Nearly 40% of employees in California emergency rooms said they had been assaulted on the job in the previous year, according to a survey by UC San Francisco and other researchers in 2007. More than one in 10 emergency room nurses surveyed in 2010 said they had been attacked in the previous week, according the Emergency Nurses Assn., which represents 40,000 emergency room nurses nationally. Many industry experts and hospital staffers say they believe violence by patients and visitors is rising but can't say for sure because it hasn't been rigorously tracked over time. The issue has recently gained attention, however, as hospital employee unions, including the California Nurses Assn., have begun pushing for broader protections and more reporting by hospitals. The violence flares most often in emergency rooms and psychiatric wards, say staffers, researchers and security officials. In emergency rooms, waiting times have grown as increasing numbers of unemployed and uninsured patients seek basic care they can't afford to pay for in doctors' offices.