2. Risk, Perception, Assessment, and Management Pertemuan 3
Matakuliah : D0702 Environmental Science
Tahun : 2009
Risk, Perception, Assessment, and Management Pertemuan 3

3. Definition
Quantitative Risk Assessment/ Risk Assessment: Estimates of risk for a wide range of environmental Phenomena. Ex: risk of hurricanes, floods, droughts, landslides and forest fires.
Risk Management: The use of the results of a risk assessment to make policy decisions.
Hazard: a probability of adverse dffects in a particular situation
Risk: a measure of the probability
Bina Nusantara University

4. Risk Perception Subjective /Different perception of risk?
Based on Statistic  more objective
Example:
In developing standards of environmental protection, the EPA often selects a lifetime incremental risk of cancer cause by smoking cigarette.
Bina Nusantara University

5. Risk Assessment
The EPA adopted a formal process for conducting a baseline risk assessment. Includes data collection an d evaluation, toxicity assessment, exposure assessment , and risk characterization.
Data collection and Evaluation. When collecting background information, it is important to identify the following:
Possible contaminants
Concentrations of the contaminants I key sources and media of interest, characteristics of sources, and information related to the chemical’s release potential
Characteristics of the environmental setting that could affect the fate, transport an persistence of the contaminants.
Bina Nusantara University

6. Risk Assessment
Toxicity assessment: process of determining the relationship between the exposure to a contaminant and the increased likelihood of the occurrence or severity of adverse effect.
Hazard identification determines wheteher exposure to a contaminant causes increased adverse effects for humans and to what lwevel of severity
Dose response evaluation uses quantitaibe information on the dose of the contaminant and relates it to the incidence of asverse reactions in an exposed population.
Toxicity valuse cn be determined from this wuantitative relation ship and used in the risk characterization setep to estimate different occurrence of adverse health effect based on various exposures levels.
Bina Nusantara University

7. Limitation of Epidemiological Studies
Epidemiological Studies of toxicity in human populations present four difficulties:
Large populations are required to detect a low frequency of occurrence of a toxicological effect.
A long or highly variable latency period may be needed between the exposure to the toxicant and a measurable effect
Competing causes of the observed toxicological response make it difficult to attribute a direct cause and effect.
Epidemiological studies are often based on data collected in specific political boundaries that do not necessarily coincide with environmental boundaries such as those defined by an aquifer or the prevailing wind patterns.
Bina Nusantara University

8. Exposure Assessment
Objective: to estimate the magnitude of exposure to chemicals of potentialconcern.
The magnitude of exposure is based on chemical intake and pathways of exposeure.
Bina Nusantara University

9. Total Exposure Assessment
The evaluation of all major sources of exposure is known as total exposure assessment. After reviewing the available data, it my be possible to decrease or increase the level of concern for a particular route of entry to the body. Elimination of a pathway of entry can be justified if
The exposure from a particular pathway is less than that of exposure through another pathway involving the same media at the same exposure point.
The magnitude of exposure from the pathway is low
The probability of exposure is low and incidental risk is not high.
Bina Nusantara University

10. Risk Management Every activities and societal decisions, pose a risk.
Risk Management is performed to decide the magnitude of risk reduction as well as the public acceptance.
The risk manager recognizes that if a very high certainty in avoiding risk is required, the costs in achieving low concentrations of the contaminant are likely to be high.
Bina Nusantara University

11. To reduce risk, the risk manager’s options fall into three categories:
Change the environment
Modify the exposure
Compensate for the effect.
Bina Nusantara University