reply to tschmidt
Re: Educate me on Radon My realtor said that there was a home that was at a 140picowhatever rate. He said that in PA, the ideal level is below 4. The EPA documentation suggests 2-4 is where you want to be (well, less than 2 is great, but supposedly hard to accomplish on your own).
This 140-level home had a system put in place and was able to get down below 4.
A government big enough to give you everything you want, is strong enough to take everything you have. -MLK
If the house is air-tight, you might have higher levels. Older homes that aren't insulated well, tend to have most air (heat) loss so that can be a factor.
I live in SE PA and several units (adjacent to me) have had testing and mitigation. I have not. Mitigation can be nothing more than company drilling/cutting hole in the basement floor, create a space and remove soil-fill, flange with PVC piping, a static gauge (liquid/display), and an outside exhaust fan inline (runs 24/7) to duct-pipe. (creates static pressure to pull the radon gas outside, away from underneath the house).
IMHO, radon has been around since before man walked this planet; it is the natural gas of isotope decay. They claim most that have died from (radon) lung cancer, don't specify whether they were also smokers, ex smokers, or in contact with other lung issues (welding, painting....). But since folks are making lower basements into living spaces, no one really knows. plus, there are stories that it helps some folks. LMGTFY...
reply to Archivis
pC/L is pico-Curies per Liter... Curies as in Marie Curie, a pioneer of radiation research, which ultimately killed her
EPA "action" level was 4.1pC/L when I bought my house in Fall 2010. The WHO was recommending under 2.9pC/L.
The general consensus amount realtors was that anything over 4.1pC/L you could request a mitigation system be installed... below that, and you were pushing your luck (i.e. might as well just ask for $1000 off the sale price).
The basement of the home I bought was a wreck, a pane was missing from a basement window and taped up with a trash bag only a day or two (supposedly) before the test, two full sized exterior windows in the basement had no sashes installed (open to outside), they were put back in with the trash bags (and the sills were so rotted they might as well have been opened an inch or two). The exterior walk out door had a 1" gap at the bottom allowing water/air to pass by easily. I ended up with mid-3's on my testing.
After I replaced the broken windows and doors the level rose to about 8-9pC/L according to an electronic radon device I bought. It's +/-5pC/L seasonally and based on the amount of rain we receive.
I suppose when I sell I will be asked to take action...