Earlier this month we received our first measurements from inside the evacuation zone and talked about how they illustrated the point that “closer to the plant” doesn’t automatically mean higher readings. To illustrate that point even furthers, Safecast volunteers Akira Sugiyama and Tatsuhiko Kodama were able to take a bGeigie all the way across the exclusion zone including almost right up to the front gates of the Daiichi plant. Here is the map of their drive which shows a few things. First of all, these are now the highest levels we’ve recorded reaching almost 12,000 CPM. Secondly, this shows just how much the levels can change, as only a few km away and approximately the same distance from the plant they drop to barely 100 CPM. A 11,900 fluctuation in just a few minutes drive is noteworthy to be sure.
These readings also point out the limitations of our color scheme and scale on the maps, something we’ll be addressing shortly.
4 Responses to “Safecasting Daiichi”
Sorry, the comment form is closed at this time.
The cutoffs, for whatever legend is developed, need to be explained. Why is it 35, 70, 105, versus 40, 75, 115 for example. It’s also hard to correlate the CPM’s to a measure of health risk beyond simply knowing that “more = bad”. I definitely think there should be a legend for “if you are here, you will exceed the annual radition expsoure cap in {1 day, 3 days, 1 week, 2 weeks, 3 months, etc}. Makes the numbers more real.
Seconded. More actionable data, please.
Unfortunately there’s no agreement in the scientific/health community about what is safe and what isn’t. There isn’t even agreement about what is the annual exposure cap. Heck, in Japan depending on where you live the exposure cap is different. Which is part of the problem with all of this, there’s a lot that is subjective and when someone says “it’s safe” or “it’s contaminated” with no data that is uselss which is why we’ve taken up the task of collecting the raw data and publishing that, so people can draw their own conclusions with factual info at least.
I was thinking more along the lines of a dynamic map where the user could provide their choice of an exposure limit, and then see the map colored by a fixed legend of time durations. It is precisely because the limits are so subjective that you would only make the tool in such a way where the user was required to provide their own value for the limit.
I agree that subjectivity should not be introduced. I think this is one method of creating the tool while not introducing subjectivity. Been awhile since I worked with Google Map API’s though, so this might be harder than I think.