MINNEAPOLIS - An ingredient in anti-bacterial soaps could turn into a pollutant when exposed to sunlight, according to a new study.

Researchers at the University of Minnesota found when triclosan in water was exposed to sunlight, it converted into a dioxin.

The study is published in the Journal of Photochemistry and Photobiology.

Dioxins are a group of chemicals that have been linked to a variety of health problems from respiratory to neurological effects. They do not degrade over time and can accumulate in body tissues, causing a larger effect over time.

Anti-bacterial products have become increasingly popular, from soaps to lotions to cleaning products.

The scientists say when tricolosan is first exposed it becomes a mildly toxic chemical. The problem occurs when it becomes treated with chlorine at water treatment plants, it then breaks down to something even more potent.

"Exposure to chlorine could chlorinate triclosan," explains Dr. Kristopher McNeill, one of the lead researchers. "After chlorinated triclosan is discharged, sunlight could convert it into more toxic dioxins."

Researchers say even low levels of this highly toxic chemical would become a problem because of its tendency to accumulate through the foodchain.