Impact assessment

Impact assessment illustration
WHO; Peter Furu/DBL; Rob Barnes

Directory of resources

The directory below provides links to web-accessible resources on impact assessment, with reference to environment and health, organized into categories of relevance to policy-making.

Policy brief: Impact assessment - bridging science and decisions

Whenever a policy decision is made, it can be presumed that decision-makers have made an assessment of potential impacts. But was this process formal or entirely informal? Was the relevant scientific evidence about environment and health reviewed publicly and systematically? Impact assessment is the process link in the chain between evidence and decision-making. Yet formal impact assessments are not conducted for many strategic policy decisions. At the project level too, impact assessment processes may fail to consider health and environment in a linked and inclusive perspective. More effective and systematic impact assessment was thus identified as an important priority for HELI, and for improving environment and health decision-making overall.

Over the past three and a half decades, a plethora of impact assessment methodologies have been developed. A variety of institutions and agencies, including UNEP and WHO, have supported the refinement and application of tools for environmental impact assessment (EIA), integrated assessment (IA), health impact assessment (HIA), and strategic environment assessment (SEA).

Overall, there is increased recognition of the value of impact assessment methods that link sectors and disciplines more inclusively. The assessment of linked health and environmental impacts can play a significant role in expanding the narrow focus and frequent shortcomings of sectoral assessment. It also ensures that the direct contributions of ecosystems to better health are duly captured in the decision-making process.

In the context of the HELI initiative, WHO and UNEP supported global reviews by experts of both health and environment impact assessment methods – evaluating impacts on decision-making; strengths and weaknesses of various approaches; and best practice for matching the approach with decision-making needs, priorities or frameworks.

Along with the expert reviews, practical guidance is to be provided to professionals and decision-makers in the conduct of impact assessment from a linked health and environment perspective, also incorporating economic valuation of health and environment aspects of policies, programmes or plans.

The guidance is synthesized from lessons learnt in the various reviews conducted by HELI of both impact assessment and economic valuation methods, and distils common elements of the various tools. Reference in this integrated guidance is made both to quantitative methods of analysis (e.g. economic valuation, burden of disease assessment) and qualitative methods (e.g. stakeholder dialogue) as an integral part of a the assessment exercise. The guidance highlights where specific methodologies may be useful in decision-making - without prescribing one particular approach.

The aim is to provide country level decision-makers and stakeholders with a range of options for assessing health and environment impacts of policies, from which they may choose methods best suited to local needs – and thereby support decision-making that is transparent, inclusive, and makes effective use of scientific evidence.


Health and Environment: Managing the Linkages for Sustainable Development

Ecosystems and human well-being: Health synthesis

Millennium Ecosystem Assessment

Health/environment journals on line





Health & environment: tools for effective decision-making

Health & environment: tools for effective decision-making

The WHO-UNEP Health and Environment Linkages Initiative (HELI): Review of initial findings

Information package in environmental and occupational health

Information package in environmental and occupational health