the dose was used and the
correlation between and real cause was not established. But that is not all.
In this study the authors found that “the absolute risks of lung cancer by age 75 years at usual
radon concentrations of 0, 100, and 400 Bq/m
3
would be about 0.4%, 0.5%, and 0.7%, respectively,
for lifelong nonsmokers, and about 25 times greater (10%, 12%, and 16%) for cigarette smokers.”
It is obvious that if we take into account the uncertainty in the risk assessment in this case the num-
bers (0.4%, 0.5%, and 0.7%) and (10%, 12%, and 16%) will be in the range of errors, that is, the same. In
other words, increasing radon concentration from 0 to 400 Bq/m
3
does not produce elevation in cancer
risk. By the way, these concentrations are considerably lower than permissible concentrations for mines.
In Table D.12 of BEIR VI the results of “average exposures” in “average Working Levels”
(WLM) are presented for 11 countries (China—286.0, Czechoslovakia—196.8, France—59.4,
Canada, United States—578.6, etc.). We know that the uncertainty in the exposure assessment is on
the order at least of tens of percent. So, we cannot trust these data with tenths of WLMs.
Our study on dosimetry and health effect of miners in Tajikistan suggested that different groups
of miners got substantially different exposure (dose) and different lung cancer mortality. So averag-
ing in this case can lead to additional uncertainty.
It seems to me that in epidemiological studies there exists some sort of tendency to present as
much as possible cases of effect (mortality, morbidity, etc.) in order to get good statistical data. With
such tendency we used old and questionable data on concentrations, even based on data on ventila-
tion. So, our good statistic in this case is compromised with bad dosimetry.
As it was shown in Chapter 14 of Ruzer and Harley (2004, pp. 483-493) in order to get correct result
we should establish a balance between the number of cases of health effect and correct dose assessment.
Data presented in BEIR VI are very valuable in terms of the assessment of concentration in
mines of different countries. But it cannot be connected to the health effect.
As a result, we have to assume that the results of this study cannot be used for quantitative cor-
relation of dose (and even exposure) of radon and its progeny and lung cancer mortality in mines,
not to mention for general population in homes.
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