Last Week's Rain Was NOT Dangerously Radioactive

Over the last few days, more analyses of the radioactivity of the rain that fell in Korea during the last week have been published.  In the end, it appears that the rain was indeed radioactive, but not dangerously so.  Nevertheless, the government's handling of the possibility of radioactive rain has been criticized.

One aspect of the situation that I am personally becoming quite annoyed with is the continuing confusion surrounding the units of radiation measurements in the news broadcasts that I have been reading.  I have pointed out such confusion in previous posts (see here and here).  It seems that the KBS again misreported units of measure in a news article published yesterday, this time claiming that analyses of water and air revealed radioactivity in MEGA-becquerels!!!  Yup, of the order of MILLIONS of becquerels.  Looking at the original data published by the Korean Institute for Nuclear Safety, it seems that the actual measurements are of the order of milli-becquerels per cubic meter (one thousandth of a becquerel per cubic meter) for the radioactivity of the air, and of the order of becquerels per liter for the radioactivity of rain water.

Published criticisms of the governments' handling of the situation has touched upon 2 issues.  First, the Korean Meteorological Administration was criticized for its reporting of weather predictions that forecast radioactive rain.  Last week, before the rain fell, weather simulations conducted by Norwegian and German meteorologists showed that, by Wednesday or Thursday of last week, radioactive materials originating from the Fukushima nuclear plant may have reached Korea.  But the KMA published its own analysis, predicting that little radiation would reach Korea.  Before the publication of the measurements showing that last Thursday's rain was not dangerously radioactive, I did not believe the analysis of the KMA, as I felt that the agency may have been trying to downplay the concerns of Korean citizens vis-à-vis the possibility of radioactive rain.  But now, I believe that the KMA's prediction may have been more accurate than the Norwegian and German one.  Nonetheless, I believe that the credibility of the meteorologists at KMA could have been bolstered if they had provided clear justifications for why they disagreed with the Norwegian and German weather simulations, and if they had presented their predictions in a more transparent manner, clearly explaining to the public how they obtained their results.  I also believe that KMA meteorologists should now undertake a detailed comparison of the European predictions, their own predictions, and the now available measurements of Thursday's weather, in order to ascertain the successes and failures of both predictions.  Doing so could help both the Europeans and the Koreans to refine their weather simulation software.

The second criticism of the Korean government's handling of the possibility of radioactive rain touched upon the disorganised manner in which the government attempted to mitigate the effects of this radioactivity.  The latter criticism is essentially an argument that the Korean government should have taken a more cautious approach to the situation, and should have strongly urged its citizens to minimize their exposure to last Thursday's rain.  Though I understand this point of view, I also understand that the government probably wanted to avoid over-reacting to the situation.  In addition, the available information about the situation was not all self-consistent.  On the one hand, European meteorologists predicted that last Thursday's rain could have been radioactive, but the meteorologists at KMA predicted that it would not be.  The Korean government chose to act on the basis of the advice of its own meteorologists, and in the end, the predictions of the Korean meteorologists appear to have been more accurate than the European ones.  However, I believe that the government should have more closely monitored the radioactivity of the rain throughout the day last Thursday.  I was disappointed, when the rain began last Thursday, to find that the Korean Institute for Nuclear Safety published measurements of the radioactivity of the rainwater only twice during the day.  I understand that it is perhaps not possible to take measurements of the radioactivity of falling rain at any desired time, as sufficient quantities of rainwater must be collected in order to conduct a meaningful analysis.  Nonetheless, I believe that more measurements could have been carried out and reported.  This would have allowed Korean citizens to better protect themselves if the rain did become more radioactive than expected.  In addition, I felt that the irregular time intervals separating the reported measurements could be interpreted as a sign that officials was selecting which measurements to report, thus mining their credibility.  In order to bolster the public's confidence in their work, the KMA and the Korean Institute for Nuclear Safety should report radioactivity measurements in a consistent fashion, at regular, pre-determined times, as they have already begun doing with measurements of the radioactivity of the air throughout Korea.