Marianne White, Postmedia News, August 13, 2010 Québec - A nurses' federation in Québec is worried about a rash of suicides among health-care workers in Québec City after at least one of the nurses blamed her difficult working conditions in a suicide letter. Management of the Québec City's teaching hospitals network (CHUQ) said this week that four of its nurses killed themselves over an 18-month period. "It's alarming and this might not be an isolated case. It could happen in other hospitals," said Caroline Valiquette, an adviser at Québec's largest nurses' union, the FIQ.  ... Rash