2012 年 86 巻 10 号 p. 558-561
Iodine is known to be accumulated in marine organisms. In human body, this element is concentrated in the thyroid gland and plays an important role in controlling its metabolism. We have analyzed iodine concentrations in different food materials, with a special reference to seaweeds. Laminaria (Konbu-algae) was found to contain a very high concentration of iodine (1500-3300 ppm, on a dry weight basis), suggesting a significant contributor to dietary intake of this element. Solubility of iodine from dried Konbu was studied and found that about 80% of iodine was dissolved in water. Iodine concentration in human milk was also determined and the concentration was in the range of 0.08-7.0 mg/L. High iodine concentrations in the milk were derived from a high consumption of Konbu by nursing mother. The average dietary consumption of iodine in Japan was estimated as 1.1mg/day. Release of radioiodine at the accident of Fukushima Daiichi Power plant was also discussed.