As I've said before, it was a bad, bad timing. March 21 is where the second largest spike in air radiation took place in Fukushima, part of Tohoku and most of Kanto, thanks to a certain event at Fukushima I Nuclear Power Plant which hasn't been fully disclosed. (All we have from TEPCO is that there was a black smoke, then gray smoke, then white smoke rising from Reactor 3 on that day.) Fukushima City residents braved the rain to attend the lecture.
The doctor looks rather ill at ease.
(H/T Tokyo Brown Tabby)
(UPDATE) A Fukushima prefectural assemblyman tweeted a few days ago that Dr. Yamashita was "removed from the post", and some English sites may have misunderstood what he wrote. According to the later clarification by the assemblyman, Dr. Yamashita is no longer in charge of radiation protection, but still fully in charge of health monitoring and follow-up research of the Fukushima residents.
It seems he has simply moved on from preaching safety as a radiation protection advisor to health monitoring after the radiation exposure. There is no official word on Fukushima Prefecture's website at all.