The Invisible Threat You Can't Feel: Why Every Home Needs a Radon Test

This week, we sit down with José Luis Gutiérrez Villanueva, a specialist radon measurement advisor at Radanova, member of the Commission on Radon Communication at the Spanish Professional Association of Physicists, and deeply involved in standards across Europe, to explore a question that fundamentally challenges how we think about indoor air quality and radiation protection: What if the single biggest barrier to protecting people from radon exposure isn't our lack of scientific knowledge or technology—but our complete failure to recognise that the only way to know your radon level is by measuring it, that no two buildings are the same, and that the invisible nature of this radioactive gas means millions of people are unknowingly breathing air that significantly increases their risk of lung cancer every single day?

Key Topics Discussed:

The European Directive That Changed Everything: Since 2014, when the new European Directive on Radiation Protection was approved, all 27 member states now have legislation in place with reference levels for radon. For the first time in the history of radiation protection in Europe, every country must have a number in their national legislation. This is a massive game changer. Before that, there were only recommendations. Some countries followed them, others did not. Now there is a legally binding reference level, and this has moved everything forward.

What Is Radon and Why Does It Matter: Radon is a naturally occurring radioactive noble gas that comes from the decay of uranium in soil and rock. It is everywhere. Outdoors, levels are usually very low, but indoors, radon can accumulate to dangerous concentrations. When you breathe radon, the gas itself is inert and exhaled, but during its journey through your lungs, radon decays into radioactive polonium, which attaches to lung tissue and emits alpha particles. These alpha particles have enough energy to damage DNA, and over years of continuous exposure, this damage accumulates and significantly increases the risk of lung cancer. After smoking, radon is the second leading cause of lung cancer.

How Passive Radon Detectors Work: Passive radon detectors use a special plastic called CR39 inside a holder. Radon gas diffuses into the holder, and when radon decays, it emits alpha particles that create microscopic tracks in the plastic. After exposure, the detector is returned to the lab where the plastic undergoes chemical etching. The etching process enlarges the tracks so they c