“they were so heavy it was crazy!!”
They were lined with lead...
Now they claim we don’t need the lead lining? They say the holes are too small for the waves to escape through. I would feel safer with the lead. :)
Forget the lead. There are other metals that are cheaper, lighter, and better electric conductors (which you want for radio frequency shielding) than lead.
You need to read up on ionizing and non-ionizing radiation.
Big difference.