A new United Nations report finds that cancer levels will likely remain stable despite possible radiation exposure following the 2011 Fukushima Daiichi nuclear power plant accident. The study, which is based on estimates of exposure and knowledge of health impacts, explored the specifics of exposure with regard to various population groups, including children. “People are rightly concerned about the impact on their health and their children's health," Carl-Magnus Larsson, chair of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), stated in a press release. “Based on this assessment, however, the Committee does not expect significant changes in future cancer statistics that could be attributed to radiation exposure from the accident.”
On March 11, 2011, a 9.0-magnitude earthquake occurred near Honshu, Japan, and a subsequent tsunami flooded nearly 500 square kilometers (about 193 square miles) of land, resulting in the loss of more than 20,000 lives. Loss of electrical power and compromised safety systems at the Fukushima Daiichi nuclear power station created severe core damage to three of the six nuclear reactors on the site. In the worst nuclear disaster since Chernobyl in 1986, large amounts of radioactive material were released into the environment over a prolonged period.
The expected low impact on cancer rates is largely due, according to the UNSCEAR report, to prompt protective actions on the part of the Japanese authorities. “The doses estimated for Japan were substantially lower than the ones observed after the Chernobyl accident,” Dr. Wolfgang Weiss, chair of UNSCEAR Fukushima Assessment, told Medical Daily in an email. “This resulted in the low impact on cancer rates — not a real surprise.” The study authors expect no discernible changes in future cancer rates and hereditary diseases and also no increase in the rates of birth defects. The authors believe it is “theoretically possible” that thyroid cancer risk may increase among those children most exposed to radiation. Thyroid cancer is rare among young children whose normal risk is very low.
"The Committee concluded that no discernible increase in cancer or other diseases is expected; however, the most exposed workers will receive regular health checks," Weiss said. Having analyzed reported radiation doses of workers, "the highest thyroid exposures were observed in 13 workers," Weiss told Medical Daily. Among these workers, "an increased risk of developing thyroid cancer and other thyroid disorders can be inferred," the authors wrote in the report. They added, "More than 160 additional workers received effective doses currently estimated to be over 100 mSv... Among this group, an increased risk of cancer would be expected in the future." However, no radiation-related deaths or acute diseases among the workers have been reported so far.
Possible effects on ecosystems, both terrestrial and marine, were also investigated by the Committee. Generally, any effects were found be transient. The possibility of damage to flora and fauna within the marine ecosystem was limited to the shoreline area adjacent to the power station with the potential for long term damage considered insignificant.