Lumber waste is helping to clean up rivers and industrial effluents, removing heavy metals like chromium and lead, according to a study by the University of Brasilia. The process is simple and quick, placing sawdust inside filters or in water reservoirs, according to the study's author, August Hosanna.

In tests, the sawdust removed 2.7 milligrams of lead per liter of wastewater from car battery factory, and 2.06 milligrams of chromium per liter of runoff from a leather factory.

The results are not always equal. “The quantity depends on the type of metal and on the wood,” Hosanna told Tierramérica. He used sawdust from illegally logged wood that had been seized by authorities and donated to the project.

The technique can be applied in the automotive industry and to factories of paints and dyes. Its effectiveness will be tested on a large scale at a sanitation company in Brasilia.