Re: Radon in Water

["Schoenhofer" <schoenho@via.at>]

Schoenhofer
Habichergasse 31/7
A-1160 Wien
AUSTRIA
Tel./Fax: +43-1-4955308
Mobiltel.: +43-664-3380333
e-mail: schoenho@via.at
-----Ursprüngliche Nachricht-----
Von: Joe Stencel <jstencel@princeton.edu>
An: Multiple recipients of list <radsafe@romulus.ehs.uiuc.edu>
Datum: Samstag, 31. Jänner 1998 19:36
Betreff: Radon in Water


>Dear RadSafers:
>

>2) Does someone have a reference for average annual dose received from
>drinking water.
>
Yes, I have. Things may have changed a little during the last few years, but
when conducting a survey in some parts of Austria I remember that I put
forward to my Ministry of Health, that using water with a radon
concentration of 100 Bq/l would result in an additional dose of about 0.4 to
0.7 mSv/year via inhalation of radon liberated from water via cooking,
washing, flushing the toalett and taking showers. This figure was
remarkable, because this was the average additional dose due to the
Chernobyl accident to the average Austrian in the first year after the
accident. The Cherobyl dose value has of course declined considerably since
1986 to almost zero, but the dose from radon in water has of course not.

Since radon concentrations in water may be as low as  few Bq/l and up to
hundred thousands of Bq/l (found in Scandinavia) there is a wide range of
possible doses because of radon alone. Other radionuclides like Ra-226,
Ra-228, Po-210, Pb-210 may add, but usually radon is the main contributor to
the dose. Its concentration in water is heavily influenced by the source
(surface water or ground water) and for ground water by geology.

For your and other RADSAFERs information: Finland and Sweden have introduced
limits for radon-222 in drinking water. In Sweden a drinking water
concentration below 100 Bq/l is regarded safe. When the concentration
exceeds 1000 Bq/l, then remediation has to be done. Between 100 and 1 000
Bq/l it has to be decided for case to case, taking other parameters into
consideration, whether remediation is necessary. In Finland the
corresponding values are 300 Bq/l and 1 000 Bq/l. Please compare this with
the EPA proposal a few years ago of about 11 Bq/l.

Franz