What are the main ways of getting into the human body of radionuclides, what are the preventive measures?

How do radionuclides enter the human body?
1) through food. Radionuclides settle in the soil, from which they are absorbed by plants along with water. A person consumes contaminated plant foods or meat;
2) through the air. Radioactive dust particles settle in the lungs, isotopes enter the bloodstream;
3) through the water.
How to exclude the ingress of these substances into the body? Use fine filters for water and air. To reduce the doses ingested with food, it is necessary to use plant varieties that accumulate little radionuclides for nutrition. Pectin substances bind radioactive isotopes well and remove them from the body (plant fruits are especially rich in them)