Drinking water standards

[andrew_mcewan@nrl.moh.govt.nz]

Franz Schoenhofer wrote
"Do I understand the table correctly that a full mouth intraoral X-ray
would
need 21 films and would give 350 microSieverts? This would be "horrible",
because the new European Union directive on drinking water has an
"indicative dose value" (I hope this is understandable, even if it might
not be English) of 0.1 mSv per year from the uptake of radionuclides, also
natural ones, from drinking water, excluding radon, K-40 and tritium. This
means, that this value should not be exceeded....

...My best wishes to New Zealand, I hope you have better weather there than
we
have in Vienna!"
_____________________________
Franz

The drinking water standards in NZ are essentially the same.
"The drinking water standard adopts MAVs (maximum acceptable values) for
total concentrations of alpha-emitting and beta-emitting radionuclides,
excluding radon-222 and potassium-40, which would limit the annual
effective radiation dose resulting from the consumption of 2 litres of
water per day to less than 5 percent of the average annual radiation dose
due to all natural sources or 0.1 millisievert per year."  The MAVs are set
conservatively and are consistent with WHO guidelines.
The MAVs are
total alpha activity: 0.1 Bq/l, excluding radon
total beta activity: 0.5 Bq/l, excluding K-40
radon-222: 100Bq/l.

And yes, the weather here over the summer has been very good if you are not
worried about drought.

Andrew

_________________________
Andrew C McEwan PhD
National Radiation Laboratory
PO Box 25-099
Christchurch, New Zealand

Ph 64 3 366 5059
Fax 64 3 366 1156
Andrew_McEwan@nrl.moh.govt.nz
________________________


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