Probability Theory and Risk Assessment PDF

TOPIC 3 UDAF3213 BY DR CHANG YING PING 1  How can risk be assessed? When is it too risky? How epidemiology relates to risk assessment?  Introduction to probability theory and statistical description. UDAF321...

TOPIC 3 UDAF3213 BY DR CHANG YING PING 1  How can risk be assessed? When is it too risky? How epidemiology relates to risk assessment?  Introduction to probability theory and statistical description. UDAF3213 BY DR CHANG YING PING 2  Apply probability theory, risk assessment to achieve food safety objective. UDAF3213 BY DR CHANG YING PING 3 UDAF3213 BY DR CHANG YING PING 4  Don't eat the sauce… Prego mushroom carbonara pasta cream recalled due to bad processing (nst.com.my) UDAF3213 BY DR CHANG YING PING 9 FDA says pesticide residue found in 10 oatmeal items - Taipei Times UDAF3213 BY DR CHANG YING PING 10 Singapore recalls two more Mie Sedaap instant noodles due to pesticide | The Star UDAF3213 BY DR CHANG YING PING 11  Who evaluates what is safe to eat and what is not? What are their decisions based upon?  Food safety organisations evaluate continuously whether new or already existing food is safe to eat.  These organisations can be global, like Codex Alimentarius and Joint FAO/WHO Expert Committee on Food Additives (JECFA). Some organisations are regional, like the European Food Safety Authority (EFSA), and some are national, like the French Agence nationale de sécurité sanitaire de l’alimentation, de l’environnement et du travail (ANSES) and the German Bundesinstitut für Risikobewertung (BfR).  →a worldwide network committed to keeping us healthy and safe. UDAF3213 BY DR CHANG YING PING 8  Malaysia: Food Safety & Quality Division (FSQD) under Ministry of Health, Malaysia ◦ http://fsq.moh.gov.my/v6/xs/index.php  Australia: Department of Health and Aged Care; Food Standards Australia New Zealand (FSANZ) ◦ https://www.health.gov.au/health-topics/food-and- nutrition/about/food-standards-and-safety  Canada: Canadian Food Inspection Agency ◦ https://inspection.canada.ca/eng/1297964599443/129 7965645317  Hong Kong: Centre for Food Safety ◦ https://www.cfs.gov.hk/english/index.html UDAF3213 BY DR CHANG YING PING 9  International Food Supply Chain Crop & Animal Production Raw Storage & Materials Distribution Ingredients Storage & Distribution Storage & Storage & Distribution Distribution Processing Storage & Food Retail Consumer & Packaging Distribution Food Service https://www.gresham.ac.uk/lectures- Packaging and-events/can-we-trust-our-food 10  On this pizza: ingredients from 17 processors in 9 countries on 3 continents https://www.gresham.ac.uk/lectures-and-events/can-we-trust-our-food UDAF3213 BY DR CHANG YING PING 11 Naturally occurring Intentionally added Unintentionally Food constituents Food additives added e.g. carbs, fats, e.g.colours, protein, vits, preservatives, flavours, Environmental e.g. minerals sweeteners dioxins/ PCBs, heavy metals (Pb, Hg), Natural toxins e.g. New ingredients e.g. pesticide/ vet drug lectins, tetrodotoxin, GM, novel foods residues cyanogenic Processing aids e.g. glycosides, caffeine, Process e.g. PAHs, enzymes, antifoaming maillard reactions, cocaine, aflatoxin agents acrylamide Other chemicals e.g. Adulterants e.g. isoflavones, Food contact materials diethylene glycol, e.g. bisphenol A fragrances melamine   What are factors that decide the safety of certain chemical use?  What is the probability of poisoning from chemicals in the environment?  Are all chemicals hazardous? Factors Determining the Safety of Chemical Use Toxicity: The inherent toxic properties of a chemical determine how harmful it can be to humans, animals, or the environment. Some chemicals are toxic even in small amounts, while others may require large exposures to cause harm. Dose: The amount of chemical exposure, also known as the dose, is a critical factor. The principle "the dose makes the poison" indicates that even chemicals considered safe can be harmful if exposure levels are high enough. Duration and Frequency of Exposure: Continuous or repeated exposure to a chemical can increase the risk of adverse effects, even if each exposure is relatively small. Route of Exposure: The way a chemical enters the body (inhalation, ingestion, dermal contact) can influence its toxicity. Some chemicals are more dangerous when inhaled than when ingested, for example. Chemical Interactions: When multiple chemicals are present, they may interact in ways that increase or decrease overall toxicity. Synergistic effects can make a chemical more harmful, while antagonistic effects can reduce its impact. Individual Susceptibility: Factors such as age, gender, genetic makeup, pre-existing health conditions, and lifestyle can affect how an individual responds to chemical exposure. Environmental Persistence: The stability of a chemical in the environment, how itUDAF3213 degrades, BY andDR itsCHANG potentialYING to bioaccumulate PING in organisms can affect 13 long-term safety.  Regulation is necessary in response to public fear and pressure  Guidelines should be issued if possible rather than strict rules for the assessment of every case in the same way  Toxicological data → the assessment and the subsequent calculation of risks and estimation of risk versus benefit UDAF3213 BY DR CHANG YING PING 14  To guarantee that all food is safe → too expensive  The alternative is to identify the risk of unsafe food, pursue management strategies to reduce the risk, and to discuss and interact to assure the food industry, food regulators and consumers appreciate (understand) the risks and strategies to reduce the risk of unsafe food. UDAF3213 BY DR CHANG YING PING 15  RISK ASSESSMENT HAZARD IDENTIFICATION HAZARD CHARACTERIZATION EXPOSURE ASSESSMENT RISK CHARACTERIZATION RISK MANAGEMENT RISK EVALUATON OF COMMUNICATION CONTROL OPTIONS INTERACTIVE SELECTION AND EXCHANGES OF IMPLEMENTATION OF OPINION AND SELECTED OPTION INFORMATION REGARDING RISKS http://sintak.unika.ac.id/staff/blog/uploaded/5811994157/files/foodsafety- UDAF3213 BY DR CHANG YING PING 16  It is a mathematical concept which refers to the likelihood (probability) of undesirable effects resulting from exposure to a biological, physical or chemical hazard.  Risk assessment on chemicals when: ◦ The chemical is likely to be a hazard to humans in the environment ◦ The likelihood of persistence of the chemical in the environment and bioaccumulation ◦ The likelihood that sensitive human may be exposed to significant levels ◦ There is an indication of hazard to human health ◦ The likelihood of exposure via use or production. UDAF3213 BY DR CHANG YING PING 17   UDAF3213 BY DR CHANG YING PING 18 https://www.youtube.com/watch?v=-E-jfcoR2W0 UDAF3213 BY DR CHANG YING PING 19 https://www.youtube.com/watch?v=-E-jfcoR2W0 UDAF3213 BY DR CHANG YING PING 20  Risk of death is defined as a probability UDAF3213 BY DR CHANG YING PING 21  Hazard:a biological, chemical or physical agent with the potential to cause an adverse health effect (e.g. Salmonella could be in food and it could make someone ill).............CODEX definition Risk: LIKELIHOOD * IMPACT the likelihood of an adverse event (e.g. a consumer gets food-borne illness) and the severity (mild illness/severe illness, death) of that event, under specific exposure conditions As exposure increases so does the probability of harm and therefore a RISK ≠ HAZARD reduction in exposure reduces the risk UDAF3213 BY DR CHANG YING PING 22  Safety: The practical certainty that adverse effects will not occur when the substance is used in the manner and quantity proposed for its use  Acute exposure: A single episode where a particular amount of a substance (e.g. overdose of a drug) enters the organism.  Chronic exposure: Repeated exposure to a substance which may then accumulate or cause a cumulative toxic effect UDAF3213 BY DR CHANG YING PING 23  Different ways from simple irritation to complex immunological reactions.  For example direct toxic action; biochemical lesions, physiological effects, teratogenicity, carcinogenicity  May be overlap between toxic response, and some chemicals may cause more than one type of effect  Some chemicals do not lead to detectable pathological lesions but rather morbidity or death of the organism UDAF3213 BY DR CHANG YING PING 24 https://www.foodsafetymagazine.com/magazine-archive1/aprilmay- 2003/prioritizing-food-safety-risk-assessmentsa-new-approach/ UDAF3213 BY DR CHANG YING PING 25 UDAF3213 BY DR CHANG YING PING 26  Food Legislation, National and International Standards, Quality and Safety Management Systems (such as ISO 9001 and 22000), Good Agricultural Practices (GAP), Good Hygiene Practices (GHP), Good Manufacturing Practices (GMP), HACCP, Risk Analysis, monitoring and alert systems for food contaminants and food-borne diseases UDAF3213 BY DR CHANG YING PING 27  HACCP: identifies, prevents, controls and monitors the most vulnerable points in a food production system. It complements general hygiene requirements for food premises  Risk assessment (the evaluation component of risk analysis) → assist in identifying hazards, critical control points and establishing critical limits for the HACCP plan determine if hazard is actually a hazard UDAF3213 BY DR CHANG YING PING 28  Hazard analysis: Hazards are analyzed by categories and emphasis is put on “significant hazards” (important hazard based on the likelihood of occurrence and severity.  It does not specify how the “collection” and “evaluation” of information are to be performed and it is usually based on periodically published guidelines on what hazard should be addressed under the “Hazard Analysis” principle.  It does not access to more complex data (exposure assessment, dose-response, etc.) → no actual definition of risk. UDAF3213 BY DR CHANG YING PING 29  Risk assessment is the process whereby hazard, exposure and risk are determined  Generally there will be a dose-effect relationship for most chemicals, there should be a safe dose  It is possible to determine a level of exposure without an appreciable risk to human health.  Other components of risk analysis are risk management and risk communication that require different types of approach UDAF3213 BY DR CHANG YING PING 30 1. Risk Evaluation  Identification of a food safety problem  Establishment of a risk profile  Ranking of the hazard for risk assessment and risk management priority  Establishment of risk assessment policy for conduct of risk assessment  Commissioning of risk assessment  Consideration of risk assessment results UDAF3213 BY DR CHANG YING PING 31 Elements of Risk Management (cont.) 2. Risk management option assessment  Identification of available management option  Selection of preferred management option, including consideration of an appropriate safety hazard  Final management decision 3. Implementation of management decision 4. Monitoring and review  Assessment of management decision  Review risk management and/or assessment necessary UDAF3213 BY DR CHANG YING PING 32 UDAF3213 BY DR CHANG YING PING 33  Support decisions that are in proportion to public health risks involved.  Enable systematic evaluation of likely impacts of measures selected, to manage risks.  Allow likely costs of compliance to be compared with expected benefits.  Provide a useful metric in prioritizing different food safety problems.  Meet obligations under international agreements and enhance trades.  Identify gaps and uncertainties in scientific knowledge to help set research priorities UDAF3213 BY DR CHANG YING PING 34  The interactive exchange of information and opinions throughout the risk analysis process  hazards and risks, risk-related factors and risk perceptions  among risk assessors, risk managers, consumers, industry, the academic community and other interested parties,  including the explanation of risk assessment findings and the basis of risk management decisions UDAF3213 BY DR CHANG YING PING 35  “Consumers require access to adequate information about potential hazards and appropriate precautions to be taken in the final preparation and serving of food.  “Communication provides the private and public sectors with the information necessary for preventing, reducing or minimizing food risks to acceptably safe levels through systems of food quality and safety management by either mandatory or voluntary means. It also provides sufficient information to permit the populations with the greatest level of risk from any particular hazard to exercise their own options for achieving even greater levels of protection UDAF3213 BY DR CHANG YING PING 36  As the process whereby the nature and magnitude of the risk is determined, it requires FOUR steps: ◦ Hazard identification: Evaluation of the toxic effects of the hazard in question ◦ Hazard characterization: Evaluation of the causal relationship between the exposure to the hazard and an adverse effect in individuals or populations, respectively ◦ Exposure assessment: Determination of the level, frequency and duration of exposure of humans to the hazardous substance ◦ Risk characterization: Estimation of the incidence of adverse effects under the various conditions of human exposure UDAF3213 BY DR CHANG YING PING 37  Toxicological Exposure Hazard Food & Drink  Acute toxicity  Allergy  Sub-chronic toxicity  Chronic toxicity  Reproductive toxicity  Teratogenicity toxicity  Genotoxicity  Carcinogenicity UDAF3213 BY DR CHANG YING PING 38  To find the answer of this question: “Could this food or anything in it be harmful?”  To identify agents that are capable of causing adverse health effects and may be present in a particular food/group of foods  The data used is normally derived from: ◦ Human epidemiology ◦ Animal toxicity studies ◦ In vivo and in vitro mechanistic or other studies  A chemical may constitute a number of hazards of different severity, only the primary hazard will be used for the subsequent stages of the risk assessment process. ◦ E.g. reversible liver toxicity (high doses) vs skin tumors (lower doses)  Although human data (not often available) is ideal, must be supplemented with animal toxicity data, generated by toxicity studies that are controlled which generate histopathological clinical chemical and biochemical data.  Epidemiological data → a causal relationship exists between exposure to the hazard and an effect in humans. UDAF3213 BY DR CHANG YING PING 39  The Food Safety Hazard Guidebook UDAF3213 BY DR CHANG YING PING 40  To find the answer of this question: “What effects does the amount of hazards cause?”  To estimates the relationship between the dose and the adverse effect in humans and determine whether evidence is strong enough to demonstrate that a substance has the potential to cause harm (the nature, severity and duration of the health effects)  This requires extrapolation from possibly high, experimental doses used in animals to levels likely to be encountered by humans.  The extrapolation from high to low doses will depend on the type of primary toxic effect. If this is a carcinogenic effect then a threshold normally cannot be assumed and a mathematical model is used to estimate the risk at low doses. If the primary toxic effect is non-carcinogenic then it will normally be assumed that a threshold exists. UDAF3213 BY DR CHANG YING PING 41  For noncarcinogens where the dose response shows a threshold, a dose can be determined at which there is no adverse effect, the No Adverse Effect Level (NOAEL).  If a NOAEL cannot be determined (if the data is insufficiently robust) then the Lowest Adverse Effect Level (LOAEL) is determined. UDAF3213 BY DR CHANG YING PING 42   To find the answer of this question: “Who may be harmed and at what level may exposure be harmful?” Experts estimate how much of the food or ingredient consumers (e.g. infants, children, adults) or sub- populations (e.g. vegetarians, vegans) are likely to be exposed to under real-life conditions, where both dose and duration are considered. The exposure must be evaluated to determine if a hazard presents an actual risk (step 4). With increased exposure, the risk also increases.  Based on science, the exposure routes, sources of exposure, final dose at the target organ, initial levels in raw material, effects of production, processing, handling, distribution, preparation, packaging, hygiene conditions, etc., are evaluated. UDAF3213 BY DR CHANG YING PING 43  The assessment is more reliable with an indication of actual exposures for both the experimental animals and humans that have provided the data on which it is based.  May use biomarkers to improve the process, for example, biomarkers for susceptibility may be important for determining specially sensitive groups for estimating an uncertainty factor.  For a new chemical substance human data is not available and toxic effects in man cannot be verified by direct experiment → extrapolation from the results of animal studies is essential.  Epidemiology studies may be useful for compounds that have been used for some time UDAF3213 BY DR CHANG YING PING 44 https://www.youtube.com/watch?v=M8hV15KzKNk UDAF3213 BY DR CHANG YING PING 45 UDAF3213 BY DR CHANG YING PING 46   To find the answer of this question: “How likely is it that people will experience exposure at a level that can cause harm in real life” To formulate a final conclusion on the level of risk. The previous steps are taken into account to calculate the likelihood of the food or ingredient causing harm according to the nature of the hazard and level of exposure. The biological, statistical and other uncertainties will have to be taken into account.  For carcinogens the risk is expressed in terms of increased risk of developing a cancer (e.g. 1 in 106). This is calculated from the cancer slope factor and the 70-year average daily intake in mg/kg/day.  From the NOAEL (or LOAEL if there is no reliable NOAEL) various parameters can be determined. ◦ For food additives this is normally the Acceptable Daily Intake (ADI) The ADI is the amount of chemical to which a person can be exposed for a lifetime without suffering harmful effects. The determination of these intake values requires the use of a safety or uncertainty factor. UDAF3213 BY DR CHANG YING PING 47  ◦ For food contaminants the parameter is the Tolerable Daily Intake (TDI). The TDI is an estimate of the daily intake of the chemical that can occur over a lifetime without appreciable health risk. Daily food consumption for a particular type of food will be used for this calculation. ◦ Food may also contain veterinary drug residues and the pesticide residues for which ADIs may be calculated.  The modifying or safety factors are as follows: ◦ 10 for human variability (intra species); 10 for extrapolation from animals to humans (interspecies variability); ◦ 10 if less than chronic doses have been used; 10 if the LOAEL rather than the NOAEL is used;  These uncertainty factors are combined and divided into the NOAEL (or LOAEL) to give the ADI or TDI. The modifying factor allows for judgement on the quality of the scientific data. UDAF3213 BY DR CHANG YING PING 48 NOAEL = 5 mg/kg body weight/day/lifetime UDAF3213 BY DR CHANG YING PING 49  In 2015, International Agency for Research on Cancer (IARC) classified processed meat, as a Group 1 carcinogen8 the same group as asbestos and tobacco. This means there is convincing evidence that processed meat can cause cancer, according to the hazard characterization (step 2).  This led to newspapers stating that processed meat is as bad for you as tobacco. Other experts said that this was not the case. So, what are their statements based upon? UDAF3213 BY DR CHANG YING PING     UDAF3213 BY DR CHANG YING PING 51 UDAF3213 BY DR CHANG YING PING 52 RISK MANAGEMENT OPTION UDAF3213 BY DR CHANG YING PING 53 54 UDAF3213 BY DR CHANG YING PING 55 Who Does What? Codex Committees and Risk Management Codex committees on:  Food Additives and Contaminants (CCFAC)  Residues of Veterinary Drugs in Food (CCRVDF)  Pesticides Residue (CCPR)  Food Hygiene (CCFH)  General Principles (CCGP)  Food Labeling (CCFL)  Food Import & Export Inspection and Certification System (CCFICS)  Nutrition and Foods for Special Dietary Uses (CCNSFDU)  Methods of Analysis and Sampling (CCMAS) 56 Who Does What? Independent Expert Bodies and Risk assessment Joint FAO/WHO Expert Committee on Food Additives (JECFA)  Food Additives  Contaminants (CCFAC)  Residues of Veterinary Drugs in Food (CCRVDF) Joint FAO/WHO Meeting on Pesticide Residues (JMPR)  Pesticides Residue (CCPR) UDAF3213 BY DR CHANG YING PING 57  Main Tasks Independent Expert Bodies JECFA Food Additives JECFA ADI Codex Committee on Codex Food Additives and Maximum Contaminants Level 58  Main Tasks Independent Expert Bodies JECFA (cont.) Acceptable Daily Intake : An estimates of the amount of a substance in food, and/or drinking water, expressed on a body weight basis, that can be ingested daily over a lifetime without appreciable health risk  Assures no hazard to the consumer  Based on risk assessment and safety factors: extrapolation to human 10 x difference between humans 10 x  Overall safety factor, 100 x  Additional safety factors (2-10 x) if data are uncertain 59 EFSA: European Food Safety Authority UDAF3213 BY DR CHANG YING PING 60 https://www.foodsafetynews.com/2014/04/risk-assessment-vs-risk- management-whats-the-difference/ UDAF3213 BY DR CHANG YING PING 61  A novel food additive to be used in a food product. Safe? Ministry of Health  Who is the risk manager?  Who is the risk assessor?  What are the tasks for the risk manager?  What are the tasks for the risk assessor?  What will be the outcome? Outcome in Relation to Malaysia: If the novel food additive is deemed safe, the outcome would be its approval for use in specific food products Is the Novel Food Additive Safe? within the limits established by the regulations. The The safety of a novel food additive is determined additive would then be listed in the Malaysian Food through a comprehensive risk assessment process. Regulations under permitted food additives, along with This involves evaluating scientific data on the additive’s any conditions for its use (e.g., maximum usage chemical composition, toxicology, dietary exposure, levels, specific food categories). and any potential adverse effects. The outcome of the risk assessment will determine if the additive is safe for If the additive is not considered safe, it will be rejected, consumption at the intended levels. and the manufacturer would be required to reformulate the product or provide additional data for re- assessment. Public health and consumer safety remain the top priorities throughout the process. UDAF3213 BY DR CHANG YING PING 62  Purpose of the risk assessment Scope of the risk management problem Importance to Food Safety Authorities How the risk assessment results would be used by the Food Safety Authorities  Examples ◦ A risk management problem is: from eating ready-to- eat (RTE) foods served in restaurants "How should FDA manage the risk of contracting listeriosis?" ◦ "What is the exposure to Listeria monocytogenes from consuming RTE foods in restaurants?“ ◦ "What is the likelihood of the general population (or a sensitive subset of the population) contracting listeriosis from eating RTE foods in restaurants?“ ◦ "How much is the risk reduced if FDA required 'use by dates' on RTE foods?" UDAF3213 BY DR CHANG YING PING 63 Interaction between government's and industry's food safety activities (Jouve 2000, Jouve et al., 1998) 64 ALOP - Apporiate level of UDAF3213 BY DR CHANG YING PING 65  A Food Safety Objective (FSO) is a nationally, regionally or internationally developed statement that expresses the level of a hazard in a food that is tolerable in relation to the level of risk possibly associated with that food. ◦ It can be considered as the maximum acceptable level for the hazard in a food. ◦ A FSO contains the food of concern, the hazard of concern and an expression of the appropriate level of protection of the population from the hazard, and has a fully traceable relationship with the risk assessment. UDAF3213 BY DR CHANG YING PING 66  L monocytogenes g  L monocytogenes   UDAF3213 BY DR CHANG YING PING 67  For the risk  For quality control in management process food manufacturing ◦ to establish the ◦ to ensure that food significance of the estimated risk, products meet certain ◦ to compare the costs of standards of quality, safety reducing this risk to the and consistency benefits gained, ◦ May vary depending on the ◦ to compare the estimated type of food product and risks to the societal the regulatory benefits derived from requirements in the region incurring the risk and ◦ to carry out the political and institutional process of reducing the risk UDAF3213 BY DR CHANG YING PING  preventing before it happens  Prevention is better than correction. ◦ Risk assessment ◦ Root cause analysis ◦ Continuous improvement ◦ Training and education ◦ Standardization ◦ Collaboration UDAF3213 BY DR CHANG YING PING 69  Food industry may prevent quality problems and guarantee the production of safe and high-quality goods by practicing proactive quality control.  The chance of product recalls, damage to their reputation, and legal responsibility can be decreased by food industry by recognizing potential risks and hazards and implementing preventive measures to eliminate them  Reactive quality control is less effective and more costly than proactive quality control. UDAF3213 BY DR CHANG YING PING 70 UDAF3213 BY DR CHANG YING PING 71 UDAF3213 BY DR CHANG YING PING 72 ◦ A food safety problem: Salmonella is a common cause of foodborne disease in the European Union. Beef or other meat products are important sources of Salmonellosis in humans. ◦ The European Food Safety Authority are going to develop recommendations about control measures in cattle production and production line of beef products (e.g. sausage) that reduce the risk for the consumers in relation to Salmonella. ◦ Because there is no perfect knowledge about the effect of different control measures, how should they know what to decide about the recommendations? UDAF3213 BY DR CHANG YING PING 73  Example: What is the expected reduction of Salmonellosis in humans by:  Reducing the prevalence of Salmonella infected cattle by 50%  Reducing the concentration of Salmonella in contaminated carcasses by 90%  Increasing the scalding temperature by 10ºC  Lowering the pH in fermented sausages from 5.8 to 5.6 UDAF3213 BY DR CHANG YING PING 74  It addresses uncertainty (i.e. what is not known about the risk) in a logical, transparent and well- documented manner that is clearly indicated to everyone involved in the risk analysis process. There is no one right way to do risk assessment. The types of process will depend on the nature of the risk (chemical or microbial or physical) and the particular context in which it occurs. Can be qualitative or quantitative. UDAF3213 BY DR CHANG YING PING 75  Two types of scientific uncertainties:  (1) those related to data and (2) those associated with inferences that are required when directly applicable data are not available.  Data uncertainties arise when evaluating information obtained from the epidemiologic and toxicologic studies of the intake levels that are the basis for risk assessments.  Examples of inferences include the use of data from experimental animals to estimate responses in humans and the selection of uncertainty factors to estimate inter and intraspecies variabilities in response to toxic substances. UDAF3213 BY DR CHANG YING PING 76 UDAF3213 BY DR CHANG YING PING 77 UDAF3213 BY DR CHANG YING PING 78  When performing risk assessment, the best source of information on specific contaminants' health effects is data from epidemiologic studies. Foodborne illness outbreaks This is because epidemiologists analyse how health-related events are distributed in specific human populations, who gets sick with what illnesses, when, and where. 79 UDAF3213 BY DR CHANG YING PING   ◦ ◦ ◦ UDAF3213 BY DR CHANG YING PING 80 https://www.youtube.com/watch?reload=9&v=Jd3gFT0-C4s 81 82 UDAF3213 BY DR CHANG YING PING 83  The presence of chemicals such as food additives, food contaminants or residues of veterinary drugs.  Direct additives, indirect additives, “chemical reaction”, residue  Public concern : the type and amount of these additives and their potential to cause cancer or other illnesses in people. UDAF3213 BY DR CHANG YING PING 84  Foodborne Pathogen ◦ Zoonotic (animal origin); E.coli 0157:H7; Campylobacter jejuni ◦ Geonotic (environment): Listeria monocytogenes; Bacillus cereus ◦ Human origin: Salmonella typhi; hepatitis A virus; Staphylococcus aureus, Shigella spp.; Norwalk-like viruses  Cause illness Contamination of raw agricultural produce; poor hygienic practices (undercooking, cross-contamination, recontamination, improper storage temperature, food handler who is a carrier. UDAF3213 BY DR CHANG YING PING 85 UDAF3213 BY DR CHANG YING PING 86  For many chemical hazards, a choice can be made as to how much of the chemical may enter the food supply.  Use of these chemicals can be regulated or restricted → residues at the point of consumption do not pose risks.  Microbial hazards are ubiquitous in the food chain  They often can exist at the point of consumption at levels that do present obvious risks to human health. UDAF3213 BY DR CHANG YING PING 87 UDAF3213 BY DR CHANG YING PING 88 Epidemiological studies; Animal studies → NOAEL; MTD Dose- response extrapolati on; Dose- scaling Estimate dietary intake; Food consumption Estimate risk; Exposure data >ADI → high risk; Uncertainties (relevance; specific human sensitivity) 89 UDAF3213 BY DR CHANG YING PING 90 UDAF3213 BY DR CHANG YING PING 91  Risk Assessment of Biological Agents in Food Food will always present minimal biological risk Biological agents of concern  Bacteria, viruses, protozoa, algae Standards and codes of practices HACCP General mechanisms in causing human illness by Biological Hazards  Produce toxins →mild symptoms of short duration to severe intoxications  Produce pathological responses  ingestion of viable organism capable of infecting host 92 UDAF3213 BY DR CHANG YING PING 93  Special features of microbial hazard  Dynamic of growth  Diversity of the microbial and the human immune response  Role of consumers UDAF3213 BY DR CHANG YING PING 94  Step 1 Hazard identification  Epidemiological studies Limitations  The expense and difficulty involved in outbreak investigations  The lack of reliable or complete epidemiological data  The inability to isolate and characterize new pathogens UDAF3213 BY DR CHANG YING PING 95  Step 2 Hazard characterization: to provide qualitative or quantitative estimates of the severity and duration of adverse effects due to the presence of pathogen in food Limitations  host susceptibility to pathogenic bacteria is highly variable  attack rates from a specific pathogen vary widely  virulence of a pathogenic species is highly variable  pathogenicity is subject to genetic variation resultant from frequent mutation  Foods will modulate the ability of bacteria to infect and/or otherwise affect the host UDAF3213 BY DR CHANG YING PING 96  Step 3 Exposure Assessment: an estimate of either the number of pathogenic bacteria or the level of bacterial toxin in food Limitations  Ecology of the bacterial pathogen concern  Processing, packaging and storing of food  Preparation steps, such as cooking, which may inactivate bacterial agents  Cultural factors relating to consumers’ practice UDAF3213 BY DR CHANG YING PING 97  Step 4 Risk characterization: depend on the considerations and information described in the hazard identification, hazard characterization and exposure assessment steps. Qualitative or quantitative estimate of the potential for adverse effects from a particular agent on a specific population UDAF3213 BY DR CHANG YING PING 98 UDAF3213 BY DR CHANG YING PING 99  Identify Food Safety Problems → justify the need for risk analysis  Develop a Risk Profile: Information on the Food Safety Problem, how it occurs, possible solutions→ let the risk manager decide whether a risk assessment is needed. ◦ Brief description of the situation; product/commodity involved; the values to be placed at risk; potential consequences, consumers’ perception; distribution of risks and benefits ◦ Identify aspects of hazards relevant to prioritizing and setting the risk assessment policy, aspects relevant to the choice of safety standards and management options. UDAF3213 BY DR CHANG YING PING 100  When a risk assessment is not considered necessary, other more appropriate actions may be taken; UDAF3213 BY DR CHANG YING PING 101  an issue requires immediate action  the risk is well described by definitive data, a management decision can be made without one  the issue has limited nature of possible risk and a specific regulatory response is unnecessary  the problem is relatively simple, a response based on common sense is sufficient UDAF3213 BY DR CHANG YING PING 102   Problem solved by Good Hygienic Practice (GHP); no risk assessment needed. UDAF3213 BY DR CHANG YING PING 103  there is little data and much uncertainty  multiple values are in potential conflict  the issue is of great concern to regulators or stakeholders  continuous decision-making is required  managers need information to guide research  managers want to establish a baseline estimate of the risk  the hazard is an emerging pathogen or agent, serious public health and/or trade concern  a national standard is more demanding than an international one  a country wants to export or import a new commodity UDAF3213 BY DR CHANG YING PING 104   ◦ ◦ ◦ ◦ ◦ UDAF3213 BY DR CHANG YING PING 105 UDAF3213 BY DR CHANG YING PING 106 UDAF3213 BY DR CHANG YING PING 107