RISK ASSESSMENT

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RISK ASSESSMENT
Wongwiwat Tassaneeyakul Department of
Toxicology Khon Kaen University
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Objectives
1) Understand the process of risk assessment. 2)
Describe relationship between risk assessment and
management. 3) What is the major component in
performing risk assessment ?
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the capacity of a substance to cause an adverse
effect in a specific organ or organ system
the probability that a hazard will occur under
specific exposure conditions
the weighing of policy alternatives and
selection of the most appropriate regulatory
actions
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RISK DEFINITIONS

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(Morgan 1993).
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How are risks measured and expressed?
Risks are measured by direct observation or by
applying mathematical models and a series of
assumptions to animal data to infer risk to
humans.
 
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STEPS IN RISK ASSESSMENT
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(NRC, 1983)
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Relationship between risk assessment and risk
management
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Step 1 Hazard Identification In this initial
step,   Information is gathered and analyzed in a
weight-of-evidence approach.  Data usually
consist of  

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Cancer risk assessment

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Step 2 Dose-Response Assessment
"The dose makes the poison."
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No observed adverse effect level

Acceptable Daily Intake (ADI)
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?????????????????????????????????????????????????
????????????????????????????????? aflatoxin B1
?????????? ???????? X one-hit , M multistage,
W Weibull, L logit, G multi-hit, ??? P
probit model ???????? (Lu, 1996).
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Step 3 Exposure Assessment
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?????????????????????? ???? LADD (Lifetime
Average Daily Dose)
LADD (conc. ) contact rate contact
fraction expos. duration ? (body weight)
(lifetime)
HEEEs (high-end exposure estimates)
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Step 4 Risk Characterization
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Risk Communication
(Raafat Sadhra, 1999).
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Risk Communication