HOW WORMS RECYCLE MORE THAN SOIL

In Business, Jul/Aug 2007

The Spring 2007 issue of Terrain has an article by Lisa Owens Viani about potential problems in earthworm tissues. Scientists have known that PPCPs - the Pharmaceuticals and Personal Care Products that make their way into wastewater - are not completely removed by sewage treatment plants. They also began examining whether the "pharma residue" might be present in biosolids. A U.S. Geological Survey team found that a mixture of household disinfectants, synthetics, etc. often are present in high concentrations. They then decided to collect earthworms from farm fields in the Midwest and western U.S. Notes Ed Furlong of the U.S. Geological Survey: "Earthworms aren't migratory - they're in the soil and reflect what's happening locally. We thought that if these compounds persist in the soil, the earthworm would be a good candidate to study."

Researchers detected 3 1 compounds, among them household disinfectant, caffeine and Prozac in the worms' tissues in concentrations ranging from 10Os to 100Os of micrograms per kilogram (parts per billion). Furlong considers these concentrations very low, but does think they need more research. "We're still coming up with questions," he says. "This is a way for people to recognize that their choices in what they use and what we as a society reflect in the waste stream - and end up in the watershed."