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What is Risk?
What is Ecological Risk Assessment?
Definition
The noun "risk" has 4 senses in WordNet.
1. hazard, jeopardy, peril, risk -- (a source of danger; a possibility of
incurring loss or misfortune; "drinking alcohol is a health hazard")
2. risk, peril, danger -- (a venture undertaken without regard to
possible loss or injury; "he saw the rewards but not the risks of
crime"; "there was a danger he would do the wrong thing")
3. risk, risk of infection -- (the probability of becoming infected given
that exposure to an infectious agent has occurred)
4. risk, risk of exposure -- (the probability of being exposed to an
infectious agent)
Risk Perception Quiz
a. Riding a bicycle to and from your suburban home to work, a
distance of 20km each way, each working day for 4 years.
b. Working for one year in a coal mine (assuming a 40 hour
working week).
c. Living 4 km from a nuclear reactor for 12 months.
d. Eating peanut butter sandwiches for lunch three times a week for
20 years.
e. Drinking two glasses of wine, twice per weekend, for 10 years.
The number of additional deaths per year for the example above are: a. 3840
(assuming 240 working days per year), b. 1920, c. 0.02, d. 78 (assuming 1
tablespoon per serve of sandwiches), e. 520 (assuming four glasses make ½ litre).
So, the ‘right’ order is c. (least risky), d., e., b., a. (most risky).
Risky Activities?
Activities that increase chance of death by one in a million per year (after Wilson
1979).
Activities
Smoking 1.4 cigarettes
Spending 1 hour in a coal mine
Traveling 15 km by bicycle
Traveling 500 km by car
Flying 1500 km by jet
Living 2 months in brick bldg
One chest X-ray
Living 2 months w/a smoker
Eating 40 tblspns peanut butter
Living 50 yrs w/in 8 km nuclear reactor
Living 20 years near a PVC plant
Drinking Miami water for 1 year
Drinking ½ liter of wine
Cause of death
Cancer, heart disease
Black lung disease
Accident
Accident
Accident
Cancer from radioactivity
Cancer from radiation
Cancer, heart disease
Liver cancer
Cancer from radiation (accident)
Cancer from vinyl chloride
Cancer from chloroform
Cirrhosis of the liver
What is ecological risk assessment?
- Ecological risk assessment is the practice of determining the nature and likelihood of
effects of our actions on animals, plants, and the environment.
- EPA - Ecological risk assessment is a process for evaluating the likelihood that
adverse ecological effects may occur or are occurring as a result of exposure to one or
more stressors.
- It is a process used to systematically evaluate and organize data, information,
assumptions, and uncertainties in order to help understand and predict the
relationships between stressors and ecological effects in a way that is useful for
environmental decision making.
An assessment may involve:
•Chemical stressors
•Physical stressors
•Biological stressors
•one stressor or many stressors
- Ecological risk assessments are developed within a risk management context to evaluate
human-induced changes that are considered undesirable. Changes often considered
undesirable are those that alter important structural or functional characteristics or
components of ecosystems.
What is ecological risk assessment?
Descriptions of adverse effects can be:
1) Qualitative judgments
2) Quantitative probabilities
ERAs can be
1) Predictive
2) Retrospective
3) Predictive AND retrospective
Other closely related terminology:
1) Hazard assessment
2) Comparative risk assessment
3) Cumulative ecological risk assessment
4) Environmental impact statement
What is ERA used for?
- Industry, government agencies, policy makers, citizens, and legislators use ERA to
support environmental management decisions.
What are ERA's basic concepts?
- Ecological risks are 1) estimated from the relationship between exposure and effects,
and 2) made with varying degrees of uncertainty.
Society of Environmental Toxicology and Chemistry (SETAC) Technical Issue Paper (TIP) 1997.
Ecological risk assessments evaluate two basic elements:
1. Exposure is the interaction of stressors with receptors. Measures of exposure
can include concentrations of contaminants or physical changes in habitat.
2. The analysis of effects evaluates changes in the nature and magnitude of effects
as exposure change.
EXPOSURE
EXPOSURE
RISK
EFFECTS
EFFECTS
Society of Environmental Toxicology and Chemistry (SETAC) Technical Issue Paper (TIP) 1997.
How is ERA done?
Ecological risk assessments include:
1)
Problem formulation: clearly
defining the problem
2)
Analysis: characterizing potential
or existing exposure to stressors
and their effects
3)
Risk characterization: integrating
and evaluating exposure and
effects information
Society of Environmental Toxicology and Chemistry (SETAC) Technical Issue Paper (TIP) 1997.
How does ERA relate to decision-making?
- Ecological risk assessment is one input to environmental management decisions. Other
inputs include stakeholder concerns, availability of technical solutions, benefits,
equity, costs, legal mandates, and political issues.
What are ERAs designed to protect?
- Ecological risk assessments may address any of a variety of environmental properties
ranging from the survival of individual members of an endangered species to the
productivity of the community in a stream or the biological diversity of an entire region.
Society of Environmental Toxicology and Chemistry (SETAC) Technical Issue Paper (TIP) 1997.
Won't protection of humans also result in protection of the environment?
- Ecological receptors can receive more exposure to contaminants in the environment
and can be more sensitive than humans.
How are ERA predictions useful?
- Although there are various sources of uncertainty in ERA, we can predict many effects
with confidence. Even when uncertainties are high, risk assessments with proper
scientific review and consensus provide the best summary of the state of knowledge.
Society of Environmental Toxicology and Chemistry (SETAC) Technical Issue Paper (TIP) 1997.
What is the future of ERA?
- Anticipated improvements in ERA will include development of standard tools and
approaches and more effective links to risk management. Increasingly, ERA will address
issues concerning its application in the management of land and natural resources.
Some challenges facing ERA include the following:
•Integrating the concerns of stakeholders and risk managers with the scientific knowledge
of risk assessors
•Conducting risk assessments that encompass large areas and involve multiple stressors
•Moving beyond effects on individual organisms and species to predicting changes in
populations and ecosystems
•Communicating ecological risks to stakeholders
Society of Environmental Toxicology and Chemistry (SETAC) Technical Issue Paper (TIP) 1997.