An aspiring sommelier, I've long had an interest in the health benefits of wine. The October 30 online edition of Chemistry Central Journal reported that only three of sixteen countries tested had wines that did not pose hazards from heavy metals.
Heavy metals pose health hazards, and have been linked to cancer and Parkinson's Disease. No U.S. wines were tested; still, how the metals end up in the wine has yet to be clearly determined.
It's probably safe to assume that domestic wines, because they are routinely tested, pose no health risk. So, continue drinking wine in moderation. Just be careful about certain foreign wines.