February 21, 2011

Antibacterial soap: Poses environmental health risks, doesn’t clean any better

Center for a Livable Future

Center for a Livable Future

To protect yourself from harmful germs wash your hands, for at least 20 seconds, with plain old soap and water.

That simple advice might be the take-away message from last week’s Food and Water Watch-sponsored congressional briefing on triclosan, an antibacterial agent found in hundreds of antibacterial soaps and other personal products from toothpaste to cosmetics to deodorant.

Food and Water Watch wants the Environmental Protection Agency and the Food and Drug Administration to ban triclosan, citing its ubiquity in the human body and discharge into the environment.   In 2008, CDC data identified triclosan in the urine of 75 percent of the population, of concern because animal studies have found triclosan can act as an endocrine disruptor.   Endocrine disruptors are chemicals that can interfere with hormone functions, and can result in adverse developmental, reproductive, neurological or immune effects. When triclosan breaks down, it can turn into dioxins, which are known carcinogens. The health risks from triclosan need to be better characterized for humans, although there likely exists enough evidence for federal agencies to consider banning it from consumer products.

triclosan_022011_1087According to some environmental and health experts, the use of antibacterial soaps containing triclosan is overkill in most non-medical uses, and there may be negative consequences as the compound makes its way through our bodies and into the environment.

“Consumers have an appetite for antibacterial soap regardless of whether or not there is an indication for it,” said Dr. Larry Weiss, the chief technology officer at natural soap company CleanWell, and a physician and expert on natural chemistry and epidemiology.  “We need to think more about when it makes sense to use an antimicrobial and when it doesn’t.”

Triclosan in Hand Soap

“We have a lot of bacteria on our hands” said Dr. Allison Aiello, Associate Professor of Epidemiology at the University of Michigan School of Public Health, and they fall into two groups: transient bacteria- which include human pathogens- and resident bacteria that stay with us all of our lives and keep our skin healthy.  The purpose of hand soap is to remove potentially harmful transient bacteria, while not completely wiping out beneficial resident bacteria.

Aiello insists there is “no data to support the [greater] effectiveness of antibacterial soap products containing triclosan, compared to plain soap.”   The effectiveness Aiello refers to is both microbial removal from hands and for the prevention of respiratory and gastrointestinal diseases related to hand hygiene.

Aiello noted that “handwashing is rarely practiced at recommended levels in the community,” which in practical terms means that handwashing for one or two seconds with antibacterial soap is just as ineffective as handwashing with plain soap.

“Hygiene is not a technology problem; it’s a human behavior problem” said Weiss. “You can throw the technology at the masses, but it doesn’t solve the underlying problem.”  To improve hand hygiene, CDC recommends washing for at least 20 seconds with soap and water, regardless of the type of soap.

Triclosan- from our homes into the environment

So what happens to triclosan in antibacterial soap after we wash our hands?  Dr. Peter Vikesland, Associate Professor in the Department of Civil and Environmental Engineering at Virginia Tech asserts, “96 percent [of triclosan] goes down the drains” and is sent to waste water treatment plants (WWTPs) or septic systems.   Once in WWTPs, most triclosan is collected sewage sludge, with only about 2 percent of triclosan passing through the plant and discharged into waterways.

This small fraction of triclosan discharged into waterway may not sound like much, but consider the amount of personal care products we use every day and it adds up. In the United States “58 percent of surface waters and rivers have detectable concentrations of triclosan,” states Dr. Rolf Halden, Associate Professor in the School of Sustainable Engineering and the Built Environment at the University of Arizona.

Studying sediment cores in waterways- analogous to growth rings on a tree-  allows scientists to trace the history of triclosan in the environment. Halden notes “the triclosan that our parents and grandparents used are still in the sediments,” dating back to the mid-to-late 1960s in sediment cores from the Chesapeake Bay (Miller et al., 2008). Triclosan was patented in 1964, which supports Halden’s findings.   Once in the environment, triclosan is toxic to algae, crustaceans, and fish at very low level-in the parts per billion and trillion range (Chalew and Halden 2009).

Back at the WWTP, Halden estimates that between 179 and 223 tons per year of triclosan and triclocarban-a cousin of triclosan- are collected in sewage sludge across the US (McClellan and Halden 2010). Halden’s work, supported by the Johns Hopkins Center for a Livable Future, indicates that triclosan’s half-life is 6 months or more when land-applied with sewage sludge to agricultural soils (Walters and Halden 2010).  Triclosan accumulates in worms in these soils, (Higgens et al., 2010) suggesting that triclosan might also be absorbed in the skin of farmers who use sewage sludge as fertilizer, or others who come in contact with the sludge.  Triclosan and triclocarban accumulates in crops, such as soybeans, grown in sewage sludge amended soils (Wu et al., 2010).

Consumer advocates push for ban

At last week’s briefing – hosted by U.S. Representatives Betty McCollum (D-MN) and Louise Slaughter (D-NY), who is a microbiologist with a MPH degree – environmental groups, industry, and federal regulators came together to discuss the status of the science on triclosan and consumer advocates’ efforts to ban the antibacterial for non-medical uses.

Food and Water Watch and Beyond Pesticides have separately petitioned the Environmental Protection Agency, which oversees some (mostly industrial) uses of triclosan, and the Food and Drug Administration, which regulates consumer uses of the antibacterial, such as in soaps.  The groups cite statutes covering pesticides, food and drugs, clean water, safe drinking water and endangered species.

The FDA is currently reviewing the evidence, and is expected to release their findings in Spring 2011.  In response to a letter from Rep. Edward Markey last year, the FDA said “existing data does raise valid concerns about the health effects of repetitive daily human exposure to these antiseptic ingredients.”

According to the EPA, the agency is coordinating with FDA on studying the potential health effects of triclosan, and may update its human health risk assessment and regulatory decision-making if the science supports a change.

The future of triclosan

Consumers’ right to choose products without triclosan is severely limited. Many personal care products that contain triclosan are not labeled as such, and only when triclosan is used as an active ingredient- such as in Colgate Total toothpaste- or for product claims in antibacterial soap are products accurately labeled.   A search of the database of the Environmental Working Group’s Skin Deep cosmetics database identified 459 products containing triclosan.

Along with product labeling, the human health and environmental concerns continue to fuel what Wenonah Hauter, the executive director of Food and Water Watch calls the “growing movement against the use of triclosan.”

Based on science presented at the hearing Halden raises the question: “Do we have the right to pollute the entire environment?  … I think we need to reconsider what we are doing.”

Fortunately some companies are beginning to listen, and are phasing out use of triclosan in products such as antibacterial cutting boards and reusable lunch bags.  Now the hope is that federal regulators will take advantage of the recent petitions to ban triclosan as an opportunity to write the final chapter on its use.

– Patti Truant and Dave Love

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