China is to unroll a national survey to identify heavy metal hotspots, chemicals and other toxic pollutants as it tries to rectify its $1tn soil pollution blight.

After years of breakneck growth that skated over environmental concerns, the country is starting to recognise the toll on health, quality of life and agricultural productivity. Among the latest casualties, hundreds of students at an elite school in eastern China fell ill because of toxins from a former pesticide site adjacent to its new campus.

Chen Jining, environment minister, said the survey would kick off a long-awaited plan for tackling soil pollution, the results of which are expected in May. But geology experts caution that the sensitivity of the issue means it may not be published, noting that an earlier one in 2014 was initially classed a state secret.