Its in his latest video, which is full of odd trivia. He's purporting that everyone in Tokyo breathed in 10 "hot particles" every day during the month of April. Same for Seattle (although he's made two different claims for Seattle, one that said they breathed in 5 per day, and another that suggested they breathed in 10 per day). I don't know how he came up with any of these figures. Different posters are already regurgitating this story on this forum. Its basically going viral on any web site that has to do with Fukushima. Its the perfect meaningless sound bite for everyone who wishes to believe in Arnie's original story that "Fukushima is Chernobyl on Ssteroids (tm)". Arnie is saying his data comes from "scientists using air filters" (?!). He is full of circular logic, such as "we know the data is true because of the information coming from the air filters".
He's also talking about people in Tokyo experiencing a metallic taste, and he's tying this in with a similar phenomenon at Three Mile Island and Chernobyl. However he ignores the facts that: Tokyo is much farther away from the source of the radiation than the populations of Three Mile Island and Chernobyl/Pripyat, and, more importantly (crucially, I would say) there never was any report of people tasting a metallic taste in Tokyo. And if the people in Fukushima were ingesting 30 times the "hot particles" that Tokyoites were, you would imagine that the tastebuds of those in Fukushima were feeling like they were gobbling handfulls of metal.