Students play an active part in Yu "Frank" Yang's Molecular Environmental Science Lab in the Department of Civil and Environmental Engineering. Credit: University of Nevada, Reno

Researchers have found that bacteria can help counteract triclosan—a widely used antimicrobial products that has been one of the top environmental contaminants since the 1960’s.

Triclosan is known to disrupt the nedocrine systems of wildlife and causes toxic effects to their reproduction and development, while also being linked to problems with antibiotic resistance. In Sept. 2016, the FDA issued a final rule banning triclosan, giving manufacturers until Sept. 2017 to comply with the rulemaking by removing or reformulating products.

Researchers from the University of Nevada, Reno tested a matrix of a bacteria strain mixed with the organic material to discover the condition that degraded triclosan the quickest,  and found a mixture that reduced the half-life of triclosan to about 10 hours. They found that triclosan degraded faster in the environment through a combination of metal-reducing bacterium and natural organic matter.

The overall outcome is determined by the concentration of organic material, microbial activities and the chemistry of the water.

Further study and development is needed to fully understand the degradation pathways of emerging organohalides and cost-effective removal strategies.

“The results are promising that we gained better understanding about how triclosan is degraded in the natural environment, and can potentially find a way of removing the contaminant from the environment and in the long term fighting the antibiotic resistance problem,” Yu "Frank" Yang, assistant professor of environmental engineering, said in a statement.

Triclosan is used in everyday items including hand sanitizer, detergents, soaps and paints. According to Yang, the antimicrobial is persistent and lacks efficient removal processes in most water treatment plants. It has been detected in natural waters, soils, sediments and biosolids.

“Antibiotic resistance induced by antimicrobial or antibiotic agents is a global problem, if they are not degraded rapidly, then bacteria in the environment get exposure and develop resistant genes and then we can't fight it,” Yang said. “If we can completely understand the degradation of antimicrobial agent, we can provide a treatment process in engineered and natural environments.”