The finding underscores the need for better preparedness training and clearer guidelines for managing such events, the researchers said. A dirty bomb combines conventional explosives and radioactive materials.

'This study suggests many issues urgently need to be addressed in order to meet the challenge posed by radiological terrorism,' said the study's co-author, Steven M. Becker, University of Alabama at Birmingham (UAB) associate professor of public health.

'There is a need for increased information and training on managing radiological events, protecting staff and treating affected patients,' he added.

In ranking the six most-voiced concerns, the top worry was that hospitals would be overwhelmed by incoming patients, Becker said. Those patients would likely be a mix of contaminated, injured and contaminated and those fearful of contamination, according to an UAB press release.

The No. two worry was emergency duty (ED) professionals' need to ensure their own family's safety, which is discounted or not mentioned in many preparedness plans, Becker said. This second concern was linked closely to the No. 3 worry that ED staffing would drop below acceptable levels based on staff family needs and fears about radioactivity.

Additionally many study participants disagreed with current federal radiological management guidelines, which state that patient stabilisation and treatment of life-threatening conditions should take precedence over decontamination, Becker said.

'Some stated unequivocally that they would not follow this guideline since they felt it was too dangerous to the hospital and its staff,' he said. Past chemical terrorism response training has put decontamination as a first priority.

In addition to highlighting serious gaps in preparedness training, the study points to the need for easy-to-follow pocket guides, posters, ED toolkits and telephone hotlines to help manage radiological events. Also, emergency staffing levels need to better account for ED professionals' concern for family and loved ones.

'It is clear from our results that crucial preparedness work needs to be done to keep hospital EDs ready for current and future threats,' said Sarah A. Middleton, program manager in the UAB Department of Paediatrics and co-author on the study. The study was funded by Centres for Disease Control and Prevention.

Their findings were published in Disaster Medicine and Public Health Preparedness, a journal of the American Medical Association.St/jg