1. Environmental Hazards
and Human Health
Chapter 17

2. Risk Assessment and Risk Management
• Process of Risk Assessment
• 1. Hazard identification
• 2. Dose-response assessment
• 3. Exposure assessment
• 4. Risk Characterization

3. Risk Assessment and Risk Management
• Risk Management
• cost analysis of remediating specific hazard
• establishing legal limits for discharge, exposure, and allowable levels of
the hazards
• EPA makes recommendation. But only the Congress can make the
recommendation into law.

4. Types of Hazards
• Biological
• Chemical
• Physical
• Cultural

5. Biological Hazards
• Non-transmissible diseases
• slow development
• cardiovascular diseases, most cancers, asthma, diabetes, malnutrition
• Infectious diseases
• A pathogen (bacterium, virus, or parasite) invades the body and
multiplies in its cells and tissues
• Diseases can be transmitted from one person to another.
• flu, HIV, malaria, tuberculosis

6. Epidemic vs. Pandemic
• Epidemic
• an outbreak of an infectious disease that
is limited to one area or region
• Pandemic
• an infectious disease spreads globally

7. Diseases to Know
• Influenza
• Common flu, avian influenza (H5N1), and Swine influenza (H1N1)
• HIV
• Malaria
• Diarrheal diseases
• Tuberculosis (TB)
• Hepatitis B
• Measles
• Severe acute respiratory syndrome (SARS)
• West Nile Virus

8. Chemical Hazards
• Toxic chemicals
• Persistence
• Solubility
• Biomagnification

9. Dose-Response Curve
• LD 50
• Median lethal dosage
• “response”
• negative health effect

10. Types of Chemicals that lead to chemical
hazards
• Carcinogen
• Mutagen
• Teratogens
• Some chemicals can cause severe damage
to human immune system, nervous system,
and endocrine system

11. Some Common
Chemical Toxins
• PCBs
• used as electrical insulators, fire retardant
materials, pesticides, and as adhesives
(banned in the U.S.)
• neurotoxin causing brain damage in
fetuses
• endocrine disruptor causing reproductive

12. Some Common
Chemical Toxins
• Mercury (cont’d)
• Mercury is found in batteries and
fluorescent lights.
• Inorganic mercury released from coal
burning is converted to toxic
methylmercury by bacteria.
• Enters the food chain and biomagnify

13. Some Common
Chemical Toxins
• Benzene
• Source: emission from burning coal and
oil and tobacco smoke
• short-term exposure: dizziness and
nausea
• long-term exposure: damage to the liver
and reproductive system, cancer, and

14. Some Common
Chemical Toxins
• DDT, PCBs, and phthalates
• DDT: banned in the U.S. in 1972; but still
used in developing countries to control
malaria and pests
• phthalates: used in the production of
plastics
• They are known as HAA: Hormonally

15. Legislation to Regulate Chemical Toxins
• FIFRA: Federal Insecticide, Fungicide, and
Rodenticide Act
• Authorize EPA to regulate the sale,
packaging, distributing, and disposal of
pesticides
• May suspend the use of pesticides that
are found to pose unreasonable risks to
human or wildlife

16. Legislation to Regulate Chemical Toxins
• Food Quality Protection Act of 1996
• Outlined requirements for assessing
tolerance levels for pesticides
• Provides extra funding for the protection
of infant and children
• Emergency Planning and Community Right-
to-Know Act (or simply Right-to-Know

17. Cultural Hazards
• Poverty
• greatest risk in developing countries
• increases the chance of being exposed to
infectious disease from living in crowded
conditions with inadequate availability to
sanitary conditions including clean
drinking water

18. Cultural Hazards
• In developed countries...
• reduce risk of death by avoiding smoking,
improving eating habits, getting adequate
exercise, and limiting alcohol intake,
practicing safe sex