Beats me. I've skimmed a few studies on the subject, but I'm certainly no expert in this field (or any related field). Most studies I've seen have been inconclusive or suggested that if there is a risk, the risk is probably pretty small. That doesn't rule out the possibility of a harmful effect, just that none has been convincingly substantiated to date, to my knowledge.

My own personal opinion: It's probably not worth worrying about. There are better things you could spend your time worrying about. But that's just a wild guess based on not much evidence. I could be totally wrong.