WMS Radon Risk Map of the Bedrock at 1 : 500 000 scale. WMS shows the prevailing radon index of different types of bedrock: 1. Low (Mesozoic and Tertiary sediments), 2. Intermediate (Quaternary sediments), 3. Medium ( Metamorphic rocks and Palaeozoic sediments), 4. High (Magmatic rocks, except for the Pre-Variscan granitoids – medium index), 5. Tectonic features, 6. Boundaries of regions