Extra sessions to begin
Yes, I do want you to do the readings
What are the basic concepts applicable to all environmental
- human health risk assessments
- ecological risk assessment
- industrial applications of risk assessments
What are the unifying concepts?
What are their currently used methodologies?
How are they applied?
Risk assessment concepts
+ The technique of risk assessment is used in a wide range of 6
professions and academic subjects
Risk assessment has become a commonly used approach in
examining environmental problems.
For instance, the approach is used to assess the environmental
risks posed by Genetically Modified Organisms (GMOs),
chemicals, ionising radiation and specific industrial plants.
Definitions in risk assessment are all-important because of the
wide range of uses of the approach, and different meanings
of terms used by different groups of experts and
“the potential to cause harm”
Can be defined as “a property or situation that in particular could lead to
A more difficult concept to define
Used to mean “chance of disaster”
In the process of risk assessment, most commonly means: ‘the combination
of the probability, or frequency, of occurrence of a defined hazard and the
magnitude of the consequences of the occurrence.”
Risk = Severity x Likelihood
the evaluation of the degree of harm or danger from some condition such
as exposure to a toxic chemical - either quantitatively or quanlitatively
The process of determining an expected annual mortality
Carried out to examine the effects of an agent on:
Humans (health risk assessment)
Ecosystems (ecological risk assessment)
Environmental risk assessment
examination of risks resulting from technology that threaten
ecosystems, animals and people.
human health risk assessments,
ecotoxicological risk assessments,
and specific industrial applications of risk assessment that examine
end-points in people, biota or ecosystems.
Many organisations are now actively involved in ERA, developing
methodologies and techniques to improve this environmental
OECD (organization for economic cooperation and development)
WHO (world health organization)
One of the major is the availability and certainty of data
What do the risks mean to those effected?
Depends on how the risk is perceived
depend heavily on how the risk is perceived. Risk perception involves
people's beliefs, attitudes, judgements and feelings, as well as the
wider social or cultural values that people adopt towards hazards and
Risk perception will be a major determinant in whether a risk is
deemed to be "acceptable" and whether the risk management
measures imposed are seen to resolve the problem.
the decision-making process through which choices can be made
between a range of options which achieve the "required outcome” – i.e.
reduction of risks to an "acceptable" level within the constraints of the
Eliminated (total ban on the use or marketing of a hazardous chemical)
(but what about the substitute?)
Transferred (risk transferred to insurance companies, eg)
Retained (more often retained w/o knowledge)
Reduced (most common approach; regulation, voluntary industry
+ As Lois Gills of Love Canal stated 10
‘From a community’s perspective, risk
assessments are ‘the risks that someone else
has chosen for you to take.’ What is a life worth
… but equally important is whose life”’
Is risk a technical matter that is determined
objectively or a social construction that
emerges from communication among experts,
affected parties, and public agencies?
+ Risk communication 11
Simplest form: any public or private communication that informs
individuals about the existence, nature, form, severity, or
acceptability of risks
An increasingly important area of risk management
The way in which information relating to risks is communicated
Closely linked to risk perception
one-way transmission of information
two-way exchange of views on the risk
Role of risk assessment in
Can be used in the design of regulation
Targets for regulation can be selected (risks > benefits?)
Societally ‘acceptable’ risk levels can be determined (ALARP)
Decisions can be made on the appropriate level of risk reduction
Can provide a basis for site-specific decisions, for instance in land-
use planning or siting of hazardous installations (eg: risk posed by
contaminated land sites in relation to the land’s proposed use and
To prioritize environmental risks, for instance in the determination
of which chemicals to regulate first – within context
To compare risks; for instance to enable comparisons to be made
between the resources being allocated to the control of different
types of risk, or to allow risk substitution decisions to be made.
What risk assessment and management can and
+ cannot do 13
A technique which can weigh-up information that is basically in
different "languages” (provides a bridge between the scientific and
A mechanism to aid decision-making (aid)
As a means of comparison between risks to determine whether
there is equity of action or that the action is proportionate to the risk
A basis for effective risk communication (but there are limitations –
need to address the value issues that underlie the perception of
A method for highlighting and prioritising research needs
Possible over-reliance and over confidence in results
Narrow focus on parts of a problem rather than the whole (parts, not
Awkward relationship between risk assessment and the
A typology of risk assessment and
Human health risk assessment
Ecological risk assessment
The former have a differing historical development and
regulatory and policy imperatives
Applied industrial risk assessment (more engineering risk
Methodology least developed for ecological risk assessment
Overview of risk assessment methods
What are the steps required in all types of risk assessment?
Number of hazards that can be examined through ERA is vast
Techniques have also evolved differently due to the
institutional basis of the risk assessor and the intended use of
the risk assessment
Nat’l Academy of Sciences model
1. Hazard Identification
2. Dose-Response Assessment
3. Exposure Assessment
4. Risk Characterisation
- Developed for human health risk assessment; formed the
basis of ecological models of risk assessment used in the
- But does not encompass all the types of ERA in use
ERA unifying steps
1. Problem Formulation:
2. Hazard Identification
3. Release Assessment
4. Exposure Assessment
5. Consequence Assessment
6. Risk Estimation
7. Risk Evaluation
Health Risk Assessment
Methodologies and techniques firmly established
Physical Risks - Ionising Radiation
Food Safety Risk Assessment
Chemical Risk Assessment
The procedures, methods and techniques for regulatory risk
assessment of chemicals in the EU is described in both legislation
and supporting Technical Guidance Documents. Implementation
is supported by the European Chemicals Bureau, part of the Joint
Research Centre, in Ispra.
Same with the US.
What about Lebanon?
International Organisations such as OECD, IPCS and ECETOC and
many National Organisations are conducting programmes on
human health and ecological risk assessment. The work
contributes both to the shaping of regulation and the response to
Human Health Risk Assessment for Chemicals
Based on the NAS model. Remember that?
Difference in methodology is due to difference in class of
chemical and toxicological end-point being assessed
All human health risk assessments of chemicals include
hazard identification, dose-response assessment, exposure
assessment and risk estimation/characterisation.
Hazard Identification is defined as "the identification of the
adverse effects which a substance has an inherent capacity to
cause" (CEC, 1993). This involves consultation of any
toxicological and epidemiological data.
CRA: Human Health Risk –
Dose-response assessment is the "estimation of the relationship
between dose, or level of exposure to a substance, and the
incidence and severity of an effect" (CEC, 1993).
The dose-response relationship is gotten from epidemiological
and toxicological data
The principle of the assessment is to compare the [ ] of a
substance to which a pop is exposed w/ the [ ] of a at which no
adverse effects are expected to occur
Risk reduction measures
Raising awareness on the safe handling of substance
Use of emission permits with set limits
Total ban of a substance or activity
CRA: Human Health Risk
Assessment for Chemicals
Typically based on the NAS model
The "determination of the emissions, pathways and rates of
movement of a substance and its transformation and degradation
in order to estimate the concentration/doses to which human
populations or environmental compartments are or may be
Environmental exposure to chemicals can be direct - as a result of
emission to the environment (air, land, water) of a substance
through industrial manufacture, use or disposal,
or indirect - through drinking water or the food chain.
+ Reminder: NAS model 25
Objective is to identify the substance(s) that could injure humans exposed to them
and thus to reduce injury
A relation exists between the dose of agent received and the response produced.
Experiments conducted. Use of epidemiological data (mainly based on
Estimation of the relationship between dose, or level of exposure to a substance,
and the incidence and severity of an effect. Typically –direct human data is
Determination of the emissions, pathways and rates of movement of a substance
and its transformation and degradation to estimate the [ ] / doses to which human
populations or environmental compartments are or may be exposed
Via lungs, via digestive tract, and via skin
A range of exposure values should be estimated
Estimation of the incidence and severity of the adverse effects likely to occur in a
human population or environmental compartment due to actual or predicted
exposure to a substance; may include ‘risk estimation’ (quantification of
likelihood); summary of data in risk assessment process + uncertainties
Different typologies of health risk
* Neurotoxic (examples of lead and pesticides)
* Immunotoxic (example of allergenic substances)
* Developmental (example of thalidomide)
* Reproductive (example of phthalates)
* Carcinogenic (example of dioxins)
HRA – biological risks
those risks associated with biological agents of concern to
public health such as pathogenic strains of bacteria, which are of
particular concern as food-borne hazards,
and those risks associated with the introduction of genetically
engineered organisms into the environment or the food chain.
The World Health Organization has adopted risk assessment as
the main way to scientifically justify food safety standards
However, significant problems exist when applying quantitative
risk assessment techniques to microbial hazards, such as the
difficulties in obtaining dose-response data and elaborating
appropriate dose-response relationships in humans
Ecological Risk Assessment (EcoRA)
involves the assessment of the risks
posed by the presence of substances
released to the environment by man, in
theory, on all living organisms in the
variety of ecosystems which make up
EcoRAs tend to focus:
risks from chemicals and Genetically
Modified Organisms (GMOs)
physical risks such as temperature rises
caused by cooling water releases from
Ecological Risk Assessment
EcoRA methodology has been developed from that already
established for human health.
The general principles are widely agreed upon but the
application of the process still provokes considerable
The Health Risk Assessment (HRA) approach lends itself well
in many respects to EcoRA but, due to the complex nature of
the potential target(s) or receptor(s), several problems have
presented themselves to practitioners.
HRA is concerned with individuals and morbidity and mortality,
EcoRA -- populations and communities and the effects of
substances on mortality and fecundity.
EcoRA has to deal with a multitude of organisms, all with varying
sensitivities to chemicals and various groups have distinct
Because of the difficulty in obtaining toxicity data on all
organisms in an ecosystem,
the recognised practice is to test selected representatives of major
taxonomic groups and use these as surrogates for the whole system.
But: This method is questionable
It may not protect the most sensitive species exposed in the
Failure to identify the effects of an agent on a potential receptor
can result in widespread damage to organisms and ecosystems.
The Risk Assessment Process for
The method for ERA as used by the EU
Four steps used in Health Risk Assessment
Effects Assessment involves the identification of the hazard based on its
physico-chemical properties, ecotoxicity and intended use, and the
estimation of a Predicted No Effect Concentration (PNEC), derived from
ecotoxicity data and the application of assessment factors;
Exposure Assessment involves the calculation of a Predicted Environmental
Concentration (PEC). This is derived using monitoring data, realistic worst
cases scenarios and predictive modelling techniques. It is a complex task
and should consider release, degradation, and transport and fate
mechanisms. Local relevant emission and distribution routes are shown in
Risk Characterisation involves the calculation of a quotient - the PEC/PNEC
ratio. If the ratio is less than 1 the substance is considered to present no risk
to the environment in a given scenario.
+ Exposure assessment: Local relevant 34
emission and distribution routes
a developing field
Many problems which need resolving such as;
Determining the effects at population and community
Selection of end-points;
Selection of indicative species;
The selection of field, laboratory, mesocosm and
The incorporation of resilience and recovery factors of the
Many organisations are actively involved in the
development of ecological risk assessment methodology,
they include the US EPA, the US NRC, OECD, SETAC and
Evaluation of risk and risk
Complex process of determining the significance or value of the
identified hazards and estimated risks to those concerned, or
The evaluation of risk is concerned with issues relating to how
those affected by risks perceive them, the value issues
underlying the perceived problem and the trade-off between
the perceived risks and benefits.
Let’s look at the factors involved in risk perception and risk
We will also examine the advantages and disadvantages of the
major approaches used in making risk management decisions -
bootstrapping, formalised methods such as cost-risk-benefit
analysis, and professional judgement.
The importance of risk evaluation
Risk evaluation attempts to define what the estimated risk
actually means to people concerned with or affected by the
A large part of this evaluation will be the consideration of
how people perceive risks.
We will provide an overview of the psychometric and cultural
approaches underpinning risk perception, offering an
insight into the reasons why risks are perceived in different
How safe is safe enough?
? = how safe is safe enough?
An ERA will characterise the risk posed by a situation and then
the process of risk management will eventually lead to a choice
of action that will achieve the desired level of "safety".
The determination of this "acceptable" or "tolerable" level of
risk may have been prescribed before the risk assessment
process begins - through societally determined acceptable
levels of risk in the form of legislative environmental quality
standards for instance, or industry derived "norms".
In this case, risk management attempts to analyse which options
for action based on the results of the risk assessment will
produce these pre-determined risk levels.
What about where no acceptable risk standards exist?
… the risk management process will attempt to derive
‘acceptable’ or tolerable risk on a case-by-case basis
Acceptable to whom?
When risk assessment and management procedures are
carried out by regulators or government, the aim is to
produce societally acceptable risk levels.
When an individual company carries out a risk assessment,
in the absence of societally determined standards, risk levels
will be determined which are acceptable to the company.
These may have reference to societally acceptable levels or
may be based on a formal risk-cost-benefit approach as
advocated by some software packages on risk reduction.
Decision making to determine "acceptable" or "tolerable" risk
uses a number of approaches.
The three major approaches to acceptable risk decisions
-- are professional judgement where technical experts devise
-- bootstrapping where historical precedent guides decision
-- formal analyses where theory-based procedures for
modelling problems and calculating the best decision are used.
These approaches are explained in detail in the readings.
Risk management action
Environmental risk can be:
transferred to another body such as an insurance company,
retained by a company or nation,
eliminated by removal of the risk agent,
In most environmental risk management conducted by nations
on behalf of society, risk reduction will be the risk
management option chosen. For individuals or companies,
risk transfer is a common approach. This may be required by
legislation, especially for infrequent catastrophic events. Risk
elimination is often very difficult because of all the social and
economic effects the removal of an agent can create.
Can the agent be substituted by another, less risky agent? For instance, can a
chemical pesticide be substituted by a biological method? What are the risks
of the new agent being introduced into the scenario? Is the new agent as
Providing information about the safe use and disposal of agents will try to
ensure that the risks assessed are the same as what actually occur in practice.
Education and information may also allow the public and users to choose lower
risk options and force the manufacturers into the production of less risky
Limit the availability of the agent by marketing bans or limits on the production
or importation of the agent. Such a risk reduction technique has severe
implications politically and economically and can often be controversial. Such
decisions are taken at a national or regional level and at an international level
such agreements are difficult to obtain.
Harmonisation of risk assessment methods
Data deficiencies and gaps
Harmonisation of test protocols for chemicals
Understanding of mixtures or multiple stressors
Improvement of exposure assessment
Internationally harmonised assessment factors
Speeding up risk assessments
Development of explicit methodologies for risk management
Increased transparency of decision-making
Peer review of risk management assessments
Increased participation in risk management
Reminder: Risk communication is defined in its simplest
form as “any public or private communication that informs
individuals about the existence, nature, form, severity, or
acceptability of risks”
As we’ll see, it actually involves more than that!
From a technical perspective,
risk assessment = the evaluation of the degree of harm or
danger from some condition such as exposure to a toxic chemical,
while risk management = the implementation of steps to reduce
the danger to the public and the environment
Risk assessment - again
Risk = Severity x Likelihood
a technical, four-step procedure:
Hazard identification. What is the potential source of danger? For example, does
a waste incinerator emit highly toxic dioxins or other hazardous chemicals?
Assessment of human exposure. Are any human populations exposed to this
hazard? If so, can the various routes or pathways of the hazardous substance to
specific organs or tissues of human bodies be traced? Finally, how much (what
dosage) of this substance enters these human bodies?
Modeling of the dose responses. What is the relationship between the dosage
that is received and harmful responses or illnesses in the exposed population?
Characterization of the overall risk. What are the overall implications of the dose
responses for the health of the exposed population?
Technical models of risk assessment use the resulting numerical value as the
basis for judgments of what is an “acceptable risk. This judgment involves
Limitations of technical model
exceedingly difficult to trace the “pathway
need to show direct correlation between particular
chemicals and the specific illnesses
Cultural-Experiential Model of Risk
technical models conflate numerical risk (expected annual
mortality) with judgments about the experience of those forced to
live with imposed or involuntary risks
big difference between those who take risks and those who are
victimized by risks others take
‘hazard’ versus ‘outrage’
experts often make assumptions about environmental risks
that are quite removed from the experience of those affected
by these risks
the context in which a risk is embedded raises a number of
questions that may affect one’s judgment of whether a risk is
acceptable or not:
Is the risk imposed by distant or unknown officials?
Is it engaged in voluntarily?
Is it reversible?
Risk = hazard + outrage
Hazard is what experts mean by risk (expected annual mortality)
Outrage should refer collectively to those factors that the public
considers in assessing whether their exposure to a hazard is
Diffusion in time & space
Problem with the Sandman
This deceptively simple formula [risk equals hazard plus outrage] has
become a staple in PR industry discussions of risk communication.
… By understanding that risk equals hazard plus outrage, [Thomas]
Buckmaster [general manger of the PR firm Hill & Knowlton] says,
risk communicators can overcome the fear and hostility of
“grassroots members, stakeholders, and the public at large.” …
Once people are outraged, they don’t listen to hazard statistics …
don’t use numerical risk comparisons.”
In fact, he says, “managing the outrage is more important than
managing the risk.”
Cultural rationality and risk
cultural rationality include personal, familiar, and social concerns in
evaluating a real risk event
+ Technical Rationality Cultural Rationality 53
Trust in scientific methods, Trust in political culture and
explanations; evidence democratic process
Appeal to authority and Appeal to folk wisdom, peer
expertise groups, and traditions
Boundaries of analysis are Boundaries of analysis are
narrow and reductionistic broad; include the use of
analogy and historical precedent
Risks are depersonalized Risks are personalized
Emphasis on statistical variation Emphasis of the impact of risks
and probability on the family and community
Appeal to consistency and Focus on particularity; less
universality concerned about consistency
Those impacts that cannot be Unanticipated or unarticulated
uttered are irrelevant risks are relevant
Two quite different models of risk communication that have
emerged since the late 1980s, reflecting the technical and
cultural meanings of risk we have thus discussed:
The traditional, technical model of risk communication seeks
to translate numerical characterizations of risk to public
while the cultural model of risk communication draws upon
the experiences and local knowledge of affected
communities as well as laboratory models, doses, and
pathways of exposures
Technical Risk Communication
the translation of technical data about environmental or health
risks for public consumption, with the goal of educating a target
one-way transfer of information
goal: to inform, change, and (sometimes) to assure
1. Inform local communities of an environmental or health hazard
Importantly, technical risk communication occurs after an
assessment has been made of the health effects of an
2. change risky behavior
3. Assure those exposed to a perceived hazard that the risk is
Technical Risk Communication
in the US, Agency officials tend to assume that individuals
underestimate the dangers of personal health behaviors such
as not wearing seat belts, smoking, etc.,
but in environmental affairs, the logic is reversed—agencies
assume that individuals have “exaggerated” fears about
chemical hazards, etc
* in Lebanon?
Cultural model of risk
3 areas where the public’s intuitive and experiential judgments
differed most from technical risk analysis:
1. “concern about low-probability but high consequence events;”
for example, a 1 percent chance that an accident will occur, but a
terrible toll of death should it happen.
2. a “desire for consent and control in social management of risks;”
the public’s feeling that they have a say in decisions about risk is
the opposite of a coerced or involuntary imposition of risk.
3. “the relationship of judgments about risk to judgments about
social institutions;” in other words, the acceptability of risk may
depend on how confident citizens are in the institution that is
conducting a study, managing a facility, or monitoring its safety.
Citizen participation in risk
US National Research Council: understanding of environmental
risk requires “a broad understanding of the relevant losses,
harms, or consequences to the interested and affected parties,
including what the affected parties believe the risks to be in
Critical rhetoric for risk communication … 3 principles
sees risk as socially constructed and rhetorical … The meaning and
value of risk in a given situation is [sic] a function of multiple and
sometimes competing discourses. …
focuses on the processes of decision making … [especially] on the
relations of power within decision making processes, asking
questions about who participates and in whose interests decisions are
seeks to contextualize and localize risk situations … [by encouraging]
Media Reporting of Risk
What factors influence what is reported about environmental
risk? What factors influence whose voices are presented in
Media Reports of Risk: Accurate Information or Sensational
low probability, but high consequence” occurrences
What are your thoughts about sensationalized risk news?
Voices of side effects…
those individuals (or their children) who suffer the “side
effects” of the risk society such as asthma and other illnesses
from air pollutants, chemical contamination, etc