Is Antibacterial Soap Bad For You? (Part 2)

by David on March 4, 2013

Last week, I introduced Triclosan, the most common active ingredient in antibacterial soaps, and explored some of the human health consequences of incorporating this compound into so many consumer products. From increasing antibiotic resistance to endocrine disruption, Triclosan has significant potential to cause human health problems. This week, we’ll look at some of the unexpected environmental effects that arise from rampant use of anti-bacterial soaps and personal care products: damaged ecosystems, drinking water contamination, and even an affected food supply. (The answer to the titular question is still yes, but now even more so!)

You know what would make this better? A butt-load of antibacterial soap.

Water, Water, Everywhere

Triclosan is one of the most common environmental contaminants in the developed world. And once it gets into lakes and streams, Triclosan can really mess up ecosystems by killing the plankton, cyanobacteria, and algae that form the foundation of aquatic food chains, and generally wreak havoc on ecologically-important microbial communities.

Oh, and also Triclosan can paralyze fish.

Yep, at concentrations as low as 0.52 micrograms per liter, Triclosan can interfere with the swimming ability of fathead minnows by inhibiting their ability to contract their muscles. As mentioned previously, Triclosan has been found to interfere with skeletal and cardiac muscle contraction in mice and human cell lines, too, so maybe it’s not a chemical that should be kicking around in the environment. Unfortunately, it’s kind of hard to get rid of quickly.

yeah, I caught this guy with nothing but patience and a bottle of Dawn

A Stubborn Contaminant

Wastewater treatment plants tend to be pretty good at getting Triclosan out of the water, or at least converting it into something else, but what it turns into and where it goes can be problematic. One of the breakdown products of Triclosan, 2,4-dichlorophenol, has been shown to be toxic to aquatic organisms and other breakdown products include dioxins. You may have heard of dioxins, because they are a group of some of the most persistent and toxic contaminants of the industrial age – well, a little sunlight and bad luck can convert Triclosan into one of those guys.

It’s not just any mud, it’s SPECIAL mud. It’s SCIENCE mud.

And it doesn’t just disappear, either. Regardless of what form it’s in, the Triclosan that is removed from the waste water has to go somewhere and it usually ends up in what is called “activated sludge.” Activated sludge is basically a type of mud that contains massive amounts of microbes which are responsible for turning our waste into compounds that are biologically useful. Around half of the Triclosan that goes down our collective drains ends up in the activated sludge where it can persist for hours to days. It can persist for even longer if the sludge is moved out of the plant and onto land somewhere.

Somewhere like, a farm, for example.

Remember when you didn’t have to worry about unknowningly eating antibacterial compounds? Good times. Good times.

Delicious, delicious Triclosan

In the United States, roughly 63% of the activated sludge used in waste water treatment plants is reused as fertilizer, meaning that Triclosan and its breakdown products may be coming into contact with human food crops. Even more alarming, recent studies have demonstrated that carrot, barley, and soybean crops are capable of absorbing Triclosan through their roots and distributing it to all parts of the plant – including the edible parts. Authors of the study on carrots and barley indicated that essentially all root vegetables are at particular risk for absorbing Triclosan and other undesirable contaminants.

I like to season my carrots with penicillin, too, because… Might as well?

There is hope, however, to avoid a Triclosan-infused future. A German research group found that environmental Triclosan levels dropped significantly following a general decrease in use of antibacterial soaps. This finding suggests that if we can kick our antibacterial obsession, if we can say no to advertisers and the allure of overpowered soap, we may live healthier Triclosan-free lives.