Inochi no Chikyuu: Dioxin no Natsu

The anime follows a group of friends Giulia, Maria, Enrico, Lucio and Angelon during the disaster as they team up with a Japanese journalist Shiro Ando, and begin their own investigation of whats occurring (during the week long period of exposure when the ICMESA refused to notify citizens of the poison). As many animals are dying and people are getting sick. The children and Shiro discover deadly dioxin was released and inform Enricos father, the town mayor, who evacuates all the citizens. Shiro continues investigating more and learns of the negligence of La Roche, a company who controls ICMESA. La Roche knew they were in violating of existing safety laws/protocols and destroyed evidence of their crimes. The children attend a press conference to ruin La Roches reputation as the destroyed proof might not be enough in a court of law to punish them.