Sunday, December 6, 2009

Hey, what's in that toothpaste?

If gingivitis is a word that strikes fear in your heart, you are problably gurgling a mouthful of a potent antimicrobial agent called triclosan. And, if you spit into the sink the juice that the toothpaste generates in your mouth, you are following directions, and saving yourself from an unnecessary and unhelpful dose of bactericide coursing through your body. But you are putting into the sewer system a chemical that is likewise unhelpful in the treatment of sewage. After all, conventional sewage treatment is completely reliant on a biologically healthy suite of microorganisms. Toothpaste is not the only source of triclosan, as it is present in many personal care products that are "anti-bacterial" but not from alcohol. Triclosan is related to another popular antimicrobial compound, trichlocarban, which has also been fingered as an endocrine disrupting compound, popularized in environmental literature for feminization of fish.

The irony is that a broad consensus among microbiologists and public health officials is that the wide use of antimicrobial chemicals does not reduce spread of illness and may, in fact, be hastening the evolution of resistance to such chemicals in the microbial community.

The presence of antimicrobial compounds in sewage has two concerns. These compounds can concentrate in the wastewater solids and reach levels in the 10 to 100 parts per million concentration. This level may be high enough to suppress the effectiveness of bacterial processes in wastewater treatment. Secondly, because many wastewater solids, aka biosolids, are land-applied, the antimicrobial compounds are introduced the bacterial rich soil environment. There impact there, while not believed very major, has not yet been fully studied.

The bottom line for me is that use of antimicrobial compounds in widely used consumer products should be greatly reduced. This is a marketing gimmick with benefits that do not come close to offsetting the potential risks to the environment.