By GEOFF BRUMFIEL [Nature] – The television and various news sources are clogged with radiation numbers and experts trying to explain them. Unfortunately the result seems to be a confusing tangle of data that is difficult to understand.
The most fundamental problem seems to be the rampant switching from micro to millisieverts. As a science reporter I love the metric system, but I do wonder if the public can easily understand that a change in radiation from 5 millisieverts per hour to 1,000 microsieverts per hour is actually a five-fold decrease in exposure rates?
Similarly, do people appreciate that the .144 microsieverts per hour seen in Tokyo yesterday afternoon is actually 70,000 times less than the 10 millisieverts per hour today at the Fukushima nuclear plant gate? (I actually got confused just trying to write that sentence, so from here on out I’m sticking to millisieverts per hour, or mSv/hr).
Let me try to put this into perspective. As I’ve already mentioned in an earlier post, the effects of radiation depend upon the total amount of radiation received over a period of time. So at a level of 10 mSv/hr, an unprotected individual at Fukushima might be able to work for 10 hours before feeling nausea and other effects of acute radiation exposure.
For long-term health effects radiation is often measured in years. Receiving 100 mSv in a year is the line at which you see a small increase in cancer risk. This risk rises with any additional dose.
Continued at Nature | More Chronicle & Notices.
