Levels of triclosan, an antibiotic compound found in anti-bacterial soaps, cosmetics and toothpastes, have been steadily increasing in Minnesota lakes and rivers, according to a University of Minnesota study.
The study's results raise new questions about the use of triclosan, which was patented in 1964 and added to consumer products in the 1970s. But beyond its use in toothpaste to prevent gingivitis, the FDA has found no evidence triclosan in antibacterial soaps and body washes provide any benefit over washing with regular soap and water.
U of M scientists studied the sediment in eight lakes of various sizes and found triclosan levels have been steadily increasing. In small lakes with a single wastewater source, the trends were directly attributed to increased triclosan use, local improvements in treatment and changes in wastewater disinfection since the 1960s.
When exposed to sunlight, triclosan and its derivatives form compounds that have potentially toxic effects.
"It's important for people to know that what they use in their house every day can have an impact in the environment far beyond their home," said William Arnold, a U of M civil engineering professor and the study's lead author. "Consumers need to know that they may be using products with triclosan. People should read product labels to understand what they are buying."
Arnold said this research can also help chemical manufacturers understand some of the potential long-term impacts from triclosan on the environment.
The research was published Tuesday in the journal Environmental Science and Technology.