How can you be sure we are only getting the results of an xray?
if some one is outside for long and getting rain is the consintration higher? Also, an xray for an adult is not as much of a problem as an xray for a child. How many xrays in a week? I'm worrried about my childrens health.
The concentration that we
The concentration that we are measuring is in extremely low (sometimes called "trace") amounts. In fact, the radiation from natural sources such as radon and potassium in the environment are many thousands of times greater than what we are seeing with our systems within both rain and air. One would have to consume many hundreds or thousands of liters of this rain water to even equal the exposure from a single x-ray. We are confident at this point there is no risk to adults or children and one does not have to vary their daily routine.
Enjoy the rain! It will be gone soon.
Cummulative Dose?
If we're all inhaling a relatively constant (albeit trace) amount of these radioactive isotopes what are the cummulative dose rates for 24 hours, 7 days, etc at these rates?
As there doesn't appear to be an end in sight to the reactor crisis, how many weeks or months would it take for this constant additional exposure to rise a level of "insignificant effects on health?"
What we have done for the
What we have done for the public is determine the amount of the sample water volume needed to consume (or air volume to breath) to equal 0.05 mSv of dose equivalent. This is the amount of dose one receives when flying cross country. In the case of the water we have sampled, we get something like 300-600 liters, and in the case of air (we are posting this soon), we get something like 196 years of normal breathing. This just gives you the scale.
To figure out the cumulative dose one is receiving due to the time varying nature of the exposure is actually quite hard, but we are working on that as well. That will take some time and some additional measurements. However, we can only come up with conservative estimates at this point: e.g.: I-131 will decay away in ~20-30 days, but let's double this. Two months of drinking the highest activity of water we see at 1L per day (EPA high average), that is 60L at 8 Bq/L or 480 Bq consumed. The dose conversion factor for I-131 is 0.68 mSv/(3.7e4 Bq) see here, so the total cumulative dose is 0.0088 mSv or 0.88 mRem. This is quite conservative and this dose is equivalent to a very short plane flight or a day in the mountains.
Hope this helps.
This is not a conservative estimate
You state the above is a "quite conservative" estimate. I'm sorry but I think you are mistaken. You are using a dose conversion factor of 68.49 millirems/microcurie or 1.85E-08 Sv/Bq. I do not see this supported in the radio dosimetry literature. The World Health Organization uses a value of 2.20e-8 Sv/Bq and this is for adults. DOE uses a value of 4.90e-8 Sv/Bq
again for adults.
For infants up to 3 years of age, the correct value is more like 1.80E-07 Sv/Bq.
Our dose conversion factor
Our dose conversion factor was derived from the NRC Allowable Limit on Intake (ALI) and you are right, this may not be the most conservative number to use. Yes, infants have a factor of 10 increase in dose conversion. My statement was more geared to the conservative nature of the exposure calculation I did. Drinking 1L of rainwater (not drinking water) for 60 days straight is the conservative part. We are working on the dilution quantification for rain to tap water but I expect it to be at least an two orders of magnitude. Plus the exposure time should be more like 3 half-lives or 24 days if one does the proper infinite integral. I more than double this time. So, I most likely have factors of 100 to 200 worked into that estimate. I will give you the order of magnitude on the dose conversion and we reach something like 10 to 20 times conservative.
I just want to remain consistent on the dose conversion factor we use in the data. I'm sure I will get some argument from the heath physicists on this number. But, we show all of our work (hopefully) so that people can understand what was done in the calculation.
What about the Petkau
What about the Petkau effect?
Why are you trolling on a
Why are you trolling on a month old post?
Rather than calling the
Rather than calling the poster a troll, how about addressing his/her question or simply standing out of the away until BRAWN does so?
Once you ingest or inhale
Once you ingest or inhale even very low levels of radioactive particles the Petkau Effect immediately starts potentially lethal tissue ionization.
The phenomenon of the Petkau Effect basically means that you are ionizing or irradiating yourself continuously from the inside out.
This insidious burning at your molecular level will impair your body long before there is a diagnosable disease.
* Cesium 137 accumulates in fatty tissues, liver, spleen and muscles
* Iodide-131 accumulates in Thyroid, breast and ovaries
* Strontium-90 concentrates in your bones and liver
* Barium-140 causes bone tumors up to 30 years later
* Tellurium-132 causes cell mutations, repeatedly via replication
* Yttrium-0 damage to liver and respiration
* Putonium-244 concentrates in your liver
* Uranium 235 accumulates in your bones and liver