Japan nuclear blast could be more deadly than Chernobyl, experts fear, Haaretz, March 14, 2011:
Professor Uzi Even of Tel Aviv University, who in the past worked for the Israel Atomic Energy Commission, told Haaretz that these two compounds [iodine and cesium] are extremely dangerous, which is why the Japanese government yesterday began distributing iodine tablets, which neutralize the threat of radioactive poisoning that primarily affects the thyroid gland. ...
Hebrew University Professor Menachem Luria, an expert on air quality and poisoning, told Channel 2 on Saturday: "This is very worrying. There is no doubt that we have not seen anything like this in years, perhaps ever since nuclear experiments were conducted in the atmosphere in the 1950s. From what we can gather, this disaster is even more dangerous than Chernobyl, both from the standpoint of the population's exposure to radioactive material and the spread of radioactive contamination in the area."
Luria continued: "Once there is an uncontrollable heating up, the nuclear fuel undergoes a metamorphosis into the gaseous phase. Since we are talking about metals and solid items, they turn into particles that are capable of traveling great distances. They can wander thousands of kilometers."