A common antibacterial agent designed to keep our hands clean is increasingly fouling American waterways, new research shows.
University of Minnesota researchers have found triclosan, a chemical commonly used in soaps and other consumer products, is being found in increasing amounts in freshwater lakes. The study, published online in the journal Environmental Science and Technology, is the latest to raise concerns about triclosan, which past studies have tied to health problems in laboratory tests involving animals.
"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 lead researcher William Arnold, a civil engineering professor in the University of Minnesota’s College of Science and Engineering. "Consumers need to know that they may be using products with triclosan. People should read product labels to understand what they are buying."
The new study found increasing consumer use of triclosan-containing products has led to a rise in levels of the chemical in Minnesota freshwater lakes. In addition, the researchers found an increasing amount of other chemical compounds, called chlorinated triclosan derivatives, that form when triclosan is exposed to chlorine during the wastewater-treatment processes. When exposed to sunlight, triclosan and its chlorinated derivatives form dioxins that have potential toxic effects.
Triclosan is widely used in hand soaps, deodorants, mouthwashes, toothpaste, bedding, clothes, carpets, toys, trash bags and other products. The U.S. Environmental Protection Agency has estimated more than 1 million pounds of triclosan are produced annually in the United States, and it is found in waterways and marine life ranging from algae to fish to dolphins, as well as in human urine, blood, and breast milk.
According to the U.S. Food and Drug Administration (FDA), other than its use in some toothpastes to prevent gingivitis, there is no evidence that triclosan provides health benefits or that antibacterial soaps are more effective than regular soap and water. Experts are also concerned overuse of antibacterial products may promote resistant bacterial strains.
Last year, researchers from the University of California-Davis and the University of Colorado released a study showing the chemical hinders muscle contractions at the cellular level, slows swimming in fish and reduces muscular strength in mice. The findings, published online in the Proceedings of the National Academy of Sciences, suggested triclosan may pose previously unknown human health risks.
The FDA and EPA are currently conducting new risk assessments of the chemical. Several manufacturers of consumer products have pledged to stop using the chemical as a precaution.