hazards and risks. risk assessment hazard identification dose-response assessment exposure...
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Hazards and Risks
Risk Assessment
Hazard Identification Dose-Response Assessment Exposure Assessment Risk Characterization
Modeling Probability
Major Types of Hazards
Cultural Hazards Chemical Hazards Physical Hazards Biological Hazards
Chemical Hazards
Hazardous Chemicals Mutagens Teratogens Carcinogens Endocrine disruptors
Hazardous Chemicals
Flammable or explosive Irritant Asphixiant allergen
Common Chemical Agents with Adverse Health Affects
Arsenic Asbestos Benzene Chlorine Formaldehyde Lead Mercury Dioxins
Biological Agents Pathogenicity Route of transmission Agent stability Infectious dose Concentration Origin Data from animal studies Prophylaxis
Common Human Diseases TB Dengue Fever Malaria Yellow Fever Cholera Trypanosomiasis Cryptosporidosis Anthrax Encephalitis
Lassa Fever Leprosy Giardiasis Salmonella Plague Encephalitis Ebola Influenza Hepatitis
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
Exposure
Inc
ide
nc
e in
life
tim
e
health studies
Linear Risk Model
Response threshold
Since we rarely have good data about threshold effects, we assume they are not present
When does a contaminant become just a harmless environmental tracer
1E-08
1E-06
1E-04
1E-02
0.001 0.1 10 1000
Exposure (ppb PCE in water)
Inc
ide
nc
e o
f c
an
ce
r (l
ife
tim
e)
public health goal
detection limit
maximum contaminant level
health studies
10-8
10-6
10-4
10-2
Tetrachloroethylene (PCE, dry cleaning fluid) is a common contaminant
Radioactive tritium (3H) is of concern at very low concentration and is present in the environment at
exceedingly low concentration
1E-10
1E-08
1E-06
1E-04
1E-02
1E+00
1.00E-15 1.00E-12 1.00E-09 1.00E-06
Exposure (ppb tritium in water)
Inci
denc
e of
can
cer
(life
time)
possible public health goal
detection limit
maximum contaminant level
health studies
10-1510-12 10-9 10-6
10-10
10-8
10-6
10-4
10-2
1
1E-08
1E-06
1E-04
1E-02
1E+00
0.001 0.01 0.1 1 10 100 1000
Exposure (ppb Arsenic in water)
Inci
denc
e of
out
com
e (li
fetim
e)
possible public
health goal
detection limit
maximum contaminant
level
health studies
1
10-2
10-4
10-6
10-8
Arsenic is an example of a different pattern where the detection limit is large compared
to possible health goals
Endocrine-Disrupting Compounds (EDC) in wastewater are a concern
An environmental endocrine disruptor is defined as an exogenous agentexogenous agent that interferes with the synthesis, secretion, transport, binding, action, or elimination of natural hormonesnatural hormones in the body that are responsible for the maintenance of homeostasis, reproduction, development, and/or behaviorhomeostasis, reproduction, development, and/or behavior." (EPA 1997)
NP is a metabolite of alkylphenol ethoxylate (APEO) surfactants and is commonly detected in treated wastewater (g/L).
• APEOs are among the most widely used groups of surfactants. Worldwide, about 500,000 tons are produced annually.
Nonylphenol (NP) is an important EDC
Nonylphenol
OH
(C9H19)
17-Estradiol
OH
HO