Greetings – Here are some fresh, local milk testing results thanks to UC Berkeley’s Dept. of Nuclear Engineering, with no thanks at all to our EPA, which stopped publishing new water or milk testing data two weeks ago. (According to EPA’s site, it takes 4 hours to get results, and 3 days to analyze them. EPA data result pages say “Updated April 6th,” but the actual tables show nothing collected after March 26th.)

Anyway, the UC Berkeley results shown below only confirm that radioactive iodine-131 does show up in Bay Area milk samples, with a spike in milk bottled around March 18th showing a “best by” date of April 4th, and decreasing after that. It does not solve for you what decisions to make about health impact. For our family, there is no drastically urgent need for children in particular to drink milk right now. Plus we’re just irritated by the ratio of placation to actual information. “Far below levels of concern” is the repeated guidance from the EPA and other public agencies.

The long-documented problems with the basis for public “safe level” standards are highlighted in separate posts. These include the fundamental difficulty that these standards are based on external exposure data collected from the one-time blasts at Hiroshima and Nagasaki, and are not based on the internal ingestion effects documented in long-term, large scale epidemiological studies available from Chernobyl health data. In addition, thyroid cancer among children resulting from the ingestion of radioactive iodine-131 isotopes in milk (and to be accurate, leafy greens) was the most significant health effect of Chernobyl, and is not reflected in the basis for “safe levels” of exposure determining EPA and other public guidances. Good news is, it breaks down quickly. Bad news is, tomorrow we have to figure out Cesium.

But here’s Berkeley:

The following are results for milk samples obtained from a Bay Area organic dairy where the farmers are encouraged to feed their cows local grass. We have detected I-131, at 0.70 Becquerels per liter and lower, as well as Cs-134 and Cs-137.

Because the “best by” date on milk is approximately 17-19 days after the milk has been bottled, our milk sample with a date of 3/25 represents milk bottled on approximately 3/5. Since this is before the Fukushima crisis, we do not expect to see any fission product radioisotopes and do not see any within our sensitivity. Our first sample of milk showing any signs of radioisotopes has a date of 4/4, which means it was bottled around 3/18. This is approximately when the trace radioactive isotopes were first seen in the Bay Area.

The first two milk measurements were done with the same setup as the Rainwater Collection Experiment, except that the milk is not distilled first before counting it with the germanium detector. The remaining measurements are being performed with a mechanically-cooled germanium detector on loan from ORTEC and AMETEK. The new detector is larger than the previous detector, and we can fit almost an entire gallon of milk in the Marinelli beaker (previously, we could measure only one quart of milk). This leads to an improvement in overall sensitivity to radioactive isotopes.