1. Risk, Toxicology, and Human Health
Chapter 19

2. Risk and Probability
Risk: the possibility of suffering harm from a hazard that can cause injury, disease, death, economic loss, or environmental damage Risk assessment: the scientific process of estimation how much harm a particular hazard can cause to human health Risk management: deciding whether or how to reduce a particular risk to a certain level and at what cost

4. Hazards Cultural hazards Physical hazards Chemical hazards
Biological hazards

5. Cultural Hazards
Diet/nutrition
Lifestyle choices (i.e. drugs)
Crime

6. Physical Hazards
Temperature
Noise/vibrations

7. Chemical Hazards
Solvents
Acids
Pesticides

8. Biological Hazards
Bacteria
Viruses
Molds

9. Toxicology
Toxicity: measures how harmful a substance is in causing injury, illness or death to a living organism Dosage: the amount of a substance a person has ingested, inhaled or absorbed through the skin (other factors include frequency of exposure, who is exposed and how well the body’s detoxification systems work)

11. Toxicology
Bioaccumulation: some molecules are absorbed and stored in specific organs or tissues at higher than normal levels Biomagnification: levels of potential toxins in the environment are magnified as they pass through food chains and webs, organisms at low trophic levels might ingest only small amounts of a toxin, but each animal on the next level up that eats them take in larger amounts

13. Toxicology
Synergism: the multiplying effect of harmful substances (asbestos and smoking) Response: the type and amount of health damage resulting from exposure to a chemical or other agent Acute effect: immediate or rapid harmful reaction (dizziness or death) Chronic effect: long lasting or permanent consequence to single or repeated doses

14. Poisons
Poison: a chemical that adversely affects the health of a living human or animal by causing injury, illness or death
Fig p. 413
Median lethal dose (LD50)

15. Chemical Hazards
Hazardous chemicals: can harm humans or other animals because it is flammable or explosive or because it can irritate or damage the skin or lungs, interfere with oxygen uptake, or induce allergic reactions

16. Three types of hazardous chemicals:
Mutagens: chemicals or ionizing radiation that cause or increase the frequency of random MUTATIONS in DNA molecules Teratogens: chemicals that cause harm or birth defects to a fetus or embryo (FAS) Carcinogens: chemicals or ionizing radiation that cause or promote (malignant) cancer

17. Biological Hazards: Diseases
Nontransmissible disease: disease caused by something other than a living organism and does not spread from one person to another (most cancers) Transmissible disease: disease that is caused by a living organism and can spread from one person to another

18. Biological Hazards: Diseases
Infectious agents/Pathogens: cause disease (examples include: viruses, bacteria, protozoa, parasites) Vectors: ways in which infectious agents are spread (examples include: air, water, food, body fluids, insects and other nonhuman carriers)

19. Bioterrorism Possible targets: air, water, and food Inexpensive
Fairly easy to produce biological agents
Recombinant DNA techniques