WHAT IS A RISK?

The word 'risk' has two distinct meanings. It can mean in one context a hazard or a danger, that is, an exposure to mischance or peril. In the other context, risk is interpreted more narrowly to mean the probability or chance of suffering an adverse consequence, or of encountering some loss.

WHAT IS A RISK ANALYSIS?Risk Analysis or Risk Assessment is a process that evaluates the likelihood or probability that adverse effects may occur to environmental values, as a result of human activities (i.e., a formal procedure for identifying and estimating the risk of environmental damage).The ERA or Environmental Risk Analysis procedure is triggered prior to a significant decision affecting the environment. It can be broken into three broad stages:

preparation, involving collecting and examining relevant background information, and establishing the focus for the assessment; conducting the assessment; and, interpreting, reporting and applying results of the assessment.

Risk assessment was described as having three interrelated components: risk identification, risk estimation and risk evaluation.

Risk Identification

Risk identification simply means recognizing that a hazard exists and trying to define its characteristics. Often risks exist and are even measured for some time before their adverse consequences are recognized. In other cases, risk identification is a deliberate procedure to review, and it is hoped anticipate, possible hazards.

Risk Estimation

This is the scientific determination of the characteristics of risks, usually in as quantitative a way as possible. These include the magnitude, spatial scale, duration and intensity of adverse consequences and their associated probabilities as well as a description of the cause and effect links. Both risk estimation and identification can involve modelling, monitoring, screening and diagnosis. The main purpose of these two management functions is to understand the environmental system and its complex pathways and processes through which risks occur.

Risk Evaluation

The third component of risk assessment is risk evaluation in which judgements are made about the significance and acceptability of risk probabilities and consequences. This stage is central to policy determination. Evaluation techniques seek to compare risks against one another, and against benefits, as well as providing ways in which the social acceptability of risks can be judged. Indeed, any judgement about social acceptability combines both political and managerial decisions since it inevitably involves a calculation of who is likely to benefit and who to suffer, and what compensation, if any, should be paid.

The information and advice provided to risk managers may be qualitative or quantitative.

Qualitative information may include: statements or evidence that the chemical is of no toxicologicalconcern owing to the absence of toxicity even at high exposurelevels; statements or evidence that the chemical is safe in the context ofspecified uses; and recommendations to avoid, minimize or reduce exposure.

Quantitative information may include: a comparison of dietary exposures with health-based guidancevalues; estimates of risks at different levels of dietary exposure; risks at minimum and maximum dietary intakes (e.g. nutrients);and margins of exposure.

CONDUCTING AN ENVIRONMENTAL RISK ANALYSIS

Risk Analysis involves six basic steps: STEP 1 - Establish the Context for ERAPREPARATION STEP 2 - Identify and Characterize Key Environmental Pressures STEP 3 - Specify Environmental Values and Indicators for the ERA

ASSESSMENT STEP 4 - Characterize Environmental Trends, Indicator Relationships and Establish Risk Classes STEP 5 - Evaluate Changes to Indicators and Risks

RESULTS STEP 6 - Report Results and Develop Risk Reduction Strategies

STAGES IN CARRYING OUT AN ENVIRONMENTAL RISK ANALYSIS

Before carrying out an environmental risk assessment it is important to clearly set out the problem being addressed and the boundaries within which any decisions on environmental risk are to be made. This is sometimes known as problem formulation and can typically define the risk of what, to whom (or which part of the environment), where (location) and when (in time). This can also assist in selecting the level and types of assessment methodology to be used in the environmental risk assessment itself.

Environmental risk assessment can be thought of as containing the following key stages.

1. Hazard identification. This would typically include identification of the property or situation that could lead to harm.2. Identification of the consequences if the hazard was to occur.3. Estimation of the magnitude of the consequences. This can include consideration of the spatial and temporal scale of the consequences and the time to onset of the consequences. When considering chemicals, this step can sometimes be termed release assessment.4. Estimation of the probability of the consequences. There are three components to this, the presence of the hazard, the probability of the receptors being exposed to the hazard and the probability of harm resulting from exposure to the hazard. This step can sometimes be called exposure assessment or consequence assessment.5. Evaluating the significance of a risk (often termed risk characterisation or risk estimation) is the product of the likelihood of the hazard being realised and the severity of the consequences. This step may also consider the uncertainty associated with both the hazard and the risk.

A concept frequently used in environmental risk assessment is that of the source pathway receptor. In this conceptual model the pathway between a hazard source (for example a source of contamination) and a receptor (for example a particular ecosystem) is investigated. The pathway is the linkage by which the receptor could come into contact with the source (a number of pathways often need to be considered). If no pathway exists then no risk exists. If a pathway exists linking the source to the receptor, then the consequences of this are determined.

Example Sources Example Pathways Example Receptors

Contaminated soils Contaminated water Leaking drums Industrial process releases

Air Water Soil Food chain

People Domestic and commercial property Infrastructure Ecosystems Animals Plants Controlled waters

At the end of the risk assessment process, existing controls should be recorded and further measures may need to be considered to reduce or eliminate the risks identified. Detailed consideration of risk management is beyond the scope of this paper but, in general terms, risk management can be achieved by reducing or modifying the source, by managing or breaking the pathway and/or modifying the receptor.

The final stage is the evaluation of the significance of the risk which involves placing it in a context, for example with respect to an environmental standard or other criterion defined in legislation, statutory or good practice guidance.

USES OF ENVIRONMENTAL RISK ANALYSIS

Some examples of the use of environmental risk analysis are given below. Assessing the impacts of chemicals used at existing sites (for example for the Control of Major Accident Hazards (COMAH) Regulations (1999), Environmental Permitting Regulations (2010) and other similar legislation). Assessing the impacts of products generated by individual companies/sites due to their use or transport etc. Assessing potential impacts of new developments, new sites or new processes as part of the planning. Assessing the impacts of products, processes or services over their life cycle (life cycle assessment or LCA). An EHSC note on LCA is available (see bibliography). Consideration of risks to the environment in a companys environmental management system (EMS) or eco-management and audit scheme (EMAS). Such schemes are based on continual environmental improvement in which risk assessment plays an important part. Registration, Evaluation, Authorization and Restriction of Chemicals Regulation. Environmental risk assessment is a key component of determining the safe use of chemicals under this legislation.

Prepared by:Mercado, MylaChE-4203