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Health and environmental impact assessment

“Health Impact Assessment (HIA) is a combination of procedures, methods and tools by which a policy, programme or plan may be judged as to its potential effects on the health of the population and the distribution of those effects within the population” (1999, WHO consensus conference).


HIA assesses the potential health risks and benefits entailed in any proposal in a rigorous fashion. HIA is a decision-making tool and is designed to take account of the wide range of potential effects that a proposal may have on a target population. It considers relevant evidence, takes into account opinions, analyses the potential health impacts of the proposal to enable informed decision making.

HIAs can be carried out prospectively, concurrently or retrospectively.

Prospective HIA is usually the most useful as health impacts can be considered before commitments made.

HIA can be used to inform:

  • The design and development of a policy or strategy
  • The commissioning of services
  • Resource allocation
  • Community participation and service user involvement
  • Community development and planning
  • Preparing funding bids


HIA involves 6 main steps:

  • Screening: a selection process which assesses policies, programmes and projects for their potential to affect the health of the population. It offers a systematic way of deciding whether a HIA is worth doing. Considerations during screening include:
  1. economic issues - size of the project and the population affected; and the costs of the project and their distribution
  2. outcome issues - nature of potential health impacts of the project; likely nature and extent of disruption caused to communities by the project; existence of potentially cumulative impacts
  3. epidemiological issues - degree of certainty (risk) of health impacts; likely frequency (incidence/prevalence) of potential health impacts; likely severity of potential health impacts; size of any probable health service impacts; likely consistency of “expert” and “community” perceptions of probability, frequency and severity of impacts.
  • Scoping: usually a steering group encompassing all the organisations involved will be formed and will set the boundaries for appraisal of health impacts. They will also agree the way in which the appraisal will be managed and allocate responsibility for decision-making.
  • Appraisal: this is the main part of the HIA and can be rapid, intermediate or comprehensive. To ensure that the views of local communities are heard a comprehensive HIA is the most effective. Appraisal includes analysing the policy, programme or project; profiling the affected population; identifying and characterising the potential health impacts, looking at the evidence base and making recommendations for the management of the impacts.
  • Presenting results: unless total consensus is reached, results should be presented as a range of options.
  • Decision-making: The ultimate result will be an agreed set of recommendations made by the steering group for modifying the project such that its health impacts are optimised.
  • Implementing, monitoring and evaluating: impacts of HIA processes are monitored to enhance the evidence base for future HIAs. Outcome evaluation is constrained by the fact that negative impacts which have been successfully avoided due to the modification of the project will not be clearly identifiable. Other beneficial outcomes include better partnership working.


Environmental impact assessment

An (EIA) is an assessment of the possible impact of a programme or project on the natural environment. The assessment ensures that decision makers consider any possible environmental impacts prior to deciding whether to proceed with a project.

Environmental impact assessment enables environmental factors to be given due weight, along with economic or social factors. It helps to promote a sustainable pattern of physical development and land and property use in cities, towns and the countryside.

EIA uses the same structure as HIA - screening, scoping, appraisal, presenting results, decision-making and implementing, monitoring and evaluating, and similarly is multi-disciplinary in its participation.

Examples of EIAs include those undertaken in relation to proposals for building new dams, constructing new run ways or on a more local scale, a town by-pass.

European Union legislation on EIA of the effects of projects on the environment was introduced in 1985 and was amended in 1997, 2003 and in 2009. For some types of project EIA is a mandatory part of the planning process whereas for other projects, EIAs are only required if the particular project in question is judged likely to give rise to significant environmental effects (screening stage of the process).[27]

The latest amendments to the Directive came into force on 15th May 2014 and there is a three year window to apply the new rules. The amendments have aimed to simplify the rules for assessing the potential effects of projects on the environment and pay greater attention to areas like resource efficiency, climate change and disaster prevention.







                                             © Rosalind Blackwood 2009, Claire Currie 2016