Loftus. Kirsten Joyce and im Kirsten Joyce. Students at Walter Johnson junior high will return to school this morning, after school was canceled for three days, due to mercury exposure. brian loftus epa agents checked the school thoroughly to make sure there was no danger to students or staff. Kirsten Joyce investigators are still working to determine who brought the chemical to school. 8 news now reporter nia wong joins us live outside the school with the very latest. Nia . nia wong good morning brian and kirsten. An epa Spokesman Says this campus is now clear to enter. They wrapped up cleaning efforts yesterday afternoon. Mainly t say most of the mercury was. This after the district says a quarter of a cup of mercury was recovered last wednesday. Leading to that 14 hour lockdown which lasted well into thursday morning. Thousands of students, their bags and shoes were screened for mercury. This investigation continued out of the classrooms as well. At last count. 7 buses were tested a