Water Filtration

interesting read. It's an old topic but still one that deserves more study.

https://slate.com/technology/2018/02...necessary.html

One thing I'm not clear on: We are always warned about "toilet" hygiene and the risk of hand-to-mouth contamination, but how is it possible to infect yourself? If Giardia were present when you relieve yourself, wouldn't you already be infected?