Triclosan is a compound found in sanitizers and cleaning supplies often used in gyms, hospitals, and other public places. The researchers noted a pattern of increasing resistance in places with high triclosan levels, suggesting that gym equipment and yoga mats exposed regularly to this chemical could serve as breeding grounds for microbes that cause drug-resistant infections.
Triclosan is a chemical designed to prevent bacterial contamination. Along with a related chemical called triclocarban, triclosan used to be an ingredient added to personal care products, such as toothpastes, soaps, and cosmetics. However, in 2016, the U.S. Food and Drug Administration (FDA) decided to ban the use of triclosan and triclocarban in antiseptic washes due to some concerns about their efficacy and safety.
Triclosan in toothpastes has substantial basis. In 1997, the FDA declared that triclosan in Colgate Total toothpaste can effectively prevent gingivitis. However, evidence that could justify its use in other over-the-counter products, particularly antiseptics, was lacking. The FDA did not find sufficient proof that triclosan can provide other benefits to human health until its ban in 2016.
On the other hand, short-term studies on animals indicate that triclosan may be associated with a decrease in the production of thyroid hormones. Some studies even suggest that triclosan can aid cancer development by acting as a tumor promoter. Moreover, others raised the possibility that triclosan may actually contribute to antibiotic-resistance shown by some bacteria.
To determine the relationship between antimicrobials and indoor microbial communities, researchers from Northwestern University in Illinois and the University of Oregon collected dust samples from different athletic facilities, such as private fitness clubs; public recreation centers; and dance, yoga, and martial arts studios. They conducted different tests on these samples to confirm the presence and quantity of antimicrobials, to assess the conduciveness of the samples to microbial growth, and to gather genetic material that can identify the microorganisms present.
The researchers discovered that gyms and public places with a lot of moisture have the highest concentrations of antimicrobials in their dust. Places with rubber mats and carpeted floors also contained high levels of these chemicals. While another chemical called methylparaben was the most common antimicrobial they identified, the researchers associated triclosan and triclocarban with the highest abundance of antibiotic-resistant microbes.
Additionally, the researchers noted that the resistance of microbes in dust increased as triclosan levels in their environment went up. The 11 athletic facilities with the highest amount of antibiotic-resistance microbes also had three times higher triclosan levels than all the other facilities combined. Fortunately, these drug-resistant microorganisms proved to be benign, so there's no need to quit the gym or throw away your yoga mats just yet.
Despite the association between triclosan and the number of drug-resistant microbes in gym dust, concrete proof is needed before this antimicrobial can truly be blamed for the development of antibiotic resistance. Erica Hartmann, an environmental engineer and co-author of the study, believes that there are many theories as to how and what causes microorganisms to develop resistance, and each of these theories need to be thoroughly investigated first before any conclusions can be made.
If you're a frequent gym-goer, don't worry about continuing your routine. Just avoid using triclosan-containing products like the cleaning sprays available at gyms. Check with an attendant first if you really need to use them. When cleaning your hands, settle for plain soap and water instead of hand sanitizers. The ban on triclosan use doesn't include these products. Additionally, the FDA is yet to find evidence that antimicrobial soaps with triclosan work better than regular soap and water.