1. Hazards and Risks

2. Risk Assessment Hazard Identification Dose-Response Assessment
Exposure Assessment
Risk Characterization
Modeling
Probability

3. Major Types of Hazards Cultural Hazards Chemical Hazards
Physical Hazards
Biological Hazards

4. Chemical Hazards Hazardous Chemicals Mutagens Teratogens Carcinogens
Endocrine disruptors

5. Hazardous Chemicals Flammable or explosive Irritant Asphixiant
allergen

6. Common Chemical Agents with Adverse Health Affects
Arsenic
Asbestos
Benzene
Chlorine
Formaldehyde
Lead
Mercury
Dioxins

7. Biological Agents Pathogenicity Route of transmission Agent stability
Infectious dose
Concentration
Origin
Data from animal studies
Prophylaxis

8. Common Human Diseases TB Dengue Fever Malaria Yellow Fever Cholera
Trypanosomiasis
Cryptosporidosis
Anthrax
Encephalitis
Lassa Fever
Leprosy
Giardiasis
Salmonella
Plague
Encephalitis
Ebola
Influenza
Hepatitis

9. Toxicity: Determining if a chemical is harmful
Size of dose over time
How often exposure occurs
Acute vs. chronic
Age of person exposed
Adult, very old, child, infant
State of health
Immune compromised
Body fat
How well body detoxifies
Lungs, liver, kidnies

10. When does a contaminant become just a harmless environmental tracer
Since we rarely have good data about threshold effects, we assume they are not present

11. Tetrachloroethylene (PCE, dry cleaning fluid) is a common contaminant

12. Radioactive tritium (3H) is of concern at very low concentration and is present in the environment at exceedingly low concentration

13. Arsenic is an example of a different pattern where the detection limit is large compared to possible health goals

14. Endocrine-Disrupting Compounds (EDC) in wastewater are a concern
An environmental endocrine disruptor is defined as an exogenous agent that interferes with the synthesis, secretion, transport, binding, action, or elimination of natural hormones in the body that are responsible for the maintenance of homeostasis, reproduction, development, and/or behavior." (EPA 1997)

15. Nonylphenol (NP) is an important EDC
NP is a metabolite of alkylphenol ethoxylate (APEO) surfactants and is commonly detected in treated wastewater (mg/L).
APEOs are among the most widely used groups of surfactants. Worldwide, about 500,000 tons are produced annually.
Nonylphenol OH
(C9H19)
17b-Estradiol OH HO