With contaminated produce continuing to be detected beyond Fukushima Prefecture, public concern over the health effects of radiation exposure continues to mount.

Experts agree that exposure to more than 100 millisieverts in total increases the risk of cancer. However, scientists have yet to achieve consensus about the degree of risk of contracting cancer below that level.

"What we know today is that there is a risk of cancer incidence and mortality from exposure to more than 100 millisierverts in total. Above that level, the percentage of cancer risk increases in proportion to exposure level," said Masayori Ishikawa, a professor in the department of applied molecular-imaging physics at Hokkaido University and a radiation therapy expert.