November 13, 2013

This week, Japan’s Nuclear Regulation Authority decided to use actual dosimeter readings for radiation exposures in repopulating communities. Previously, the agency took aircraft-borne monitor readings and estimated exposures based on the assumption that people remain outdoors 8 hours per day. It turns out that these estimates grossly over-stated the case. The change in methodology is to be applauded as rational and reasonable.

Three months ago, several hundred people returned to their homes in Tamura’s Miyakogi district, and each person was issued a dosimeter. In September, the government appropriated $27 million in funds to also give each of the prior returning evacuees a dosimeter to be monitored by the Prefecture. Since then, thousands of returnees have had their actual exposures monitored. All show that previous dose estimates were exaggerated. Some of the dosimeter-based exposures were seven times lower than had been estimated. The least level of exaggeration was by a factor of three. Many international experts have been saying Japan’s aircraft-based estimates of exposures were too high for nearly two years. Now, there’s actual data to show they have been correct all-along.

Those locations that have been opened to returnees have witnessed less than 40% of the pre-3/11/11 population take advantage of it. The government’s goal has been for 100% repopulation. Those staying away say they are either skeptical of government assurances, don’t trust Tepco, believe any radiation exposure is tantamount to a death sentence, or a combination of the three. But, there are many reluctant individuals who don’t know what to think and opt for the cautious path. These might be the ones the new data could positively influence. The new methodology does not change the long-term goal of having all repopulated areas eventually below Japan’s goal of 1 millisievert per year.

The precious few news outlets carrying the good news speculate the shift to dosimeter-based exposure postings is a ploy to get people to return home once their communities are cleared for repopulation. Skeptics claim the move will increase distrust in the government. Ichiro Kowata, an Iitate evacuee, apparently sums up the general criticism, “Younger people say they can’t trust statements that suddenly declare areas to be safe when they have been called dangerous until now.” On the other hand, radiation specialists are fully supportive of the use of dosimeter-based data. Hirosaki University’s Shinji Tokonami says, “We support the idea of focusing on individual dose readings, but it will be a difficult problem how to put it in place.” Will thousands accept the new, much more=correct exposure data, or reject it? Only time will tell.

One thing is for sure… this is in no way a government ploy to get more Fukushima evacuees to go home. Radiation dose estimations based on aircraft monitoring are historically wrong. Such estimations are regularly skewed to the extremely conservative. Actual measurements are always lower than the aircraft-based projections. The real should always take precedent over the assumptive. If the new dosimeter-based data convinces some evacuees to go home, there should be rejoicing rather than continued protestations of doubt. Isn’t that what most of the evacuees and most everyone else in the world wants?

The Press also adds that Tokyo wants those communities with exposures below 20 millisieverts per year (by aircraft monitoring) to be opened to repatriation, and imply this new data source is a scheme to make it successful. As posted here many times, there’s millions of people around the world who live in natural background regions at or above 20 mSv/yr, and have cancer rates below their national peers. Besides, the Press is merely speculating on what the Tokyo government is thinking…implying a nefarious agenda, if you will. The Japanese Press is bending over backwards to perpetuate fear, uncertainty and doubt…and nothing more.

The NRA should be roundly commended for shifting from assumption to actuality. The world should know what a correct thing Japan’s NRA has done. The question becomes whether or not the international Press will pick up on this. I’m not optimistic. As of this writing, I have found nothing about it outside of Japan. The international Press should be happy that returning evacuees are actually at many times less risk than had been assumed. Alas, it seems they don’t care.