1. What are you most scared of? Fireworks discharge Lightning Gunshot Earthquake Car accident

2. Your chance of dying from... Fireworks discharge – 1 in 386,766 Lightning – 1 in 84, 079 Gunshot – 1 in 6,309 Earthquake – 1 in 148,756 Car accident – 1 in 66 Statistics from National Safety Council

3. Chapter 10: Risk, Toxicology, & Human Health

4. What is risk? Risk – possibility of suffering harm from a hazard

5. Impacts of risks on humans Mortality Morbidity Loss of quality of life Loss of work days Property damage

6. Examples of Cultural Hazards Smoking Smoking Poor Diet Poor Diet Poverty Poverty Unsafe sex Unsafe sex

7. Examples of Chemical Hazards Air Air Water Water Soil Soil Food Food

8. Examples of Physical Hazards Fires Fires Earthquakes Earthquakes Volcanic eruptions Volcanic eruptions Floods Floods Tornadoes Tornadoes Hurricanes Hurricanes

9. Examples of Biological Hazards Pathogens Pathogens Pollen Pollen Allergens Allergens Animals Animals

10. Quantitative Measures of Risk Probabilities - a mathematical statement about the likelihood of harm Can be expressed in three ways: 1:100 1/100 “One in one hundred”

11. Quantitative Measures of Risk Ex: 1:6,210 - risk of dying from alcohol (1 person in 6,210 people will die of alcohol related illness) The bigger the bottom number (denominator) the less the chance Ex: chance of winning Power Ball lottery: about 1 in 80,000,000 Ex: chance of laughing at with Mr. Strogen today: about 1 in 3

12. Toxicology Dose – the amount of a substance that a person has in their body Can be: Ingested Inhaled Injected Absorbed “The dose makes the poison”

13. Sensitivity to Toxins The amount of damage (response) is related to the dose you get Response is related to age, gender, and genetic makeup

14. Toxicology Solubility - what can the chemical dissolve in? Water-soluble toxins Oil/Fat-soluble toxins Which do you think is generally “better” for the health of an organism? Water is “better” since it can be diluted Fats aren’t good since chemicals can gather in body fat of animals

15. Toxicology Persistence - how long a chemical stays in the environment Roundup (kills plants) breaks down in 24 hours when exposed to light DDT (kills insects) breaks down in 2 to 15 years

16. Toxicology Bioaccumulation chemicals stored in organs (fat) of animals Biomagnification chemicals are passed to each member of the food chain large amounts in animals at top of chain

17. Interactions Synergistic interactions: when two (or more) risk factors have a greater effect together than each by themselves Ex: being exposed to asbestos and smoking gives you a 400 times greater chance of developing lung cancer than if you experienced only one of those risks + =

18. Interactions Antagonistic interactions: an exposure of two (or more) chemicals results in a reduction in the effect compared to when taken individually Ex: mercury toxicity can be reduced by consuming the chemical dimercaprol + =

19. Toxicity Assessment An interesting animal study concerning the artificial sweetener saccharin Animal studies indicated that saccharine caused bladder cancer in animals. In 1977, the FDA proposed a ban on its use. Studies later reveled that the doses given to animals were the equivalent of a human drinking 100 cans of soda a day. Human tests never linked saccharine to human cancer because the way that saccharine caused cancer to rats does not happen in humans. Saccharine was taken off the FDA’s possible cancer list in 2000, after 25 years of needless worry. Worry is still around today.

20. Toxicity Assessment Poisons – materials that kill at a very small dose (50 milligrams or less per kilogram of weight) The LD 50 (lethal dose) is the amount that kills 50% of a test population in a given time

21. Toxicity Assessment The LD 50 of this chemical is 7 The dose that kills 50% is the LD 50

22. LD 50 LD 50 = 5.3

24. STEPS TO MEASURE RISK Toxicity Ratings

25. Threshold

27. Case Study – DDT Dichlorodiphenyltrichloro ethane Used as an insecticide beginning in the 1940s, primarily in tropical areas of the world with malaria and typhus Highly effective at killing insects USNAS estimates that DDT saved 500 million lives

29. In 2010, malaria killed 655,000 people There are currently 216 million people infected Every minute, an African child dies of malaria

30. Case Study – DDT 1962, Rachel Carson wrote Silent Spring, which described the negative effects of pesticides, like DDT: Cancer in humans Thinner egg shells, reproductive problems, and death in birds Carson was concerned with the widespread spraying of chemicals, especially since we didn’t fully understand its effects on the environment or humans

31. Case Study – DDT Silent Spring resulted in a public outcry to ban DDT 1972, banned in the US 2004, banned worldwide (some exemptions) Often cited as the beginning of the “environmental movement”

32. DDT Discussion How much do you agree with the following statement? Despite its usefulness at preventing diseases like malaria (and saving millions of lives each year), DDT should be banned worldwide because of its negative environmental and health effects.

33. Chemical Risks Neurotoxins: chemicals that disrupt the nervous system Carcinogens: chemicals that cause cancer Teratogens: chemicals that interfere with the normal development of embryos and fetuses Allergens: chemicals that cause allergic reactions Endocrine disruptors: chemicals that interfere with the normal functioning of hormones

35. Risk Assessment vs. Risk Management Risk Assessment “What is the hazard?” Risk Management “How can the risk be minimized?”

36. Risk Analysis

37. Qualitative vs. Quantitative Qualitative risk assessment: judging the relative risk of various decisions (ex: low, medium, or high) Judgments based on perception, not on actual data Quantitative risk assessment: determining the probability of an event occurring using data (ex: 83% chance)

38. Probabilities of Death in U.S.

39. Risk Analysis Risk = Probability of being exposed to a hazard Probability of being harmed if exposed x

40. Risk Analysis What is riskier: flying on a plane for 1,000 miles per year or eating 40 tablespoons of peanut butter per year? The probability of a plane crash is low, but the probability of dying if the plane crashes is high The probability of eating peanut butter is high, but the probability of developing cancer from the peanut butter is low Both behaviors produce a risk of 1 in 1 million

41. Chemical Regulation