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?

This was my initial thought too. Like if I grow a bunch of nice smelling flowers, and crack open a window during the spring. Am I worse or better off than purchasing a scented candle.

Should we as a species stop nice smelling things entirely.

No, but I wouldn't complain if we stopped scenting every damn cleaning and hygiene product. Please, no scented hand soap, or laundry detergent, or especially dish detergent. I'm not gonna complain if people want scented conditioner, but you probably don't need scented shampoo if you're going to condition anyways.

Intuitively I'd guess the scented candle is worse than the flowers. I doubt soot and vaporized wax are good for you.