Articles by Fawn Pattison

Following the path of contaminants from your bathroom to the birds

This is a story about sludge, worms, and songbirds, and it starts in your bathroom cabinet.

When we treat our wastewater to remove "biosolids" -- a polite term for our human waste -- all sorts of other things end up in the leftover sludge, including the drugs we take and the "personal care products" like lotion, shampoo, makeup, and cologne that we slather on our bodies, which have been absorbed through our skin and then excreted in our waste. The treated wastewater is usually discharged into the local river, and the sludge that's been removed from it frequently becomes fertilizer for agricultural production.

Researchers at the U.S. Geological Survey have found that the hungry earthworms who feed on this sludge in farm fields contain concentrated levels of our drugs and personal care products in their bodies. In fact, a USGS study published in February found that the compounds bioaccumulate in earthworms, meaning that the worms bear higher levels of these pollutants than the surrounding soil does. The USGS researchers note that worms could become monitoring species to help us determine the relative pollution levels in soil, but state that the pollution in these worms have "unknown effects" for wildlife (read the story in Science News).

"Unknown" maybe in that particular study, but researchers in the U.K. published a disturbing study about a week later that provides some insight into what happens to the polluted worms: Birds eat them.