At an event hosted by Bank Tejarat, a book on nonperforming loans (NPLs) in the banking system was unveiled this week. Asghar Pourmatin a co-author of the book said they have sought the best expert counsel on the issue in order to elaborate on ways to prevent bad debts from accumulating in the banking system, Banker reported. During the event, pundits gave reviews of the book and offered further suggestions on how to tackle the problem of toxic debts. The NPLs held by commercial banks stood at 938 trillion rails in the month ending Nov. 21, 2014, though independent experts believe the figure could be double. Bad debts are a serious challenge Iranian banks are dealing with to replenish their resources.