A Canadian research team has found an effective way to monitor the anti-polution work being done by soil microbes. Turns out the microbes prefer thelighter carbon 12 isotope over the heavier carbon 13. Tracking the shifting carbon isotope balance in contaminated soil is a good way to monitor the decontamination progress of microbes in soil laced with toxic hydrocarbons. Previous tracking methods could only tell if a specific site was more or less contaminated, not if the hydrocarbons were actually being biodegraded. Lower local contamination could occur if the toxics simply leached out into a nearby stream or migrated through the soil to another location. These man-made contaminants come from dry cleaning fluids, industrial solvents and by-products from our petroleum industries. Here's the full report on the EPA website. It's helpful the hydrocarbons can be converted in the soil that absorbs them, else they eventually end up in our water or the entire site has to be dug up and the dirt buried where it won't leach. What kind of nasty toxics do the little beasties convert for us? Try benzene, toluene, ethylbenzene, xylene, ethyl tertiary butyl ether, methyl tertiary butyl ether, and the ever-popular perchloroethylene. A tasy menu for devouring microbes.