If you smell something, are you eating it?

Just to set the scene, some info. If you can smell an onion, the "scent" is also likely to make your eyes water. As I understand it you are detecting small particles of onion in the air, which are irritating to your eyes when they land in them. Also I read that sharks can detect (smell? taste?) 1 part of blood in a million parts of water. Our noses are presumably not that good. So- what I'm asking is, if you can smell something, does that mean that you are ingesting air containing more than 1 part per million of it? Consider some of the things we smell in our daily lives!