The environmental damage caused by years of unchecked toxic waste matriculating into the Kansas River is still evident – especially in Lawrence.

Just as it has for the past 20 years, the Kansas Department of Health and Environment recently issued its annual advisory against eating bottom-feeding fish found in the river between Lawrence’s Bowersock Dam and Eudora.

The main concern is high levels of PCBs found in fish taken out of the river for samples. PCBs – polychlorinated biphenyl – are subject to regulation under the Toxic Substances Control Act and have not been in use since the 1970s.

“It’s a decades-long process for it to degrade to the point that it is no longer a concern to human consumption,” Steve Cringan, KDHE environmental scientist, said of the carcinogen. “We are probably a couple of decades into that process, but it may take another couple of decades before we have trouble measuring it.”

There are no advisories against eating fish in other parts of the river. The river in Wyandotte County was removed from the advisory list in 2004.

It is difficult to determine why the PCBs are still high in the Lawrence-Eudora river stretch, Cringan said. One factor is that the dam serves as a blockage that makes it difficult for fish to migrate into the area from the west, he said.

Years of testing have found that fish in a 10- to 15-mile area showed similar chemical levels, while beyond that distance they differed, Cringan said.

The Kansas River flows into the Missouri River at the state border. Because of that, the fish population is more variable, Cringan said.

Bottom-feeding fish that are affected by PCBs are considered to be channel, blue and flathead catfish, carp, drum, bullhead, sturgeon, buffalo, carpsuckers and other sucker species.

Fish consumption advisories like this one warn against eating of any kind of bottom-feeding fish found in the Kansas River between Lawrence and Eudora. Those kinds of fish contain high levels of PCB, or polychlorinated biphenyl, a toxic substance.

Crappie, walleye and bass sometimes are found in the river, usually because of spillage from lakes, Cringan said. They are safe to eat.

Trend data from most Kansas long-term monitoring sites show a decrease in mercury and PCBs. Chlordane levels also have dropped dramatically. Chlordane stopped being used in 1988. Chlordane also had once been found in high levels in fish in the Lawrence area.

Despite the decline in some levels of chemicals in the river, pollution is still a major concern, according to Laura Calwell, who serves as the Kansas Riverkeeper, an advocate for the river through the Friends of the Kaw organization. Intentional dumping is a problem up and down the river, she said.

Last March, Friends of the Kaw organized a cleanup of 1,400 tires dumped in the river near Linwood. Battery casings have been found in the river near Manhattan, Calwell said.

“The biggest problem for the river is litter, oil and gas residue, and pet waste from city storm sewers,” Calwell said. “Then there is agricultural runoff: pesticides, fertilizer and animal waste.”

Calwell emphasized the need to properly cook fish even if it is caught in “safe” areas of the river or any body of water.

She also urged anyone on or along the river to properly wash their hands before eating. She advised carrying a bottle of rubbing alcohol or liquid hand sanitizer.

“You don’t want to get that bacteria into your digestive system,” she said.

Friends of the Kaw has a Web site, www.kansasriver.com, with information about the river and its environment.