Science question on odors--solve this debate (system, problem, issue, scientific)

[Tracysherm]

I was just having a fun debate with someone, and wondered what the rest of you think.

When encountering something that smells disgusting--like manure, garbage, a dead animal on the road, a stinky bathroom, my friend (and others like him) says to breathe through your mouth, so you don't smell it.

I say the opposite. Since odors are actually molecules of the disgusting thing that become airborne, do you really want molecules of manure, garbage, dead thing, or someone's poo in your mouth? No thanks, I say, I'd rather breathe through my nose, perhaps put something over my nose like a tissue or my perfumed wrist, and get the heck away from whatever smells. I'm keeping my mouth sealed shut.

Which do you agree with? Do you agree with it just in practice or scientifically too? If you know more about the science behind odors and fragrances, please share in plain language.

All I know is that molecules of things with a smell become volatile and airborne, and react with the sensory cells in our nasal cavities. Beyond that, I know very little about how smells work. But to me that means "if you smell dog poop, that means you have dog poop molecules in your nose." Better in your nose than in your mouth; right?

[harry chickpea]

The digestive system has a lot more defense mechanisms than the respiratory system, but I doubt it matters much other than one way you might smell it less.

[TurcoLoco]

When I encounter a really disgusting smell (seldom), I tend to stop breathing (hold my breath), turn the hell around and walk away.

[jtur88]

The fact that you can detect a smell is not an indicator that harmful or toxic substances are in the air. They can be present regardless of whether you can't smell them, or regardless if you find the smell disagreeable.

The rule of thumb is that odors that are animal-sourced tend to be repulsive, and from plant sources pleasant-smelling to humans.

[Tracysherm]

I'm not worried about "harmful" or "toxic" so much as "disgusting." For a smell to reach your olfactory senses, molecules of the "stuff" you're smelling have to be in your nose. So if you open your mouth, logic says that those molecules are going into your mouth. I'm not so concerned about getting a disease, but by the idea that I am letting "poop" or something else repulsive in my mouth if I breathe through my mouth.

I guess I would not be good at having germ-phobic OCD, as I'm more concerned with something being "yucky" than making me sick.

[silverworks]

I just LOL when you include your friend and others like him on the smelly category. wow. anyway i also do the same as turco does. and breaking news there are many air fresheners and even candles to help you with that smelly problem. i prefer lysol coz apparently it kills germs on contact. but i know febreeze is kind of beating lysol now, i think.

[Tracysherm]

I'm pretty much talking about times when air freshener is not handy, like walking down the street and there's a dead racoon on the road, or when I'm in the back yard scooping dog poo (with my mouth shut). Believe me, in my house, office, and car, I have air freshners handy!