Minuscule Radioactive Fallout Reaches U.S.

VIENNA -- A diplomat with access to U.N tracking of Japan's radioactive fallout says it has reached Southern California but first readings are "about a billion times beneath levels that would be health threatening."

The diplomat was citing readings Friday from California-based measuring station of the Vienna-based CTBTO. He asked for anonymity because the Comprehensive Test Ban Treaty Organization does not make its data public.

Source