I took two 10 minute readings from a sealed foil package of 12oz Organic NonFat Dry Milk, non-instant Grade A. The date code on the package was 10351BEXP1111, I believe that corresponds to a packaging date of February 4, 2011.
The procedure was as follows
10 minute timed count from the back of the package; 426 total counts.
10 minute timed background count from the table under the package; 329 total counts.
10 minute timed count from the front of the package; 457 total counts.
10 minute timed background count from the table under the package; 351 total counts.
The result is that the PRE-FUKUSHIMA milk radioactivity read 30% above background
The corresponding average reading from the milk container was 0.0126 mR/hr
The corresponding average background reading was 0.0097 mR/hr
I will update with future readings as I start to use more pre-Fukushima dried milk.
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i am sure you have listed this before, but what sort of counter are you using?
ReplyDeletethank you so much for initiating this research -- it is sorely needed.
it would be good to get an industry FAQ (a man page as it were) on how to decode production dates -- so i could know what canned milk is good, either because it is pre Fukushima or because it is more than 80 days past canning (which would of course only be effective in the case of I-131 -- no longer the only radioisotope of concern)...
also -- i was under the impression that the testing of milk was significantly more involved, since I-131 was mostly a beta emitter and the milk itself would act as a shield against any I-131 present. ot to mention, of course, the foil package and the table.
ReplyDeletefrom Wikipedia
"Iodine-131 can be "seen" by nuclear medicine imaging techniques (i.e., gamma cameras)... since about 10% of its energy and radiation dose is via gamma radiation... the other 90% of radiation (beta radiation) causes tissue damage without ... any ability to see or "image" the isotope..."
but let this not detract from my saying: thank you. i must applaud your initiating this process, it is crucial.
and waiting for the EPA is obviously not, how you say, effective.
Dried powdered milk is relatively easy to test because all the liquid has been removed. The foil packaging would block all alpha, and probably a significant portion of beta radiation. The Geiger counter used is a medcom Inspector with a pancake tube.
ReplyDelete< The date code on the package was 10351BEXP1111 >
ReplyDeleteThe first five digits in the code above are probably a Julian date, representing the date of packaging. The first two digits, 10, would indicate the year, 2010. The third, fourth and fifth digits would indicate the day of that year, in this case (approximately) December 17 (the 351st day out of 365).
Thanks for measuring and posting your exposure readings.
Ray