Three D.C. workers were exposed to a toxic vapor Monday morning while working on their regular trash collection route in Northeast Washington, but the type of exposure is not being released by the city. The crew was decontaminated on the scene by Fire and Emergency Medial Services and two were transported to the hospital. None of the injuries were life-threatening. The incident spurred Department of Public Works Director William Howland to remind residents that toxic substances -- which includes batteries and cleaning fluids -- need to be disposed of safely. DPW holds monthly drop-off events for residents on the first Saturday of each month. The next event, where residents can also take sensitive documents for shredding, is this Saturday from 8 a.m. to 3 p.m. at DPW's Fort Totten Transfer Station off Michigan Avenue in Northeast. Liz Farmer