Discussion
The overall health impact of accidental chemical exposures is unknown, as national data have
not been available in the UK. Responsibility for management and documentation of accidents
varies with the type and location of the chemical exposures. Population-based surveillance
could provide information to describe the hazards to enable public health services to be better
prepared for such incidents and to manage them more e Vectively.7–11 The All Wales Environmental Health Surveillance Project is the first population-based surveillance system of acute chemical incidents to have been described in Europe, although a similar surveillance system has been operational in some States in the United States of America since 1990.12–14 We have shown the
necessity for a multi-agency approach as there was little overlap in the incidents reported by
the various participating agencies. The combined reports from the three participating
agencies, together with press cuttings, indicated that on average 2.6 chemical incidents
involving community exposures and requiring an immediate public health response occurred
each week in Wales with a population of about 2.9 million.We undertook active surveillance to improve the timeliness of returns, and all eligible participating agencies consistently reported
incidents or “nil returns” on a monthly basis.However, the representativeness of the system
and the quality of the health outcome data could be improved further. The results in Gwent, where 52 incidents were reported only by the Fire Service suggests that the sensitivity
of the surveillance system would have been improved by the participation of all fire services, as well as of other agencies in Wales.Press cuttings were shown to be a useful source of data that uniquely identified 54 incidents.Health Authorities have been required since 1993 to have plans in place to respond to public health aspects of chemical incidents.15 The need for public health doctors to have a central role in planning for, and managing chemical incidents is well recognised.16–18 However, in this project the health authorities were only involved in the management of 34 of the 402 incidents. At the time, the primary public health focus for emergency planning was the Control of Industrial Major Accident Hazard (CIMAH) Regulations, 1984,19 recentlyamended by implementation of the COMAHDirective. Only 14 incidents over the three years of the project were reported at CIMAH sites. Early consideration must therefore be
given to the need to develop plans and guidelines for dealing with the public health risks that arise more commonly at other sites.20 The identification of high risk locations and types of incidents, together with the chemicals most likely to be involved will also be of use to persons involved in emergency planning, to assure the availability of appropriate expertise,equipment and medicines in the future. Listing the chemicals most frequently involved in incidents is already helping to prioritise the development of toxicological profiles for use by public health professionals in Wales and to develop training programmes for emergency responders and public or environmental health professionals.This multi-agency system demonstrated how surveillance could improve planning and management for chemical incidents. National surveillance of chemical incidents for the whole of the United Kingdom has subsequently been developed, improving on the sensitivity of this system by the addition of more reporting agencies.We would anticipate that hypotheses generated from surveillance will lead to work of prevention of such incidents and protection of the public health. This system could provide the basis for other systems such as centralised reporting of major incidents.21