USA Today:

And so the bag wars begin! As more cities move to ban disposable grocery bags, reusable bags are now coming under their own scrutiny. A Florida newspaper found lead in some reusable bags, raising health and environmental concerns.
Sen. Charles Schumer, D-N.Y., is asking for a federal investigation after a series by The Tampa Tribune that found lead in bags bought at Winn-Dixie, Publix, Sweetbay, Walmart and Target, reports USA TODAY colleague Stephanie Armour. Lead, considered a toxin, can cause learning disabilities in children and fertility problems in adults.
“Federal agencies need to put a ban in place for reusable bags that have lead in them,” Schumer said in a statement. In a letter to the Food and Drug Administration, he said: “Any situation where lead bags are coming into contact with the food being purchased by Americans needs to be immediately investigated and resolved.” He told the Associated Press that many of reusable bags sold in the U.S. are made in China.
Schumer says Publix Super Markets and Winn-Dixie are already asking suppliers to make reusable bags with less lead. He commended Wegmans Food Market, a 77-store chain, for announcing Sept. 20 that it would stop selling two designs because testing suggested they may have elevated lead levels.