Triclosan study in the Midwest Lakes

MINNEAPOLIS - The compound triclosan is found in much anti-bacterial soap, cosmetics and toothpastes, but it's presence could be at a cost to the environment.

University of Minnesota scientists have now found it in Minnesota waters and at increasing amounts. The discovery has some researchers worried.

Researchers say those anti-bacterial soaps that we think get us cleaner are actually be polluting our lakes and rivers. That's according to a new University of Minnesota study published in the journal Environmental Science and Technology.

It says the active ingredient in those soaps, triclosan, is building up in lake sediment.

In the two-year study, U of M civil engineering professor Bill Arnold and his team took sediment samples from eight Minnesota bodies of water, including Lake Superior, the Duluth Harbor, Lake St. Croix and Lake Pepin, Lake Winona near Alexandria, Lake Shagawa in Ely, East Lake Gemini and Little Wilson in the Superior National Forest.

They found that all of them, except Little Wilson, contained increasing levels of triclosan.

Little Wilson is the only one that does not receive waste water from a waste water treatment plant.

"We ought to be concerned that we are putting it out into the environment," Arnold said.

Some of the lake sediment samples researchers took were more than 100 years deep.

"As you go deeper in the lake you go back in time," Arnold said, 
They found that the levels of triclosan, and its derivatives, increased with every decade since it was invented in the 60s.  "Because the levels in the sediments now are the highest they've been, we know the levels in the water also have to be higher than they've been in the past," Arnold said.

Arnold said "triclosan can kill algae", which could be bad for the food chain. He also said "triclosan breaks down into seven derivatives, including four dioxins, in the environment."

Dioxins are toxic chemical compounds. High level exposure to dioxins is known to cause adverse health effects, but Arnold said more study is needed to see if the triclosan levels in our lakes are actually causing problems.

U of M Environmental Health Sciences professor Craig Hedberg said "triclosan and its derivatives pose no human health threat yet, but that could change."   "If they accumulate in the environment, there are opportunities for them to work back up through aquatic food system and ultimately there could be some human exposure," Hedberg said.

So is our drinking water safe? Arnold said "water treatment for our drinking water removes triclosan."  He said the danger at the sink is actually the anti-bacterial soap.  "Rubbing the soap on your hands is going to give you a much higher dose than anything in the environment," Arnold said.

He questions why it is needed since it has been shown that using regular soap gets you just as clean.

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