I am going to disagree with the following bit of advice from that report:
Radiation risk during nuclear accidents should be communicated to the public using a
qualitative, intuitive scale vs. the traditional quantities of dose rate and activity. For
example, the units of ‘natural background dose equivalence rate’ could be adopted. To
avoid the necessity of adjusting for local background variations, the world average dose-rate
from natural sources should be used: 2.4 mSv/year or 0.27 μSv/hr. Thus the elevated levels
due to contamination would be presented in terms of the factor by which natural background
radiation is exceeded. This approach has several advantages. First, no effort is needed to understand the unit used. For instance, 10 times natural background is easier to grasp than
2.7 μSv/hr since no prior learning in a specialized field is required. Second, there is never a
need to convert between unit systems or to be mindful of numerical prefixes (milli-rem,
micro-Sv, etc.). Third, this method of conveying information about radiation levels reinforces
the concept that some level of radiation exposure is both natural and normal. Finally, use of
this unit implies no estimation of the magnitude of the health hazard from the radiation
levels. This is important since we do not know how hazardous chronic, elevated
background dose rates are, though it is noted that there are regions of the world with
background radiation dose rates one order of magnitude higher than the world-average and yet with no measureable health consequences.
The most frustrating reports have been when instead of absolute numbers, we were told only so many times the legal limit, or so many times above background. Much more preferable to have actual absolute numbers to work with.
When the accident first happened, we were treated to endless variations on the exposure chart: how many Sieverts from one chest x-ray, from one trans-Pacific flight, etc. The public quickly learned the new unit, and later about units such as Bq/kg. This was a good thing, I think.
Also, background varies by location, so using "world average background" as the standard unit adds a layer of confusion. If I live in an area with a normal background rate of 0.1 uSv/h, and it goes up to 0.2 uSv/h, then my background has doubled, even if it is still below the world average of 0.27. How would one express this in a non-confusing way using the proposed units?
Give me numbers, and teach me parenthetically what the numbers mean, if necessary. But don't remove the absolute scale from reports, please.
(And yeah, I understand that the Sievert is a problematic unit, with all kinds of assumptions built in, but it is still better than "N times the legal limit," which tells me nothing. Was the legal limit conservative or aggressive? What was it in numerical terms?)
