Radioactive iodine found in breast milk -- at what point will we start to get concerned?

The breast milk of four Japanese mothers has been found to contain small quantities of radioactive iodine.

The government faced calls for a full investigation into the impact of the nuclear disaster on mothers and babies following the discovery.

The radiation contamination came to light after tests were conducted on breast milk samples taken from nine women living northeast or east of Tokyo.

Four of these women were found to be contaminated, with the highest reading of 36.3 becquerels of radioactive iodine per kg detected in the milk of the mother of an eight-month-old baby in Kashiwa, Chiba prefecture.

There are no current legal safety levels for radioactive substances in breast milk as set by the Nuclear Safety Commission of Japan.

However, the breast milk readings were below the safety limit of 100 becquerels per kg of tap water consumption by infants under one year of age and no radioactive cesium was found. (read more)