|Assessing the Health Consequences of Major Chemical Incidents - Epidemiological Approaches, 1992 (WHO - OMS, 1992, 104 p.)|
|3. Supportive action|
As stated, the epidemiologists goal, as a member of a multi-disciplinary emergency response team, is:
· to prevent or minimize the adverse health consequences associated with an incident;
· to optimize the decision-making process in the management of the response; and
· to minimize the risk of such incidents in the future.
The response will be adequate and appropriate only when all those participating in incident management accept that they are members of a team and that their roles and responsibilities within it will alter with the nature of the incident and the phase of the response. During an incident, epidemiologists are members of the public health team handling the implications of the event for human health. This is only one group within the total structure of response management. The managers of the emergency response team should appreciate the contribution that epidemiology can make, particularly in establishing priorities for action, and proper decision-making based on timely and appropriate information.
Once the epidemiological team has been designated, certain key requirements need to be met. The team leader must rapidly identify those with whom the group has to cooperate to fulfil its allocated tasks and the person within the management structure to whom it should report, as well as the frequency of such reports.
The emergency services may ask the public health team urgently to address several types of question:
· the toxicological nature of the released substances (or combustion products in a fire) and the likely health effects;
· advice on clinical management, such as the prediction of health effects as a basis for patient monitoring;
· the types of casualty to be expected;
· the risk of health effects to emergency personnel;
· the risk of environmental contamination and its possible effects on human health;
· the potential effect on public health of the emission, including the identification of sensitive populations; and
· in a continuing incident such as a chemical fire, advice to emergency officials on the health criteria for evacuating sectors of a community.
The public health team should have access to external expertise in clinical toxicology, occupational hygiene, environmental chemistry and occupational medicine, as well as epidemiology. The team may have either a local or a national base, but it is important that the members have met before the incident (during the preparatory phase) and are able both to come to the scene of the event, if necessary, to provide direct advice, and to arrange for environmental sampling and health data collection. The team should include health scientists and practitioners from the chemical industry, who may have considerable expertise and resources in dealing with major incidents. The epidemiologists have a key role in ensuring the quality of the data collected by the team.
The team needs expertise in hazard identification, exposure estimation, dose-response assessment and risk characterization. The teams work includes identifying the communitys health needs and responding to them. Examples include attending to the psychological effects of chemical disasters, with the public health team playing a leading role in ensuring that the appropriate preventive health response is made.
The active participation of representatives of industry - from either the enterprise directly associated with the event or other companies or expert organizations - facilitates the management of an incident. These bodies may have a range of experts with unique skills and immediate access to information essential to appropriate health risk assessment. Their role within the team must be clearly defined, however, and potential conflict between their professional contributions and their organizational responsibilities must be recognized.
Public opinion tends to assume that industrys legal defaults and/or products are responsible for an incident. The correctness of this assumption is usually determined later, after rigorous investigations. Epidemiologists should be cautious in their evaluations; in not doing so, they would not only fail to adhere to a scientific behavioural code but might also impair the collaboration needed to identify precise causal associations (and sometimes legal responsibilities). It is essential, for example, that the public health sector manage the studies, and not delegate the task to industry.
Epidemiologists work in support of public health agencies. Whether epidemiologists are employed in the public or health sectors, academic or national institutes or industry, their knowledge, skills and data should be available to all of these in the response to an incident. To fulfil this role, the epidemiologist needs to take advantage of the skills and knowledge of the colleagues who will help to amass and analyse relevant data and thus to determine the response needed. These tasks require the cooperation of a range of different professionals, including primary care workers, specialists in referral centres, local environmental health officers or hygienists, and staff and specialists in laboratories and toxicology centres. As well as participating in the design, implementation and analysis of the epidemiological studies, all contributing professionals need to feel ownership of them, agree the findings and take part in their dissemination.
In many countries, poison information centres provide information needed for health-related responses to major chemical incidents. These centres possess relevant data on the diagnosis, treatment and rehabilitation of people affected in an emergency, as well as on the features of prolonged exposure and potential long-term effects. They provide ready (ideally, round-the-clock) access to advice on acute and chronic poisoning by chemical, biological and/or radioactive agents. The annually updated listing of the poison centres registered by WHO is included in the INTOX computer database of the International Programme on Chemical Safety (IPCS).
Public authorities at the regional and national levels have the major responsibility for protecting the health of the population. They therefore take the lead in developing health-related components or preparedness plans as part of overall emergency planning. Each country needs to have the means to organize the collection, collation and dissemination of information for use during both the planning for and the response to an environmental incident. This information is essential for improving decision-making and minimizing the adverse public health consequences of incidents. Appropriate epidemiological, laboratory and toxicological skills are required for the rapid evaluation and assessment of risks. Such capacities may not be available locally and a team of experts with the appropriate expertise, including expertise in environmental monitoring, needs to be available for rapid deployment, especially in large or unusual incidents. Such groups need regional, national or even international planning and development. Public health officials at the local level should be aware of the skills of such teams, their location and the means of rapidly calling for their assistance at any time.