Density

I mentioned training with certain types of barrier to radiation & want to share my own experiences with SIS.

Bricks                                   No good at all

Sandstone building               Almost as bad as bricks

Thick concrete                     Good

Roofing lead                         Poor

Dirt                                       Very good
Thick tree trunk                    Poor

Ingestion was very serious for performance & is in the end fatal by bowel cancer.