Food Toxicology 2nd SEMESTER, 2018/2019 SESSION Lecturer: Prof Monia Perugini E-mail [email protected] Phone: 0861266988 W E L C O M E ! Course requirements CFU = 4 (total 32h of course) Number of units: 4 units Lecture period: 4 hours /week (32 hours/total) One Practical period 12 or 16 hours/total Grading Final Examination 100% Course Learning Objectives Upon successful completion of the course students should: Have broad base knowledge about sources, nature and control of toxic substances in human food system Acquire critical thinking and analytical skills in risk assessment Have a high level of understanding and interpretative capacity in food science and toxicology interface. General program 1. Definitions of terms; concepts of toxicology, acute and chronic toxicity food and safety 2. Pesticide residues 3. Naturally occuring toxins (Mycotoxins, Glycoalkaloids, Marine biotoxins) 4. Food additives (Antioxidants,Preservatives,Colourants,E mulsifiers and Stabilisers, Sweetners) FOOD TOXICOLOGY Food Intake Health Risks Microbiological Risks Toxicological Risks Infection Intoxication What is food safety? Potential health risks from food consumption microbiological, viral and parasitic concerns hormone residues (growth promoters) animal drugs (antibiotics) chemical residues (pesticides) preservatives genetically modified foods (GE) Food Safety is everyone’s responsibility Food safety— What needs to be regulated? • Food additives • Food labeling • Dietary supplements • Novel and GE foods • Food security and protection of food supplies Food Safety Systems—Institutions • OECD: Organization for Economic Cooperation and Development – Promotes policies for highest sustainable economic development in member states – Establishes guidelines for chemical testing, toxic chemicals, pesticides, and biotechnology • Food and Agriculture Organization (FAO) of the United Nations – Leads international efforts to ensure sufficient nutrition for all • World Health Organization (WHO) of the United Nations – Provides scientific advice on matters related to food safety through its Food Safety Department The Evolution of Food Safety Systems The Codex Alimentarius Commission has issued (since 1963) 237 Food standards for commodities 41 Codes/Hygiene or technological practice 25 Guidelines for contaminants 185 Evaluations on pesticides 1,005 Evaluations on food additives 54 Evaluations on veterinary drugs 3,504 Documents/Limits pesticide residues Acidity regulators – 17 What Exactly We Ingest When We Eat Food: Glazing agents – 5 Flavoring agents – 3 An example: Common Food X Emulsifiers – 8 Antioxidants – 6 Colors – 2 Butylate Hydroxyanisole Sweeteners – 11 Chronic exposure – gall bladder, endocrine, Bulking agent – 1 lungs, thorax respiration tumors Mutagen – DNA inhibition, unscheduled Processing aid – 1 DNA synthesis, DNA damage Chronic exposure – reproductive damage Prolonged repeated exposure can cause allergies in sensitized individuals Food X: Chocolate 200 mg/kg Concept Hexane Flammable Delayed target organ effect Peripheral nervous system Kidney Testes-tumors Reproductive effects Potentially carcinogenic 1 mg/kg FDA states that – Safety can not be proved absolutely but…. In order to achieve the general objective of a high level of protection of human health, EU feed/food legislation shall be based on risk analysis (process consisting of three interconnected components: risk assessment-risk management-risk communication) except where this is not appropriate to the circumstances or the nature of the measure Risk assessment shall be based on the available scientific evidence and undertaken in an independent, objective and transparent manner General Principles of Risk Analysis Risk is associated with hazard & exposure First Step: Hazard Identification – Formaldehyde causes cancer – Cholera toxin causes severe diarrhea Second Step: Hazard Characterization – Quantitative and qualitative assessment of the nature of the hazard – Dose-response relationship – Usually animals are administered 3 doses: very small to doses that exceed multiple orders of what would be expected to determine NOAEL=(No Observed Adverse Effect Level) – Margin of safety determination: – To account for interspecies and intra-species variation, NOAEL is divided by 100 (uncertainty factor) A hazard is something that can cause harm, e.g. electricity, chemicals, stress, etc. A risk is the chance, high or low, that any hazard will actually cause somebody harm. Toxicology and Risk Analysis • Risk assessment – Scientific evaluation of the probability of harm resulting from exposure to toxic substances. • Risk management – Risk management is the decision-making process involving considerations of political, social, economic and science/engineering factors with relevant risk assessments relating to a potential hazard so as to develop, analyze and compare options and to select the optimal • Risk communication – The science of communicating effectively in situations that are of high concern, sensitive, or controversial. Risk communication principles serve to create an appropriate level of outrage, behavior modification, or mitigating response, that is in direct proportion to the level of risk or Hazard. Concern Level, Tolerance Levels Are required for Pesticide residues Drugs used in food producing animals Heavy metals Food-borne molds and mycotoxins Bacterial toxins Substances produced by cooking SOME DEFINITIONS Safety: is the absence of evidence of toxicity Toxicity: is ability to cause harm/adverse effect Toxin/poison: poisons are substances that cause harm to organisms when sufficient quantities are absorbed, inhaled or ingested. A toxin is a poisonous substance produced within living cells or organisms. SOME DEFINITIONS TOXICOLOGY: multi-disciplinary application of scientific knowledge to the study of toxins and their effects on people, animals, wildlife and the environment. FOOD ADDITIVES: Any substance/mixture of substances other than the basic component that is added to food as a result of any aspect of processing, storage and preservation. Toxicology is the most diversified of all scientific disciplines, so toxicologists usually specialize in some aspect of toxicology Medical Toxicology/ Clinical Toxicology: diagnosis and treatment of human diseaeses caused by poisons Veterinary Toxicology: diagnosis and treatment of diseases of domesticated and wildlife caused by poisons Food Toxicology: is the study of the nature, properties, effects and detection of toxic substances in food and their disease manifestation in humans Forensic Toxicology: deals with the legal and medical aspects of poisons in people and animals; Environmental Toxicology: deals with effects of pollutants on the environment and wildlife. Regulatory toxicology:use scientific data to decide how to protect humans and animals from excessive risk. SOME DEFINITIONS Contaminant or pollutant? Natural sources Antropogenic sources Food contaminants are compounds included unintentionally in foods. Some are harmless and others are hazardous because of the toxicological risks from their intake to the consumers. Sea = Pollutants How can we measure the chemicals in food? 1. Concentrations units ppm = 1 part per million = 1 mg/Kg or 1µg/g or 1mg/L ppb = 1 part per billion = 1 ug/Kg or 1 ng/g or 1 ug/L ppt = 1 part per trillion = 1 ng/Kg or 1 pg/g or 1 ng/L 2. Half-life - Biological half-life: this is the period of time required for the concentrations or amount of drug Compond Half-life DDT 15 years in the body to be reduced by one half. Lindane 2 years Parathion 130days Malathion 11 days Non dobbiamo dimenticare che …… . “Tutte le sostanze sono dei veleni; non ne esiste una che non sia un veleno. La giusta dose differenzia un veleno da un rimedio” “E’ la dose che fa il veleno” - Paracelsus 1493-1541 SOME DEFINITIONS Safety is relative and there is no absolute safety Thus there are toxic and non toxic doses for any substance Frequency-response curve: a plot of the % of individual with specific response as a function of dose Dose amount of drug per body weight expressed as mg/kg Dosage total amount of a drug administered to an organism. Important: Characteristics of organism Body weight DOSE-RESPONSE CURVES The dose–response relationship, or exposure–response relationship, describes the change in effect on an organism caused by differing levels of exposure (or doses) to a stressor (usually a chemical) after a certain exposure time. This may apply to individuals (e.g.: a small amount has no significant effect, a large amount is fatal), or to populations (e.g.: how many people or organisms are affected at different levels of exposure). Cumulative response-curve (compounds A and B) Maximum Efficacy B 100 A % Maximum Response 50 0 0 X DRUG DOSE B has greater max efficacy than A ~ Potency B 100 A % Maximum Response 50 0 0 X DRUG DOSE A is more potent than B ~ Dose – response curve for an essential nutrient Dose response curves Dose response relationships describe the effect on an organism caused by differing levels of exposure (or dose) Dose levels are usually expressed in mg/kg body weight of the test animal for solids and mg/m3 or parts per million for aerosols/vapours The dose response curve is a valuable tool to understand the levels at which substances begin to exert adverse effects and the degree of harm expected at various levels How the chemicals can enter in our body? How Toxicity Is Assessed ? In vitro/animal studies Systemic toxicity studies (such as clinical signs and symptoms, clinical