Poison gases? But what about bacteria?

Ok, so the topic of poisonous gases given off by gold/silver has been covered extensively(and I'd still wear gloves, and wash my finds before I started diving into the loot).  

Anyways, how about bacteria and/or viruses?  How long does some of that stuff live for?  Even as recently as a hundred years ago, there were viruses around that wiped out large populations.  Now I know I'm stretching things a bit here, but what if someone was burying their treasure in a chest that was fairly tightly closed, and they were also sick at the same time?  Also, cleanliness wasn't habitual back in the "old days".  So what about bacteria?  I read something about Zahi Hawass stating that bacteria is a real threat even on 1000 year old mummies.  I know that silver has anti-bacterial properties, but what about gold?  And do the bacteria just die, or do they just not stick to the silver?

I have already decided that upon finding a cache, I'd air it out for a few minutes just in case any fumes were enclosed with it.  What can I say, I'm extra cautious.  I mean it's not like I know what's inside a container until I open it.  

Lastly, I want to finish this post by asking: Just how would you wash your treasure(assuming it's metal, or stone)to eliminate any and all bacterial, viral, or artificial threats("nasty people" leaving a coat of poison on the treasure they were burying)to your health?

HIO Prime:  good points, however I don't think that they would sprinkle arsenic  etc, on the metal, if they ever intended to recover it themselves.

Besides they didn't know how deseases were transmitted in the older days.

May I also mention that they did play on the psychlogical aspects in those days, the churches / religions have been doing this since Able.

Airing out a deposit is standard practice here in Mexico, right on.

Don Jose DE La Manchu