Marc Martin wrote

I just learned from someone that PLASTIC is an effective shield for 
"longitudinal waves", which *might* explain why I've always been 
under the impression that my plastic badge holder was the most 
effective "shield" for my work ID badge.

Years ago I discovered that PP and PE plastics shielded the energy radiation from orgonite. 
Using the terminology of Wilhelm Reich, this beneficial energy is usually called orgone, while the negative energy from Marc's work ID badge is called DOR. We can also say positive and negative longitudinal/scalar/Tesla waves. 
Anyway, I think this is a matter worth some serious research.