Scientists at the University of Minnesota say the findings are directly linked to the increasing use of such anti-bacterial soaps and other products over the past decades.
The researchers also reported detecting chemical compounds called chlorinated triclosan derivatives, created when triclosan is exposed to chlorine during wastewater disinfection processes.
When exposed to sunlight both triclosan and its chlorinated derivatives form dioxins that have potential toxic effects in the environment, they said.
Triclosan is added to many consumer products including soaps and body washes, toothpastes, cosmetics, clothing, dish washing liquid and kitchenware.
"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," university engineering Professor William Arnold said. "Consumers need to know that they may be using products with triclosan. People should read product labels to understand what they are buying."
The U.S. Food and Drug Administration has found no evidence triclosan in anti-bacterial soaps and body washes provide any benefit over washing with regular soap and water.