Cohen, who was a health physicist, made the point that the two million fatal doses per pound applied to plutonium as an aspirate. And the entire dose has to be aspirated. Dispensed as an airborne cloud it would quickly settle and only a very small fraction would ever be inhaled by human beings.
Ingested, plutonium is no more toxic than caffeine. Cohen publicly offered to ingest the same amount of plutonium as Nadar would caffeine.
Cohen makes the point that if plutonium were simply washed down the sink, only about 0.01% would ever be ingested, mostly harmlessly. No one is proposing careless disposal of plutonium, merely that the hysteria over plutonium is not founded on facts. When facts contend with hysteria, hysteria wins.