(DEKALB, Ill.) -- The emergency dispatchers who remain calm and unemotional while handling 911 calls may not witness the carnage their front-line police and firefighting colleagues encounter, but they can be just as vulnerable to post-traumatic stress disorder from all they hear and imagine, researchers report.
The men and women who field 911 emergencies hear some of the most soul-searing sounds imaginable: the anguished wailing of gunshot victims, the final words of someone they can't deter from suicide or the last thoughts of workers trapped in the Twin Towers on Sept. 11, 2001. But the stresses of their experiences sometimes haven't been considered traumatic because the dispatchers haven't left their computer consoles.
"This is a population of people who are routinely exposed to events that should be considered traumatic," said Michelle Lilly, a psychology professor at Northern Illinois University in DeKalb, Ill., who co-authored a study assessing the psychological impact of the crises dispatchers experience from afar. "People think of the job as stressful, but not really traumatic."
Lilly, head of NIU's Trauma, Mental Health and Recovery Lab, and research associate Heather Pierce, a former 911 dispatcher married to a police officer, analyzed surveys completed by 171 emergency dispatchers from 24 states. The survey takers were asked to describe the worst calls they had handled. The group comprised predominantly of white women just under the age of 39 with nearly 12 years on the job, according to the study published Thursday in the Journal of Traumatic Stress.
Most said their worst experiences involved imperiled children or sending firefighters, police officers or emergency medical technicians who were friends and loved ones into harm's way.
"I was blown away by how upsetting some of (the incidents) would be for most people," Lilly said Wednesday as she described accounts of dispatchers talking parents "through CPR after they have discovered their child has drowned in the pool."
She was particularly shaken by a call involving two young siblings, one of whom had a mental health problem. The healthy child called 911 and locked himself in a room for protection, but the dispatcher "could hear the sibling trying to take the hinges off the door and intending to attack."
All the dispatcher could say was, "Help is on the way. We'll get there as fast as we can," Lilly said.
Such situations can engender feelings of fear, helplessness and horror which, when unaddressed, can set the stage for PTSD. Lilly and Pierce found that 3.5 percent of the survey respondents reported symptoms "severe enough they probably would qualify for a diagnosis of PTSD," Lilly said.
Copyright 2012 ABC News Radio