Download presentation
Presentation is loading. Please wait.
Published byMargery Evans Modified over 6 years ago
1
Chapter 1.1 : Introduction to General Concepts of Food Chemical Risk Assessment
OBJECTIVES Understanding what food chemicals are? Why are they present in food? Why some chemicals present in food are unsafe? What basic information and questions need to be answered when assessing their safety?
2
Introduction to General Concepts of Food Chemical Risk Assessment
CONTENT Introduction to general Risk Analysis and Risk Assessment Introduction to toxicity/toxicology General Concepts of Food and Nutrition and Lifestyle Factors Basic Food Chemistry -The elements, molecules, chemicals (wanted and unwanted) Food Processing Why Perform a Food Chemical Risk Assessment? Basic Elements of Food Risk Assessment Hazard, Exposure and Risk – The Dose Makes The Poison
3
Introduction to General Concepts of Risk Assessment
“Risk assessment is the process of estimating the potential impact of a chemical, physical, microbiological or psychosocial hazard on a specified human population under a specific set of conditions and for a certain timeframe.” (ENHRA, 2002). Note that Codex definition dose not include psychosocial hazard. Risk Assessment is intended to “provide complete information to risk managers, specifically policymakers and regulators, so that the best possible decisions are made.” (Paustenbach, 1989). There are uncertainties related to risk assessment and it is important to make the best possible use of available information “Risk assessment may be done as a relatively rapid ‘desk top’ study for simple issues or may be a large and complex process where there are significant health concerns. There are numerous models of risk assessment to suit the many contexts in which risk assessments are undertaken.” (ENHRA, 2002)
4
Introduction to Food Chemical Risk Assessment
Food risk assessment is a scientific discipline that uses a formal approach which includes certain pre-defined terms such as “hazard”, and “hazard identification” which have been defined by Codex Alimentarius, FAO/WHO, and WTO. Nevertheless as a scientific discipline its way of working can be derived from the questions that are posed to it. Hence it is proposed to develop the concept of food chemicals risk assessment and its principles together with the participants using examples rather than providing terms and definitions. A global food chemical training module faces the challenge that for some important aspects of chemicals risk assessment such as genotoxicity, carcinogenicity approaches applied by food safety authorities differ. In order to understand and appreciate such differences, it is necessary to explain those without judging them or even taking sides on controversial issues (e.g. use of growth hormones). Examples and case studies will be selected from the available training materials reviewed in the first phase of the project.
5
Models of Food Chemical Risk Assessment
It is not intended at this early stage in this module to expand in detail on specific definitions of food chemical risk assessment as these will be discussed in detail in later modules. However, in general, it is useful to introduce some commonly accepted stages: Issue identification/Problem Identification Hazard identification Dose-response assessment Exposure assessment for the relevant population Risk characterisation The concept of Toxicity The concepts that “The dose makes the poison” and “Risk = Hazard x Exposure”. By introducing the terminology for these stages in general early, it will make it easier to use some examples in the following slides, and the terms will be defined and expanded upon in later modules (e.g. Module 2). Only Issue Identification, Hazard Identification, Toxicity and “The dose makes the p0ison” will be discussed in this early module.
6
Typical Risk Assessment Model
7
Table 1. Concept Example of Lead Issue identification
Lead is a very toxic heavy metal contaminant that is found in the environment either occurring naturally or as a result of human activity, and is taken up by plants that are eaten by humans Hazard identification Lead is a neurotoxin even at very low levels, and is especially toxic to the foetus in utero and in infants and young children, causing brain damage and learning deficits Dose response assessment Lead is toxic even at very low levels, but the toxic effects are dose responsive so that as the dose becomes larger, so does the toxic effect get larger Exposure assessment in relevant population Humans are exposed to lead via contamination in the environment as a result of contamination from natural or man-made processes. The whole population, adults and children, is at risk from the toxic effects of lead, but the most sensitive part of the population is to the foetus whilst in utero, and in infants and young children due to their sensitivity to the neurotoxic effects of lead exposure, even at very low doses Risk characterisation The risk to humans in general is high; the risk from exposure to lead to the foetus in utero, and in infants and young children is very high to extreme Concept of toxicity Lead produces a range of adverse health effects in animals and humans (toxic effects), by targeting body organs especially the human brain Dose makes the poison Lead has been shown to produce toxic effects at even very low levels; the higher the concentration of lead, the more adverse is the toxic effect Risk = hazard x exposure Using this concept, the risk to humans from the exposure to the hazard (lead toxicity), especially the foetus, infants and young children, is high to very high even at very low exposures Table 1.
8
Issue Identification/Problem Identification
Issue Identification identifies issues/problems amenable to risk assessment and assists in establishing a context for the risk assessment by a process of identifying the problems that the risk assessment needs to address. It includes: What is the concern ? What is causing the identified concern ? Why is the concern an issue/problem ? How the concern was initially identified ? How the concerns were raised ? Whether the issue/problem is amenable to risk assessment ? Whether risk assessment is appropriate ?
9
Hazards vs Issues/Problems
Food chemical “Hazards” need to be distinguished from food chemical “Issues/Problems”. Issues establish a context for the risk assessment and assists the process of risk management. Issues have dimensions related to perceptions, science, economics and social factors. Examples of food chemical issues include community concern over the use of gene technology to produce foods, use of new food additives and a new food microbiological standard. Food chemical “Hazards” relate to the capacity of a specific agent to produce a particular type of adverse health effect. An example of a food chemical hazards includes the capacity of heavy metals found in food to cause a variety of serious health problems (toxicity) at certain concentrations.
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.