by Randy Weckman, College of Agriculture
The issue of PCBs, polychlorinated biphenyls, is widely known. Improper disposal of industrial waste and common household items like old paint, rubber, plastic, refrigerators, and washing machines have allowed PCBs to enter our soil and water supplies.
PCBs are suspected of causing a slew of reproductive, neurologic and immune disorders in animals and people. They are particularly troublesome because they tend to remain in soil and water for a long time, and they move from these elements into fish and, ultimately, people at the end of the food chain. Kentuckians are currently warned by the Department of Water to restrict their consumption of fish from several local rivers and lakes, including the entire length of the Ohio River and portions of the Mud River, Drakes Creek and Green River Lake, because of PCB contamination in the flesh of fish.
Wide-scale field sampling and laboratory testing of soil for contamination using current technologies are almost insurmountable tasks. Elisa D'Angelo, an assistant professor of agronomy at the University of Kentucky, is testing the use of biosensorsgenetically engineered microorganisms that can detect even low levels of PCBs in soil and water samples. (These biosensors were developed by Sylvia Daunert in the UK Department of Chemistry.) The biosensors D'Angelo is using are genetically engineered bacteria that glow when exposed to PCBs.
"The microorganisms glow when PCBs are present and glow even brighter as the concentration increases. With this technology, we can survey a large number of soil and water samples quickly and inexpensively, which should allow us to notify the public of potential health risks in water supplies and in soils," D'Angelo says.