article: Nearly 500 Chinese children are reported to have developed dermatitis, blood abnormalities, leukaemia and lymphoma thought to be a result of air, soil and water toxins at their new school. There is widespread media anger, with news outlets prominently reporting that children are experiencing "serious health problems" in Changzhou, Jiangsu province. The news has triggered a social media campaign calling for local authorities to be made answerable. Tens of thousands of social media users are discussing the incident, asking why earlier campaigns went ignored. It is not the first time that people have taken to social media in large numbers over toxins endangering children's health in the city in eastern China. 'Take notice' On 17 April, China's national state broadcaster China Central Television (CCTV) reported that nearly five out of six pupils at Changzhou Foreign Language School who underwent medical checks had health problems. Its primetime news bulletin contained interviews with parents saying that they have been complaining for months. CCTV posted the report on its Sina Weibo platform, which instantly received tens of thousands of shares, and comments from users calling for "relevant departments to take notice". By 18 April, the story had gone viral on social media. It has been the most discussed topic in the past 24 hours, with more than 90,000 Weibo users actively using the hashtag #ContaminatedSchools. Users of the microblog say this is not the first time that health and safety in schools within the city have been a viral talking point. Lujia Cangcang shared a map of the area highlighting that other schools had also been affected. "Do not just focus on the private schools, there are public schools affected too," she said. Her post received more than 100 likes. Yin Yihao adds: "If I remember correctly, this incident was exposed a year ago, but from start to finish was not given huge exposure [and] was repressed locally." Social media users have sparked angry online campaigns about hazardous toxins in Changzhou schools before. In October, thousands of Weibo users set the hashtag #PoisonousTrack trending. According to Sina Jiangsu, a number of parents at schools citywide said that their children had had nosebleeds and dizziness after a new school running track was built using plastic. It added that the "poorly constructed" track may have contained toxic toluene, xylene, lead salt and "maybe even toxic plasticisers". It also appeared that the incident was not limited to Changzhou. In an online poll of more than 800 users, more than 60% said that a "large, choking" smell was coming from plastic running tracks. Some social media users at the time called on supervisors and regulators to reveal safety reports so that users could determine whether this was part of a wider "fraudulent enterprise". BBC Monitoring reports and analyses news from TV, radio, web and print media around the world. You can follow BBC Monitoring on Twitter and Facebook.
summary: The Chinese authorities are investigating reports that hundreds of children have become sick after their new school opened next to a former industrial site.