ResourcesGlossary: the science
Radon progeny
Short answer
Radon progeny are the radioactive atoms with short half-lives that radon quickly decays into. Also called radon decay products or radon daughters, they are solid particles, not a gas.
What radon progeny means
ATSDR describes how they behave: progeny are solid particles that can attach to dust and other particles and move with the air. Breathed in, WHO says, these particles are deposited on the cells lining the airways, where they can damage DNA and potentially cause lung cancer.
Some of the decays expel high-energy alpha particles, which ATSDR calls the main source of health concerns.
How fast radon turns into progeny
ATSDR puts it in round numbers: one half of a given amount of radon decays to radon progeny every 4 days. Each row halves the radon left in the row above.
| Days | Radon atoms left | Atoms that have become progeny |
|---|---|---|
| 0 | 1,600 | 0 |
| 4 | 800 | 800 |
| 8 | 400 | 1,200 |
| 12 | 200 | 1,400 |
| 16 | 100 | 1,500 |
What it means for your home
A home radon test reports the gas, in
Smoking raises the stakes. ATSDR says cigarette smoking greatly increases the chance of lung cancer for someone exposed to radon and its progeny at the same levels as a person who does not smoke.
Where to go next
- Radon level interpreter. Read your result against EPA's levels.
- Radon and lung cancer risk: what the evidence shows. The risk at each level, for people who smoke and people who never have.