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Health Risk Assessment of Contaminants in Food
MSc in Environmental and Public Health Management, HKBU
EPHM 7330 Food Protection and Safety Management
AOW Leung (Dept of Biology, HKBU)E-mail: [email protected]
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Food Safety
Protection of the food supply from harmfulcontamination
Prevention of the development and spread of harmful contamination
Effective removal of contamination andcontaminants
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Food Safety Hazards
Food safety hazard: Any factor present in foodthat has the potential to cause harm to theconsumer, either by causing illness or injury. Biological hazards Chemical hazards Physical hazards
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Biological Hazards
Bacteria Salmonella, Listeria moncytogenes, Vibrio
parahaemolyticus
Parasites and protozoa Entamoeba histolytica, Cyclospora cayetanensis
Viruses Hepatitis A
Microtoxins
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Chemical Hazards
Toxic metals (i.e. lead, mercury, cadmium) Environmental pollutants (i.e. PCDD/Fs, PCBs) Pesticide residues (i.e. DDT, HCH)
Additives (i.e. preservatives) Contaminants produced during food processing
(i.e. PAHs, acrylmide) Veterinary drug residues (i.e. antibiotics, growth
stimulants) Plasticisers and packaging migrants (i.e. Bisphenol
A)
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Industrial andenvironmental
Source Associatedfood
PCBs Transformers Fish, animal fat
Dioxins By-product Fish, animalfat
Mercury Chlor-alkali FishLead Vehicle emission,
paintCanned food,acidic foods
Cadmium Sludge, smelting Grains, molluscs
Radionuclides Accidentalrelease
Fish,mushrooms
Nitrate/nitrite Fertilizers Vegetables
Chemical Hazards
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Physical Hazards
Glass Hair Metal
Pebbles Wood Plastic Parts of pests Bone Fruit pits
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The hazards associated with an agent will beaffected by: the structure and associated physicochemical
properties the metabolism and toxicokinetics of the
substance
the results of a series of toxicity tests conductedboth in animal models and/or in in vitro systems
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When can these hazards arise in thefood supply?
Before the raw material enters foodprocessingDuring storage of raw materialsDuring food processing (i.e. PAHs)During packagingDuring storage of the end-productDuring cookingDuring eating
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Health Risk Assessment (HRA) Health Risk Assessment A method used to characterize
the magnitude and probability of an adverse effect fromexposure to a substance i.e. a chemical, physical ormicrobiological agent in food.
Risk Assessment - A scientifically based process consistingof the following steps: (i) hazard identification, (ii) dose-response assessment (hazard characterization), (iii)exposure assessment, and (iv) risk characterization
Aim: To evaluate whether the chemical, physical ormicrobiological agent has the potential to cause adverseeffects in humans based upon review of all available dataon toxicity and the biological mechanism that leads totoxicity
Risk = Hazard X Exposure 11
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Definition: Adverse effect is defined as "...anybiochemical, physiological, anatomical,pathological, and/or behavioral change thatresults in functional impairment that mayaffect the performance of the whole organismor reduce the ability of the organism to
respond to an additional challenge . (USEPA)
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Why do we need risk assessment?
Develop standards for levels of toxic chemicals orpathogenic microorganisms in food
Construct what -if scenarios to set priorities forcorrective action.
Articulate community public health concerns
Developing consistent public health expectationsamong different localities
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Health Risk Assessment
ExposureAssessment
RiskCharacterization
Dose-Response
Assessment
HazardIdentification
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Four Stages of a Health RiskAssessment
Stage 1: Hazard Identification Determine whether there is an actual threat to
our health from a contaminant by identifying thesubstance of concern and evaluating its inherenttoxicity
Stage 2: Dose-Response Assessment
Assess the response of living organisms at variousdoses of the substance
At what dose will we see effects? At what dosewill we see no effects?
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Four Stages of a Health RiskAssessment
Stage 3: Exposure Assessment Determine the levels of exposure that are actually
occurring within the population of concern
Various routes of exposure How much is actually getting into the body
Stage 4: Risk Characterization
Information obtained from Stages 1-3 arecompiled to characterize the magnitude andprobability of an adverse health effect on thepopulation being exposed
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Risk Analysis
Risk assessment How big is the risk? What factors control the risk?
Scientific process Risk Communication
How can we talk about the risk with affected individuals? Social and psychological process
Risk Management What can we do about the risk? Political process
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Stage 1: Hazard Identification
Hazard Identification - The identification of biological, chemical, and physical agentscapable of causing adverse health effects andwhich may be present in a particular food orgroup of foods.
HAZARD: biological, chemical or physicalagent with the potential to cause an adversehealth effect (CODEX)
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Hazard Identification What kinds of contaminants and foods are
involved? Contaminants of concern
Toxicity Persistence Mobility What are the health effects that this agent can
cause?
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Hazard Identification
Determine the potential of an agent to causeadverse health effects Types of injury Conditions of exposure
These characterize the ' inherent toxicity ' of the substance /agent
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Hazard Identification
Types of injury Systemic: liver and kidney damage, reproductive
toxicity, developmental toxicity affecting the fetus,
cancer Contact: skin irritation, rash, blisters or other
injury at the site of contact with the agent
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Hazard Identification
Conditions of Exposure Conditions under which the various types of injury
occur and are based on duration of exposure
Acute : one or a few doses over a few days Subchronic : repeated exposures from 14-90
days duration Chronic : repeated exposures beyond one yearand up to a lifetime
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Sources of Data
Human studies (epidemiology, case reports orvolunteer studies)
Toxicity studies conducted in laboratoryanimals
Alternative approaches, including use of invitro models such as cells cultures or tissueslices, and comparisons with structurally-related chemical substances
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Evaluating the Inherit Toxicity of a Substance
Gather information from databases and scientific literature Epidemiological Studies : Frequency, distribution, and cause of
disease within a human population Best source of information because they are based on human
exposures and provide a clear and direct link between exposureand adverse effects
Limited , no data for new substances Accidents and Case Studies : Poisoning incidents Animal Studies : Used to predict the effects of substances on
humans based on their effects on animals because some animalsexhibit a response similar to humans (i.e. development al studies onrats and rabbits)
Cell Culture Studies : Short term tests used to observe the effects of substances on specific cell types and are often used to determinethe potential for genotoxicity.
Structure-Activity Relationship Analysis : Study the toxicity of substances with similar molecular structures
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Stage 2: Dose-Response Assessment
Dose-Response Assessment - The determinationof the relationship between the magnitude of exposure (dose) to a biological, chemical orphysical agent and the severity and/or frequencyof associated adverse health effects (response) .
Qualitative and/or quantitative evaluation of thenature of the adverse health effects associated
with biological, chemical and physical agents Also referred to as Toxicity Assessment or Hazard
Characterization
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Dose-Response Assessment To determine the capacity of an agent to cause harm, it is necessary to
quantify the toxicity (adverse effects) from exposure Aim: Obtain a mathematical relationship between the amount of a
toxicant involved in an exposure to the risk of an adverse outcome
Dose = amount of chemical/body weight
Possible responses
-no response-temporary response-permanent response-chronic functional impairment-death
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Dose-Response Assessment Identify chemicals of concern To estimate the nature, severity and duration of the adverse effects
resulting from ingestion of a particular substance, need information on: fate and distribution of the chemical agent in the body The action of the chemical agent on tissues or functions in the body
Toxicokinetic studies Data on absorption, distribution, metabolism and elimination of
chemicals and major metabolites Effects of dose level and duration on the metabolism Comparative studies in human volunteers to support extrapolation of
animal toxicity data Rates of movement are determined by measuring the amount of chemical
in various body fluids and tissues, such as blood and urine at timedintervals after a controlled exposure
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Dose-Response Assessment
Gather toxicity information for chemicals of concern Determine toxicity values for non-carcinogenic
effects Determine toxicity values for carcinogenic effects
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Dose-Response Relationships
Definition : Endpoint is defined as an effect observedin a toxicity study
Definition : LD50 is the lethal dose for 50% of the testpopulation Used to rank the acute toxicity of a substance
among all other known substances.
Choose the study that displays the most sensitivespecies at the most sensitive endpoint
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NOAEL/LOAEL
Definition : NOAEL (No-observed-adverse-effect level) is anexperimentally determined dose at which there was no statisticallyor biologically significant indication of the toxic effect of concern -the highest dose level at which there was no statistically or
biologically significant indication of the toxic effect of concern
Definition : LOAEL (Lowest-observed-adverse-effect-level ) is thelowest observed adverse effect level (in case that effects were seenat all dose level used in the key toxicity study)
NOEL for the most sensitive endpoint: is referred to as the 'criticalNOEL Used to determine safe exposure levels for humans If the dose range in a study does not the display a NOEL, it may
give a dose where there is a Lowest Observed Effects Level(LOEL). In this case the estimated NOEL is calculated by dividingthe LOEL by an ' uncertainty factor ' of 10
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Dose-Response Relationships
Animal tests are acute exposures at high doses dueto time constraints
Results are extrapolated down to environmentallevels
Typical dose-responsecurve
Response is usuallydeath
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Dose-Response Relationships
Effects at the low end cannot be seen clearlyon a linear scale
Typicallogarithmicdose-responsecurve
NOEL no observableeffects level
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Dose-Response Relationships
The dose of the substanceadministered in toxicitytests is usually expressedas the mass of thechemical usually inmilligrams per unit of testanimals body weight(usually kg)
LD50 dose that is lethal to50 % of the population
The smaller the LD 50 value,the more potent thechemical
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Threshold effects (dose-response)
A threshold is levelbelow which noeffect occurs on the
population (curve B) Toxin A has nothreshold; even thesmallest amount has
some measurableeffect on thepopulation
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Non-Carcinogenic Effects
Allowable Daily Intake - The US Food and DrugAdministration, the World Health Organization, andthe Consumer Product Safety Commission use the Allowable Daily Intake (ADI) to calculate permissiblechronic exposure levels. The ADI is determined by applying safety factors to the
highest dose in chronic human or animal studies that hasbeen demonstrated not to cause toxicity.
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Acceptable daily intake (ADI)
- Acceptable Daily Intake (ADI): the amount of achemical to which a person can be exposed on adaily basis over an extended period of time(usually a lifetime) without appreciable risk(deleterious effect) on the basis of all knownfactors at the time
- ADI concept has often been used as a tool in
reaching risk management decisions (e.g.establishing allowable levels of contaminants infoodstuffs and water.)
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Acceptable daily intake (ADI)
- ADI is derived from an experimentallydetermined "no-observed-adverse-effect level(NOAEL)
- ADI (human dose) = NOAEL (experimentaldose)/safety factor
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Non-Carcinogenic Effects ( cont )
Minimum Risk Levels (MRLs), used by ATSDR,are similar to the EPA's Reference Dose (RfD)and Reference Concentration (RfC).
An MRL is an estimate of the daily humanexposure to a hazardous substance that is likely tobe without appreciable risk of adverse noncancerhealth effects over a specified duration of
exposure.
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Non-Carcinogenic Effects ( cont )
Reference Dose - The US Environmental ProtectionAgency has slightly modified the ADI. For the EPA,the acceptable safety level is known as the Reference
Dose (RfD) an estimate of a daily exposure level for humanpopulations, including sensitive subpopulations, that islikely to be without an appreciable risk of deleterioushealth effects during a lifetime
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Non-Carcinogenic Effects ( cont )
The position of the EPA is that humansare as sensitive as the most sensitivetest species unless other data are
available.
RfD = NOAEL or LOAELUF1 x UF2 x Ufx
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Non-Carcinogenic Effects
Safety Factors (SF)/Uncertainty Factors (UF) x10 Human variability x10 Extrapolation from animals to humans x10 Use of less than chronic data x10 Use of LOAEL instead of NOAEL x10 Incomplete database
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Margin of safety (MS) MS = NOEL/ estimated daily dose
Margin of safety must be greater than 100 or1000 to be acceptable because NOELestimation is inadequate
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RfDs for the Chronic (Non-carcinogenic)Effects of Various Chemicals
Chemical Most Sensitive Organor Effect
RfD (mg/Kg/day)
Aldrin Liver 0.00003
DDT Liver 0.0005
Paraquat Chronic pneumonitis 0.0045
Fluoride Objectionable dentalfluorosis, cosmeticeffects
0.06
Styrene Red blood cell, liver 0.2Ethylene Glycol Kidney 2
50Source: Elements of Toxicology and Chemical Risk Assessment. Revised Ed. July 1988. ENVIRON Corporation. Washington DC
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Carcinogenic Substances
Dose/Response Assessment for carcinogens isdifferent from non-carcinogen substances
No threshold whereby small doses elicit noresponse (i.e. carcinogens have an effect atany dose)
It is assumed that as the dosage of acarcinogen increases , the risk or probability of getting cancer also increases
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Carcinogenic Effects
Mathematical models are used to extrapolatefrom the high doses used in animalexperiments to the low doses to which
humans are normally exposed in a chronicsetting.
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53Source: ExtoxNet FAQs
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C Ri k Sl F (P i
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Cancer Risk Slope Factors (Potenciesfor Various Chemicals)
Chemical Carcinogen Slope Factor(mg/kg/day) -1
Aldrin 17
Carbon tetrachloride 0.13
Chromium IV 41
Dimethyl nitrosamine 51
nickel refinery dust 0.84Trichlorethylene 0.11
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Source: Elements of Toxicology and Chemical Risk Assessment. Revised Ed. July 1988. ENVIRON Corporation. Washington DC., Asreported in EPA's Integrated Risk Information System (IRIS) as of November 1987
Slope Factors and RfDs
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Slope Factors and RfDs
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IRIS Database (Methylmercury)
USEPA Integrated Risk Information System (IRIS)Reference dose for chronic oral exposure of methylmercury: 1 x 10 -4 mg/kg-day
Critical effect : Developmentalneuropsychological impairment
Most extensive data available are onneurotoxicity, particularly in developingorganisms
The nervous system is considered to be the mostsensitive target organ for which there are datasuitable for derivation of an RfD
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IRIS Database (Methylmercury)
Studies to determine whether there were dose-related effects on anumber of neuropsychological endpoints:
Seychelles Island study: 779 mother-infant pairs from a fish-eatingpopulation (Myers et al., 1995a-c, 1997; Davidson et al., 1995,
1998) neuropsychological endpoints, maternal-hair mercury levels
Faroe Island study: 900 mother-infant pairs (Grandjean et al., 1997) Cord-blood mercury, maternal-hair mercury, specific behaviours
Identified methylmercury-related developmental neurotoxicity New Zealand study (Kjellstrom et al., 1989, 1986)
Children were assessed on a number of neuropsychologicalendpoints
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ATSDR Database
Agency for Toxic Substances and Disease Registry (ATSDR), based inAtlanta, Georgia, is a federal public health agency of the U.S. Departmentof Health and Human Services.
Public health statement on chemicals Physical and chemical properties Fate of the chemical when it enters the environment Possible exposure routes Distribution and elimination from the body Health effects (acute and chronic exposure)
Effect on sensitive populations (i.e. children, pregnant women) Medical tests to determine exposure Toxicological information Guidelines and regulations limits on the concentrations in air, water,
food, workplace environment, body loadings60
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Stage 3: Exposure Assessment
Exposure Assessment - The qualitative and/orquantitative evaluation of the likely intake of biological,chemical, and physical agents via food as well asexposures from other sources if relevant.
Determine actual levels of exposure and absorption of a contaminant among the population of exposedindividuals Concentration of the contaminant
Frequency and duration of exposure Actual absorption is determined by toxicological studies
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Exposure Assessment
Exposure assessment involves describing thenature and size of various populationsexposed to a chemical agent, and the
magnitude and duration of their exposures .
Without exposure there can be no toxicity (i.e.likelihood of exposure through consumptionof food)
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Steps In Exposure Assessment
Characterization of exposure setting Identification of exposure pathways Quantification of exposure
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Characterize The Exposure Setting
What are the situations which could lead toexposure?
What would lead to high exposure, mediumexposure, and low exposure?
Describe the situations for the variousexposure scenarios.
What is the population exposed?
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Exposure Pathways
Oral exposure Dermal exposure Inhalation exposure Uptake from these routes of exposure differ based
upon the chemical and physical properties of thetoxicant as well as the permeability of the surface atthe site of absorption (i.e. lung vs. skin vs. GI tract)
The absorbed dose is an average of the daily intakevalue for one route
The absorbed dose for all three routes of exposure areadded together for a total average absorbed dailydose (AADD)
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Exposure Pathways
Contaminated food ingestion of contaminated fishtissue, vegetables and fruit grown in contaminatedsoil or covered with contaminated dust, meat, anddairy products
Contaminated breast milk nursing infants whosemothers were exposed to highly toxic lipophiliccontaminants
Contaminated groundwater ingestion (drinkingwater), dermal contact (bathing), and inhalation of volatile organic compounds (showering)
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Exposure Pathways ( cont )
All potential exposure pathways areconsidered with an analysis of the contaminants released the fate and transport of the contaminants the population exposed to the contaminants
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Sensitive Populations
Some sections of the population are at greaterrisk due to exposure of the chemical hazardthan others: Elderly Infants and children (exposure for children is
higher under the same conditions as adults due to
differences in body weight) Immunocompromised Pregnant women
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Exposure:
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where ADD = average daily dose or intake (mg/kg/day)
C = concentration of the contaminant in a specifiedmedia (mg/kg) IngR = ingestion rate (mg/day) EF = exposure frequency (days/yr)
ED = exposure duration (years) BW = average body weight (kg) AT = averaging time (days) CF = conversion factor (1x10 -6 kg/mg)
C x IngR x EF x ED
BW x AT
x CFADD =
pAverage dailydose byingestion
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where SA = surface area of the skin that contacts the
contaminant (cm2
) AF = skin adherence factor soil (mg/cm 2) ABS = dermal absorption factor (chemical specific)
(unitless)
C x SA x AF x ABS x EF x ED
BW x ATx CFADD =
Average daily dose by dermal absorption
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Exposure factors for a child and an
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Exposure factors for a child and anadult (US EPA, 1997a)
Exposure factors Child Adult Ingestion rate, IngR (mg/day) 200 50
Inhalation rate, InhR (m3 /day) 7.6 20
Exposed skin area, SA (cm 2) 2800 a 5700 a
(face, forearms, hands, lower legs, 50th percentile)
Skin adherence factor, AF soil (mg/cm 2 /day) 0.2 0.07
Body weight, BW (kg) 15 70Exposure frequency, EF (days/yr) 350 350Exposure duration, ED (yr) 6 6
Averaging timeFor noncarcinogens, AT (days) = (ED x 365 days/yr)For carcinogens, AT (days) = (70 yr x 365 days/yr)
219025550
219025550
a EPA, 2001
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Quantification of Exposure
General statement Concentration of the chemical x Intake x Retention
Factor x Length of Exposure
For Noncarcinogens Maximum Daily Dose (MDD) or ADD
For Carcinogens Lifetime Average Daily Dose (LADD)
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Lifetime Average Daily Dose
= Concentration of a Chemical Chemical xContact Rate x Contact Fraction x ExposureDuration
________________________________Body Weight x Lifetime
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LADD Calculation Example
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LADD Calculation Example
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LADD Calculation Example ( cont )
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Important Note to Calculation of LADD
Be aware of the units used for consumption of the chemical (How often the chemical isobtained).
You may need to back calculate the number tomg/kg/day averaged over 70 years (a lifetime) If the units are already in mg/kg/day, then no back
calculation is needed, if units are mg/kg/month, thenyou only need to calculate back from months to days.
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Stage 4: Risk Characterization
Final phase of the heath risk assessmentprocess Combines the information from
Hazard identification Dose-response assessment Exposure assessment
Determines the probability of an adverseeffect to a human population by a toxicsubstance and outlines permissible exposurelevels from which standards of exposure areset.
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Risk Characterization
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Risk Characterization
Quantify risks from individual chemicals
Quantify risks from multiple chemicals
Combine risks across pathways
Assess and present uncertainty
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Risk Characterization
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Risk Characterization
Exposure Assessments and Dose-response Assessments are integrated togive a probability of a negative effect. Risk characterization is conducted for
individual chemicals and then summed formixtures of chemicals Additivity is assumed.
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Characterizing Risk for Non-carcinogens
For Non-carcinogenic chemicals: A hazard quotient (or noncancer toxic risk) , HQ , is
determined by dividing the average daily dose for a givenexposure pathway by the reference dose, RfD:
Average daily doses < RfD (i.e. HQ 1) may result inincreasing probability that adverse health effects will occur(US EPA, 1993).
RfD ADD HQ
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Characterizing Risk for Non-carcinogens
Permissible concentrations for chemicals inthe environment are calculated based on bodyweight, intake, frequency and duration of
exposure, and the RfD Permissible concentration =
RfD x Body Weight______
Intake x Duration x Frequency
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Characterizing Risk for Non-carcinogens
The Risk of exposure for non-carcinogenic effectsis expressed as a Margin of Exposure (MOE).
MOE = __ NOEL___
EXPOSURE A MOE over 10, after extrapolation to humans, is
considered low risk. There the No Effects Level
(NOEL) is a lot higher than the actual exposureoccurring among the most exposed individualswithin the target population.
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Characterizing Risk for Non-carcinogens
It is also assumed that the toxic risks due to potentiallyhazardous substances are additive, therefore the HQ for each of contaminant for a given exposure route can be added togenerate the hazard index (HI) , as follows:
where i represents the different contaminants HI can also be calculated for a certain contaminant by summing
the HQs of the contaminant for different exposure pathways. If HI>1, this indicates the probability of a noncarcinogenic
adverse effect, otherwise, it is assumed to be negligible.
HI = HQ i
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Qualitative descriptions for noncancer
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Qualitative descriptions for noncancertoxic health risks (ATSDR, 1995b)
HazardQuotient
(HQ)
Qualitativedescriptor
Lifetime cancer risk (Risk)
1 minimal 1/1,000,000
>1-5 low> 1/1,000,000 to
< 1/10,000
>5-10 moderate 1/10,000 to 1/1,000>10 high 1/1,000 - < 1/10
1/10
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Ch i i Ri k f C i
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Characterizing Risk for Carcinogens
Carcinogens pose a risk at any dose and the probabilityof developing cancer increases with dose thus cancer risk can range from being negligibly low at low
dose ranges or unacceptably high at high dose ranges
Virtually Safe Dose This was initially defined (1961) as 1 extra cancer death
per 100 million people exposed Found unenforceable by FDA in 1977 Currently the EPA uses 1 extra cancer death per 1 million
people exposed . California uses 1 extra death per 100,000 people exposed
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Characterizing Risk for Carcinogens
For Carcinogenic Chemicals
Risk = Lifetime Average Daily Dose (LADD) x Slope Factor
Units for LADD are mg/kg/day Units for Slope Factor are (mg/kg/day) -1
Therefore units cancel and you get a unit-less number This unit-less number represents the increase in the number
of cancer cases per year due to chemical
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Qualitative descriptions for lifetime
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Qualitative descriptions for lifetimecancer risk (ATSDR, 1995b)
Lifetime cancer risk
(Risk) Qualitative descriptor
1/1,000,000 very low and acceptable
> 1/1,000,000 to < 1/10,000 low
1/10,000 to 1/1,000 moderate1/1,000 to < 1/10 high
1/10 very high
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Example
Calculate the risk assuming an LADD of 0.002 mg/kg bodyweight/day and a Slope factor (potency) of Aldrin at 17 (mg/kgbody weight/day) -1
= LADD x Slope factor= 0.002 x 17= 0.034= one in 29
This is a very high value, statistically, one in 29 people exposed willget cancer from the lifetime average daily dose of 0.002 mg/kg/day.Since we can't change the potency of Aldrin we must determinewhat daily dose over a lifetime would give us a maximum of one ina million risk:
= one in 1,000,000 / Slope factor= 0.000001 / 17= 0.00000006 LADD
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Ri k A t
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Risk Assessment Provides an effective framework for determining the relative urgency of problems and the
allocation of resources to reduce risks
Risk assessment is used routinely to make decisions by:
FDA (Food and Drug Administration)
OSHA (Occupational Safety and Health Administration)
EPA (Environmental Protection Agency)
These agencies use risk assessment in a variety of situations:
Setting standards for chemical or pathogens in water/food
Assessing risk from GEMS (genetically engineered microbes)
Conducting baseline analysis of contaminated sites to determine need for cleanup
Cost/benefit analysis
Development of cleanup goals
Constructing what if scenarios
Evaluation of existing and new technologies for pollution prevention and control
Articulation of public health concerns
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Problems with Risk Assessment
A basic problem with human health risk assessment is the sparseness anduncertainty of the scientific data
Variability within dose-response curves There is uncertainty associated with each step of the assessment. The
various sources of uncertainty include:
-Extrapolation from high to low doses
-Extrapolation from animal to human responses
-Extrapolation from one route of exposure to another limitations of
analytical methods-Estimates of exposure
-Vulnerable populations that may be impacted differently than the
general population by the outcome of a risk analysis
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Risk Communication and Management
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g
Identify decisions and immediate actions Define goals
Remediation Management
Address considerations Social Economic Political Technical
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Food Surveys
Dietary surveys: estimate actual food intakes invarious subgroups of the population Takes into account such factors as age and ethnic
background
Market basket surveys: measure the amount of achemical (i.e. pesticide residues) and otherselected contaminants in freshly prepared andready-to-eat foodstuffs
Detailed theoretical daily intake calculations arecarried out when there is a potential for highexposure levels in humans
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Risk Assessment Studies (Centre for
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(Food Safety)
Risk Assessment Studies DateThe first Hong Kong Total Diet Study: Inorganic Arsenic Feb 2012
The first Hong Kong Total Diet Study: Dioxins and Dioxin-likePolychlorinated Biphenyls (PCBs)
Dec 2011
Polybrominated Diphenyl Ethers in Foods of Animal Origin April 2009
Mercury in Fish and Food Safety April 2008
Dietary Exposure to DDT of Secondary School Students July 2006
Polycyclic Aromatic Hydrocarbons (PAHs) in Barbecued Met July 2004
Dietary Exposure to Heavy Metals of Secondary School Students Oct 2002
Dietary Exposure to Dioxins of Secondary School Students Oct 2002
Source: http://www.cfs.gov.hk/english/programme/programme_rafs/programme_rafs_fc_01.html97
Food Safety Management Systems
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Food Safety Management Systems
Health risk assessment Hazard-Analysis Critical Control Point (HACCP)
a risk management methodology used by the food andrelated industries for the control of food safety hazards toacceptable risk levels
ISO 22000 a generic food safety management system standard that
defines a set of general food safety requirements thatapply to all organizations in the food chain
Codex Alimentarius WHO and FAO have developed risk-based approachesfor the management of public health hazards in food
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Useful Websites
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Useful Websites
United States Environmental Protection Agency(USEPA)http://epa.gov/riskassessment/basicinformation.htm#risk
USEPA Integrated Risk Information System (IRIS)http://www.epa.gov/ncea/iris/help_ques.htm#whatiris
Agency for Toxic Substances & Disease Registry (ATSDR)http://www.atsdr.cdc.gov/
ExtoxNet FAQshttp://extoxnet.orst.edu/faqs/risk/riskhome.htm
http://epa.gov/riskassessment/basicinformation.htmhttp://epa.gov/riskassessment/basicinformation.htmhttp://www.epa.gov/ncea/iris/help_ques.htmhttp://www.atsdr.cdc.gov/http://extoxnet.orst.edu/faqs/risk/riskhome.htmhttp://extoxnet.orst.edu/faqs/risk/riskhome.htmhttp://extoxnet.orst.edu/faqs/risk/riskhome.htmhttp://www.atsdr.cdc.gov/http://www.atsdr.cdc.gov/http://www.atsdr.cdc.gov/http://www.epa.gov/ncea/iris/help_ques.htmhttp://www.epa.gov/ncea/iris/help_ques.htmhttp://epa.gov/riskassessment/basicinformation.htmhttp://epa.gov/riskassessment/basicinformation.htmhttp://epa.gov/riskassessment/basicinformation.htm