Triclosan is a common ingredient in many personal care products such as antibacterial soap. But what are the long-term effects of using it?
It’s that time again, when kids say goodbye to summer fun and head back to the classroom. Kids may moan and groan, but many of them secretly look forward to seeing their friends and being exposed to interesting new experiences—unfortunately, new experiences won’t be all they’re exposed to.
Along with fun field trips and new friends, kids will be exposed to some less pleasant realities such as bacteria and viruses. These, as we all know through the recent H1N1 epidemic, can be exponentially more malicious than a schoolyard bully and perhaps just as persistent.
To combat these bacterial and viral bad guys, a plethora of antibacterial soaps and disinfectants have been introduced, containing a host of unpronounceable active ingredients that claim to help destroy these invaders.
Triclosan to the rescue
Triclosan is one such ingredient that has been used for decades in products including toothpastes, soaps, kitchen utensils, and even toys. While the name is not as difficult to pronounce as others of its kind, the actual effects of this ingredient on our bodies and the environment are much less straightforward.
Past studies on triclosan found it effective in eliminating certain germs; but more recent research illustrates the paradoxical nature of this substance’s approach to dealing with bacteria and viruses.
How triclosan works
Triclosan has the effect of inhibiting the synthesis of fatty acids in the cells of infecting bacteria (organisms comprised of single cells). Fatty acid synthesis is an integral mechanism of cell reproduction, thus its disruption by triclosan causes bacteria to cease reproduction. But it does not kill the bacteria. Nor does it kill viruses.
Triclosan and bacteria
In hospitals and health care facilities, triclosan has indeed proven effective in neutralizing certain harmful bacteria. However, a 2005 study published in the Journal of Antimicrobial Chemotherapy, which examined the interactions of triclosan on bacteria, questioned its use as a household antimicrobial agent. This was because the effectiveness of triclosan was found to be restricted to strict protocols involving triclosan concentrations, water temperature, and, most importantly, length of exposure.
How, in non-lab environments, can we be certain of triclosan’s inherent effectiveness? The problem is that the effectiveness of triclosan in neutralizing bacteria is restricted to prolonged contact—minutes as opposed to the seconds that most people engage in handwashing.
Some bacteria are very susceptible to triclosan; however, naturally resistant bacterial strains such as E. coli require increased amounts of the ingredient to inhibit the spread of these bacteria and are even able to build low-level resistance.
The method by which E. coli bacteria gains limited resistance to triclosan is through cross-resistance from other antibiotics, which provides certain defences against triclosan. There are no studies at this time to show triclosan leads to direct resistance, but this cross-resistance may mean that triclosan exposure could lead to bacterial mutations against other antibiotics.
Triclosan and viruses
Bacteria and viruses are often thought of as one and the same, but there are more than a few significant differences. The most noteworthy is that viruses, unlike bacteria, do not contain cells. They require host cells to pass on infection.
The common cold and flu are well-known forms of viruses. As mentioned earlier, the effect of triclosan is to stop fatty acid synthesis in cells, but how does this help when there is no cell? As you might guess, it doesn’t.
Multiple studies have shown that physically washing your hands with non-antimicrobial soap or even warm tap water by itself are more effective than triclosan in battling non-enveloped viral contaminations.
Instead of just focusing on the efficacy of triclosan, more recent publicity has brought widespread attention to the potential side effects it can have on our bodies and our environment—both intimately connected.
Triclosan and our bodies
Because chemicals can have unanticipated consequences, it is important for us to consider how the accumulation of this ubiquitous ingredient can affect our bodies.
In blood and breast milk
A 2006 study found triclosan in the breast milk and blood plasma of Swedish mothers who use personal products containing the substance. A more recent Australian study (2008) found “the triclosan concentrations were a factor of two higher in the blood serum of Australians” (both male and female) than the participants in the study in Sweden, where the researchers concluded “the use of triclosan is expected to be low due to consumer advisories.”
In our personal care products
Researchers and regulators have been studying the chemical effect that triclosan-containing personal care products (toothpaste, hand soaps, deodorants) creates when exposed to the chlorine in most of our tap water. The chemical reaction creates chloroform, a known carcinogen.
Researchers estimate that under some conditions the use of triclosan can increase a person’s annual exposure to chloroform by as much as 40 percent above background levels in tap water.
Alcohol-based hand sanitizers are different from antibacterial soaps: they do not contain triclosan, but rely on at least 70 percent alcohol to kill bacteria (by disrupting its cell membrane) and viruses (by disrupting the virus’s outer coat). Although it’s effective, health authorities still caution that good handwashing techniques using regular soap and water do a superior job.
Triclosan and our environment
Since triclosan was first added to commercial liquid hand soaps in 1987 the percentage of those products containing triclosan has increased to at least 76 percent. And what happens to this soap once we’ve used it? Of course, it goes down the drain ... and into our sewage system ... and eventually into our waterways and soil.
A multitude of studies in several countries have proven wastewater treatment plants to be ineffective in completely removing triclosan. A very recent study done in January analyzed sediment from a wastewater effluent area in the Mississippi River and discovered the chemical reaction resulting from chlorine in the treatment plant produces several forms of dioxins.
The researchers found that these triclosan-derived dioxins had increased over the past 30 years by 200 to 300 percent, though levels of all the other dioxins had dropped 73 to
90 percent. The problem with these new triclosan-derived dioxins is that we don’t yet know what their long-term effects will be to our environment and, ultimately, to ourselves.
In agricultural fertilizer
The byproducts of water treatment plants (called biosolids) are often applied as fertilizer on agricultural fields. Many studies have found high concentrations of triclosan in this treated sewage sludge and subsequently remediated agricultural soil. And, according to the Canadian Water and Wastewater Association, approximately 50 percent of biosolids are being recycled to land.
In aquatic life
As you can imagine, triclosan has also been found in aquatic life, from wild Atlantic bottlenose dolphins to frogs.
Toxicologists are particularly concerned about triclosan because of its structural similarity to thyroid hormones, which play a crucial role in early human development. A recent study from the University of Victoria (UVic) has shown that triclosan can alter the metamorphosis of a frog by influencing its thyroid hormone production.
“Thyroid hormones and the mechanisms by which they affect cells are highly conserved from frog to mammal,” says Dr. Caren Helbing, a UVic molecular biologist. “It’s highly likely that what affects frogs could affect mammals, even humans.”
Are we too clean?
With the power of marketing, we’ve become a germ-averse society. Researchers are concerned about our overuse of antimicrobials, including triclosan. A 2010 study by researchers at Northwestern University in Illinois concluded that exposure during early childhood to microbials can reduce the inflammatory processes related to diseases associated with aging in adulthood.
If we truly care for our kids and their health, as well as the health of the planet, we may just want to think twice about our need for “clean.”
—Source: Health Canada