Health Impact Assessment (HIA)

The HIA procedure


3. Identifying health hazards and considering evidence of impact

This is where a large amount of HIA work is carried out. An example of appraisal can be drawn from a health and equity assessment of a large oil project in Africa. The work began with a panel of experts (the World Bank required the Chad and Cameroon Governments to hire a panel of experts to guide the assessment process) who examined the proposal in detail. The panel drew on a variety of documents provided by the consortium that included information on a limited number of determinants of health - social and economic issues, wildlife and biodiversity (note that HIA would usually assess more determinants of health than this). The papers also listed specific health hazards and diseases in the project area. The relationships between the determinants of health and key elements of the proposal were investigated (often laid out in a table/grid like fashion for clarity).

In this case study, normal procedures for collecting field data did not occur. The panel of experts believed this was a barrier to carrying out a thorough appraisal. Normally within an HIA the best available qualitative and quantitative evidence would be collated using a range of methods, including interviews, focus groups, surveys and community profiling (to name a few). Without the mandate to carry out other data collection, the panel of experts carried out secondary analysis of existing data to estimate the likely number of deaths per year from the most important health and safety risks.

With such information (given the lack of other usual information sources) the panel used this data to rank important health risks. Such identification and description of the type and size of health impacts (both positive and negative) is typical of the appraisal stage of HIA. The largest risk by far was that posed by HIV. Focussing on how different groups of people and communities were affected by the proposal was carried out. For example, truck drivers would transport pipeline products from a port in Cameroon (where HIV infection rates are high) over 1000km into the interior of Southern Chad (where infection rates are far lower). The role of long-distance truck drivers is important in the spread of HIV in Africa and this was addressed in recommendations.

Often, in other HIA case studies, facilitated workshops are held to appraise the evidence. Drawing together a wide range of stakeholders allows different views to emerge and helps develop partnership working.


Jobin W. (in press) Health and equity assessment of a large oil project in Africa. International Journal of Public Health (WHO bulletin).