According to Kolnet, an online media source focused on the Tohoku region of Japan, the number of under-18s in Fukushima Prefecture diagnosed with thyroid cancer has increased to 12, while the number of possible cases has reached 15.

The numbers were released as part of an ongoing investigation by the Fukushima Prefecture Board of Health into the effects of the radiation released in the explosion at Tokyo Electric Fukushima Daiichi Power Plant in 2011. The investigation has examined about 174,000 adults and children from towns surrounding the crippled plant.

In the last report, made in February, there were only three confirmed cases of thyroid cancer and seven suspected cases.

According to a representative of Fukushima Medical University, which has been running the tests, they cannot conclusively link the incidences to Fukushima Daiichi, because although there were confirmed cases of cancer linked to the Chernobyl incident, many of these did not present until four or five years after or even later.

Some have pointed out that comparisons to the Chernobyl incident may not be particularly enlightening anyway, as intensive medical examinations into children exposed didn’t even begin until years after. Additionally, compared with that of Chernobyl, the population in Fukushima was exposed to less radiation, had more iodine in their diet, and had access to iodine prophylaxis, so the negative impact is expected to be much less.

However, according to one study that might be a more useful comparison, of 250 schoolchildren examined in Nagasaki in 2000, only 0.8% of them had thyroid nodules, of which none were found to be malignant. Additionally, the incidence of thyroid cancer in the general population is just one or two in 12 million children.

This suggests the numbers in Fukushima may already be high, and some experts believe they are even higher than the Board of Health investigation has claimed due to weaknesses in their methodology, such as not accounting for migration and not bringing children with small nodules in to be reexamined.

Source: Kolnet