Home Page

Geiger Counter Readings Juneau Flats

January 8, 2024 version. Standard glass tube Geiger counts per minute for background radiaton at C Street between 9th and 10th Street in Juneau are now taken every 30 minutes. These counts of ionizing radiation hits don't tell you much. You can't directly compare readings. Mine are only about 1/3 of what a more sensitive unit with a pancake tube and mica window would show.

The readings have no connection whatsoever to cell phone, microwave or other radio emissions. They're about nuclear background radiation. There would have to be something devastating to make a significant change. You can find the raw counts per minutes for this and hundreds of other sites at gmcmap.com. But the readings must be taken with a huge dose of salt. Different counters have different sensitivity, and many will give erroneous high radiation counts at low temperature and high humidity. Raw data isn't trustworthy. For trustworthy data, visit the US EPA's Radnet (epa.gov/radnet).

What Good is the Home Counter?

A real benefit of a geiger counter is to see if you have radioactive treasures at home. To do that, you have to be really close to the object in question. You cannot measure at a distance.

An example is my Aladdin incandescent kerosene lamp mantle. Adjacent to it, an unused spare mantle that hasn't had the coating burned off registers 1,500 counts per minute. How bad is that? A card that came with the counter suggests that over 1,000 CPM is very high, you should leave the area ASAP. But this isn't background radiation. It's a contained object. From a foot away it shows no rise from background at all. To be sure, breathing the dust or a child ingesting it would be very, very not good. But sitting on the shelf? I would judge it's no more dangerous than the kerosene itself.

Another example is my Grandfather's old self-winding Bulova watch (1953, date code L3 serial 5497642). At the crystal, the Geiger counter shows 3,600 counts per minute. How bad is that? That card suggested that over 2,000 counts per minute is so extremely high that you should evacuate and call the government. But, again, this is not background radiation. It's a contained object. From a foot away, there's no detectable rise from background radiation.

That doesn't mean it's harmless. Children love to take old clocks and watches apart. That would be a very bad idea for this. I was considering having it cleaned and the Kreisler flex band fixed. That, too, is probably unwise. The watchmaker might be harmed. The watch doesn't glow in the dark any more because the radium broke down the phosphor. The black on the hands isn't dirt. It's radiation burns. Wearing it on the wrist might be dubious. But as an intact object on display? It's probably no more risky than a bottle of rubbing alcohol.

The Alaska DEC seems to agree. They indicates that it's perfectly legal to dispose of it in household trash (). Alaska DEC. 2020. Radiological Waste. Solid Waste Program, July 21. (Radiological Waste at Archive.org.)

Lots of people have radioactive treasures at home. (). EPA. 2021. Radioactivity in Antiques. RadTown, Jun. 2. (Radioactivity in Antiques at Archive.org.) The only way you're going to find out is to get your very own Geiger Counter and sweep everything you've got. Mine is a GQElectronics.com GMC-500+, which has an M4011 standard tube. If you contribute to GMCMap.com, by default, it sends data about every two minutes. I had changed it to every three hours to reduce Internet traffic but have now revised that to every 30 minutes. When I bought it, it ran about $160 delivered. It's cheap insurance to uncover treasures that could cause harm.

If you're worried about radon, a Geiger counter is the wrong tool. You can buy a Radon Guard model HRDM-01 battery-operated continuous reading digital detector for about $90 delivered. Mine claims about 1.33 long-term, 1.15 one-week, and 0.98 one-day average (pCi/L). Those are very low levels. Oddly, it reads higher if the window is open. Is it accurate? It's reasonably consistent with three mail-in tests I've used since about 1985. But the measurement in my house doesn't tell you anything about yours. Results can be drastically different just next door. You must get your own.

Is there any value in the background counts?

It's just possible that the background counts per minute might someday have value. It's only almost completely impossible that a catastrophe like Fukushima 2011 could affect us here. The whole US West Coast is dotted with nuclear plants and waste sites that are in earthquake and tsunami zones. Furthermore, if anything ever did go wrong, from any cause, the experts would be in denial. That's just human nature. They'd even change the rules so that vastly higher exposure than historical levels would be taken as the new normal (). Little, Jane Braxton. 2019. Fukushima Residents Return Despite Radiation. Scientific American, Jan. 16. (scientificamerican.com/article/fukushima-residents-return-despite-radiation.).

On the other hand, background radiation might be normal yet there might be hotspots only detectable at minimal distance. The Fukushima nuclear reactor meltdowns showered Japan with radioactive microparticles. Yet in areas where background radiation was normal, hot spots were nevertheless found in vacuum cleaner bags and automobile air filters as far away as Tokyo (). Bass, Thomas A. 2021. Fukushima today. Bulletin of the Atomic Scientists, Mar. 10. (Fukushima Today at archive.org.)

Don't forget the limitations. Geiger counters only offer raw counts per minute (CPM). Those counts don't tell you how much stronger the radiation is than the detection threshold. The specific CPM can be wildly different between different models. You can get vastly inflated readings from low temperature and high humidity. They give not a clue of radon exposure.

I'm only putting the continuing count on the web because it's a baseline of what's normal here. You can expand the dot on the map to check or download the twice an hour readings.

If something here is inaccurate or misleading, please write. I am not an expert. If nobody tells me I got something wrong, how am I to know?


📧 Send Comment Walt.Gregg.Juneau.AK.US/contact
🏡 Home Page Walt.Gregg.Juneau.AK.US
  Global Statistics   gs.statcounter.com