Many houses in Denmark have basements. Radon depends on geology, and occurs in relatively high concentrations on the rocky island of Bornholm: https://www.sst.d

Many houses in Denmark have basements. Radon depends on geology, and occurs in relatively high concentrations on the rocky island of Bornholm: https://www.sst.dk/da/Borger/Straaling_-miljoe-og-klima/Om-ioniserende-straaling/Radon-i-boliger/Kort-over-radon-i-Danmark https://www.sst.dk/da/Borger/Straaling_-miljoe-og-klima/Om-i... I Denmark, Radon accounts for about 9% of lung cancer cases: https://www.sst.dk/da/Borger/Straaling_-miljoe-og-klima/Om-ioniserende-straaling/Radon-i-boliger https://www.sst.dk/da/Borger/Straaling_-miljoe-og-klima/Om-i...