The most radioactive thing that surrounds us in everyday life, you will not believe - it is snow. As a result of the measurements, it was found that the radioactivity of the snow at the moment it hits the soil averages 5.5⋅10-11 Ci / g. The greatest activity is observed at the beginning of the snowfall, which seems to be quite natural, since the first "portions" of the fallen snow "sweep" active products from the lower layers of the atmosphere, violating the established equilibrium. It has also been shown that there are large fluctuations in the amount of activity from day to day.
I'm afraid we are all radioactive anyway, to some extent. Some of the potassium in our blood is radioactive, the food we eat is radioactive, and the earth itself is radioactive. However, the level of radioactivity of all of the above is quite low and does not cause any particular harm to health. If you want, watch the video from the Veritasium project translated by the VertDider team, it refers to the question indirectly, but it shows quite well in comparisons what real radioactivity is: