Hikin Jim, you're a wealth of knowledge!

And I'm sure, in Nogie, that ice was fairly fresh....

And yes she went undiagnosed, and then misdiagnosed, for nearly 2 years, just suffering through bouts as the critter went through it's cycle. If I recall, it finally took a third stool sample before a doctor spotted it (humiliating for her).

And yep, dirty hands probably account for the vast majority of contamination.

For the particulate matter, you know as well (since you live in SoCal) as I that you can practically taste the air out here, it's gotta be something more than just CO2 making the sky thick. An ounce of prevention, but you could bet if I was in dire straits I'd take the chance.