With North Korea getting squirrely, and accidents with public emergency alerting for missile detection making front page news people are worried about protection against fallout radiation.
Unfortunately, there is a lot of misinformation. Even worse some is intentional. I spent a good amount of years teaching basic radiological response and how to stay safe around radioactive contamination. My federal instructor certification is still valid, and I still want to help people know how to protect themselves.
I have a lot of historical documents on radiological safety, and since Civil Defense has died in this country and been replaced by feel good measures like TSA (who hasn’t stopped a single threat yet), the historical documents are about the best we have as citizens.
This 1955 PDF on Protection Against Fallout Radiation is still relevant and useful if you are worried about nuclear war. It comes from a time when the government trusted that is given proper information, citizens could protect themselves. This of course was before the nanny state and hesitation from litigation.
Now, you could not expect FEMA to give information on war because it is scary and might offend our enemies.Protection Against Fallout Radiation (1955)