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CMAJ - September 19, 2000JAMC - le 19 septembre 2000

Public Health
Tornadoes and disaster management

CMAJ 2000;163(6):756 See:  eLetters  


Canada and the United States experience some of world's worst tornadoes. They develop during severe thunderstorms when cool northern air masses collide with hot air flowing from the Gulf of Mexico, throwing the center of the thunder cloud into an inverted spin. Tornadoes typically move at ground speeds of 20 to 90 km/h in a southwest–northeast path.

About 80 tornadoes are reported in Canada each year, resulting on average in 2 deaths, 20 injuries and millions of dollars of property damage.1 The tornado alleys are in southern Ontario, Alberta, southeastern Quebec, interior British Columbia, western New Brunswick and a band stretching from southern Saskatchewan to Thunder Bay, Ont.

Most of the serious injuries and deaths occur because the victims became airborne, solid objects become airborne or structures collapse. A review of 10 tornado reports from 1962 to 1994 suggests that most of the injuries are contaminated soft-tissue lacerations (54%) and fractures (30%); the next most common are blunt trauma (7%), head injuries (7%) and minor strains (2%). Most deaths occur at the scene and result from severe head injury, cervical spine trauma or crush injuries.2

Clinical management

Disaster planning and response require the cooperation and coordination of many bodies — the head of the local municipality, the public health unit, the Red Cross, social services, public transport, emergency medical services personnel and hospitals. It is up to individual Canadians to know what to do in an emergency.3 If people are unable to cope, the different levels of government are expected to respond progressively, as their capabilities and resources are needed.

Each hospital and level of government has an emergency management plan, although these are tested only infrequently because of the cost involved. Emergency physicians play a key role during disasters, providing the medical interface between emergency medical services personnel, the community and the hospital. Local emergency response organizations are normally the first on the scene. If they are overwhelmed, they may seek assistance from the province or territory, which, in turn, will ask the federal government for help.

Several recurring problems plague disaster response: a lack of accurate information from previous experiences, poor understanding of the response plan and the unique character of each disaster.4 Many logistical problems faced during disasters are caused not by shortages of medical resources but, rather, by the failure to coordinate their distribution.5 It is essential that medical personnel involved in the response understand the key components and phases of an emergency response (Table 1).4

Tornadoes present unique problems. Search-and-rescue efforts are hampered by debris and blocked roads. Communication between rescue personnel and receiving hospitals is typically poor. Many of the casualties, including seriously injured people, present to the hospital by private vehicle instead of ambulance, so staff need to know proper vehicle-extraction methods.

The closest hospital to the disaster receives the largest number of victims, yet may also have suffered damage. The disaster plan should provide for the short-term supply of water and power to the emergency department. Irrigation supplies for wounds will be in high demand, as will broad-spectrum antibiotics and large quantities of tetanus toxoid. The need for follow-up care for delayed primary closure of wounds and counselling should also be anticipated.2


Adequate warning of an approaching tornado and proper preparation and action by the population are the most important factors in reducing tornado-related injuries and deaths.2 Physicians in tornado-prone areas can help educate residents about how to respond to these disasters. The information they need is available on Environment Canada's Web site.1 More important, physicians can help by understanding the nature of these disasters, contributing to the development of a local disaster plan and knowing their roles in it.

Further information is available from Emergency Preparedness Canada6 and a recent article by Sookram and Cummings.7 — Erica Weir, CMAJ

Thanks to Dr. Edward Ellis, Ottawa­Carleton Health Department.


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Envoyez une lettre électronique


    1.   Tornado! [fact sheet]. Ottawa: Environment Canada. Available: www.pnr-rpn.ec.gc.ca./air/summersevere/ae00s02.en.html.
    2.   Bohonos J, Hogan D. The medical impact of tornadoes in North America. J Emerg Med 1999;17:67-73. [MEDLINE]
    3.   Be prepared, not scared [brochure]. Ottawa: Emergency Preparedness Canada; 1999. Cat no D82-39/1999E. Available: www.epc-pcc.gc.ca/publicinfo/self_help_ad/self_help/self_bepre.html.
    4.   Waeckerle J. Disaster planning and response. N Engl J Med 1991;324:815-21. [MEDLINE]
    5.   Auf der Heide E. Disaster planning part II. Emerg Med Clin North Am 1996;14:453-79. [MEDLINE]
    6.   Emergency Preparedness Canada Web site: www.epc-pcc.gc.ca
    7.   Sookram S, Cummings G. The physician's role in Canada's disaster response system. Prehosp Disaster Med 1999;14(3):155-8.

© 2000 Canadian Medical Association or its licensors