BEIJING, China (AP) — China’s central government said Monday it will investigate a report that close to 500 students became sick with illnesses including cancer at a school built near recently shut chemical plants in eastern China.

State broadcaster CCTV said in a report Sunday that high concentrations of some toxic chemicals may have caused cases of lymphoma and leukemia among students at the Foreign Languages School in the city of Changzhou, about 170 kilometers (105 miles) northwest of Shanghai.

The Education Ministry said Monday it has sent a team to investigate, while local officials in Jiangsu province said they will re-examine the issue after initially denying any soil quality issues in interviews with CCTV. The broadcaster said school and local officials may have only tested the site for common pollutants but overlooked chemicals and heavy metals involved in pesticide manufacturing next to the school site.

The ministry “attaches the greatest importance” to the reported problems and is committed to “safeguarding students’ physical and mental wellbeing,” the ministry said on its official microblog.

China has been wracked by public health scares, and countless Chinese took to social media again this week to fume about a case that touched a particularly sensitive subject: children. Last week, hundreds of officials across the country were punished over the sale of faulty children’s vaccines.

The case also underscored the severity of China’s groundwater pollution — an issue overshadowed by the country’s notorious air quality problems — just one week after the Ministry of Water Resources published findings showing that more than 80 percent of water in shallow groundwater wells in China is unfit for human consumption.

The Changzhou school with more than 2,000 students is adjacent to sites once occupied by Changlong, a chemical company that was previously fined by provincial regulators for environmental violations.

CCTV’s investigative segment quoted a whistleblower who said workers dumped or buried chemical waste and many employees had contracted skin diseases themselves. One environmental assessment of soil at the site found levels of the toxic chemical chlorobenzene of nearly 95,000 times the national limit, while in another instance, testing was still ongoing as construction of the school began, resulting in “in a classic case of ‘build first, assess later,'” CCTV said.

In an apparent effort to pre-empt the report, the school published on its website late Friday the results of two environmental assessments in March showing that the campus met environmental standards.

A statement on the Changzhou city government website also said separate tests conducted last month at the behest of the school and parents showed indoor air quality, soil and groundwater were all up to national standards.

Of the school’s 2,451 students, all were in classes except for one on leave, four out sick and five in the process of transferring to a different school. Of 210 teachers, all but three were in school, the statement said.

“We welcome supervision from the media and all walks of life. We will look into the relevant issues raised in the report … and will make all information available to the public,” the statement said.