Iodine 131 exposure during childhood increases risk of developing thyroid cancer

Alan H. Lockwood, MD, professor of neurology and nuclear medicine in the University at Buffalo's School of Medicine and Biomedical Sciences calls the Japanese Health Ministry's advice not to give tap water to infants "prudent."

Lockwood, a board member of Physicians for Social Responsibility, can discuss human health effects of radiation. Six weeks after the Chernobyl accident, he examined survivors at a Moscow hospital.

He notes, "The reason that iodine-131 is so dangerous in children is that their normal growth and development, especially of the brain, depends on the thyroid gland. And if there is exposure as a child, the risk of developing thyroid cancer later in life is higher."

It is reasonable to expect that the higher levels of radioactivity in the water will not last very long, Lockwood says, noting, "Iodine-131 has a relatively short half-life, just over eight days."

"It is quite predictable that radioisotopes have been detected in the Japanese food supply," he adds, noting that radioactivity in food is a definite concern. "Japanese officials appear to be on top of this situation and have kept these foods out of the Japanese food supply.

This is a reasonable preventive action that is in accord with one of the central principles of public health. Radiation levels should be kept as low as reasonably achievable, a principle referred to in radiation safety circles by the acronym, ALARA."