I have no idea which type of radiation it was that was cited in the book Think! by Michael R. LeGault, I do recall that it was fallout from Chernobyl and it was measured in range from the meltdown epicenter..

Depends upon the source of radioactivity. Cesium less dangerous, Strontium and tritium more dangerous. The greatest danger is probably to Japanese.

Mentioned in sci-fi occasionally too..

For example Robert Heinlein in Starship Troopers

I read one, and I do have the book on my shelf and could find it, that constant low exposure to radiation actually has a positive effect on people/life. I'm not saying such is the case here but I highly doubt the alarmists that closed Shoreham nuclear power plant out of evacuation fears for Long Island would readily admit that no harm has come from the nuclear radiation caused by the reactor meltdowns at Fukushima .

Over simplified article that makes the optimistic, premature assumption that the radiation being released every day into the Pacific will not have detrimental effects in the food chain.
Cui bono.