Meat is a dietary staple for many Americans and often the centerpiece of barbeques, potlucks and family functions. However, new data confirmed by the Food and Drug Administration shows that 80 percent of antimicrobial drugs made in the U.S. end up in meat, meaning you might want to think twice before sinking your teeth into a burger.

Earlier this month, the FDA banned the routine use of cephalosporin antibiotics in livestock feed, but restrictions on penicillin and other medically important antibiotics were postponed. The ban came almost two weeks after the FDA announced it would not restrict the use of antibiotics such as penicillin.

FDA spokeswoman Laura Alvey said the restriction was enacted to protect human health. When animals are given low doses of antibiotics, they develop resistance to them, as do the people who consume them.

“We are particularly concerned because little is known about the toxicological effect of cephalosporin drugs when used in food-producing animals,” Alvey said.

The FDA declined to comment on why the proposed ban of penicillin and other drugs was not passed.

“This is a step in the right direction, but much more is needed to really have an impact on the threat to human health,” said Richard Wood, chair of Keep Antibiotics Working, one of several advocacy groups that work to eliminate the frequent use of antibiotics in food animals.

Livestock are fed low doses of antibiotics on a regular basis to promote growth and prevent disease in crowded conditions, said Chris Hunt, senior policy advisor for the advocacy group Sustainable Table.

“Antibiotics enable animals to grow faster with less feed, so it reduces the cost of producing them on a large scale, which is appealing to industrial farmers,” Hunt said.

Regulating the U.S. agriculture industry is often challenging because members of Congress find it difficult to oppose the livestock industry, Wood said.

“Most Congress members see this as primarily an agriculture issue, but it’s also a public health issue,” Wood said. “Once they understand that, their support is unquestioning.”

Humans aren’t the only ones affected by the antibiotics in meat. They also contaminate soil, water and air, Hunt said.

“Manure with undigested drugs produces this chemical cocktail of pollutants when it decomposes,” Hunt said.

Although research on the issue is still being conducted, the concerns surrounding routine antibiotic use in animals is nothing new. In 2009, Congresswoman Louise M. Slaughter introduced the Preservation of Antibiotics for Medical Treatment Act, a bill designed to ensure antibiotic effectiveness in humans by regulating their use in animals more closely. PAMPTA has not yet been passed.

“This has been introduced and re-introduced, but it never really goes anywhere,” Hunt said. “The problem is the agriculture industry has a lot of power and is able to prevent any kind of meaningful change.”