Essentials of Toxicology
Risk Assessment Chapter 4
Definitions
• Risk Assessment
– Risk is the probability of an adverse outcome with exposure to a substance – Hazard relates to the intrinsic toxic potential of the substance
• Risk characterization the relates to the qualitative and quantitative assessment of risk that associated with a specific hazard
Definitions
• Risk communication – The process of informing interested parties • Decision making – What to do, how to do it and who to do it for!
Bioassay and Assessment
• • • • SAR In Vitro and In Vivo Short Term Tests Animal Bioassay Epidemiology
Epidemiology
• Cohort • Case control • Cross Sectional Study
Risk Characterization
• Effects versus critical effect that leads to increased morbidity and mortality
– NOEL – NOAEL – LOEL – LOAEL
Definitions
• RfD is the NOAEL divided by the Uncertainty Factor time the Modifying Factor • Why do we use factors of 10? • Safety factor of 100 is 10 times 10. • Safety factor of 1000 is 10 to the 3d power.
What are you afraid of?
What is the Value of Human Life
• • • • By the Person By the Year By the Event Other life units?
Question
• Risk
– is systematic – Is scientific – Is based on the characterization of the potential for adverse health effects – results from exposures to hazardous agents – All of the above – None of the above
Question
• Risk Assessment
– Is a defined by a linear Probit function – Is easily avoided if you know where to hide – Requires three consistent inputs to be accurately estimated – Is a way of measuring adverse outcome – All of the above – None of the above
The Last Question: How long is the Break?
• • • • • • 1 minute 10 minutes 100 minutes 1000 minutes All of the above None of the above
UC 59 WC Coke Machine