Radiation experts in the USA say that the lack of information about radioactivity released from the smoldering reactors makes it impossible to gauge the current danger, project how bad a potential meltdown might be or calculate how much fallout might reach the USA.
Conflicting accounts of the radiation levels emerged in Tokyo and on Capitol Hill. Japan's Nuclear and Industrial Safety Agency said Wednesday that the radiation detected at the Fukushima plant had fallen steadily over the past 12 hours. But U.S. Nuclear Regulatory Commission (NRC) chief Gregory Jaczko told a House energy subcommittee earlier in the day that radiation levels at the Fukushima plant were "extremely high."
History may offer hints of what's to come. At Three Mile Island, near Harrisburg, Pa., only a small amount of radiation was released before the meltdown was controlled. Chernobyl spewed radiation for days, which rode wind currents worldwide.
Radioactive iodine falls from the plume in rainfall and settles on the grass, where it's eaten by cows and builds up in their milk. Children who drank commercial milk during the Cold War nuclear tests received about one-tenth of that, on average, Hoffman said. That was enough to boost their thyroid cancer risk to one in 100, more than twice the usual risk.
Cesium is absorbed by plants and works its way through the food chain, getting into meat and milk. Unlike radioactive iodine, which has a short half life, cesium lingers in the environment. "Radioactive iodine will be gone in a month," Hoffman said. "Cesium's going to be around for decades."
Source: USA Today