It seems like everything is a carcinogen nowadays. How I haven't died from cancer already really amazes me.

With that said, I don't think dry cleaning your woolens once a year will really bother you. Maybe if you got your suit for work dry cleaned every other day for 30 years it might, but even then my guess is it has the most effect on the people who work in dry cleaning places....and the ones I know are older than average, so I don't feel like I'm in that much danger.