Nearly 500 students have reportedly been diagnosed with health problems ranging from dermatitis to leukemia since the Changzhou Foreign Languages School in East China's Jiangsu province moved to its current campus in September.

The students' families claim this is due to seriously polluted plots of land across the road, citing a test report that says the concentrations of chlorobenzene in the underground water and soil at the former sites of chemical plants were respectively 95,000 times and 79,000 times above safe levels.

A news release from the Changzhou government reported by Xinhua News Agency on Monday insisted the site had passed an environmental evaluation and was safe, and the school is in normal order with only several students on sick leave. The local environmental protection agency says their tests of the campus found nothing unusual.