KSU researchers track antibiotics in river waters

Manhattan, Kan. -Kansas State University (KSU) researchers say recent water samples they've taken in the Kansas River basin indicate that current treatment methods aren't good enough to eliminate common antibiotics in the state's surface waters.

The researchers tested four sites in the lower portion of the basin, near the point where the Kansas River drains into the Missouri River in eastern Kansas.

The findings don't represent a threat to drinking water, researchers add. But the project sheds light on a more ominous issue regarding antibiotic resistance in which the Food and Drug Administration (FDA) is wrestling with in animal agriculture.

But, says KSU's Alok Bhandari, the presence of antibiotics in Kansas' rivers and other surface waters increase the potential for bacteria to develop resistance to those antibiotics.

Bhandari, who is leading the KSU study with Dr. Robert Hunter, a veterinary pharmacologist at KSU and two graduate students, says antibiotics typically make their way into public waterways through human waste.

He noted that as much as 90 percent of antibiotics taken in may be excreted through waste.

The Kansas River Basin serves approximately 1.3 million people, and includes about 100 wastewater treatment plants. None of those facilities apparently are capable of eliminating antibiotics in the water - because most city water treatment plants are not designed to remove them, according to Bhandari.

And, he notes, the U.S. government doesn't have rules in place to monitor or eliminate antibiotics and other drugs in the nation's waters.

"We [as a country] don't regulate them, so most facilities don't look for them," he said.

Bhandari says, "Our next step is to look at how to modify existing treatment procedures in wastewater treatment plants in order to better remove them."

KSU tested four wastewater treatment plants for the presence of three antibiotics commonly given for urinary tract infections, pneumonia, fever, skin rash and other infections. They found that two of the antibiotics regularly showed up at levels of one part per billion - a very small amount, according to Bhandari.

But, he adds, "these are only two of the antibiotics. If you consider all of the antibiotics we [humans] use, you have to wonder if the effect is additive, or if some of the antibiotics decrease the effect of others. That's what we don't know."

On average, the four wastewater treatment plants in this study - all considered larger facilities - discharged 20 million gallons of water per day into the Kansas River. Bhandari said they're typical of "probably 90 to 95 percent of wastewater treatment plants in the country."

He said that understanding the amount of antibiotics in surface waters will bring about future changes in wastewater treatment plants. In addition to improving equipment to detect antibiotics and similar contaminants, technology to eliminate those must be developed. Newer-built treatment plants in other parts of the country already are addressing some of these issues.

The work at KSU is supported by the Kansas Water Resources Institute.