About iodine-131. As you know, iodine accumulates in thyroid gland, and that is most noticeable during the formative phase of thyroid gland, i.e. in small children.
However, when the first researcher in Ukraine was saying in 1991 "There are an increasing number of thyroid cancer", researchers in Japan and the US were publishing articles in Nature magazine saying "There is no causal relationship between the radiation and thyroid cancer." Why did they say that? Because there was no data prior to 1986, there was no statistical significance.
The statistical significance was finally noted 20 years later. Why? Because the peak that started in 1986 disappeared. So even without the data prior to 1986, the occurrence of thyroid cancer and radiation exposure from Chernobyl had the causal relationship. Epidemiological proof is very difficult. It is impossible to prove until all the cases are done.
Therefore, from the viewpoint of "protecting our children" a completely different approach is required.
Dr. Shoji Fukushima from a national institution called Japan Bioassay Research Center, which researches health effects of chemical compounds, has been studying diseases involving urinary tract since the Chernobyl accident.
Dr. Fukushima and doctors in Ukraine studied parts of bladders removed during more than 500 cases of prostatic hypertrophy surgery. They found out that in the highly contaminated area where 6Bq/liter was detected in urine, there was a high frequency of mutation of p53 though 6Bq may sound minuscule.
They also noticed many cases of proliferative precancerous conditions, which we assume was due to the activation of p38 MAP kinase and the signal called "NF-kappa B," leading inevitably to proliferative cystitis, with carcinoma in situ occurring with considerable frequency.
Knowing this, I was astounded to hear the report that 2 to 13Bq/liter [of radioactive cesium] was detected from the breast milk of seven mothers in Fukushima.