Radiation exposure: Danger for Japan and America

japan radition

 "It 's very unlikely that it would be no risk of people in this country," said David Brenner, director of the Center for Radiological Research at Columbia University. "The distance is simply too great cloud is so scattered when it reaches the United States"

Even in Japan, not far from the reactors - the real threat is relatively low, experts say radiation.

"There is an evacuation zone, which means that very few people have more doses comparable to a chest, which is a relatively low radiation doses," said Brenner.

Radiation can damage human cells. It is measured in something called millisievert. A emits X-rays on 1/10th milisievert.

Nuclear plant workers are limited to 20 milli-sievert per year. One hundred milli-Sievert in a single dose may increase the risk of cancer, and 100 to 500 can cause damage to bone marrow, leading to infection and death.

Reports said radiation levels were as high as 400 milli-Sievert hour at the plant Tuesday. But they have fallen dramatically - first with 11.9, followed by zero-point-six.

To put this in perspective: Chernobyl, among those who became ill after the dose of radiation ranges from 800 to 1,600,000 millisievert - much higher than what is measured to date in Japan.