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A Small Dose of Risk Assessment – 12/16/11 An Introduction To Risk Assessment – Risk Management and Precautionary Principle A Small Dose of Risk Assessment.

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Presentation on theme: "A Small Dose of Risk Assessment – 12/16/11 An Introduction To Risk Assessment – Risk Management and Precautionary Principle A Small Dose of Risk Assessment."— Presentation transcript:

1 A Small Dose of Risk Assessment – 12/16/11 An Introduction To Risk Assessment – Risk Management and Precautionary Principle A Small Dose of Risk Assessment

2 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Decision Making Risk Assessment and Risk Management in Context of Societal Issues

3 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Risk Assessment "We should remember that risk assessment data can be like the captured spy: If you torture it long enough, it will tell you anything you want to know." (William Ruckelshaus -1st administrator of U.S. EPA 1984.)

4 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Managing the Commons Garrett Hardin The Tragedy of the Commons (Science, 1968) Extensions of “The Tragedy of the Commons“ (Science, 1998) Elinor Ostrom – Revisiting the Commons: Local Lessons, Global Challenges (Science, 1999)

5 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology The Tragedy Cattle Farmers Return on Investment Return for me Not the commons Society suffers

6 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology No Technical Solutions “It is our considered professional judgment that this dilemma has no technical solution.”

7 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Problems – Solutions?  Tick-tack-toe  Nuclear disarmament  Bioterrorism  Fish from the sea  Cancer  Lead and kids  Fetal alcohol syndrome  Commons ….

8 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Toxicology Issues / Solutions?  Cancer (soot & benzene ….)  Radiation exposure  Plant and animal toxins  Pesticides  Drugs  Lead and Mercury  Fetal alcohol syndrome  ….

9 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Freedom? Restriction of Freedom? Responsibility knowing the problem? What does toxicology say about managing the commons?

10 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology What is the goal of risk management? “Conditions that ensure that all living things have the best opportunity to reach and maintain their full genetic potential.” Steven G. Gilbert, 1999 Environmental Health

11 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Examples of Risk Risk Management Examples Alcohol Lead Mercury

12 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Ethyl Alcohol C H H H OHC H H

13 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology FAS Child

14 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Effects of Prenatal Alcohol

15 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Fetal Alcohol Syndrome (FAS) Researchers at the Univ. of Nantes Early 1970’s FAS – Univ. of Washington 4,000-12,000 infants per year in US 1 to 3 births per 1,000 world wide?? Most common preventable cause of adverse CNS development

16 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Fetal Alcohol Effect (FAE) Milder form of FAS 7,000-36,000 infants per year in US World wide? Characteristics Growth deficiency Learning dysfunction Nervous systems disabilities

17 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology  6500 BC. - Lead discovered in Turkey  500 BC-300 AD.- Roman lead smelting produces dangerous emissions (wine)  100 BC. - Greek physicians give clinical description of lead poisoning  2 BC "Lead makes the mind give way.“  1920’s - Lead in gasoline, lead in paint Awareness of Lead

18 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Lead in Families

19 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Recycling Lead

20 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Fetal Effects of MeHg

21 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Life-Long Effects of MeHg

22 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Precautionary Principle "When an activity raises threats of harm to the environment or human health, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically." - Wingspread Statement on the Precautionary Principle, Jan. 1998

23 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Key Words of Toxicology Hazard X Exposure = Risk Individual Susceptibility Dose / Response

24 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Early Risk Assessment “What is food to one man may be fierce poison to others.” Lucretius (c. 99 B.C.–c. 55 B.C.)

25 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology "If someone had evaluated the risk of fire right after it was invented, they may well have decided to eat their food raw." Julian Morris of the Institute of Economic Affairs in London Perspective

26 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology “One death is a tragedy. A million deaths is a statistic.” Joseph Stalin Perspective

27 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology  1775 – Percivall Pott – Occupational – cancer of scrotum in chimney sweeps  1895 – Bladder cancer in workers in aniline dye industry Historical Awareness

28 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology  Founding of American Conference of Governmental Industrial Hygienists (ACGIH).  Chemical Substances Committee established to investigate and recommend exposure limits for chemical substances.  Threshold Limit Values (TLVs) for 148 chemicals (exposure limits) Recent Awareness

29 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Superman

30 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Risk of What? Obvious Death, Cancer, Acid burn, Birth defect, asthma, Subtle Decreases in learning and memory (lead), Sensitivity of the individual (child)

31 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Risk Assessment Process of estimating association between an exposure to a chemical or physical agent and the incidence of some adverse outcome.

32 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Policy developed to deal with hazards identified through risk assessment Process of evaluating alternative regulatory options and selecting among them Risk Management

33 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Framework for RA and RM Identify hazards Characterize risks Control risks Epidemiology Toxicology In vitro tests Structure/Activity Analysis Potency Exposure Susceptibility Information Regulation Substitution

34 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Objective of Risk Assessment  Evaluate the risks  Environmental contaminant, drugs, pesticides, industrial chemical  Evaluate uncertainty of data  Set target levels of exposure  Food, air, water, work place  Provide information to agencies  Regulatory agencies, Manufacturers, Environmental/Consumer Agencies

35 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Steps in Risk Assessment  Hazard Identification  Exposure Assessment  Dose-Response Assessment  Risk Characterization

36 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Hazard Identification Review human and animal data to determine if a chemical or agent has biological effects

37 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Hazard Identification  Research  Structure-Activity Analysis  Short-term Screening Tests  Animal Bioassays  Human Epidemiological Data

38 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Structure-Activity Analysis Does structure resemble that of a known toxic agent? Computer modeling

39 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Short-term Screening Tests Cell Culture, Tissue Culture Does the chemical or agent adversely effects cells?

40 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Animal Bioassays Animal Studies Does the chemical or agent causes effect animals? What is the potentially for human toxicity?

41 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Toxicity Endpoints  Carcinogenicity  Mutations  Altered immune function  Teratogenicity  Altered reproductive function  Neuro-behavioral toxicity  Organ-specific effects  Ecological effects (wildlife, environmental persistence)

42 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Pros and Cons - Animals Advantages  Monitor progress of toxicity/carcinogenicity  Can directly link with exposure  Can be used to predict human risks Disadvantages  Can be very expensive (>$1 M)  Can take many years

43 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Human Epidemiological Human Studies Does the chemical or agent causes adverse effect in human populations?

44 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Pros and Cons - Humans Advantages  Yields information in humans  Yields associations relevant to “real world” exposures Disadvantages  Can be very expensive (large N, many years)  Lack control relative to lab  Many confounding variables

45 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Human Variability Human Subject Variability Lifestyle – risk of exposure to …. Occupation – risk of exposure to …. Breathing & digestion – uptake of chemicals Metabolism & kidney function – elimination Age, gender & disease – susceptibility to toxicity

46 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Examples of Variability Children spend more time on floor – more hand to mouth behavior than adults Occupation – exposure to other chemicals Rate of breathing higher in children than adults Lung function and susceptibility are altered by smoking or asthma Disease effects liver function The overall dose-response behavior is subject to both intra-individual and inter-individual variability.

47 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Uncertainty Measurements error in experiments Extrapolation from animal studies to human Sample sizes for animal and human studies Selection of endpoint Intra and inter subject variability

48 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Exposure Assessment  Route of exposure (skin, oral, inhalation)  Amount of exposure (dose)  Duration of exposure  To whom (animals, humans, environment)

49 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Home environment Current events Workplace School Government Decisions (war) Global and local environment Exposure Issues

50 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Dose-Response Assessment How much exposure to a chemical or agent will cause what effect?

51 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Chemical Potency Dose Response Threshold (NOAEL ED50

52 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Hazard (including sensitive populations) –May require low dose extrapolation Exposure –Route of exposure, amount, duration dermal, oral, inhalation, injection Risk Characterization Risk = Hazard X Exposure

53 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology  Uncertainty  Perception  Comparison  Education  Regulation Risk Management

54 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology How do you know? How good is the data? Uncertainty

55 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Use of Uncertainty Factors Divide Dose by Power of 10 Human variability Interspecies extrapolation Children Subchronic to chronic extrapolation Absence of a NOAEL Database uncertainty

56 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Use of Uncertainty Factors Animal Dose Response Data NOAEL (No Observed Adverse Effect Level) Divide by 10 (Account for inadequate animal data) Divide by 10 (Animal to Human Extrapolation) Divide by 10 (Human Variability or Individual Sensitivity) Reference Dose (RfD) Or Acceptable Daily Intake (ADI)

57 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Reducing Uncertainty Upstanding mechanism of action Physiologically based pharmacokinetic models (distribution and metabolism) Sample size

58 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Comparing Risks  By probability  By expected value  By outrage  By exposure  By experts

59 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Annual Risk Of Death In The U.S. HAZARDRISK PER MILLION All causes9,000.0 Motor vehicle accidents210.0 Work accidents150.0 Homicides93.0 Drowning37.0 Poisoning, Solids/liquids17.0 Railroads0.9 Civil aviation0.8 Bits and stings0.2 “TO LIVE, IS TO RISK DYING”

60 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Adapted from Kraus and Slovic (1988), Risk Anal., 8: 435. Characteristics of Risk Characteristic Level Examples KnowledgeLittle knownFood additives Much knownAlcoholic drinks NewnessOldGuns NewSpace travel VoluntarinessNot voluntaryCrime VoluntaryRock climbing ControlNot controllableNatural disasters ControllableSmoking DreadednessLittle dreadVaccination Great dreadNerve gas CatastrophicNot likelySunbathing potentialLikelyWar EquityDistributedSkiing UndistributedHazardous dump

61 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology  Food coloring                 Saccharin Microwave ovens Aspirin Anesthetics Power Tools Alcohol Motor vehicles DNA Research Nuclear Power Asbestos Herbicides Pesticides Smoking Dynamite Warfare Handguns Risk Perceptions Catastrophic potential Involuntariness Personal risk Inequity Dread Newness Lack of scientific knowledge Exposure is unknown/unknowable Knowable  Lead Unknown Known DreadedLittle Dread

62 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Adapted from Slovic et al. (1979), Environ., 21: 14. Differences in Risk Perception Activity/Agent Rank by Risk Analyst Rank by non- Risk Analyst Motor Vehicles12 Smoking24 Alcohol36 Handguns43 Surgery510 Motorcycles65 X-rays722 Pesticides89 Electric Power918 Swimming1019 Nuclear Power201

63 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Precautionary Principle "When an activity raises threats of harm to the environment or human health, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically." - Wingspread Statement on the Precautionary Principle, Jan. 1998

64 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Authorship Information For Additional Information Contact Steven G. Gilbert, PhD, DABT Web: This presentation is supplement to “A Small Dose of Toxicology”

65 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Case Study LEAD

66 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology "Lead makes the mind give way." Ancient Awareness Greek Dioscerides - 2nd BC

67 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology CDC Blood Lead Levels

68 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Lead - Absorption ORALLY CONSUMED LEAD ABSORBED CHILDREN – 30-50% OF LEAD ADULTS – 5-10% OF LEAD Increased During Pregnancy

69 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology 25 DAYS -- BLOOD 40 DAYS -- SOFT TISSUE 20 YEARS -- BONE Half-life Of Lead

70 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Children Vulnerability CHILDREN are more vulnerable exposure than ADULTS SIZE CONSUME MORE FOOD INHALE MORE AIR DEVELOPING NERVOUS SYSTEM

71 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Needleman, NEJM, 1979

72 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Case Study Mercury

73 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Hg – Like Water

74 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Hg – Solid Enough to Sit On

75 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Outbreaks of MeHg Poisoning PlaceYearCases Minamata Nigata Guatemala Ghana Pakistan Iraq Iraq19601,002 Iraq197140,000 On-going2001???

76 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Iraq Infant - Effects of Mercury

77 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Inorganic - elemental mercury vapor Hg 0 Biotransformation Organic - Methylmercury - CH 3 Hg + Bioaccumulatio n Mercury to Methyl Mercury

78 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Mercury Release 50-75% mercury of released in the environment related to human activities

79 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Atmospheric Hg

80 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Ambient Water Sediments Edible Fish Inorganic Mercury Methyl- Mercury In Humans Biomethylation Bioaccumulation Exposure Discharge Biotransformation of Mercury

81 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Blindness - Deafness Cerebral Palsy - Seizures Abnormal reflexes & muscle tone Retarded motor development Visual and Auditory Deficits Delayed motor development Altered DRH performance Neurobehavioral Effects

82 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Decrease in Brain Size Cell loss Disorganization of cells Cell migration failures Effects On The Brain

83 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology  MONKEY - 25 µg/kg - LOAEL  RAT - 10 µg/kg - LOAEL  RAT - 50 µg/kg - replicated Animal - Risk Assessment

84 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology  2.5 µg/kg - NOAEL (animals)  0.25 µg/kg - Human  µg/kg - Sensitive populations Animal - Risk Assessment (the rule of dividing by 10)

85 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology ppm hair - LOAEL ppb blood - LOAEL µg/kg 0.06 µg/kg - RfD Human - Risk Assessment

86 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Mercury Fishing Advisories  In 2000, 41 States have over 2000 fish consumption advisories  An increase form 27 in 1993  Pregnant women, nursing mothers, women who intend to have children, and children under 15

87 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Reduce environmental release Restrict global production and sale Advise women of child bearing age Research mechanisms of action Assess neurodegenerative effects Recommendations

88 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology MeHg Consumption Limits US EPA – 0.1 ug/kg-day US FDA – 1 ppm (mg/kg) in tuna

89 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Mercury A Global Issue Mercury distribution and exposure is a global problem

90 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology A Small Dose of ™ Risk Assessment

91 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Additional Information  Web Sites  World Health Organization - The International Programme on Chemical Safety (IPCS) – Risk Assessment –  U.S. Environmental Protection Agencies - National Center for Environmental Assessment (NCEA) – Access:

92 A Small Dose of Risk Assessment – 12/16/11 A Small Dose of Toxicology Authorship Information For Additional Information Contact Steven G. Gilbert, PhD, DABT Web: This presentation is supplement to “A Small Dose of Toxicology”


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