Environmental Management: Principles and practice

Risk assessment
One can define risk as the expression of the chance or probability of a danger or
hazard taking place, and risk assessment as going beyond predicting probability to
identifying objectively the frequency, likelihood, causes, extent and severity of
exposure of people or things or activities. Put simply, risk is ‘probability x
consequence’ (Suter, 1993). Risk assessment (appraisal or analysis) is a loose term—
it considers hazard and vulnerability: how people react to risk and their pattern of
exposure. Risk assessment has been defined as ‘the process of assigning magnitudes

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and probabilities to the adverse effects of human activities (including technical
innovation) or natural catastrophes’ (P.Pritchard, 1993). It involves identifying
hazards; estimating the probability of their occurrence; evaluating the consequences;
using these findings to assess risk; presenting the conclusions, ideally with some
indication of reliability of estimate. Hazard assessment and risk assessment are not
precise arts: different assessments may assign different predictions to a risk. In the
end the environmental manager must exercise judgement.
Risk assessment may go on to identify coping strategies or establish what people
will pay to avoid a risk. Some recognize risk appraisal as the assessment of
communities’ attitudes to risks. Risk assessment can be divided into that concerned
with risks to the environment or biota and that concerned with risks to humans. Risk
assessment typically consists of risk identification, risk estimation (establishment of
nature and levels) and risk evaluation (assessment of probability of occurrence,
consequences, etc.) (P.Pritchard, 1993). Risk assessment studies effects, pathways
or factors involved (e.g. laboratory experiments into toxicity). Often, risk assessment
involves weighing dangers against benefits (e.g. the threat of asbestos-related illness
versus its value in protection against fire).
Risk assessment is an analytical tradition, not a legal definition, with centuries-
old roots in the actuarial, investment and insurance professions, which has spread to
engineering, development of new materials (especially chemicals, pharmaceuticals
and biotechnology innovations), economics, healthcare and criminology. Risk
assessment may also take the form of screening a new product or activity, to ensure
that it is safe for user and environment, before releasing it for general use—i.e.
laboratory or test-bed assessments. Insurance companies and bankers need to know
risks before providing cover or loans. Administrators use risk assessment to reduce
the likelihood that they could be accused of negligence if something goes wrong and
for contingency planning.
According to Suter (1993:3), risk assessment can provide:
♦
a quantitative basis from which to compare and prioritize risks;
♦
a systematic means of improving understanding of risks;
♦
a means of making assessment more useful and credible by giving prob
abilities to predicted impacts.
Legislation like the US Toxic Substances Control Act 1976 (which requires
regulation if there is a risk to human health or environment through use or release of
a harmful chemical or biological agent) or the UK Environment Act 1995 (which
requires local authorities to carry out risk assessment and maintain registers of
contaminated land) makes it increasingly important for the environmental manager
to commission and interpret risk assessments (Asante-Duah, 1998). Separation of
‘natural’ from ‘man-made’, industrial or technical hazard assessment, and general
risk assessment, is maintained by practitioners and literature rather than reflecting
different concepts.
Unlike EIA, risk assessment tends not to address development alternatives,
and is at present less likely to be required by government policy or law (also true for

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technology risk assessment). Risk assessment is often better at estimating magnitude,
certainty and timing of impacts than EIA. Risk assessment and hazard assessment
are often applied where there is more uncertainty than EIA faces (Covello et al.,
1985:16). Mainstream EIA differs from risk and hazard assessment in that it focuses
on impacts caused by human actions (crime risk assessment also does so). EIA can
increase planners’ accountability to the public; risk assessment is likely to be more
concerned with internal management or be applied by a regulatory agency.
Hazard and risk assessment usually use a template (to help order the process)
to generate a statistical estimate of probability of occurrence of a certain level of
impact (not a forecast but a statistical recurrence, e.g. a 1 in 100 year chance of a
serious flood) and use it to produce a zoned map which can be used to determine
land use or building regulations, prepare contingency or emergency procedures (e.g.
provide hurricane shelters, tsunami protection walls and warning systems). Insurance
companies often use risk assessment to determine premiums: for example, mapping
risks against postcodes/ZIP codes.
Some threats appear suddenly, others creep up and for these it may be possible
to give a warning forecast.
Well-developed areas of risk assessment include: ecological risks, health risks,
technological and industrial risks. Like EIA, risk assessment is mainly applied at
project level or to a particular process, although it is sometimes used at policy, plan
and programme levels.
Environmental risk assessment is a sub-field of risk assessment which seeks
to assess risks to the environment resulting from industrial activity and other
developments. Ecological risk assessment, another sub-field, seeks to define and
quantify risks to non-human biota (i.e. assess the likelihood of adverse change in
an ecosystem as a result of human activity). Since 1990 the EPA have promoted it
in the USA.