Revision as of 13:04, 14 June 2011

The concept

Integrated environmental health impact assessment provides information on potential environmental influences on public health, in order to help people make better decisions to protect and improve human health. It can be defined as:

Key features of IEHIA are that:

• It is specifically designed to deal with complex issues, which would usually be beyond the scope of more traditional forms of health risk or impact assessment (see links to Other assessment methodologies, left);
• It considers both positive and negative effects on health – i.e. it recognises the environment as both a hazard and a source of beneficial resources (environmental services and capital);
• It attempts to provide a synoptic and balanced measure of impacts, by weighting and summing the various health effects;
• It is designed to be participatory – and thus to involve all the key stakeholders with interests in the issue.

The need for IEHIA

The environment affects human health in many different ways. It operates directly, through the influence of natural hazards such as earthquake and storms. It acts as a conduit for pollutants and other stressors generated by human activities, and a setting within which exposures to such hazards take place. It is also a source of many of the resources that are vital for human life, such as water and food, and thus has major benefits for human healthy and well-being. In almost every case, these environmental hazards and benefits are influenced by human intervention - by policies and technologies. Environment and human action thus interact, often in complex ways, to affect human health.

Assessments are therefore needed to help evaluate and guide these human actions. Integrated assessments are needed because the issues concerned are often complex and interwoven, so that problems have multiple causes, and interventions may have mutliple, and far-reaching effects.

Integrated environmental health impact assessment is therefore aimed at helping decision makers better understand both the environmental factors that affect human health and the consequences of their decisions, so that policies and technologies can better serve human needs.

IEHIA in relation to other assessment methodologies

Integrated environmental health impact assessment does not stand alone. It has developed from (and complements) many other approaches to assessment that have been developed, for somewhat different purposes, over recent decades. These include:

• Risk assessment – which traditionally has focused on the relatively immediate and direct health risks from potentially dangerous substances (e.g chemicals) or practices (e.g. manufacturing processes), often in relation to cancer;
• Comparative risk assessment – which extends traditional forms of risk assessment to the evaluation and comparison of multiple risks (from different sources or agents) across large population groups;
• Health impact assessment – which evaluates the potential health implications of policy or other developments, usually at a relatively local scale (and usually without trying to aggregate the impacts);
• Integrated environmental assessment – which assesses the overall environmental (but rarely human health) impacts of large, complex pressures or developments.

The file (Comparison of assessment methodologies) illustrates the relationship between the first three of these and integrated environmental health impact assessment, and shows how the latter provides an encompassing framework for all these approaches.

References: Briggs, D.J. 2008 A framework for integrated environmental health impact assessment of systemic risks. Environmental Health 7, 61 doi:10.1186/1476-069X-7-61

Hazards and benefits

The environment affects human health both negatively and positively. On the one hand it is the source for, and a setting in which exposures occur to, hazards of many different kinds: physical hazards such as earthquakes, storms, floods, fire or traffic accidents; biological hazards such as vector-borne diseases and pathogens (e.g. malaria, lymes disease, BSE); and chemical hazards, such as pollutants in the air, water or soil. On the other hand, the environment provides most of the basic resources needed for human life (e.g. water and food), as well as many of the amenities which add to our well-being (e.g. places for recreation, relaxation and mental stimulation).

Many of the issues that merit integrated impact assessments involve some combination of these hazards and benefits. Likewise, the vast majority of policies and technologies affecting the environment (whether deliberately or accidentally) have the potential for adverse and beneficial effects. Hazards and benefits are nevertheless different in their expression. They lead to different types of health consequence: hazards typically cause clinically detectable injury or harm; benefits are commonly more subtle in their effect, influencing our socio-psychological state and mental well-being. In many cases, also, they affect different people, in different areas or social groups. Hence, many issues involve both winners and losers.

In doing assessments, therefore, we need to make sure that we have considered and included the benefits as well as the hazards that might arise, and in both cases have properly delineated the populations that might be affected. Otherwise, the assessment will be biased. Considering these very different types of impact, however, also means that we must choose our outcome indicators withspecial care. It is not always sufficient to measure the impacts only in terms of the burden (or absence) of disease. Instead, we need meaures that allow us to sum and compare the negative and beneficial outcomes - for example, monetary measures or indicators of overall well-being.

Steps in IEHIA

The range of questions facing decision makers is large and varied. Integrated environmental health impact assessments thus take many different forms, and often need to be developed and adapted to match the spcific issue being addressed. The issues are also often complex, and touch the lives of a wide range of stakeholders. As a result, many assessments do not proceed in a neat, linear way, but are, instead, somewhat circular and reiterative.

In general terms, however, we can define four key steps in any assessment: issue-framing, design, execution and appraisal.

1. Issue framing is done to define clearly what is to be assessed, and who should be involved.
2. Design consists of deciding how the asssessment will be done - including the data and methods that will be used.
3. Execution is the stage of actually doing the assessment - collecting the data and running the models to determine health impacts.
4. Appraisal involves reviewing and interpreting the results of the assessment, and communicating these to the end-users.

These steps (known by their initials as the IDEA framework) provide a valuable struciture within which to organise and run assessments. Following this framework helps to ensure that assessments are targetted as the right issue, are based on good scientific principles. NOte also that stakeholders should be involved (in different types of discource) at every stage, in order to make sure that the assessment is acceptable to the people concerned, and thus that it can provide a sound basis for effective decisions.

Issue framing

Issue framing represents the first stage in doing an integrated environmental health impact assessment. It is at this stage that we specify clearly what question we are trying to address, and who should be involved in the assessment.

By the end of the issue-framing stage, therefore, we should have defined the scope of the assessment, and the principles on which it will be done. In the process, we should also have resolved any ambiguities in the terms and concepts we might be using, so that everyone involved has a common understanding of what the results of the assessment will mean.

Issue-framing can rarely be done as a singular, one-off process. Considerable reiteration if often required to deal with new insights, as they emerge. The order in which issue-framing is done also needs to be adapted according to circumstance. Five main steps, can, however, be recognised:

1. Specifying the question that needs to be addressed;
2. Identifying and engaging the key stakeholders who need to be involved;
3. Agreeing an overall approach to the assessment and the scenarios that will be used;
4. Selecting and constructing the scenarios on which the assessment will be based;
5. Defining the indicators that will be used to describe the impacts.

For the sorts of complex (systemic) problems that merit integrated environmental health impact assessment, issue framing can be extremely challenging (see link to Challenges in issue framing, left). Care and rigour in issue framing are therefore crucial if the assessment is to be valid and useful: failure to give the necessary attention at this stage will almost certainly undermine the value of everything that follows.

Challenges in issue framing

Describing complex issues in a way that captures the interests of all the stakeholders concerned, yet can also form a sound and practicable basis for assessment, is inevitably difficult.

Difficulties arise both from the complexity and ambiguity of the issues that need to be assessed, and the multitude of stakeholders (often with different and conflicting interests) who are concerned. As a consequence, issue framing has to deal with several challenges:

• how to identify all the stakeholders who might have interests in the issue and engage them in the process;
• how to define the conditions (in the form of realistic yet relevant scenarios) under which the issue will be assessed;
• how to set practicable limits to the issue without unfairly excluding some stakeholders’ interests and thereby biasing the assessment;
• how to define and agree on a series of indicators that will adequately and fairly capture an describe the results of the assessment.

All four require that issue framing is done as a reiterative process, with each version of the issue being reviewed and debated to ensure that key elements or stakeholders have not been neglected. It also needs to be an open process, with additional stakeholders being invited to take part when new (and unrepresented) interests emerge.

This reiterative process of issue framing often involves a clear cycle, comprising:

• a phase of ‘complexification’, as new factors and relationships are discovered, and new interests taken into account;
• a phase of simplification, as the issue is paired down by eliminating redundant or irrelevant elements, in order to focus on what matters most.

Defining the question

All assessments are done in response to a ‘question’ or ‘concern’. This initial question is often not phrased specifically for the purpose of assessment, but instead to raise awareness and get attention. Even when an official body commissions an assessment, the question may not be clearly and fully described. In most cases, therefore, the issue of interest will need to be carefully considered and redefined.

The aim of doing so is to make sure:

• that it is unambiguous and clearly understood;
• that it really does reflect the issue about which people are concerned;
• that it can form the basis for a sensible and realistic assessment;
• that the rationale for doing an assessment is clearly recognised.

To achieve this the question needs to be phrased in a clear and structured way. Typically, this involves defining (at least in general terms):

• the causes (e.g. human activities, environmental stressors, agents) and/or types of health impacts of concern;
• the area or population of interest;
• the timescale of the concern.