Welcome back my fellow radiation nerds. Today we will explore a the radioactivity of a noble gas that is the second leading cause of lung cancer, Radon 222!
During my recent trip to US, I visited a couple of famous uranium mining sites including Mi Vida and Cotter mines. There I collected a few small samples of the uranium minerals and while the radiation coming from those samples might be a bit high when measured up close, it is important to remember that they are point sources and with distance, the activity drops quickly back to normal levels. Furthermore, the plastic display boxes I keep the samples in, prevent the spread of any particles and pieces that might have fallen off the main mineral.
However what concerns me is not the radiation coming from the Uranium minerals, but a gas emitted by them called Radon.
So what’s the deal with radon?
Radon 222 is a naturally occurring radioactive element with an atomic number of 86 and it is a part of the uranium decay chain, directly being produced by the decay of Radium 226. It was first identified in 1899 by Ernest Rutherford and Robert B. Owens at the McGill University in Montreal, making it the fifth radioactive element to ever be discovered. It has a half-life of 3.8 days and it decays into Polonium 218 through alpha emission with an activity of 5.67 × 10¹⁵ Bq/g (5.67 PBq or 153 Curies).
What makes Radon particularly dangerous, is its possible buildup in side of buildings as it escapes from ground as a result of natural uranium decay. Its detection is challenging as Radon is a noble gas and it doesn’t have any smell, taste or colour and can only be detected using specialised equipment. This results in Radon gas being the second leading cause of lung cancer, second only to smoking cigarets.
Furthermore, Radon decay products can easily attach themselves to anything they come in contact with, this includes cloths, hair and also lungs if inhaled. While the half-life of radon is only 3.8 days, it decays into toxic, heavy metals including Polonium, Thallium and Lead. This means that if inhaled, these elements will remain in the lungs and eventually be absorbed by the body.
In some countries, Radon tests are mandatory for residential and public buildings and the levels should not exceed 300bq/m3, although WHO recommends to keep the levels below 100Bq/m3 and EPA recommends action if radon levels exceed 148 Bq/m³ (about 14 pCi/L).
If you have ventilation system with air filters inside your building, you can do a simple experiment and check the filters for Radon using a simple geiger counter. I did that at my parent’s place and their filters clearly showed increase levels of radiation. This is perfectly normal and should not be anything to worry about as long the Radon levels inside the house are within the recommended limits.
A gamma spectroscopy of an active carbon sample that has been exposed to radon gas shows interesting spectrum. While it is similar to Uranium or Radium, it clearly misses peaks from isotopes found higher in the decay chain
Here is a gamma spectrum of uranium ore for comparison. As you can see, the peaks from U-235 and Ra-226 are missing
Isn’t my geiger counter good enough?
Now you may wonder, I have a geiger counter, can’t I use it to measure radon? Well, technically yes, but it’s a bit more complicated than that. While a Geiger counter can detect radiation from radon decay products, it is not an ideal tool for the detection of radon gas or measuring its concentration. In order to do that a dedicated radon meter must be used which is specifically designed for this purpose and will give precise, long-term measurements, which are essential for evaluating any potential health risks from radon exposure.
Aranet Radon Plus & Aranet Radiation Meters
In order to keep track of the radon levels at my home, I reached out to the amazing guys over at Aranet who have kindly provided me with their Radon Plus & Radiation meters which inspired and made this video possible.
The meters look great and have very nice, elegant design and use a E-Ink displays, which looks fantastic and consumes very little energy allowing them to run for multiple years on just two AA batteries which come included in the box. The initial setup and connecting the meters to the Aranet phone app was a piece of cake and the app allows to get much more insight about the data being recorded.
Both meter are fairly compact and have the same width and hight, however they do differ in their depth as the Radon Plus uses ionisation chamber which requires extra room compared to pin diode detector used by background radiation meter.
Aranet Radon Meter can switch between different averaging periods from 10 min, 24h, 7d, 30d. Radon levels do fluctuate depending on the weather, temperature and other environmental factors and this allows for obtaining precise and accurate readings over time.
If you want to learn more about those meters, make sure to either check out Aranet website (click here) or their YouTube channel.
My Radon Levels
Coming back to my concern about the radon levels. After setting up both meters, I allowed them to run for a few day so that they could collect an average measurement. When I checked the Aranet app, I saw that the readings for Radon concentration were around 40Bq/m3 depending on the time of the day and the background radiation hovered at around 0.10uSv/h, which is more than acceptable and within the recommended limits.
Realistically, having just a few small uranium minerals should not cause any significant increase in radon levels but I’ll continue to monitor the readings just in case, especially since winter is coming and ventilating my home isn’t as easy as in the summer time.
What to do if my levels are high?
Although I haven’t measured any significant levels of radon at my home, this might not be true for everyone. If the your levels are elevated, the easiest solution is ventilate the room more often. In some extreme cases, a more drastic measures have to be taken which can include sealing off the basement floor or installing an active ventilation system but I’d recommend consulting a specialist first before taking any action.
Where to get Radon and Radiation home meters
If you are a collector of uranium minerals, radium watches or other items that can produce radon gas, a Radon meter is a definitely a must. This being said, if you live in an area with known to have high levels of Radon concentration, investing in a Radon meter is definitely a good idea.
The team at Aranet has also provided me with discount code for all viewers of the channel. So if you decide to buy a meter from Aranet, make sure the enter ALLRAD5 at checkout which will give you 5% off from your order. Alternatively you can also use the links in the description of the video:
Radon meter: https://bit.ly/4dNCZdn
Radiation meter: https://bit.ly/3ZkwkTI
Thank you Aranet once again for providing me with the meters and making this video possible!
I’m curious to hear about your experiences with Radon. Do you live in high radon area, do you use a Radon meter and how do you control the levels at your home? Let me know in the comments below!
Thank you so much for reading this post, I hope you enjoyed it and learned something new! If yes, please make sure to subscribe to the email list so that you get notified when new posts are added. Also feel free to check out my Ko-Fi page where you can donate a nice cup of radioactive coffee and support my work financially.
and remember, stay active!
