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.

Monday, November 2, 2009

Capturing the gas!

Global climate change, greenhouse gases, cap-and-trade... these topics are reported daily on the media.
The serious business of managing emissions of climate-altering gases has hardly begun moving. The enormity of the task, as the 350 rallies on 10/24 highlighted, is almost enough to paralyze citizens and the politicians who represent them. We don't know where to start.
So, let's start with the most basic... the FOOD WE EAT.
Our bodies are "digesters," as we exhale we give off CO2, a byproduct of assimilating food, and as we emit flatulence, we give off CH4, methane.
This is no different that the function of the compost pile, the oft-cited methane from cow farts, and the escaped gases from landfills.
While we have little control over bodily functions, we can take responsibility for the manner in which organic waste is handled. Putting organic waste into tanks in the absence of oxygen compels decomposition by microorganism along reducing, as opposed to oxidizing, pathways. A "reduced" carbon originating from microbial decomposition of carbohydrate is methane gas. Methane is "natural gas," and can be stored and transported for use in heating and electrical generation. The "oxidation" of methane is the blue flame on the stove, but it can also be the fuel for hot water heater, furnaces, and for running engine generators for electricity.
So, let's reduce reliance on fossil natural gas sources by delivering our food and body wastes to anaerobic digesters for recovery of methane biogas.