Cleaning Up PCB

PCB Labeling

Batman step aside! You're no match for these polluting villains.

Polychlorinated biphenyls, or PCBs, make the Riddler look like a saint. They're found worldwide in our soil and water -- even in Arctic ice. And like the Riddler, PCBs are insidious. They accumulate in plants and animals, working up the food chain until they reach us. Then, they cause cancer or birth defects.

The United States banned PCBs in 1977, but the "Joker" was on us: Getting rid of PCBs takes super-human effort! The most common clean-up is large-scale dredging and dumping of waste materials into landfills. Incineration, the other approach, creates dioxins and other toxic compounds.

Both approaches are less than ideal. What's needed is a biological process, a microbe in shining armor. Enter a hero from the Dehaloccoides, or Dhc family. The Dhc microbe is a crafty crime-fighter. It replaces PCB chlorine molecules with hydrogen, making the PCB into a non-toxic "law-abiding citizen" of sorts.

The Dhc microbe does all this undercover, since it can't live in the presence of oxygen. Not quite a caped crusader, but it's as close to Batman as science gets.

Script by Dan Maxwell

Discovery Links

To learn more about today’s topic, please explore the links below:

• Researchers Close In On Natural Solution To PCB Contamination
• Sediment management Work Group Comments on US EPA's PCB Cleanup and Disposal Regulations
• Fox River Dredging Experience
• Disposal of PCB Capacitors from Light Ballast