Antibacterial Soap Chemicals Showing Up In Freshwater Lakes
January 22, 2013

Antibacterial Soap Chemicals Polluting Freshwater Lakes

[Watch Video: Chemical In Soap Found In Minnesota Lakes]

Lee Rannals for — Your Universe Online

A chemical from antibacterial soap is winding up in some freshwater lakes in Minnesota, according to research published in the journal Environmental Science and Technology. This came to light after engineering researchers from University of Minnesota performed a study to find out where the chemicals that make up antibacterial soap end up.

They found that a common antibacterial agent known as triclosan used in soaps and other products is being increasingly found in several Minnesota lakes. They said the findings are directly linked to an increased use of triclosan over the past few decades.

Researchers also found an increasing amount of other chemical compounds called chlorinated triclosan derivatives. These chemicals form when triclosan is exposed to chlorine during the wastewater disinfection process.

Once these chemicals are exposed to sunlight, triclosan and its chlorinated derivatives form dioxins that have potential toxic effects in the environment.

Triclosan was first patented in 1964, and then was introduced into the market in the early 1970s. Since then, it has found uses in many consumer products, including soaps, body washes, toothpastes, cosmetics, clothing, dishwashing liquid, and kitchenware.

The U.S. Food and Drug Administration (FDA) has found no evidence that the chemical in antibacterial soaps and body washes provide any benefit over washing with regular soap and water. The FDA and Environmental Protection Agency (EPA) are still studying the effects of triclosan on animal and environmental health.

"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," the study´s lead author William Arnold, a civil engineering professor in the University of Minnesota´s College of Science and Engineering, said in a statement. "Consumers need to know that they may be using products with triclosan. People should read product labels to understand what they are buying."

He said this research can help chemical manufacturers understanding some of the potential long-term impacts from triclosan on the environment.

The team spent some time studying the sediment of eight lakes of various sizes throughout Minnesota with varying amounts of treated wastewater input. They gathered sediment cores a few feet long from each of the lakes.

Once they sliced the core into several segments a few inches thick, they worked with researchers at the Science Museum of Minnesota's St. Croix Watershed Research Station to date the sediment.

The team used high tech methods to analyze the chemicals contained in the sediments over time. Some of these sediments dated back for more than 100 years.

No triclosan or chlorinated triclosan derivatives were detected in lakes with no wastewater input. Overall, concentrations of triclosan, chlorinated triclosan derivatives, and their dioxins were higher in small lakes with wastewater input.

"The results were similar to other recent studies worldwide, but this was the first broad study that looked at several different lakes with various wastewater treatment inputs," Arnold said. "While wastewater treatment removes the vast majority of triclosan, these systems were not designed with this in mind. We need to continue to explore all aspects of this issue."