In recent years, there has been a small bit of backlash against the ubiquitous use of antibacterial soaps. Indeed, research beginning in 2002 has continued to confirm that based on both effectiveness and potential negative side effects, there really is no reason to use these soaps and plenty of reasons not to.
The active antibacterial agent in question is triclosan. The only real question that can result from numerous scientific studies about triclosan is whether or not its potential negatives are strong enough to stop using it. (Indeed, the only piece (opinion) questioning the validity of the research showing both potential resistance problems and toxic byproducts of triclosan (Swofford, 2005) was written by a member of the soap industry.) However, given unambiguous results showing that soap containing triclosan is indistinguishable in its effectiveness against bacteria as regular soap (and, frankly, given that most illnesses most household users of antibacterial soaps are concerned about are actually caused by viruses, which do not respond to antibacterials) any potentially negative side-effects of its use should be unacceptable.
Here is the problem. Humans are dumping all kinds of chemicals into our (and other organisms’) water supply, that are not removed during sewage treatment (even when the water properly goes through sewage treatment). Among these is triclosan (Gomez et al., 2007), which has been found in large proportions of human urinary samples (Calafat et al., 2008). Not only do we know nothing about how ingesting all these various chemicals may be affecting us over the long term, we cannot begin to know the complex ways in which they are interacting with each other to create new, and potentially more toxic compounds. Both laboratory (DeLorenzo et al., 2008) and field research (Kinney et al., 2008) suggests that triclosan bioaccumulates, which means its concentration could increase up the food chain (the same phenomenon responsible for the crash of bald eagle populations a few decades ago, due to DDT). Other laboratory studies suggest that it reacts with light and chlorine (ubiquitous in our drinking water) to form types of dioxin, a toxic compound (Sanchez-Prado et al., 2006). These studies are just scratching the surface of potential interactions between triclosan and other ubiquitous pharmaceuticals such as painkillers and sex hormones from birth control. Laboratory studies have also demonstrated that bacteria such as E coli and Salmonella can become resistant to triclosan (Yazdankhah et al., 2006).
Proponents of antibacterial soaps claim that none of these studies have shown that toxicity is common in the field, and resistance also has only been shown in the laboratory. So, let’s get this straight: we should continue to use this completely useless agent, because research has not yet shown that it is definitely harmful in the short term. Brilliant reasoning. The abstract of a recent review paper sums up the state of our knowledge quite nicely:
Abstract (Aiello et al., 2007)
Background. Much has been written recently about the potential hazards versus benefits of antibacterial (biocide)-containing soaps. The purpose of this systematic literature review was to assess the studies that have examined the efficacy of products containing triclosan, compared with that of plain soap, in the community setting, as well as to evaluate findings that address potential hazards of this use-namely, the emergence of antibiotic-resistant bacteria. Methods. The PubMed database was searched for English-language articles, using relevant keyword combinations for articles published between 1980 and 2006. Twenty-seven studies were eventually identified as being relevant to the review. Results. Soaps containing triclosan within the range of concentrations commonly used in the community setting (0.1%-0.45% wt/vol) were no more effective than plain soap at preventing infectious illness symptoms and reducing bacterial levels on the hands. Several laboratory studies demonstrated evidence of triclosan-adapted cross-resistance to antibiotics among different species of bacteria. Conclusions. The lack of an additional health benefit associated with the use of triclosan-containing consumer soaps over regular soap, coupled with laboratory data demonstrating a potential risk of selecting for drug resistance, warrants further evaluation by governmental regulators regarding antibacterial product claims and advertising. Further studies of this issue are encouraged.
If the only weapon we have to stop this idiotic dumping of even a potentially harmful chemical into our water systems and environment is consumer demand, then let’s use it. Stop using anti-bacterial soaps now, and maybe the fools producing them will stop, because it is no longer profitable.
Aiello, A.E., Larson, E.L. & Levy, S.B. (2007) Consumer antibacterial soaps: Effective or just risky? Clinical Infectious Diseases, 45:S137-S147.
Calafat, A.M., Ye, X., Wong, L.Y., Reidy, J.A. & Needham, L.L. (2008) Urinary concentrations of Triclosan in the US population: 2003-2004. Environmental Health Perspectives, 116:303-307.
DeLorenzo, M.E., Keller, J.M., Arthur, C.D., Finnegan, M.C., Harper, H.E., Winder, V.L. & Zdankiewicz, D.L. (2008) Toxicity of the antimicrobial compound triclosan and formation of the metabolite methyl-triclosan in estuarine systems. Environmental Toxicology, 23:224-232.
Gomez, M.J., Bueno, M.J.M., Lacorte, S., Fernandez-Alba, A.R. & Aguera, A. (2007) Pilot survey monitoring pharmaceuticals and related compounds in a sewage treatment plant located on the Mediterranean coast. Chemosphere, 66:993-1002.
Kinney, C.A., Furlong, E.T., Kolpin, D.W., Burkhardt, M.R., Zaugg, S.D., Werner, S.L., Bossio, J.P. & Benotti, M.J. (2008) Bioaccumulation of pharmaceuticals and other anthropogenic waste indicators in earthworms from agricultural soil amended with biosolid or swine manure. Environmental Science & Technology, 42:1863-1870.
Sanchez-Prado, L., Llompart, M., Lores, M., Fernandez-Alvarez, M., Garcia-Jares, C. & Cela, R. (2006) Further research on the photo-SPME of triclosan. Analytical And Bioanalytical Chemistry, 384:1548-1557.
Swofford, W. (2005) Triclosan research misreported? Environmental Science & Technology, 39:271A-272A.
Yazdankhah, S.P., Scheie, A.A., Hoiby, E.A., Lunestad, B.T., Heir, E., Fotland, T.O., Naterstad, K. & Kruse, H. (2006) Triclosan and antimicrobial resistance in bacteria: An overview. Microbial Drug Resistance-Mechanisms Epidemiology and Disease, 12:83-90.