Benzene causes CANCER. Benzene is also know as an AROMATIC RING, because lots of fragrances contain these benzene structures. So I figure scents can cause cancer, and do scary stuff. Thus I shun commercial perfumes, air fresheners, and other gross shite.
I do however, indulge in aromatherapy, but only with essential oils, and never synthetics.
And if I use incense, I only use a lil' wiff. (mostly because otherwise we'd get sick from the over kill, and it's technically not allowed here)
I also am ok with excessive incense out doors because it keeps the winged bitey insects away.