High Levels

Wish AtomicDave was still on here and his station. What is going on over in the Southwest region of the USA?? 3 stations readings really high the last couple of days. I'm seeing this on the NETC site. Wish Dave's station was still online.

Hi Frank

I think the NETC site is a bit alarmist. I only ever worry about a sustained rise in radiation levels and I've never seen that here in Spain. I tick along at about 0.15 microSieverts per hour and I would only be bothered if that, say doubled, and remained doubled over at least 8 hours. Even then, is 0.3 microSieverts per hour worth getting too worried about?

Now an increase to 1.5 microSieverts per hour, then I would be heading for the hills

Hi, ya it can be. I watch it all the time along with our site here. Pretty much know the norms for the USA visually, but that area has been high now for a few days and 3 site. Most of the time I see one site here and there, but 3 sites in a general area like that raises an eyebrow. I did see some postings in regards to it thou, mostly stating weather conditions and how the heavy overcast skies trapping Radon and other components is what is causing it. Yet, I also read how readings on the west coast are also increasing as well and I guess one of them is heading to the coast this weekend to take some measurements. Should be interesting to see the results. And of course, there is nothing wrong and we are all safe says the government..

Interesting that you mention radon because today I carried out a very crude experiment to detect radon gas and its daughter decay products in the rain.

I placed a mesh bag of activated charcoal pellets at the bottom of a rain water downpipe and left it for about 4 hours in light rain. Before rain exposure the bag was measuring 12 cpm averaged over 5 minutes using an SBT-9 probe. After rain exposure I measured 25 cpm over 5 minutes using the same SBT-9 probe. Crude, I know, but it does point to radon washout, however weak.

Next time I will log the cpm not over 5 minutes, but several hours to see if the characteristic decay curve of radon daughter products presents itself.

bethsalem wrote:

Hi Frank

I think the NETC site is a bit alarmist. I only ever worry about a sustained rise in radiation levels and I've never seen that here in Spain. I tick along at about 0.15 microSieverts per hour and I would only be bothered if that, say doubled, and remained doubled over at least 8 hours. Even then, is 0.3 microSieverts per hour worth getting too worried about?

Now an increase to 1.5 microSieverts per hour, then I would be heading for the hills

I'd be worried.
While 0.3 (or even 0.2) uSv/h may seem insignificant as a short term external dose, once inhaled it could be a totally different story - especially for my young children.
As an example, lets say you are measuring this 0.3 (or 0.2) with an sbm20, and it turns out that you are detecting the gamma componant of some Am241 and other alpha emmitters in a cloud of dust thats just blown in from....somewhere.
Nothing to worry about?
I think that geiger counters are not not much good for quantifying radiation unless you have identified what it is that you are measuring, and know the parameters of the gm tube you are using.

Juzzie, I agree with you that the geiger counters we commonly use, such as the SBM-20 or the SBT-9, are only really good at telling you that something is amiss when they show an increase in radiation levels. They can't tell you which isotopes are causing the increase so I suppose the importance of initiatives such as Radmon are that low-cost, extensive networks of detectors can help identify a problem so that a release of radiation cannot go unreported or unobserved, because ultimately it's our health and the future of our children that are at stake.