Health impact assessment: the wider context.

At the World Summit on Sustainable Development, the International Association for Impact Assessment (IAIA) submitted a briefing paper on the important contribution impact assessment (IA) can make to carrying out the agenda for sustainable development (1). The paper emphasizes the need to make human health and safety an integral part of the impact assessment of policies, plans, and, of course, development projects. Such an integrated perspective was adopted by WHO in its support of Health Impact Assessment (HIA) in the 1980s, and has been reinforced by the Memorandum of Understanding signed with IAIA in 2001. It can also be seen, for example, in the Gothenburg consensus paper which briefly considersHIA in relation to other forms of impact assessment (2). Publications in a number of countries have adopted a similarly wide, impact-assessment context for HIA (for example, 3). However, for many new practitioners of this discipline, particularly in the public health area, HIA is a recent innovation, designed specifically to serve their needs as health professionals. The wider context of impact assessment is often unrecognized. It is very encouraging to see HIA more widely adopted to improve health outcomes in both industrialized and developing countries, but there is a real concern that too much effort is being spent on reinventing impact assessment itself, rather than building on what already exists. Moreover, there has been a large amount of information sharing between individuals and groups in the public health community in various countries, especially in Asia, Australasia, and Europe, as they develop guidelines, models or case studies for HIA. This has resulted in a high degree of recycling of information within these networks, often with little reference to wider impact-assessment literature. The danger of evolving in isolation is obvious. One consequence of this process, I would argue, has been the proliferation of suggested approaches to HIA (e.g. Europe has seen the development of perhaps a dozen HIA ‘‘models’’ such as the Liverpool model and the Swedish County Councilsmodel). These do not, as yet, appear to have been the subject of searching critical review, and seem to be used by practitioners almost as a menu of options from which to choose a model for a given HIA exercise. Without critical review and evaluation, there can be little real sense of direction in the future development of the practice of HIA. Also, we have seen the introduction and rapid uptake of new terminology, such as ‘‘prospective’’, ‘‘concurrent’’, and ‘‘retrospective’’ HIA (for example, 4). Not only are these terms largely redundant, but they may also be dangerous, as they suggest that there are distinct forms of HIA in relation to purpose and timing. IA encompasses not only the prediction or forecasting of particular, significant impacts but also their subsequent management, and may continue until the planned activity has ceased and, if necessary, the local area has been rehabilitated (5). Hence, all impact assessment is ‘‘prospective’’ in nature. ‘‘Concurrent’’ HIA is, in IA circles, a form of monitoring carried out within the overall IA process to assist impact management. ‘‘Retrospective’’ HIA would refer in IA circles to health impact auditing, and is part of evaluating the IA process and learning about actual impacts for future assessments. The implication that there are three types of HIA is thus misleading: these are in fact three phases of a unified HIA process. Two broad approaches to HIA are usually recognized in the literature: the biomedical approach and the social determinants approach. Methods and techniques have developed around these two groups. From our perspective, the difference mainly concerns direct and indirect impacts on health. The biomedical approach often deals with the assessment of direct effects of, say, pollutants on local populations, and frequently uses risk assessment and epidemiological methods. The challenges here are largely technical, such as how to make specific links between exposure and health outcome, and how to supply the data needed for epidemiological assessment. But IA was developed more specifically to deal with indirect impacts, and it is these that provide the bigger challenges for HIA in the future. Indirect effects can be environmental in nature, but they are especially associated with changes in the social, economic and cultural conditions of local populations likely to result from a given policy, plan or project. If HIA is viewed as a stand-alone method, its practitioners may be faced with the task of making their own social, economic, cultural and environmental impact assessments, all as a precursor to examining the human health consequences of a proposal. Clearly, this is inefficient, and it is important that HIA practitioners, where appropriate, work with other IA professionals to provide the basis for informed assessment of health effects. The wider IA literature is rich in discussion and accumulated experience about the process of IA, and HIA practitioners should be drawing on this fund of knowledge. It would help, for example, with questions about the effectiveness of HIA in policy development, and it would inform practitioners about key phases of the assessment process such as defining the scope of the assessment, evaluating the social significance of impacts, and reviewing the quality of the assessment. The current surge in HIA development is very welcome, but that growth needs to be managed effectively in order to maintain the integrity and value of the method. Reinforcing its links with the wider IA community can only help in this regard. n