Amount of radiation in 3 gallons of milk from Hilo, Hawaii surpasses annual maximum contaminant level set by EPA
April 11th, 2011
Comments from EPA: New Radiation Highs in Little Rock Milk, Philadelphia Drinking Water, Forbes blog of Jeff McMahon, April 11, 2011:
… EPA lumps these gamma and beta emitters together under one collective MCL, so if you’re seeing cesium-137 in your milk or water, the MCL [Maximum Contaminant Level] is 3.0 picocuries per liter; if you’re seeing iodine-131, the MCL is 3.0; if you’re seeing cesium-137 and iodine-131, the MCL is still 3.0.
Here’s a somewhat historic EPA document that speaks directly to that issue:
Although not having a 4 mrem per year equivalent level specified in the current drinking water regulations as do tritium and strontium-90, the compliance monitoring scheme indicates that an iodine-131 level of 3 pCi/L is the MCL compliance level (presumably derived from the NBS Handbook); the ANPRM indicates that 700 pCi/L is the 4 mrem/year equivalent.
… If we lump together the three radionuclides in that Hilo, Hawaii reading, we get 61 pCi/L. …
[P]eople should not be exposed to more than 4 millirem per year. To make sense of that number we need to be able to express picocuries as millirems, but that’s what that legacy document does that I quoted above:
“the compliance monitoring scheme indicates that an iodine-131 level of 3 pCi/L is the MCL compliance level; the ANPRM indicates that 700 pCi/L is the 4 mrem/year equivalent.”