Hmm, seems a bit too dismissive. I don't think you can say that the wind direction is immaterial, also Chernobyl spread measurable radiation over a very large area...

Yeah you're probably right. But I don't see any reason why the Chief scientific advisor to the British govt would downplay the situation. But ultimately what can be done? Maybe they're just trying to encourage people to get back to work and return to school.

I checked some of the wikipedia articles, they cite a few reports linking tens to hundreds of thousands of cases of cancer from across the region which were reportedly linked to Chernobyl. In the case of Japan, I'd say the risk to any other countries is very minimal, but the risk to tokyo is not insignificant... (also the Japanese nuclear industry has a poor track record with being honest and open about their accidents).