According to a study conducted by the U.S. Department of Agriculture's (USDA) inspector general, the United States' standards for beef are too loosely regulated by federal agencies. The standards do not set limits on many potentially harmful antibiotics, pesticides, and chemical residues, the study says.
The USDA's investigation focused on chemical residue contamination rather than bacteria, such as E. coli and Salmonella. Unlike bacteria, chemical residues are more likely to build up over time and no amount of cooking will kill them. When this buildup occurs, some of the residues can become carcinogenic.
Only one type of pesticide trace is currently tested and there are no limits for certain heavy metals, like copper, the study found. In 2008, Mexican authorities turned a shipment of U.S. beef away because the copper levels exceeded the Mexican limit though they complied with U.S. standards. The report also explained that when cattle test positive for chemical residue it's hard to find the source of the contamination.
The USDA said it plans to take action quickly to correct the shortcomings cited in the study by implementing some of the suggested changes, which include testing for more kinds of residue and setting limits on how much of each substance is allowable. The National Cattlemen's Beef Association said that while they believe U.S. beef is very safe, they always support new ways to improve food safety systems.