That's a very small part of it. I just hate the new look in some places, like the color-changing Safari toolbar, and it's just useless and annoying to me. Maybe 'completely unusable' was a bit of an exaggeration…YMMV.
Not entirely sure, but a lot of these VOCs come from stuff in your house (carpet, paint, plastics).
When I lived in Augusta, GA the air around the city would occasionally reek due to a nearby paper mill. The smell would blow over the city after an hour, but anything that slipped into drafty homes would remain for hours; I'd only notice after returning from walking the dogs.
I started to wonder what I was breathing and found a list of possibile offenders: formaldehyde, acetaldehyde, benzene, chloroform, tetrachloroethylene, and trichloroethylene 
I was hoping my plants would help (the link nate_meurer posted casts some doubt).
I remember a few of us developers resisting a push for 10-12 hours days at a company I worked at. It was easy to find precedent in research and blog posts about how it wasn't sustainable.
It's been interesting to see what my wife experiences as a medical resident lately, in contrast to what I'm used to in the software world: 10-16 hours a day, 6 days a week, and it's incredibly normal, necessary, unquestioned. Today's residents have it easier with the lower 80-hour restrictions in place. When there's talk about the workload, it tends to center around how the lower limits might actually be bad (eg, this recent New Yorker piece http://nyr.kr/15hELxF).