Your revisit of last October's toxic sludge disaster in Hungary is reassuring in many respects (see http://go.nature.com/nhpboi). The Hungarian government is taking further steps to avert future ecological effects of the disaster.

The 800-hectare spill from an alumina factory was highly alkaline, leading to fears that arsenic and metals such as mercury and chromium could have leached into the soil and polluted the underlying water table after heavy rainfall.

Prompt governmental measures reduced the pH from 12 to 8–8.3 and rescued the River Danube's Torna creek. The government is also removing the top 15–18 centimetres of soil at the accident site. It hopes to grow a bioremediating forest of Pteris vittata, a fern that hyperaccumulates arsenic, to help restore soil conditions and revive the former flora and fauna.