When chemical disasters strike

World Health • 46th Year, No. 5, September-october 1993 11 When chemical disasters strike Peter J. Baxter F ollowing incidents like the ex-plosion at a cyclohexane plant at Flixborough, England, in 1974 and the release of dioxin at Seveso, Italy, in 1976, great efforts have been made by governments and industry to prevent major chemical accidents involving large vapour or flammable gas explosions, fires or toxic releases into the air, food or water. However, despite legislative and engineering measures aimed at reducing the risks, the possibility of a disaster can never be ruled out. Emergency response measures should therefore be an integral part of planning for accidents at hazardous installations, and during the distribution and transport of chemicals. Health professionals in such specialties as occupational health, public health, primary care and emer- gency medicine urgently need to be involved with the emergency services -and involved in the planning, pre- paredness and rehabilitation phases, not just as part of the emergency response to a disaster. Thus the health sector should participate in disaster management rather than having simply a limited "therapeutic" role. The essential feature of chemical disasters which distinguishes them from other types of disaster is the need to be able to defme very quickly the health hazard posed by a toxic release (for example, a dense chemical cloud) which means rapidly identifying the chemical or chemicals concerned, obtaining knowledge of their acute and long-term effects, and determin- ing who, if anyone, in the general population has been exposed. Unfortunately it may be difficult or impossible to determine the chemicals involved in the event of a runaway reaction or chemical fire, and even if the identity of the chemical is avail- Explosion in Flixborough, England, in 1974 . Rapid identification of the chemicals involved is vital in order to treat casualties . able, knowledge of its toxicology in humans, particularly with regard to its chronic health effects, may be sparse or non-existent. This was the case following the release of methyl isocyanate at Bhopal, India, in 1984, which killed 2500 people living nearby. Yet without such information on the health hazards, the medical management of casualties and of the exposed population, who may n~ed to be urgently evacuated from a contami- nated area, will be severely hampered. A multidisciplinary team Information-gathering by a multi- disciplinary team in order to make a rapid health-risk assessment should therefore be an essential part of pre- planning for chemical accidents, both at the local and national level. The toxicological databases held by poisons centres, chemical response centres or chemical companies may be inadequate for decision-making in a major disaster, or even in a more modest incident where a community believes it has suffered serious exposure. The team should have the expertise to confirm the nature of the chemical release, and to investigate its likely health effects on the casualties and on the exposed "well" population. Certain aspects of the management of casualties, whether at the scene or in the hospital, namely the sorting of casualties, decontamination and the treatment of acute symptoms (such as the pulmonary effects of irritant gases) may proceed along standardized lines regardless of the chemical agent concerned, but the treatment of sys- temic effects and the adm.inistration of antidotes involves knowing precisely the chemicals involved and their toxic effects. Unfortunately, hospitals are generally poorly prepared for under- taking even ordinary routine measures for treating chemical casualties. Since medical treatment is likely to be only supportive in most serious chemical incidents, it follows that preventing exposure must be the main aim of the emergency services. Psychological or stress reactions may prove to be more important than the toxic hazard, and preventing these must also be an essential part of disaster management. • Or Peter). Baxter is Consultant Occupational Physician at the University of Cambridge Clinical School, Addenbrooke's Hospital, Cambridge CB2 200, England.