Ask Kevin: Radioactive fly ash?

Kevin,

I very much like your show, and last night saw the episode in which you poured a foundation using "fly ash" to substitute for cement. While this may have certain environmental advantages, some fly ash is slightly radioactive, depending on the original coal. This may result in a foundation with issues similar to the radon accumulation issue in homes with basements. Especially in an energy efficient home, where the air circulation level may be low, I would at least look into what the radon emitting characteristics of the fly ash will be.

Best regards,
Cas Milner

Yikes! I learn something new every day. Someone else alerted me to the radioactive possibility in fly ash. I actually had a Geiger counter brought in to test our concrete. There was no evidence of radioactivity. Radon is different from Radioactivity. It emanates naturally from the ground, particularly in certain regions, especially (but not only) regions with granitic soils. However, not all granitic regions are prone to high emissions of radon. Depending on how houses are built and ventilated, radon may accumulate in basements and dwellings. Many methods can reduce radon in homes. I would like any scientific information you or others have about radioactivity in fly ash.

Sincerely,

Kevin