Soil Needs Decades to Recover from a Spill

ScienceDaily (Dec. 8, 2010) — Twelve years after the spillage at Aznalcóllar (Spain), a team led by the National Museum of Natural Science (NMNS-Spanish National Research Council) states that the soil affected has recovered “reasonably well.” Their study of nematodes (microscopic soil worms that are indicators of the biological state of soil) confirmed the “enormous” impact of heavy metals and is useful for predicting the effect of the red mud spillage in Hungary.

One month ago, a spillage of red mud with toxic material from the aluminium holding pond in the city of Kolontar devastated the west of Budapest (Hungary) and reached the Danube. The immediate consequences were the loss of ten human lives and the destruction of houses and crops. In Spain, the Aznalcóllar spillage in 1998 affected species in the soil in Doñana including killing several species. Some nematodes disappeared in the first few months after the disaster.

“The abundance and diversity of these animals was affected immediately, but in the long term, the nematodes themselves did not suffer any irreparable damage,” the main author of the study and researcher at the NMNS (SNRC) in Madrid Alfonso Navas said.

The study, published recently in Nematropica, compared samples from the unpolluted and polluted areas. According to the results, the diversity and maturity of nematodes was “significantly” lower in the polluted area than in the unpolluted area. “Nickel and Copper appear to be the most toxic metals for the nematode community,” Navas added.

“The issue is not whether or not the nematodes disappear, because that is impossible, but whether the nematode fauna, which plays a biological role and recycles organic matter, has suffered damage and also whether the soil has felt the effects of the spill,” the researcher specified. “It could take tens of years for the soil to recover,” the expert added.  read more