CE 3231 - Introduction to Environmental Engineering and Science

1. CE 3231 - Introduction to Environmental Engineering and Science Readings for This Class: Chapter 4 Ohio Northern University Chemistry, Microbiology & Material Balance Introduction Water & Air Pollution Env Risk Management Risk and Risk Assessment We always make decisions based upon the amount of risk involved in a given activity. However, we often overstate the risk for events that are unlikely to happened and down play the risk for events that happen all the time. Here we discuss risk and how risk assessment factors in to environmental decision making.

2. Indoor Air Quality Common indoor air pollutants Challenges with regulating indoor air quality

3. Lecture 30Risk Assessment(Risk I)

4. Risk & Risk Assessment Topics Covered Include: Class definition of risk Risk in reality Annual vs lifetime risk Risk Assessment Paradigm

5. What is risk?

6. Risk in Reality What is the riskiest activity you do? How does risk factor into your decision making? Does this risk apply equally to everyone? Should it? Do you take steps to minimize risk?

7. Risk in Reality - Top Annual Risk of Death (2004)

8. Life-time and annual risk • Life-time risk of death from all causes: • In 2001, 3.9 million deaths, 541,532 were cancer-related. The risk of dying from cancer in a lifetime: • If average life expectancy is 70 years, then annual risk of dying from cancer is

9. Risk in Reality • If cancer, heart disease, and respiratory disease are responsible for the over whelming majority of deaths each year, how do we reduce these outcomes? • What causes cancer? Heart Disease? Respiratory Disease? • How do we make decisions to reduce mortality and morbidity across a population? • Why are we interested in doing so?

10. Risk Assessment Paradigm http://foodrisk.org/overviewriskanalysis/intro/

11. In developing standards for environmental protection, EPA selects a lifetime incremental risk in the range of 10-7 – 10-4 as acceptable

12. Risk Assessment – 4 Steps

13. Step 1: Hazard Identification • Does situation/agent pose an adverse risk? Adverse risk: “...any biochemical, physiological, anatomical, pathological, and/or behavioral change that results in functional impairment that may affect the performance of the whole organism or reduce the ability of the organism to respond to an additional challenge."

14. Step 2: Dose-response assessment • If an adverse risk is present what is the relationship between the dose of an agent received by a receptor (organism or ecosystem) and the incidence of an adverse effect on that receptor • Dose is the mass of chemical received by the exposed individual • - Receptor is the organism receiving the dose

15. Step 2: Dose-response assessment • Virtually all data used to derive the dose-response curve are from animal studies • Difficulties using the animal study data:

16. 100% 80% 60% 40% 20% 0% 0 1 10 100 1000 10000 Dose ( mg/kg-body mass) Step 2: Dose-response assessment Dose-Response Curve Compound A Compound B Response (e.g. mortality) LD50 LD50 NOAEL LD = Lethal Dose, LD50=Dose causing 50% mortality NOAEL = No Observed Adverse Effect Level

17. Step 3: Exposure Assessment • Through what exposure pathways (source) and routes (media) are people exposed? How often and how long is the exposure?

18. Step 4: Risk Characterization • What is the likelyhood of an adverse effect due to a given exposure? • Effect Level • LOAEL • NOAEL

19. Step 4: Risk Characterization • Threshold vs. Non-threshold effects • Cancer • Non-cancer

20. Quantitative Risk Assessment • To Quantitatively assess the risk we need to: 1. Magnitude, frequency, and duration of every pathway of exposure 2. biological characteristics of receptors (body weight, absorption,etc.) 3. Potency (dose-response) character of agent