Re: Re[2]: Radon in tap water

[Schoenhofer <schoenho@via.at>]

At 01:56 03.12.1996 -0600, you wrote:
>       According to the Chenical Handbook, Radon is highly soluble. 
>Several investigators have made radon measurements in the water supply.
>/?/One of the studies was in Maine, and C.T. Hess was involved. (REF. Hess 
>CT, KorashJK, and Einloth CJ, "Radon in houses due to radon in 
>potable water"-in "Radon and Its Decay Producs:Occurrrence, 
>Properties and Health Effects", Hopke, PK, editor, ACS Symposium 
>Series 331, American Chemical Society , WAshington, D.C.)
>Collman GW, Loomis DP, and Sandler JP in Brit. J. Cancer -vol. 63, pps 
>626-629, 1991 report on" Childhood Cancer and radon concentration in 
>drinking water in North Carolina". They cite Kahlos and Asikainen as 
>source for the estimate that..."10 to 15% of total radon in indoor air 
>may typically be attributed ,directlky to ougassing from tap water."
>Citations are made to Colthern CR, Lappenbusch Wl and MichelJ "Drinking 
>Water Contribution to natural background radiation" Health Physics vol50, 
>p. 33, 1950 and to KahlosH and Asikainen M, 'Internal radiation dose s 
>from radioactivity of drinking water in Finland", Health Physics vol. 39, p 
>108, 1980 . It is possible that neithr of these articles deals with 
>radon, but I doubt it.  
>	As you suggest it is not drinking the water but inhalaing the 
>RAdon after outgassing which seems to major routa
> Hope this helps, 
>gjohn@bgumail.bgu.ic.il
>            John Goldsmith, Ben Gurion University of the Negev.
>------------------------------------------------------------
John,

Yes, I know most of the literature you cite. The Health Physics vol 50 is in
my opinion still one of the best informations available about radioactivity
in drinking water. I have met Matti Asikainen personally a long long time
ago - it was in 1980. He stopped working in this field a few years after.
The statement of the 10 to 15% of radon in indoor air from outgassing from
water might be true in some extreme cases in Finland, where tens of
thousands of Bq of radon per liter are present in drinking water, but not
under normal circumstances - whatever might be normal (let us assume this
might be up to a few hundred Bq per liter.

Hess and Howard Prichard have worked a lot on the question of radon in
drinking water. Prichard has determined the ratio of radon in household
water and in air to be approximately 1: 10 000, which is in my opinion still
a very good estimate. So radon in drinking water contributes to the dose to
the public via degassing and inhalation. The Swedish Radiation Protection
Institute has recently put forward that the ingestion dose has been
underestimated, especially for children. 

Franz
Schoenhofer
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