U.Va. Survey Reveals How National Capital Region Residents Would React to 'Dirty Bomb' Attacks

May 3, 2010 — Most people in the National Capital Region would follow instructions to stay where they are after a radiological dispersion device, or "dirty bomb," attack, according to a recent University of Virginia survey of more than 2,600 of the region's residents. The survey also indicates that if an evacuation were ordered, most people would stay close to the region and not travel far.

Those findings, along with others from the survey – commissioned by the Virginia Department of Emergency Management and conducted by U.Va.'s centers for Survey Research and Risk Management of Engineering Systems – provide emergency and transportation officials with valuable information on public actions during emergencies. Results from the survey will help refine emergency response, traffic movement and evacuation plans.

"The survey provides in-depth information on how residents say they will respond if a regional disaster occurs," said Michael Cline, state coordinator for the Department of Emergency Management. "The survey data are beneficial to planners and government officials in the NCR as well as surrounding states as we look at potentially providing shelter, transportation and public information to people in need."

The survey explored how people get their information in an emergency, which information sources residents trust, the amount of advance preparation people have completed, and the actions they would take under increasing levels of personal threat, explained Tom Guterbock, director of the Center for Survey Research, who developed the survey with James Lambert, associate director of the Center for Risk Management for Engineering Systems.

Three scenarios – at minimum, moderate and maximum hazard levels – were created for the survey, starting with a single dirty bomb released in the region, but not near the survey respondent. The maximum level involved a situation with multiple dirty bombs released throughout the region and exposing the population to radiation.

The scenarios were varied to learn the effects of four factors: the level of hazard, whether the respondent was at home or at work, whether there was prior notice of the event, and the source of information and instructions about the event.

Among the overall findings:

•    Of those at home during the event for all three scenarios, nearly 80 percent said they would decide to stay home.
•    For those at work during a minimal event (in which no shelter-in-place order is given for the respondent's area), only 41 percent said they would stay at work, with 33 percent leaving to go home.
•    For those at work during a moderate or maximum event when a shelter-in-place order is given, approximately 70 percent said they would stay at work.

Survey results related to residents' evacuation plans revealed:

•    People located in Virginia at the time of the event said they were likely to stay south of the Potomac River. Those in Maryland or Washington, D.C., said they were likely to stay north of the river.
•    In every threat level, a majority (70 percent to 80 percent) of evacuees said they would go to destinations within the National Capital Region. In more hazardous conditions, a pattern of traveling farther away is evident, with most respondents saying they would travel farther into Virginia and Maryland.
•    Together, the states outside of Washington, D.C., Virginia and Maryland would receive 21 percent to 30 percent of evacuees, depending on hazard level. Under a mandatory evacuation, Delaware could receive 1.3 percent of evacuees, Pennsylvania 5.2 percent and West Virginia 2.5 percent.  People going to other northern states total 5.4 percent; other southern states, 5 percent; and other states to the west, 2.5 percent.
•    About 90 percent of those in a mandatory evacuation situation said they would travel by motor vehicle.
Other findings include:

•    The president, the Department of Homeland Security and the governor were cited as the most trustworthy sources of information, with the youngest respondents giving the president the highest level of trust.
•    During the first 48 hours after a major local emergency, whether they chose to stay or to evacuate, residents expect emergency managers to supply information about the emergency and help with any needed decontamination, more than they expect food distribution or anti-looting patrols.
•    About 54 percent have prepared a personal emergency plan, an emergency supply kit, or arranged a meeting place away from home for use by family members. Only 13 percent had done all three.
•    About 15 percent of respondents said they had experienced the events of Sept. 11, 2001, in a way that caused them to take action by either sheltering-in-place or evacuating, and those attacks were often listed – along with weather-related events – as motivation to get prepared for an emergency.
•    Denial and "not wanting to deal with it" were most likely to hold people back from preparing.
"Understanding whether residents will decide to 'stay or go' is the basis for developing effective emergency plans and systems for the National Capital Region and surrounding areas," Cline said. "This survey will be an important tool as regional emergency officials consider the safety of millions of people."

"What makes this survey especially useful is the experimental design that allowed us to test reactions to many different scenarios. In addition, by including cell phones in the survey sample we were able to represent the full cross-section of area residents, including young adults and others who are otherwise hard to reach," Guterbock said.

"Emergency managers in the Washington metro area are going to benefit markedly from the unique teaming of systems engineers and social scientists that U.Va. has provided to address the critical challenge of sheltering or evacuation on such a large scale," Lambert said.

Work began on the survey in February 2009, with data collection accomplished from September to December. The Center for Survey Research called cell phone and landline phone numbers of randomly selected area residents to gather data for the survey.

Before the survey was conducted, questions were refined and interpreted in several workshops with emergency managers, public information officers and first responders from the National Capital Region. Content also was tested on three focus groups with 50 residents of Maryland, Virginia and Washington.

The project is one of seven being conducted in partnership by Delaware, Washington, Maryland, Pennsylvania, Virginia and West Virginia, which have been collaborating for several years under the Regional Catastrophic Planning Grant Program of the U.S. Department of Homeland Security. 

A report on the survey, "Population Behaviors in Dirty Bomb Attack Scenarios: A Survey of the National Capital Region," is available here.