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Development of Risk Assessment Methods for Fishery Products

by the Fish Site Editor
08 August 2009, at 1:00am

Both risk and risk assessment have become a kind of buzz word today. In the new hygiene package from the European Union (EU), the focus is on risk assessment and risk-based inspections. Another aspect has been developing in recent years, namely risk-benefit or cost-benefit analysis, says Gujn Gunnarsson, The Directorate of Fisheries, Iceland.

Introduction

This kind of analysis has been applied to financial issues for quite some time. In the food safety perspective, this method is used to weigh the benefits of consuming a certain foodstuff against the risk associated with consuming it. A good example of this kind of analysis was published in the Journal of American Medical association in 2006 (Mozaffarian and Rimm, 2006).

In this paper I will go briefly into the history of risk assessment in a food safety context, and also take a look at newer trends, namely risk-benefit analysis. When looking at risk-benefit analysis, it will be interesting to ask the question of whether regulators should take into account in their work only the risk associated with certain products, or should they also look at the benefits. Lastly, I will present some of the work the Icelandic Directorate of Fisheries has started in order to fulfil the requirements of the EU in the new hygiene package when it comes to risk assessment and risk-based inspections.

Some definitions

In order to understand the concepts of risk assessments and risk-benefit analysis, it is important to define some of the concepts used in this field.

The most important concept to define is “risk”. What is risk? Risk is a function of the probability of an adverse health effect and the severity of that effect, consequential to a hazard(s) in food (FAO, 2004). In other words: The likelihood that a hazard will affect us and the severity of its consequences if it does.

Another important concept is “Risk analysis”. It is a process consisting of three components: risk assessment, risk management and risk communication, which all interact one with the other.

“Risk assessment” implies a scientifically based process, consisting of four steps: hazard identification, hazard characterization, exposure assessment and risk characterization (FAO, 2004).

These three definitions are the same as used by the EU in regulation (EC) No 178/2002 of the European Parliament and of the Council of 28 January 2002, laying down the general principles and requirements of food law, establishing the European Food Safety Authority and laying down procedures in matters of food safety. Other definitions can be found in this regulation or in FAO Fisheries Technical Paper No. 442: Application of risk assessment in the fish industry (FAO, 2004).

If we take a closer look at risk assessment, it consists, as noted above, of four steps.

  • The first step is hazard identification. That involves identifying those biological, chemical and physical agents capable of causing adverse health effects and that may be present in a particular food or group of food. Examples are Listeria monocytogenes in smoked fish, or methyl mercury in seafood.
  • The second step is hazard characterization, involving qualitative and/or quantitative evaluation of the nature of the adverse health effects associated with biological, chemical and physical agents that may be present in food. Hazard identification can further be divided into two parts, description of the hazard and dose-response relationship if it exists.
  • The third part is the exposure assessment; it is a qualitative and/or quantitative evaluation of the likely intake of biological, chemical and physical agents via food, as well as possible exposure from other sources. It is important to know the level of contamination in food at the time of consumption, and the number of servings of food that is potentially dangerous.
  • The final part of the risk assessment in the risk characterization. That is the process of determining the qualitative and/or quantitative estimation, including attendant uncertainties, of the probability of occurrence and severity of known potential adverse health effects in a given population, based on hazard identification, hazard characterization and exposure assessment (FAO, 2004).

Basically we are putting together all the work from earlier steps in the risk assessment to provide an estimate of the risk, which is the outcome of risk characterization. The estimate can in turn be qualitative, giving an estimate in terms of “high”, “medium” or “low”. It can be a semi-quantitative estimate, where an estimate is in the form of risk ranking, i.e. a certain number in a given range, or it can be a quantitative estimate, where you predict the number of people you expect will become ill from the particular product+hazard pairing.

There are several different types of risk assessments that fall under three broad categories:

  • Quantitative risk assessment, which is a risk assessment that provides numerical expressions of risk and indication of the attendant uncertainties.
  • Semi-quantitative risk assessment, which can be seen as a mixture of qualitative and quantitative data.
  • Qualitative risk assessment, which is a risk assessment based on data that, while forming an inadequate basis for numerical risk estimation, nonetheless, when conditioned by prior expert knowledge and identification of attendant uncertainties, permits risk ranking or separation into descriptive categories of risk.
Table 1
Qualitative risk assessment
Risk criterion Raw molluscan shellfish Canned fish Dried fish
Bad safety record + + -
No CCP for the hazard + - -
Possibility of contamination or recontamination + + -
Abusive handling possible + - -
Growth of pathogens can occur + - -
No terminal heating step + + +
Risk category High Low No risk
Adapted from Huss, Reilly and Ben Embarek (2000).

Several methods have been used for qualitative risk assessment; an example is the one proposed by Huss, Reilly and Ben Embarek (2000) (See Table 1).

Here pluses are ascribed to hazards, and then risk is ranked as “high” (four or more pluses) or “low” (less than four pluses).

For semi-quantitative risk assessment we use a mixture of qualitative and quantitative data. This requires a lot of work, but not as much as for a full quantitative risk assessment. To facilitate this kind of risk assessment, Sumner and Ross (2002), developed a simple spreadsheet tool, Risk Ranger, in Microsoft® Excel software and used standard mathematical and logical functions.

Quantitative risk assessments are complex and usually take a long time. It is a probabilistic approach that offers many advantages, but also some difficulties. It makes full use of the available information and facilitates integration of microbiology, toxicology and epidemiology. It takes into account the overall degree of variability and uncertainty, addresses sensitivity, and appreciation of the confidence that can be placed on the analysis and its findings. It involves complex modelling, often Monte Carlo simulation. Tools such as the @Risk software program have been used to facilitate the process. One problem is that this kind of risk assessment is very time consuming, taking up to three years or more, and resource demanding.

For seafood, there have been several quantitative risk assessments carried out:

  • Risk assessment of Vibrio vulnificus in raw oysters (FAO/WHO, 2005b).
  • Risk assessment of choleragenic Vibrio cholerae O1 and O139 in warm-water shrimp in international trade (FAO/WHO, 2005a).
  • Risk assessment of Listeria monocytogenes in ready-to-eat foods (FAO/WHO, 2004a,b).
  • Quantitative risk assessment on the public health impact of pathogenic Vibrio parahaemolyticus in raw oysters (FDA, 2005).
  • Quantitative assessment of the relative risk to public health from food-borne Listeria monocytogenes among selected categories of ready-to-eat foods (FDA, 2003).
  • Listeria monocytogenes in smoked fish in Sweden (Lindqvist and Westöö, 2000).

As implied by the brevity of the list, there are not many quantitative risk assessments available for seafood, or for any other food for that matter, the reason being the complexity and the time it takes to implement a quantitative risk assessment.

We have only discussed microbiological risk assessments (MRAs); they have a very short history compared to chemical risk assessments. To date, there are available, from FAO/WHO, chemical risk assessments for more than 1500 food additives, more than 40 contaminants and more than 90 residues of veterinary drugs. The beginning of MRA at FAO/WHO can be traced back to the guidelines on risk assessment issued in 1999 by Codex Alimentarius (CAC, 1999). Since that time, several MRAs on food have been published, but, as has been said before, an MRA is time consuming and resource demanding (Voysey and Brown, 2000).

Risk-benefit analysis

A relative new way of thinking of food and risks associated with food has been emerging in recent years. Instead of looking only at the risk associated with a certain foodstuff, the benefits from consuming it are also taken into the equation, hence the term “risk-benefit analysis”.

In January 2004, Hites et al. (2004) published an article in Science that caused much debate about the safety of farmed salmon and potential harmful effects of contaminants in the salmon, especially salmon from Northern Europe. Other studies followed on the benefits versus the risk of consuming salmon, among other things (Gochfeld and Burger, 2005; Mozaffarian and Rimm, 2006). What these discussions have done is to make the issue of balancing the risks and benefits of fish consumption a very visible public health topic. Scientists have mainly been focused on the beneficial effects of n-3 polyunsaturated fatty acids (PUFAs) versus the negative effects of some contaminants, such as methylmercury and dioxins. There have, however, also been claims that antioxidants and other substances in fish can also have beneficial effects on health (Astley, 2003; Gunnarsson et al., 2006).

This illustrates the complexity of risk-benefit analysis. It is very difficult to list all the substances that have beneficial effects vs. those that have negative health effects. To make it even more complex, substances that are considered to be beneficial can in high doses be dangerous. The bottom line is that this topic is a very complex one, but at the same time very interesting and important.

Upcoming requirements

Iceland is not part of the EU, but is a part of the European Free Trade Association (EFTA). Through this organization Iceland and other EFTA countries (excluding Switzerland) signed an agreement with the EU creating the European Economic Area (EEA). Basically this means that Iceland gains access to the Internal Market, but in turn has to comply with EU laws and regulations on most issues.

The Directorate of Fisheries in Iceland is the competent authority responsible for implementing these regulations and has to ensure Icelandic fish producers comply with these regulations. Regulation (EC) No. 178/2002, Chapter II, Article 6 states:

“In order to achieve the general objective of a high level of protection of human health and life, food law shall be based on risk analysis except where this is not appropriate to the circumstances or the nature of the measure.”

This focus on risk and risk analysis is further emphasized in Regulation (EC) No 882/2004 of the European Parliament and of the Council of 29 April 2004, on official controls performed to ensure the verification of compliance with feed and food law, animal health and animal welfare rules. In Article 3, Chapter I, it says:

“Member States shall ensure that official controls are carried out regularly, on a risk basis and with appropriate frequency, so as to achieve the objectives of this Regulation, taking account of: “(a) identified risks associated with animals, feed or food, feed or food businesses, the use of feed or food or any process, material, substance, activity or operation that may influence feed or food safety, animal health or animal welfare; “(b) feed or food business operators’ past record as regards compliance with feed or food law or with animal health and animal welfare rules.”

The Directorate of Fisheries in Iceland has started work on risk categorization of the fish industry and of establishments. The evaluation has been done according to a Danish model (Fødevarestyrelsen, 2006) and is based on six risk categories:

  1. Microbiological risk associated with the type of product and final use.
  2. Microbiological risk associated with the type and scope of handling of the products.
  3. Processes that decrease the microbiological risk.
  4. Chemicals from the primary production stage (catch).
  5. Risk because of the use of chemicals in the production process.
  6. Estimation of the size of the consumer group.

The production processes are then divided into:

  • High risk (fresh fish, frozen);
  • Medium risk (salted, dried, cold smoked, gravad); and
  • Low risk (canned).

Every production type is evaluated according to the 6 risk categories. Points are allocated in a pre-determined manner, and these are then used to place the individual sector into an inspection-frequency bracket (2–4 visits a year, 4–6 visits, etc.). For example, frozen fish received 55 points, which results in an inspection frequency of 2–4 times a year.

After the different branches of the industry have been evaluated in general, the individual establishments are evaluated according to 4 main categories:

  • conditions in the establishment and in the production process;
  • risk associated with production conditions;
  • own-check system (HACCP, etc.); and
  • results of earlier inspections or sampling.

To assist in this evaluation, the Directorate of Fisheries has developed an evaluation scheme for use in the evaluation process. There still is a lot of work needed in order to make the Danish model fit Icelandic reality, but the results will be used to develop a risk-based control programme.

Conclusion

Risk assessment of food can be a highly complex process, depending on the type of risk assessment used. A quantitative risk assessment is the most comprehensive risk assessment, and also the most complex. To illustrate that, only a handful of quantitative risk assessments are available today. The process involves various experts from different disciplines: food science, toxicology, biology, microbiology, chemistry, etc.

Risk-benefit analysis is an emerging field. The idea is to take into account both the benefits and risk associated with consuming a certain product. It has been especially interesting to follow the developments in this field in the debate about the health benefits of seafood: good fish/bad fish. The challenge in this field is huge: “How do you weigh up the different benefits versus the risks?” and “What is the dose-response of the different parameters?” Many other factors need to be considered, which makes this a very interesting, but also a very difficult and complex, field.

One question arises with this emerging analysis: “Should regulators take account of the benefits of certain foodstuff when creating legislation, maximum limits, etc?” This is not an easy question to answer. This is still a very new field and I would recommend that, before benefits are taken into the equation, some international guidelines should be issued providing guidance on how a risk-benefit analysis should be conducted.

July 2009

the Fish Site Editor