spikes in gross gamma Air monitoring data on EPA website
I live in Burlington, VT. The EPA posting of Gross Gamma Air monitoring for Burlington, VT from 3/4/11-5/3/11 shows episodic spikes in the data, the last of which was on 4/27. We have been experiencing heavy rains for the last 3 weeks. There is flooding in many people's basements, especially for those who leave near rivers or near the shores of Lake Champlain. I am a physician, and am concerned about the safety of Vermont residents, especially those who now have water in their homes. Is it possible that the spikes in the gross gamma count rate are due, not to electrical interference (as is suggested on the EPA website), but instead to isotopes (airborne particulate) being brought to ground by significant amounts of rain?
Can you please suggest how the significance of the spikes in the Gross Gamma count rate can be evaluated?
Thank you, Dianne Pierson MD
old conversation
This might be interesting to you?
http://www.nuc.berkeley.edu/node/3667
my opinion....
Is that we really don't know without more information from the EPA. They know how to study those numbers and put together a profile of exactly what is causing those rises, but the don't seem to be speaking about it much.
Maybe the BRAWM team has some keener insights.
LT, PhD
Doesn't see too bad
From the EPA precipitation data, it doesn't look like
there were extremely high levels in the area. I've copied
some of the data for the New York state and New England
area. Looks like Boston had the highest measured I-131
at 92 pCi/L back on 3/22. Most measurements were much lower
than that. And the I-131 should be pretty much gone by now.
And the Boston 4/19 measurement seems to support that. byu
comparison, Richmond Ca. had a measurement of 138 pCi/L on
3/22. Olympia Wa. had 125 pCi/L on 3/24. So, the Boston
3/22 report doesn't seem over the top. Also, no other
isotopes were detected in any of the below samples. So,
I didn't show those.
You can look for yourself at the following site:
http://www.epa.gov/japan2011/rert/radnet-sampling-data.html#all
State Location Date Collected Sample Type Unit I-131
MA Boston 04/19/2011 Precipitation pCi/l Non-detect
MA Boston 04/20/2011 Precipitation pCi/l 7.2
NH Concord 04/14/2011 Precipitation pCi/l Non-detect
NY Albany 04/19/2011 Precipitation pCi/l Non-detect
NY Yaphank 04/19/2011 Precipitation pCi/l Non-detect
NY Yaphank 04/15/2011 Precipitation pCi/l Non-detect
CT Hartford 04/15/2011 Precipitation pCi/l Non-detect
CT Hartford 04/18/2011 Precipitation pCi/l 2.5
MA Boston 04/14/2011 Precipitation pCi/l Non-detect
NH Concord 04/18/2011 Precipitation pCi/l Non-detect
NY Albany 04/11/2011 Precipitation pCi/l 3.9
CT Hartford 04/08/2011 Precipitation pCi/l 12
MA Boston 04/06/2011 Precipitation pCi/l 9.8
NH Concord 04/05/2011 Precipitation pCi/l 47
NY Albany 04/05/2011 Precipitation pCi/l 22
NY Yaphank 04/04/2011 Precipitation pCi/l 15
CT Hartford 04/04/2011 Precipitation pCi/l 19
MA Boston 04/04/2011 Precipitation pCi/l 15
MA Boston 04/05/2011 Precipitation pCi/l 20
NH Concord 03/24/2011 Precipitation pCi/l 24
MA Boston 03/22/2011 Precipitation pCi/l 92
CT Hartford 03/18/2011 Precipitation pCi/l Non-detect
CT Hartford 03/18/2011 Precipitation pCi/l Non-detect
CT Hartford 03/25/2011 Precipitation pCi/l 26
MA Boston 03/18/2011 Precipitation pCi/l Non-detect
NY Albany 03/16/2011 Precipitation pCi/l Non-detect
NY Albany 03/23/2011 Precipitation pCi/l 30
I should also mention
While I don't believe the levels seen above should be of
much concern in the first place, if basements are being
flooded by river or lake water, the levels of I-131 that
did come down with the rain would be even further diluted.
I would guess that levels in river and lake water would be
non-detectable.
The BRAWM team measured 2.889 pCi/L (0.107 Bq/L) in the
creek on campus on 3/25 at 16:40. Which is not a "river".
http://www.nuc.berkeley.edu/UCBAirSampling/StrawberryCreek
That was during rainfall that measured 3 Bq/L and 1.45
Bq/L for the periods of 3/24 18:10 to 3/25 11:23 and 3/25
11:23 to 3/26 10:15.
You can get results from the Vermont Department of Health
as well. The most current appears to be around 4/19-4/22.
You the links below "Information, Resources & Test Results".
The links above that are broken.
http://www.healthvermont.gov/enviro/rad/japan2011.aspx