1 / 30

Chapter 14: Risk, Human Health, and Toxicology

Chapter 14: Risk, Human Health, and Toxicology. By Emmaline Meill, Jae Young Park, and Anya Lukianchikov. Case Study: Cigarette Smoking. Cigarette smoking is the world’s most preventable cause of suffering and premature death among adults. 1950-2005, it has killed 85 million people.

adele
Download Presentation

Chapter 14: Risk, Human Health, and Toxicology

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 14: Risk, Human Health, and Toxicology • By Emmaline Meill, Jae Young Park, and Anya Lukianchikov

  2. Case Study: Cigarette Smoking • Cigarette smoking is the world’s most preventable cause of suffering and premature death among adults. • 1950-2005, it has killed 85 million people. • Kills 440,000 Americans prematurely each year.

  3. Case Study - Continued • Cigarette smoking causes numerous other diseases: • Heart Disease • Cancer • Emphysema • Bronchitis • Stroke • 2004 study found that cigarette smokers die on average 10 years earlier than non-smokers.

  4. What’s in a cigarette?

  5. Case Study - Continued • Suggested reforms: • Federal tax on cigarette packets • Banning cigarette advertising • Banning tobacco products to anyone younger than 21 • Education programs

  6. 14-1 Risks and Hazards • Risk is the possibility of causing harm from a hazard that can cause injury, disease, death, economic loss, or environmental damage. • Risk Assessment is the estimation of how much harm a hazard can cause to human health. • Risk management is deciding whether or how to reduce a risk to a certain level and at what cost.

  7. Risks and Hazards - Continued • Four types of hazards • Cultural • Biological • Chemical • Physical

  8. Boo, the Bubonic Plague (Yersinia pestis) bacterium 14-2 Biological Hazards: Disease in Developed & Developing Countries Necors, the Necrotizing Phaciatis bacterium Ebola, the Ebola Virus particle

  9. Science: Diseases • Nontransmissible • Transmissible/Infectious • WHO: World Health Organization Good news: falling death rates Bad news: increased resistance

  10. Growing Germ Resistance to Antibiotics: Contributing Factors • Rapid bacteria reproduction • Modern high-speed travel/trade • Overuse • Underuse MRSA is a big one

  11. Case Study: Growing Threat of TB • 9 million/yr infected; 1.7 mil/yr killed • Factors: • Lack of screening/control plans • ↑ Resistance • Pop. growth, urbanization • AIDS

  12. Viral Diseases • Biggest killers: HIV, Flu, Hep B • Flu – 40,000 dead/yr in US, bad epidemics • Media focus on more “exotic” diseases Influenza is much worse than I am!

  13. Case Study: HIV/AIDS • Most serious & rapidly growing health threat • Long incubation period, $$$ drugs • Effects in Africa: • ↓ life expectancy of 700 mil by 15 yrs • Productive ppl. killed, less productivity • Age structure • WHO global strategy

  14. Case Study: Malaria • 1/5 ppl. at risk • Malaria Cycle • Best thing now: Prevention • Prevent mosquito growth • Zn & Vit. A Suppliments It’s got quite the history, like me!

  15. ↓ Incidence of Infectious Diseases • Death rates falling – allID’s overall • Easily preventable ones now treated • Bad news: little funding for LDC IDs • Kill more than other IDs combined Diseases that are easily preventable are now being treated more in LDCs, reducing death rates.

  16. Bioterrorism • Biological WMDs since WWII • Deadlier strains; new types of pathogens • Easy to spread • Combatting I might be one of them!

  17. 14-3 Chemical Biohazards • Toxic Chemical • Hazardous Chemical • Agent types • Mutagen: DNA • Teratogen: birth defects • Carcinogen: cancer

  18. Effect of Chemicals on Bodily Systems • Disrupts • Immune: weaken • Nervous: disrupt/harm – kill cells • Neurotoxins • Endocrine: disrupt effect of nat. hormones • Hormonally Active Agents (HAAs)

  19. 14-4 — Toxicology: Assessing Chemical Hazards • Toxicity depends on several factors • Dosage • Frequency • Person exposed • Effectiveness of detoxification systems • Genetic makeup • Multiple chemical sensitivity • Factors affecting severity of a toxin • Persistence • Solubility • Bioaccumulation • Biomagnification • Antagonistic/Synergistic interaction

  20. Assessing Chemical Hazards (cont’d) • Responses to toxin • Acute effects • Chronic effects • Body functions • Kidney/liver • Enzymes • Cell reproduction

  21. Effects of Trace Levels of Toxic Chemicals • Trace amounts debate • Misconceptions • Increasingly detected amounts  good news • Natural vs. Synthetic chemicals Nightshade

  22. Estimating the Toxicity of a Chemical • Poison/toxin’s lethal doses • Animal tests (LD50=50%) • Wide variations between two extremes (completely lethal vs. barely)

  23. Using Case Reports and Epidemiological Studies to Estimate Toxicity • Case reports = not precise, gives clues & hints • Epidemiological studies — experimental vs. control groups • Limiting factors • Few people • Linking back to exact, specific chemicals • Can’t predict/evaluate future hazards

  24. Using Laboratory Experiments to Estimate Toxicity • Animal testing • Expensive, takes long • Animal welfare groups • Computer simulations • Tissue cultures • Chicken egg membranes • Dose-response curve • Nonthreshold dose-response model • Threshold dose-response model • Difficulties • Valid? • Exposure to many chemicals  chemical interactions • Economically/Scientifically impossible

  25. Protecting Children from Toxic Chemicals • Children more susceptible • Consumption levels • Environment • Body not developed • 2003 US EPA — assume 10x more exposure ~boyfriend~

  26. Why Do We Know So Little about the Harmful Effects of Chemicals? • Faulty/limited methods • 10% of 80,000 chemicals studied, 2% adequately tested • Few regulations • “innocent until proven guilty” • Lack of funds/workforce/etc.

  27. Pollution Prevention and the Precautionary Principle • Pollution prevention based on precautionary principle • 2004 global treaty banning Persistent Organic Pollutants (POP) aka “dirty dozen” • DDT, 8 persistent pesticides, PCBs, dioxins, furans • Businesses vs. supporters  technology debate

  28. 14-5 Risk Analysis • Today, the greatest risk is poverty • Risk analysis involves: • Identifying hazards • Ranking risks • Making decisions about reducing risks • Informing the public about risks

  29. Perceiving Risks • Many people shrug off the high-risk chances of death or injury from voluntary activities they enjoy. • Factors can give people a distorted sense of risk

  30. Best Ways to Reduce Health Risks • Avoid smoking • Lose excess weight • Healthy diet • Exercise regularly • Don’t drink alcohol • Avoid excessive sunlight • Practice safe sex

More Related