Scented products cause indoor air pollution on par with car exhaust

I fully support research like this, because it's always good to get proper data about phenomena. However, I can't help feeling that the results are unsurprising: how could you smell the scented candles if they weren't producing nanoparticles? Surely the existence or abundance of these nanoparticles was never in question?

> how could you smell the scented candles if they weren't producing nanoparticles?

By smelling a gas?

Gases are also made of particles. Molecules that you can smell are easily a nanometer across.