Reused paper can be polluted. (Environment).

Recycling isn't always as green as it seems. German engineers have discovered that toxic substances found in some paper products end up in bathroom tissue made by recycling that paper. When that product is flushed, the researchers say, the pollutants might harm fish and other wildlife.

Researchers at Dresden University of Technology in Pirna, Germany, realized that many thermal papers--like those used in cash registers and fax machines--incorporate bisphenol-A (BPA). If ingested, this chemical can mimic the activity of estrogen and related female sex hormones (SN: 7/3/93, p. 12). Figuring that people might throw thermal papers into their recycling bins, the Dresden engineers decided to look for BPA in recycled paper.

Dirk Vogel notes that his team detected sizeable quantities--up to 45 milligrams per kilogram of paper--in two of three brands of recycled bathroom tissue tested. They measured even higher concentrations of nonylphenol and nonylphenol ethoxylates, which are estrogenic pollutants that the engineers suspect derive from waste-paper processing.

Because such pollutants may also lace recycled paper towels, Vogel suggests that consumers resist composting such papers to prevent any pollutants they may carry from leaching into the soft.--J.R.