It mostly depends on where your house is located, if the minerals contain uranium, and then type of building material, level of ground air intake and ventilatio

It mostly depends on where your house is located, if the minerals contain uranium, and then type of building material, level of ground air intake and ventilation. "Some types of rocks have higher than average uranium contents. These include light-colored volcanic rocks, granites, dark shales, sedimentary rocks that contain phosphate, and metamorphic rocks derived from these rocks." (https://pubs.usgs.gov/gip/7000018/report.pdf https://pubs.usgs.gov/gip/7000018/report.pdf) See also this map of the areas in the US which documents radon levels, which however doesn't predict radon levels of each house, only points to a general risk. https://www.epa.gov/radon/find-information-about-local-radon-zones-and-state-contact-information#radonmap https://www.epa.gov/radon/find-information-about-local-radon...