Official : Federal agencies need to set limits on potentially harmful chemical residues . In U.S. , there are no legal limits for some heavy metals , like lead , in beef . Study focused on contamination by biological agents , rather than bacteria .
Official : Federal agencies fail to set limits on potentially harmful chemical residues . In U.S. , there are no set limits for some heavy metals , like copper , in beef . Study focused on contamination by chemical residues , rather than bacteria .