Media reports had said 500 students had suffered various illnesses, including cancer, since Changzhou Foreign Language School moved to new campus adjacent to a former chemical waste dump last year.
But the health department investigation found only 133 people with abnormal indicators including thyroid, lymphatic, hepatic or renal anomalies.
On Tuesday, a local health authority investigation team said checks on 597 people associated with the school had found no cases of leukemia. One case of lymphoma found occurred before the school relocated.
However, some parents claim that 493 students have suffer from dermatitis, eczema, bronchitis and reduced leucocyte counts.
Students also complain about a pungent odor on campus.
SOUNDBITE (CHINESE) Student
“The odor was strongest between Christmas and our winter vacation.”
SOUNDBITE (CHINESE) Student
“Very pungent, just like what you could smell when nearing a chemical plant.”
The campus is one street away from a plot of land that was home to three chemical plants until they were shut down in 2011.
The plot, equal in size to a dozen soccer fields, was scheduled to be rehabilitated after an appraisal in June last year, and was slated to be sold for commercial development after the soil was restored.
Head of the Changzhou environmental science institute Xu Puqing said the soil restoration should have been conducted under cover.
SOUNDBITE (CHINESE): XU PUQING, Head, Changzhou environmental science institute
“The soil restoration should have been done in a closed space. After the soil was dug out, the waste dumpt became a pollution source.”
But the contractor, Changzhou Heimudan Construction Investment, carried out the work in the open air.
SOUNDBITE (CHINESE): LI FEI, Changzhou Heimudan Construction Investment
“The soil restoration needs to be conducted in a closed way according to our initial plan. But we didn’t do it. Because the contaminated soil recycling company we work with didn’t have such risk requirements. They think it is ok to take the soil dug out directly.”
A strong pungent odor was noticeable in the area during the process and on Dec. 25, 2015 the company stopped the operation after complaints from the public.
The plot was then reassigned for public greening and communal facilities rather than commercial use.
The government adjusted the restoration plan and, in February, an assessment panel declared the restoration complete, assessing the air quality as meeting national standards.
Parents have observed that building work on the school began in October 2013, well before any environmental appraisal was made.
The ministries of environmental protection and education have sent teams to Changzhou to assist investigations and to ensure the pubic is fully informed.