Las Vegas, Nevada - Air Monitoring
Per the instructions on your Frequently Asked Questions page, here are two Web sites which are providing air monitoring data for Las Vegas, Nevada and surrounding areas: http://www.ansatunlv.com/air_monitoring.html and http://www.cemp.dri.edu/cemp/. Any feedback from Dr. Chivers regarding how these results compare to those obtained at Berkeley in terms of potential health effects would be greatly appreciated. Thank you very much for all of the work that you are doing!
Preliminary results from
Preliminary results from UNLV here is quite comparable to our results. I have not performed a time based comparison but the amounts are close. To compute Bq/L to pCi/L just multiply by 27. So, for example, our first air sample is 3.77e-6 Bq/L . 3.77e-6 * 27 = 1.02e-4 pCi/L. This is very close to what they are seeing.
My $0.02: (a lay person's
My $0.02: (a lay person's interpretation. Dr. Chivers please correct if necessary)
The data show that the I131 and Cs137 levels are very similar in Las Vegas as compared to the Bay Area.
At a first glance, the Las Vegas team's readings look like 10 fold higher than the Bay Area readings. However, the LV team used an air filter cartridge filled with charcoal, which is more sensitive than air filter.
According to EPA's recent published readings from sampling setups in which either filters and cartridges were used, the cartridges gives a 5 to 10 fold higher readings than filters.
Therefore taking everything into account, the recent readings in LV is very similar to the readings in the bay area.
Joe.
Looks right. We are going
Looks right. We are going to test activated charcoal so we can correct our numbers. Factors of 5-10 is feasible.
Air Monitoring
Thank you for all of your important and reassuring work. Just wondering how your comparison turned out between the HEPA air filter cartridges you use to collect air samples and the activated charcoal filters UNLV was using. Have you been able to quantify an accurate percentage of particulate capture? I have read that activated charcoal collection is likely to yield 5 to 10 times more particulate matter than the filters BRAWM uses, and that BRAWM is assuming 100% particulate capture for its filters. If Berkeley's filters are not actually capturing 100% of particulates passing through them, how would this affect calculations of air concentrations? I was following this discussion up until March 29th, and have been waiting eagerly the results of your investigation since then. Given that EPA has used both activated charcoal and HEPA filters (obtaining significantly higher levels with the charcoal), does anyone know which air filtration setup is the basis for recently published EPA data? (The primary sources of my information regarding this topic can be found on older pages of this forum, including: "methods for sampling radio-iodine" and, "Amount of I-131 underestimated by a factor of ten due to filter inefficiency?") Also, do you know of any US organizations yet testing for either beta (Sr-90) or alpha radiation? Thanks again!
good questions
hope we get a response. if the uc tests are off by such a high factor that is troubling.
I had pointed this out already 2 weeks ago but UC did not react
I had pointed this out 2 weeks ago. Actually the factor is rather x100 according to my calculations. To repeat: the current UC berkeley readings are similar to readings taking in Germany. that is not possible by virtue of the fact that Germany is another 6000 miles away. The correction factor is 100 to 1000.
Not 10.
If you take an average of 1.9 pic/cubicmeter measured by the EPA compared to UC measures which are something like 1/100 000 pico per cubicmeter, you see how big the difference is. It is at least a factor 100 if not 1000, I calculated 100 000 x more than the German results per EPA, so take UC berkeleys result which equals the German results for iodine and multiply that by 100 000.
I mentioned that to the Chivers team 2 weeks ago and nothing happened. No correction was taken.