Study Finds That Antibacterial Enhances Endocrine Disruption

(Beyond Pesticides, January 9, 2008)

Triclocarban, an antibacterial compound widely used as an additive to a range of household and personal care products including bar soaps, detergents, body washes, cleansing lotions, and wipes, has been found to have an amplification effect on the activity of natural hormones, which in turn can lead to adverse reproductive and developmental effects.

In the study, published online November 29, 2007 in Endocrinology, researchers from University of California- Davis and Yale University investigated the endocrine disrupting properties of triclocarban and other polychlorinated diphenyl urea compounds by exposing human cells and rats to levels similar to those found in people. Triclocarban was found to have a synergistic interaction with the sex hormone, testosterone- present in both males and females. This interaction produced a positive, amplified biological effect, which is likely to hyperstimulate native sex hormones. This amplification of sex hormone activity occurs at the target cell and can result in developmental defects or decreased reproductive function. Researchers further explained that ovulation and ovarian function in females can be disrupted, while sperm quality can be decreased in males.

The researchers also point out that the results of their study create a new category for endocrine disruptive substances to include “hormone amplifiers or enhancers” rather than simple agonists or antagonists in order to accommodate the synergistic property demonstrated by triclocarban. They also note that since triclocarban has the potential to amplify synthetic compounds, further investigation into its interaction with oral contraceptives and hormone replacement therapy is needed.

Triclocarban, like its cousin triclosan, has been linked to numerous health and environmental effects. When disposed into residential drains and carried to streams and rivers, it kills beneficial organisms in soil and water. Both of these chemicals have been found in breast milk and fish. Triclocarban, along with triclosan, survives treatment at sewage plants and most ends up in waterways and sludge spread on agricultural fields, and may end up on produce. Researchers at the John’s Hopkins Bloomberg School of Public Health found that triclocarban was the fifth most frequent contaminant among 96 pharmaceuticals, personal care products and organic wastewater contaminants evaluated and that levels of triclocarban in water resources nationwide are much higher than previously thought.

In 2005, the U.S. Food and Drug Administration led a panel of experts and industry representatives to weigh and analyze different germ killing methods. The panel found “no firm scientific evidence that the flood of antimicrobial products we observe has any discernible benefit over the use of regular soap and water.”

TAKE ACTION: You can stay healthy and put pressure on manufacturers to phase out antibacterials by not using products with triclosan or triclocarban. Stay hygienic the most effective way, by using plain soap and water.

Source: Environmental Science and