Measurement of airborne fission products in Chapel Hill, NC, USA from the Fukushima I reactor accident, By S. MacMullin, G.K. Giovanetti, M.P. Green, R. Henning, R. Holmes, K. Vorren, J.F. Wilkerson, Submitted on 17 Nov 2011 [Emphasis Added]:
We first detected airborne fission products in Chapel Hill between 20:00 UTC on March 18, 2011, and 20:00 UTC on March 19, 2011. We measured a maximum activity of 4.2 ± 0.6 mBq/m3 of 131I in the interval between March 29, 2011 and March 30, 2011. [...]
It should be noted that the measured 131I only represents particulate species collected in the air filters. This accounts for only about 50% of the total 131I in the air. The rest is distributed in gases [...]
The maximum activity detected was 4.2 ± 0.6 mBq/m3 of 131I, which did not include a correction for the volatile iodine components. This is below the air activity limit of 7.8 mBq/m3 set by the Environmental Protection Agency [...]
As the study notes, the 4.2 mBq/m3 figure “accounts for only about 50% of the total 131I in the air” as only particulate species were collected. Therefore, around 8.4 mBq/m3 was likely in the air, which exceeds the EPA limit of 7.8 mBq/m3.
h/t Link to study from Bobby1
Download the study here
Published: December 29th, 2011 at 11:54 am ET