KU researchers find that everyday drugs can damage the environment

LAWRENCE -- University of Kansas researchers have discovered that products found on every drugstore shelf can damage living things in the environment.

According to Val Smith and David Graham, some over-the-counter products and prescription drugs kill algae populations, cause birth defects in reptiles and disrupt sexual development in fish. Drugs can also indirectly give rise to super-bacteria.

All these scenarios pose a threat to the environment and human health.

"People take it as a matter of faith that since it goes down the drain, it's just harmless," said Smith, KU professor of ecology and environmental studies.

But a 1999 U.S. Geological Survey study shows that the chemicals people wash down the drain or flush down the toilet after excretion don't just disappear.

The study tested 139 streams across the country for nearly 100 different chemicals. It showed that 80 percent of them contained at least one chemical, and 54 percent contained five or more.

According to the USGS study, little is known about how the products affect life throughout the ecosystem. And that's exactly what Graham, associate professor of engineering, Smith and researchers across the country are determined to find out.

In a study recently published in Environmental Science & Technology magazine, Smith and graduate student Brittan Wilson report testing the effect of antibiotic chemicals on algae populations. They gathered natural algae from Cedar Creek, downstream from a wastewater treatment plant in Olathe.

Smith and Wilson exposed the algae to triclosan, a component of toothpaste and acne soaps; Tergitol NP 10, an ingredient in hair dyes and spermicide; and ciprofloxacin, a widely-prescribed antibiotic used to treat people with bacterial infections.

Of the three chemicals, Tergitol had particularly dramatic effects, Smith and Wilson said, throwing natural algae levels out of whack.

Tergitol killed off virtually every "good" algal species -- those that insect larvae eat, for example -- allowing inedible types of algae to flourish. Since algae are a fundamental link in the food chain, a shortage of edible algae can affect larger organisms such as fish.

Antibiotics also spur the development of super-bacteria, or bacteria that are resistant to drugs, in rivers and streams.

In unpublished studies by Graham and colleagues, data show that tetracyclines, often included in cattle feed, can give rise to bacteria that are resistant to the drug.

Even cattle given normal tetracycline doses can excrete leftover amounts of the drug in urine, Graham said. When this waste runs off into streams and rivers, resistant bacteria are carried into the environment.

From there, Graham said, tetracycline resistance may be transmitted to other microbes.

Tetracyclines are a "broad-spectrum" class of antibiotics. They're used to treat a host of infections, including Lyme disease, pneumonia, acne, gonorrhea, bladder infections and pinkeye. Should the bacteria that cause these diseases become resistant to tetracyclines and then infect humans, when the infected person takes the drug, it simply won't work.

Graham also studies EE2, or ethynyl estradiol. That's the main ingredient in birth control pills and estrogen replacement therapy drugs. EE2 is an endocrine disruptor, or compound that confuses the body's hormone system.

Because EE2 interrupts growth cycles by mimicking estrogen, male organisms exposed to it can become "effeminate," sterile, hermaphroditic or other options that are, according to Graham, "not quite male."

Animals with complex growth cycles such as amphibians, reptiles and fish are especially sensitive to EE2. Its effects are being observed in bodies of water across the globe.

A study by Graham and colleagues at the Experimental Lakes Area, or ELA, in Ontario, Canada, shows that traces of EE2 in wastewater cause sterilization of male fish.

A mere five nanograms of EE2 per liter of water has caused the majority of male fish to become sterile or extinct after just three years.

A nanogram is "just a handful of molecules," Graham said.

Graham, with assistance from the Environmental Protection Agency, is performing small-scale studies that parallel the Canadian exploration, at KU's Nelson Environmental Studies Area north of Lawrence.

The results of the two studies are much the same, Graham said.

The problem of "effeminization" is taking its toll worldwide. "There are rivers in the midlands in England that have no male fish" due to EE2 in the water, Graham said.

Graham and colleagues say that the lack of males could threaten entire fish populations, depleting an important food source for humans.

Physical defects also show up in alligators or frogs -- defects such as "an extra leg, or the nondevelopment of a tail, or something like that," according to Graham.

Graham believes that in the past, most drug developers tended not to consider the effects of drugs on the environment.

"In some respects, people are retroactively running around like crazy trying to determine whether all these drugs are having a major effect," he said.