Ordering of Perceived Risk

1. Ordering of Perceived Risk

2. Risk, Toxicology, and Human Health G. Tyler Miller’s Living in the Environment 13th Edition Chapter 11

3. Human Health Health is a state of complete physical, mental, social and spiritual well-being and not merely the absence of disease or infirmity or The ability to lead a socially and economically productive life

4. Holistic Concept of Health This concept recognizes the strength of social, economic, political and environmental influences on health Determinants Heredity Health and family welfare services Environment Life-style Socio-economic conditions

5. Risk and Probability • Risk • possibility of suffering harm from a hazard that can cause injury, disease, economic loss, or environmental damage. • Probability • mathematical statement about how likely it is that some event or effect will occur. Risk = pExposure x pHarm

6. Risk Assessment and Management

7. Risk Analysis Identifying hazards Risk assessment Ranking risks Comparative risk analysis Determining options Risk management Informing decision makers Risk communicaiton

8. How well do we perceive risks? Most of us do poorly at assessing the relative risks from the hazards that surround us.

9. What do you think are the highest risk hazards in the U.S.?

10. Cause of Death Deaths Tobacco use 431,000 Alcohol use 150,000 Accidents 95,600 (42,000 auto) Pneumonia and Influenza 84,400 Suicides 30,500 Homicides 19,000 Hard drug use 15,000 AIDS 14,000 Fig. 16.1, p. 396

11. Hazard Shortens average life span in the United States by 7-10 years Poverty Born male 7.5years Smoking 6 years Overweight (35%) 6 years Unmarried 5 years 2years Overweight (15%) Spouse smoking 1 year Driving 7 months Airpollution 5 months Alcohol 5 months Drug abuse 4 months 3 months AIDS Drowning 1 month Pesticides 1 month Fire 1 month Natural radiation 8 days Medical X rays 5 days Oral contraceptives 5 days Toxic waste 4days Flying 1 day Hurricanes, tornadoes 1 day Fig. 16.15, p. 414 Living lifetime near nuclear plant 10 hours

12. Yet some of these people are terrified of dying from… • Commercial plane crash • 1 in 4.6 million • Train crash • 1 in 20 million • Snakebite • 1 in 36 million • Shark attack • 1 in 300 million

13. Toxicology Toxicity measures how harmful a substance is. Toxicity depends on . . Dose the amount of a potentially harmful substance a person has ingested, inhaled, or absorbed. Response the type or amount of damage

14. Toxicity Dose - the amount of a potentially harmful substance a person has ingested, inhaled, or absorbed. Solubility Persistence Bioaccumulation Biomagnification Chemical interactions Antagonistic: reduces Synergistic: multiplies

15. Bioaccumulation and Biomagnification Fig. 11-4 p. 231

16. Toxicity ToxicityLD50Lethal DoseExamples Super < 0.01 less than 1 drop dioxin, botulism mushrooms Extreme <5 less than 7 drops heroin, nicotine Very 5-50 7 drops to 1 tsp. morphine, codeine Toxic 50-500 1 tsp. DDT, H2SO4, Caffeine Moderate 500-5K 1 oz.-1 pt. aspirin, wood alcohol Slightly 5K-15K 1 pt. ethyl alcohol, soaps Non-Toxic >15K >1qt. water, table sugar (LD50 measured in mg/kg of body weight)

17. Toxicity Response - the type or amount of damage Acute effect: immediate or rapid Chronic effect: permanent or long lasting

18. Genetic Variation in Individual Responses to Toxins

19. “The dose makes the poison.”Paracelsus, 1540 Anything can be harmful if ingested in a large enough quantity.

20. Poisons a chemical that has an LD50 of 50 mg or less per kg of body weight LD50 The median lethal dose The amount that kills exactly 50% of the animals in a test population, within a 14 day period Determined by controlled experiments

21. Laboratory Investigations Animal Studies Populations of lab animals usually rodents Measured doses under controlled conditions Takes two to five years Costs $200,000 to $2,000,000 per substance Newer methods

22. Laboratory Investigations Newer methods Bacteria Cell and tissue culture Appropriate tissue Stem cells Chicken egg membrane

23. Laboratory Investigations Validity Challenged Human physiology is different Different species react different to same toxins Mice die with aspirin Species can be selected depending on physiological area Pigs circulatory very similar to humans

24. Major Types of Hazards Fig. 11-1 p. 228 • Chemical hazards • Biological hazards • Physical hazards • Cultural hazards

25. Chemical Hazards Toxic chemicals substances that are fatal Hazardous chemicals cause harm Flammable or explosive Irritating or damaging to skin or lungs Interfering or preventing oxygen uptake Inducing allergic reactions

26. Chemical Hazards Mutagens Cause random changes in DNA Passed on to future generations Teratogens cause birth defects alcohol, PCBs, thalidomide, steroid hormones, heavy metals

27. Chemical Hazards Carcinogens promote uncontrollable cell growth (malignant or cancerous tumors) metastasis cells break off from tumors and travel in body fluids Immune, Nervous, and Endocrine System disruptors Viruses (HIV), Ionizing radiation, Diet, Neurotoxins, Hormonally Active Agents

28. Biological Hazards: Diseases Non-transmissible disease not caused by a living organism is not spread from one person to another Transmissible disease caused by living organisms Bacteria, virus, protozoa is spread from one person to another

29. Biological Hazards: Diseases Pathogens – infectious agents Vectors – organisms that spread pathogens Insects World’s Seven Deadliest Diseases acute respiratory infection acquired immune deficiency syndrome (AIDS) diarrheal diseases tuberculosis malaria hepatitis B measles

30. Biological Hazards: Diseases Common Viral Diseases influenza or flu Ebola West Nile Virus rabies AIDS Treatment Immunization with vaccines

31. Malaria - A Protozoal Disease Anopheles mosquito (vector) in aquatic breeding area eggs adult larva pupa 1. Female mosquito bites infected human, ingesting blood that contains Plasmodium gametocytes 4. Parasite invades blood cells, causing malaria and making infected person a new reservoir 2. Plasmodium develops in mosquito 3. Mosquito injects Plasmodium sporozoites into human host

32. Waterborne Bacteria Disease symptoms usually are explosive emissions from either end of the digestive tract Escherichia coli Vibrio sp. Barbara E. Moore, Ph.D., Department of Biology, University of Texas at San Antonio

33. Waterborne Protozoans • Disease symptoms are usually explosive emissions from either end of the digestive tract *P. Darben Giardia sp.* Barbara E. Moore, Ph.D., Department of Biology, University of Texas at San Antonio

34. Waterborne Human Viruses Hepatitis A virus Hepatitis E virus Norwalk virus* Rotavirus* *F. Williams Barbara E. Moore, Ph.D., Department of Biology, University of Texas at San Antonio

35. Case Study on Eradicating Dracunculiasis Water and Sanitation – Critical Elements in Development - Mike Lee CSU @ Hayward

36. Guinea Worm Disease People have suffered from Guinea Worms for centuries – the “fiery serpent” was mentioned in the bible People are infected by drinking water that contain the larvae in a tiny freshwater crustacean called Cyclops A year later, larvae mature into 3 feet worms that emerge through skin blisters This is such a painful process that men and women can’t work, children can’t attend school Water and Sanitation – Critical Elements in Development - Mike Lee CSU @ Hayward

37. The Guinea Worm grows down the leg and its sex organs appear at the ankle or on the foot usually, bursting when it senses water, releasing ova. http://www.pmeh.uiowa.edu/fuortes/63111/GUINEA/ Water and Sanitation – Critical Elements in Development - Mike Lee CSU @ Hayward

38. No vaccine for Guinea worm is available. People do not seem to build up any resistance and the disease can be reinfected over and over. No research is being conducted for any vaccine or cure. Worms are removed slowly each day by winding around a stick. http://www.pmeh.uiowa.edu/fuortes/63111/GUINEA/ Water and Sanitation – Critical Elements in Development - Mike Lee CSU @ Hayward

39. Spread of Diseases Increases international travel Migration to urban areas Migration to uninhabited areas and deforestation Hunger and malnutrition Increased rice cultivation Global warming Hurricanes and high winds Accidental introduction of insect vectors Flooding

40. Reducing Spread of Diseases Increase research on tropical diseases and vaccines Reduce poverty and malnutrition Improve drinking water Reduce unnecessary use of antibiotics Educate people on taking antibiotics Reduce antibiotic use in livestock Careful hand washing by medical staff Slow global warming Increase preventative health care

41. Epidemiology Study of the distribution and causes of disease in populations how many people or animals have a disease the outcome of the disease (recovery, death, disability, etc.) the factors that influence the distribution and outcome of the disease

42. Physical Hazards • Ionizing radiation, airborne particles, equipment design, fire, earthquake, volcanic eruptions, flood, hurricane, tornado • Example: Radon • Source: • Arises naturally from decomposition of uranium in the Earth • Occurs at dangerous levels in some buildings and homes “sick buildings” • Can cause lung cancer

43. Cultural Hazards • Sociological • Results from living in a society where one experiences noise, lack of privacy, and overcrowding • Population growth • Beyond carrying capacity when environmental resources can support no further growth

44. Cultural Hazards • Psychological • Environmental factors that produce psychological changes expressed in stress, depression and hysteria