Guidelines for Environmental Risk Assessment and Management
[This document refers, in a number of instances, to the then Department of the Environment, Transport and the Regions (DETR). The text of this document has not been updated since the transfer of environmental protection functions to Defra.]
Chapter 1
Introduction to the guidelines
1.1 Background
Society is increasingly conscious of the harm that its activities can cause to the environment, and the harm to people or the loss of quality of life that can result from environmental degradation. We recognise the need to manage our activities in a way that minimises the risks of environmental damage, while at the same time ensuring economic growth and social progress. The interaction between human activity and the environment is complicated and difficult to quantify, and it is not easy to judge where the balance should lie between environmental protection and economic and technological progress. Environmental risk assessment is a key element in the appraisal of these complex problems, and for formulating and communicating the issues so that transparent and equitable policy, regulatory or other decisions can be taken.
The proactive application of risk assessment
In recent years, there has been a shift from reactive measures to protect the environment to more proactive approaches aimed at preventing or minimising (rather than remediating) environmental damage and loss. This change in emphasis has been reflected in the use of risk assessment at the outset as part of the package of tools for making decisions about environmental management, particularly in the context of sustainable development. This document encourages the use of formal risk assessments as part of a proactive approach to environmental protection. While such an approach should be the norm, risk assessments may sometimes usefully be applied retrospectively if previously unidentified risks come to light. Environmental surveillance and monitoring to collect information over a long period of time can help to detect previously unidentified risks as well as provide a basis for forecasting future impacts.
The guidelines presented in this document provide a common framework for risk assessment as a key part of the process of appraisal for environmental decision-making. They build on the UK Department of the Environment's 1995 publication A Guide to Risk Assessment and Risk Management for Environmental Protection. The guidelines set out some basic principles which the Department of the Environment, Transport and the Regions (DETR) and the Environment Agency would normally intend to use in the assessment and management of environmental risks and which are recommended for all public-domain risk assessments. The guidelines provide decision-makers, practitioners and the public with a consistent language and approach for environmental risk assessment and management.
The need for and conduct of risk assessment must be seen in the broader context of the proper appraisal of projects, programmes and policies. For central Government this is nested with HM Treasury's 'Green Book', Appraisal and Evaluation in Central Government, and in guidance from the Regulatory Impact Unit. More specifically, in 1998, DETR issued summary guidance on environmental appraisal: Policy Appraisal and the Environment: Policy Guidance. This explicitly places risk assessment as a key part of a proper environmental appraisal (see paragraph 6.6 of the DETR document). And more recently, a Cabinet Office-led working group has produced a Policy Makers Checklist, which brings together all the available guidance on existing impact assessments and appraisals as a first stage in the creation of an integrated system in support of sustainable development. The checklist, part of the Government's Modernising Government agenda, is accessible via the Cabinet Office Regulatory Impact Unit's internet site (see Section 1.8).
For the Environment Agency, a broader policy context for risk assessment is provided by the Agency's general duties on sustainable development (see 1997's Introductory Guidance on the Agency's Contribution to Sustainable Development) and costs and benefits (see 1997's Taking Account of Costs and Benefits). From an operational perspective, the majority of the Agency's risk assessment activity takes place within the context of the specific statutory responsibilities administered by its individual regulatory functions. These may command more specific requirements with respect to risk assessment not covered by these general guidelines.
The guidelines describe general principles and provide case studies to demonstrate how environmental risk assessment and management processes can be applied across a diverse range of activities. The framework set out here can be applied to a wide range of hazardous activities and environmental systems, and across a diversity of spatial and temporal scales. The principles described can be applied at all levels of environmental protection, from broad policy development to site-specific risk management decisions.
These guidelines do not provide detailed prescriptive guidance, but aim to highlight basic concepts and point to more detailed information and other resources where relevant.
The target audience
The guidelines are intended to be used, in conjunction with existing appraisal and other relevant guidance, primarily by risk assessors and risk managers in DETR and the Environment Agency. They are also recommended to other Government departments, agencies and organisations to meet the Government's commitment to place the environment at the heart of all policy-making. Because Government policy covers a very wide range of activities, establishing a set of common principles for environmental risk assessment and management is essential. In addition, these guidelines are relevant to other public or private sector organisations involved in making decisions that may have an impact on the environment. It is, therefore, the aim that the principles set down here should be adopted in all routine decisions concerning environmental policy, management and protection.
What is 'the environment'?
In general, the term environment covers the physical surroundings that are common to everybody including air, water, land, plants and wildlife. This document adopts the definition used in the Environmental Protection Act 1990 that the environment '... consists of all, or any, of the following media, namely the air, water and land'. These guidelines focus on the application of risk assessment and management for the protection of the whole or part of our general surroundings and also for the protection of human health through exposure to our general surroundings. They do not apply to the protection of individuals or of the larger public body, as in consumer or public health protection.
Hazard and risk: problems with terminology
One of the difficulties with the concept of risk is that it relates to common experiences for which a language has been developed across a diverse range of disciplines and activities. This language often lacks precision, and its ambiguity can lead to confusion. It is not the intention of these guidelines to be prescriptive about terminology, but it is important to set out clearly the way that the terms hazard and risk are used here:
hazard - a property or situation that in particular circumstances could lead to harm.
risk - a combination of the probability, or frequency, of occurrence of a defined hazard and the magnitude of the consequences of the occurrence.
A complicating issue for environmental risk assessment is the lack of an easily defined measure of what constitutes harm to the environment. In some cases definitions of environmental damage are laid down in statute, but in others appropriate criteria will need to be selected on the basis of scientific and social judgements. These issues are discussed throughout the guidelines.
These guidelines propose a framework which consists of parallel, interlinked and complementary processes - science-based risk assessment, stakeholder involvement and risk management - which should be seen as fitting within the general options appraisal perspective described above.
Risk assessment
Guidance on the scientific aspects of risk assessment is based on that provided in the Department of the Environment's 1995 guidance document, brought up to date where necessary. Ways of estimating the probability of harm being caused to the environment and of evaluating the severity of that harm are described. The guidelines show how to base an assessment of risk on these two measures. They also deal with the considerable uncertainty that is likely to exist in the quantification of both the probability and the consequences of any hazard.
Stakeholder involvement
Stakeholders are those parties concerned with, or affected by, risk and may include Government, regulatory authorities and other agencies, professional and industrial bodies, environmental and local interest groups and individual members of the public. All activities involve a certain level of risk and it is the role of risk assessment to inform decisions about accepting, managing or removing those risks. The objectives, interests and responsibilities of stakeholders may be varied and contradictory.
The guidelines emphasise the importance not only of communicating the scientific aspects of risk assessment in a coherent and transparent way, but also of understanding underlying concerns, particularly those of the general public who may be affected by decisions based on risk assessments.
During the risk assessment and stakeholder dialogue, the broader significance of a risk is evaluated as a basis for risk management decision-making. This process essentially determines the acceptability of a risk. Having evaluated the significance of a risk, a decision must be made as to whether the risk is acceptable as it stands, whether it should be modified, or whether it should be removed altogether. This process involves consideration of the various options available to manage a risk, deciding which of these is the preferred option and communicating the basis for any decisions taken.
The final decision on how best to manage environmental risks should, therefore, always be informed both by science and by stakeholder concerns, and will often be a political decision.
Structure of the guidelines
This document promotes a tiered approach to environmental risk assessment, together with pointers to useful sources of advice and information. This tiered approach has a broad international consensus. A comprehensive bibliography is provided at the end of the document, as are case studies to illustrate the processes of risk assessment and management. This approach is reflected in the structure of the guidelines as follows:
- A framework for environmental risk assessment and management (Chapter 2)
- The social aspects of risk (Chapter 3)
- Problem formulation (Chapter 4)
- Risk screening and prioritisation (Chapter 5)
- Quantification and dealing with uncertainty (Chapter 6)
- Evaluating the significance of a risk (Chapter 7)
- Options appraisal and decision-making (Chapter 8)
- Monitoring (Chapter 9)
These guidelines are intended to be read and used within this tiered approach. While they follow a logical progression, each chapter covers a distinct element of the risk assessment and management process and can, therefore, be used independently.
1.5 Environmental risk management and sustainable development
Sustainable development aims to achieve a better quality of life for everyone now and for generations to come. The needs of the present should not compromise the ability of future generations to meet their own needs (intergenerational equity). Sustainable development is concerned with achieving economic development in the form of higher living standards while protecting and enhancing the environment. The overall aim is to ensure that these economic and environmental benefits are available to everybody.
The Government's vision of sustainable development is based on four broad objectives:
- social progress which recognises the needs of everyone;
- effective protection of the environment;
- prudent use of natural resources; and
- maintenance of high and stable levels of economic growth and employment.
The achievement of sustainable development requires collective partnership approaches to decision-making for environmental protection. It is about integrating economic demands and social needs with the capacity of the environment to cope with discharges, pollution and other perturbations, and to support human and other life. Decisions based on environmental risk assessments must therefore also take account of the likely economic and social impacts of the options under consideration.
1.6 Risk management and the precautionary principle
In the Rio Declaration adopted by governments at the United Nations Conference on Environment and Development in 1992, the precautionary principle was interpreted as follows:
'Where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation.'
The UK Government's interpretation, which is set out in Chapter 4 of its sustainable development strategy, A Better Quality of Life, is based on the Rio definition. It states that precautionary action requires assessment of the costs and benefits of action and transparency in decision-making.
The precautionary principle means that it is not acceptable just to say 'we can't be sure that serious damage will happen, so we'll do nothing to prevent it'. Precaution is not just relevant to environmental damage - for example, chemicals which may affect wildlife may also affect human health.
At the same time, precautionary action must be based on objective assessments of the costs and benefits of action. The principle does not mean that we only permit activities if we are sure that serious harm will not arise, or there is proof that the benefits outweigh all possible risks. That would severely hinder progress towards improvements in the quality of life.
There are no hard and fast rules on when to take action: each case has to be considered carefully. We may decide that a particular risk is so serious that it is not worth living with. In other cases society will be prepared to live with a risk because of other benefits it brings. Transparency is essential: difficult decisions on precautionary action are most likely where there is reason to think there may be a significant threat, but evidence for its existence is as yet lacking or inconclusive. Decisions should be reviewed to reflect better understanding of risk as more evidence becomes available.
The extent to which precautionary action is necessary should be given careful thought for three reasons. First, action that is taken to protect one aspect of the environment can sometimes cause damage elsewhere (unintended consequences). Second, it may be better in certain circumstances not to take action if the consequences of doing so are irreversible (reversibility). Third, a decision on whether to take precautionary action should take account of the potential benefits forgone as a result of such action.
Because of the general lack of consensus over practical application of the precautionary approach, the use of risk assessment to inform decisions about environmental protection has sometimes been presented as being in conflict with the precautionary principle. In reality, risk assessment is often employed where issues are not clear and can be used to identify effects considered serious enough to warrant precautionary action. Risk assessments can sometimes point to the possibility of significant environmental damage, albeit in the presence of large uncertainties, and it is in such cases that precautionary action is particularly valid.
Dealing with uncertainty
Uncertainty can affect all stages of risk assessment and management processes. Analysing the sources and magnitudes of uncertainties can help to focus discussion, identify knowledge gaps and feed into decisions about the most appropriate risk management options, including whether or not precautionary action is necessary. Uncertainties generally fall into the following categories:
- model - where models provide only an approximation of the real environment;
- sample - where uncertainties arise from the accuracy of measurements or validity of the sample;
- data - where data are interpolated or extrapolated from other sources;
- knowledge - where the scientific base does not provide sufficient understanding; and
- environmental - where the inherent variability of the environment leads to errors in our approximations.
To evaluate and use risk assessments effectively as a credible basis for decision-making, it is important to understand how different sources of uncertainty contribute to the overall variability of the final risk estimates. Sensitivity analysis is an important part of this process and is a method used to examine the behaviour of a model by measuring the variation in outputs resulting from changes to its inputs.
Uncertainty analysis and evaluation are concepts which run throughout the risk assessment and management processes and discussions about them arise throughout these guidelines.
Time-scales
Because of the complexity of the natural environment, conducting a full risk assessment can in some cases be very time-consuming. Sometimes, it will therefore be necessary to consider precautionary action on the basis of hazard or initial risk assessments. In so doing, it is always necessary to account for the possible social and economic implications of any such action, in line with the requirements of sustainable development.
The previous edition of these guidelines used the terms 'intended course of action' or 'intention' to cover a wide range of possible actions which may prompt the need for a risk assessment. For the purposes of these guidelines, an intention is taken to mean 'any course of action, intentional or otherwise, which by its nature may pose a risk to the environment (natural or built), and the life it sustains' (Chapter 4).
In addition to demonstrating a clear understanding of the intention and its impacts, there is a further question, which research on risk perception shows is probably the most important of all - is there a justifiable need for this activity?
When proposed and existing projects are reviewed, normally the importance of quantified risk estimates, costs and benefits are all covered. However, the social justification of the activity is rarely included as an explicit consideration. Very often it is this social dimension that colours the whole dialogue (are we imposing a risk on the community which has no particular justification?). Perhaps there are perfectly good alternatives, for example, in the scale, location and management of an intended activity. Or perhaps apparently unreasonable opposition to a small risk is a consequence of not making the socio-economic benefits of the activity clear. It should be noted, however, that in some regulatory regimes related to safety, socio-economic factors are not legally considered grounds for withholding approval - the decision must be made on a scientific evaluation of risk alone.
Key references
Calow P (1998) Handbook of Environmental Risk Assessment
and Management, Oxford, UK, Blackwell Science
A comprehensive treatment of the basic principles of environmental
risk assessment and management. The publication consists of authored chapters
which address the scientific principles of risk assessment ranging from
industrial chemicals to genetically modified organisms (GMOs), and which
also discuss the way in which risk assessment is used in decision-making
for risk management.
Department of the Environment (1995) A Guide to Risk Assessment
and Risk Management for Environmental Protection, London, UK, HMSO
The guide explores the underlying principles of systematic risk
assessment and management as a contribution to the UK's Sustainable Development
Strategy.
Department of the Environment (1991) Policy Appraisal and the Environment,
London, UK, HMSO
DETR (1998) Policy Appraisal and the Environment: Policy Guidance,
London, UK, DETR
The 1991 document highlights the need to examine environmental
impacts within policy decision analyses. The 1998 guidance does not replace
the previous document, but presents a more focused guide for the non-specialist.
DETR (1998) Opportunities for Change. Consultation Paper on a Revised
UK Strategy for Sustainable Development (Document reference 97EP0277),
London, UK, DETR
A consultation document on a new sustainable development strategy
for the UK; see resulting strategy at UK Government (1999).
DETR (1998) Sustainable Production and Use of Chemicals. Consultation
Paper on Chemicals in the Environment (Document reference 98EP0058),
London, UK, DETR
This consultation document sought views on ways in which a more
precautionary approach to chemicals in the environment could be adopted
and helped in the preparation of a new and coherent strategic policy on
chemicals in the environment (see next entry).
DETR (1999) Sustainable Production and Use of Chemicals
-- A strategic approach. The Government's Chemicals Strategy, London,
UK, DETR
The Strategy sets out Government policies to avoid harm to
the environment or to human health through environmental exposure to chemicals.
It covers chemicals entering the environment through commercial production
and use. New policies described include a voluntary scheme for assessments
and risk reduction strategies by industry, and a Stakeholder Forum.
Douben PET, ed (1998) Pollution Risk Assessment and Management,
Chichester, UK, Wiley & Sons Ltd.
Provides an extensive discussion of the basic principles of integrated
pollution control and risk management.
Environment Agency (1997) Introductory Guidance on the Agency's
Contribution to Sustainable Development, Bristol, UK, Environment
Agency
Provides initial guidance on how the Agency will contribute to
sustainable development. It explores the background to the Agency's sustainable
development duty, the legislative and policy context and briefly describes
the wider concept of sustainable development.
Environment Agency (1997) Taking Account of Costs and Benefits,
Bristol, UK, Environment Agency
Provides guidance for Environment Agency staff on how the 'Cost
and benefits' duty in Section 39 of the Environment Act 1995 may be carried
out.
Environment Agency (1998) Consensus Building for Sustainable Development,
Bristol, UK, Environment Agency
This document sets out the Environment Agency's agenda for building
collective partnership approaches for decision-making as a contribution
to achieving sustainable development. It provides some useful and practical
illustrations of models for consensus building.
Health and Safety Executive (1999) Reducing Risks, Protecting People,
Sudbury, UK, HSE Books
A discussion document on the framework of risk-based health and
safety regulation in the UK with a valuable review of recent developments
in risk-based decision-making.
HM Treasury (1997) Appraisal and Evaluation in Central Government:
Treasury Guidance, London, UK, TSO
This document deals with risk and environmental impacts as aspects
of the general appraisal framework for projects, programmes and policies.
ILGRA (1996) Use of Risk Assessment Within Government Departments:
Report prepared by the Interdepartmental Liaison Group on Risk Assessment,
Sudbury, UK, HSE Books
This reviews the principles and practices used in Government for
risk assessment with a view to identifying best practice and encouraging
common approaches.
ILGRA (1998) Risk Assessment and Risk Management: Improving Policy
and Practice within Government Departments, Sudbury, UK, HSE Books
The second report to Ministers deals with regulatory frameworks
for regulating risk, risk communication and the use of experts in decision-making.
Lees N, Woolson H, O'Hara J & Wynne B (1997) Environmental
Information: A Guide to Sources (Second edition), London, UK, The
British Library Science Reference and Information Service
An easy-to-use and comprehensive directory of where to go for information
and help on environmental issues.
Royal Commission on Environmental Pollution (1998) Setting Environmental
Standards, Twenty-first Report, London, UK, TSO
A comprehensive review of the process of establishing standards
for environmental protection with recommendations for a more participatory
approach to their development.
Spackman M (NERA) (1998) Developing a Common UK Approach to Negotiations
on Risk Assessment at International Level, London, UK, Health and
Safety Executive
This document reviews various aspects of approaches to risk assessment
and compares UK and European perspectives.
UK Government (1994) Sustainable Development: The UK Strategy (Cm
2426), London, UK, HMSO
This document sets out the UK strategy for sustainable development
in the light of the United Nations Conference on Environment and Development
held in 1992. It highlights key areas for future action to achieve sustainable
development and seeks to set this information in the context of the UK's
international role and in response to Agenda 21.
UK Government (1999) Sustainable Development: A Better Quality
of Life. A strategy for sustainable development for the UK (Cm 4345),
London, UK, TSO
The UK Government's revised sustainable development strategy.
US EPA (1998) Guidelines for Ecological Risk Assessment (EPA/630/R-95/002F),
Washington DC, USA, US Environmental Protection Agency
These guidelines were written to improve the quality and consistency
of ecological risk assessments. They should be of particular interest
to risk assessors and risk managers, highlighting and discussing important
principles and terminologies for the ecological risk assessment process.
Electronic information sources
Cabinet Office Regulatory Impact Unit internet site -
www.cabinet-office.gov.uk/regulation/index.htm
DETR internet site - www.dtlr.gov.uk
Environment Agency internet site - www.environment-agency.gov.uk
Green Channel internet site - www.greenchannel.com/main.cfm - a web-site which promotes communication of environmental information. It provides a forum for professional, public interest and commercial organisations.
US Environmental Protection Agency internet site - www.epa.gov
-
this web-site hosts a variety of pages on environmental risk assessment
and internal links to supporting information.
Defra is not responsible for the contents or reliability of the linked web sites and does not necessarily endorse the views expressed within them. Listing should not be taken as endorsement of any kind. We cannot guarantee that these links will work all of the time and we have no control over the availability of the linked pages.
Page published 2 August
2000;
Page last modified
19 September, 2002