Trader Joe's is sued over lead, cadmium levels in dark chocolateNEW YORK, Jan 4 (Reuters) - Trader Joe's was sued on Wednesday by a consumer who accused the grocery chain of misleading and endangering shoppers by selling dark chocolate that contains harmful levels of lead and cadmium.The proposed class action was filed in the federal court in Central Islip, New York, one week after a similar lawsuit was filed there by the same four law firms against Hershey Co (HSY.N).Both lawsuits were filed after Consumer Reports last month said 23 of the 28 dark chocolate bars it tested contained potentially harmful levels of lead, cadmium or both heavy metals for people who eat more than one ounce of chocolate a day.In Wednesday's lawsuit, the plaintiff Thomas Ferrante said he bought both products after reading their labels, and would not have done so or would have paid less had he known their contents.Some studies suggest that the antioxidants and relatively low levels of sugar in dark chocolate could help prevent cardiovascular disease."