Sir John Beddington, Government Chief Scientific Adviser, spoke to Her Majesty’s Ambassador to Japan David Warren on 25 March with an update on the situation in Japan. Transcript of phone call (16.00 hours local time) 25 March.

[JB] Let me take water first and I will ask Hilary Walker [Health Protection Agency] and JM to comment. First of all, we think that the advice being given by the Japanese authorities is extremely sensible: We would recommend that advice is followed. The other thing I would comment on is that radiation levels that the Japanese use in developing their recommendations are more cautious that the ones we have in the UK or Europe more generally. In terms of the mains water supply as was reported on 23rd March, it is pretty much safe to drink for all age groups for a short period. In terms of consumption of water, babies should avoid it. I think I’ll pass to Hilary for her comments on that.

[Hilary Walker: HW] As John was saying, the Japanese recommendations are much more cautious than ours. You must remember that these levels are based on assumptions of consumption over quite a long period of time.

[JB] Yes, this is just a one-off occasion. An explanation for it will be sought, but at the moment the recommendations from the Japanese seem completely sensible. Just to add to that it is completely safe for washing. You don’t have to go and buy bottled water to bathe your children in.

The other thing I’d like to say in terms of water is around the stable iodine tablets. There is absolutely no point in taking them at the moment. They only last for 24 hours. The only situation in which you need to be thinking about taking them is if their advice is that a radioactive plume is moving over in a few hours. Don’t take them at the moment because there is absolutely no point whatsoever.

That concludes the things on water. The sort of concentrations that we’re seeing mean the recommendations by the Japanese authorities were entirely precautionary and sensible. I would just like to ask Jill Mearer [Department of Health] to comment.

[JM] I would like to say that levels that were found were below any where we would be making recommendations in the UK not to drink water. They are more precautionary than the UK. If we had these levels in the UK we would not be advising people not to drink the water. Also, we must remember that the doses that we use to define these levels are based on 2 whole months of consumption. Now there are things happening in Japan and increased levels of radioactivity occasionally found in food and water. But you can see yourself that the Japanese authorities seem to get on to deal with them within a matter of hours. And there was only one day when the advice was for babies to not drink water. So again you have got a big level of precaution there. It seems completely unlikely that something would go amiss for 2 months when the authorities are being so vigilant.

via Updated advice on Japan from Government Chief Scientific Adviser to UK Ambassador.