Is third-hand smoke harmful too?

I love keeping my “summer blond” year-round, but I’ve heard the highlighting chemicals can cause health problems. True?
—Rachel B., New York, NY

Not quite. Highlights are a safe health bet, as long as they’re applied only to the hair shaft and not to the scalp, where they could burn your skin or seep into your bloodstream. Women yearning for darker locks, however, should take note: Preliminary studies have found tentative links between some permanent dark-color dyes (typically applied to hair and scalp) and certain cancers. That’s not to say you shouldn’t tint your locks—just keep it to a few times a year, and ask your colorist about newer, safer dyes.

We all know smoking is awful, and second-hand smoke is bad. Is third- hand smoke harmful too?
—Sue R., Baltimore, MD

Yes. Inside every plume of smoke are traces of some
250 poisonous gases such as cyanide, ammonia, arsenic, and cadmium. They can linger on hair, skin, and clothing for months after a smoker stubs out her butt. Research shows third- hand smoke may also contain lead, which can mess with brain function. That’s bad news for smokers and the people around them. You don’t need to run next time your smoker buddy visits, but do your best to minimize your day-to-day exposure.