Microbiologists, Alison Cupples and Jerry Sims (USDA/University of Illinois) and Rob Sanford (University of Illinois) recently completed a study showing that bromoxynil (brand name buctril) is degraded by some microorganisms that thrive in an anaerobic atmosphere, that is, one without oxygen such as an underground aquifer.
"Most research focuses on the aerobic fate of herbicides, therefore our knowledge of what happens to these compounds under anaerobic conditions is still very limited," said Cupples. "The research itself is basic science, but it shows that anaerobic microbes exist with the necessary tools to degrade these compounds. This is good news for natural cleanup of anaerobic environments like groundwater. Obviously further studies are needed before this discovery is actually used for remediation."
Sims explained that some pollutants tend to drop to the bottom of aquifers. "Pollutants move in the water and work their way into the groundwater in the bottom of lakes and streams where anaerobic activity occurs," he said. "And if soil is wet for days or weeks, it can become anaerobic, too."
Areas prone to flooding or poor drainage can also result in anaerobic atmospheres in which bromoxynil would break down and not be as harmful to the environment. "What we've discovered is a new reaction that can happen to pollutants," said Sims.
In addition to herbicides, Sims pointed out that brominated fire retardants are used in lots of everyday products -- products that eventually wind up in landfills. "These compounds are structurally similar to bromoxynil so these findings give hope that such chemicals would break down when they reach an atmosphere without oxygen like a landfill.
