thanks and a quick question
Thank you for providing such a service to the public. Your research and explanations for non-scientists have been both reassuring and very interesting, and the team's hard work is appreciated. You represent UCB very well.
Do the numbers on today's air sampling charts mean that you would need to breathe the air for more than 80,000 years to equal a round trip flight to the east coast, according to the data?
Thanks again.
The data from 3/25 - 3/26,
The data from 3/25 - 3/26, for example, has a minimum of 2.53e+03 for Cs-137. This means that you would need to breathe the air for 2500 years to have a total radiation dose equal to the round trip flight.
and what studies . . .
support your conclusion that inhaling Ce-137 is the same as a comparable dose of background radiation?
Please review posts
Please review posts throughout this forum on our dose calculations and our explanation of using the ICRP standards for dose conversion factors. Dose conversion factors provides for the differences between different types of exposures and pathways. In the end a radiation dose represents a probability of incidence of cancer from radiation exposure. We have used the ICRP number of 5.5% cancer incidence for 1 Sv exposure. This exposure has conservatively been estimated at .01mSv and thus the linear non-threshold probability (LNT) of cancer incidence would be 1 in 1.8 million. The CDC reported normal cancer incidence rate in the US is 1 in 200.
I am far from a scientist
I am far from a scientist and cannot even follow the conversion math very well so forgive me if this is addressed somewhere. I noticed you mention a "linear" cancer curve but my understanding of the studies of Chernobyl is that the cancer incidence shows up as a logarithmic curve and suggests much greater than expected impact at relatively low levels.
Thank you
The linear no threshold
The linear no threshold model is currently the accepted standard by ICRP. However, the logarithmic curve you speak of is normally called "supra-linearity" dose response. I have not reviewed these studies and I trust the ICRP to maintain an unbiased review of all literature on this subject. Some studies have suggested hormesis, or the positive effect of low-level radiation to stimulate the bodies natural repair processes. Kind of an evolution of a symbiotic relationship between our bodies and the natural low-level radiation that has always surrounded us. The problem is that there is great uncertainty in all of these studies and the safest model to use is LNT. The wiki link above give a decent explanation.
Very helpful thank you.
Very helpful thank you.