ABSTRACT
Introduction: Humans are constantly exposed to a wide variety of environmental contaminants from different sources. The risk assessment of exposure to chemical compounds includes hazard identification, hazard characterization, exposure assessment and risk characterization. Human biomonitoring (HBM), as a method to measure the chemicals or their metabolites in human body fluids and/or tissues, might be used at any stage of risk assessment. However, the most used role of HBM in this process is in the exposure assessment. In order to estimate the body burden of the varied exposure, the Swedish National Food Agency (NFA) applies HBM to complement the traditional calculations based on chemical analyses of the food content and consumers' selfreported food intake, or food purchase statistics. Aim: To summarize the two main HBM studies performed by the Swedish NFA over the last two decades, i.e. POPUP (Persistent Organic Pollutants in Uppsala Primiparas) and RIKSMATEN (national food survey), and to show how they can give complementary information to improve risk assessment of environmental contaminants. Results: Levels of a wide range of compounds, including environmental contaminants, have been measured in human samples collected from these studies. These results, collected over a number of years, make it possible to study the general temporal trends for the measured environmental contaminants. Additionally, the identification of exposure determinants and exposure pathways has been conducted by aid of collected data on food consumption and life-style factors, and possible associations have been reported. Conclusion: Overall, the gained results demonstrate how HBM studies provide important information both on the current state and the temporal trends of human exposure to environmental contaminants. Combined with other imperative data collected, HBM is an important complementary tool for risk assessment of environmental contaminants, which in many cases have diet as main source. Consequently, HBM is important in risk management of these contaminants to implement and follow-up risk reducing or preventive actions within the food sector, as well as to provide an early warning on potential threats to public health.
ABSTRACT
Background: Assessments of food-related health risks and benefits performed by national or international experts are still to a large extent separate processes. Diets, foods, and even single food ingredients, may potentially be associated with both beneficial and adverse health effects. Therefore in some cases it is important to consider both health risks and benefits, by assessing the balance between potential risks and benefits, ideally by expressing risk and benefit on the same scale. In Sweden risk-benefit assessments in the food sector are the responsibility of the Risk and Benefit Assessment Department at the National Food Agency (NFA), which brings together the scientific disciplines toxicology, nutrition and microbiology and related fields. In 2012 a project was initiated to develop a general procedure for risk-benefit assessments at the NFA. The results of this project, and an in-house working procedure, have been published in a governmental report [1] and presented at the Scientific conference “Shaping the Future of Food Safety Together” hosted by the European Food Safety Authority (EFSA) in Milan, Italy, in October 2015 (http://www.efsaexpo2015.eu/). The objectives of the project were to: • Summarize previous national and international experiences in the field of risk-benefit assessment • Develop a working procedure for practical use at the NFA • Test the procedure in a case study Principles of Risk-benefit Assessment From the overview and evaluation of the risk and benefit assessment literature it was concluded that no international consensus on the general principles or approaches for conducting risk-benefit assessment of foods and food components has so far been reached. The workflow suggested by EFSA [2] was used as a starting point for the development of the proposed NFA procedure for risk-benefit assessment. Tiered, stepwise approaches have been the preferred procedure in the majority of published risk-benefit assessments. In such an approach the nature of the question and the availability and type of data on for example food composition, exposure and health consequences determine at what tier the assessment can be stopped. The advantage of a stepwise methodology is that it is conceptually easy to use by the assessors and promotes transparency of the process. The NFA Procedure for Risk-benefit Assessment The developed risk-benefit assessment procedure contains three steps, from a qualitative assessment of risks and benefits separately to a quantitative assessment expressing risks and benefits on the same scale: 1) Initial assessment of risks and benefits separately 2) Enhanced assessment where different metrics for risks and benefits are weighted 3) Expressing risks and benefits on the same scale, for example mortality or DALYs (Disability Adjusted Life Years). Fig. 1. The relation between the three different steps in the NFA working procedure (1). Dialogue between the risk-benefit assessor and the risk-benefit manager is crucial after each step Case Study of the Risk-benefit Assessment Procedure The procedure was applied in a case study to assess the risk and benefits with a decreased content of nitrite and salt in processed meat, when done in combination with a decreased maximum storage temperature [3]. The potential health benefits for the general population, in terms of lower risk of exceeding ADI and lower risk of high blood pressure of decreased nitrite and salt intake was weighed against an increased risk of Clostridium botulinum and Listeria monocytogenes infections. The two first steps of the procedure could be applied, and it was concluded that the reduction of salt and nitrite levels would only have marginal effects on public health. Moreover, this reduction would not result in increased growth of microorganisms. The reduction of storage temperature from 8°C to 5°C would however result in a positive effect due to a reduction of growth of L. monocytogenes, but no effect on growth of C. botulinum. Future Activities at NFA Considering the complexity and the continuous development of the risk-benefit assessment area there is a need for national and international collaboration. At NFA we have initiated collaborative work with the Karolinska Institutet in Stockholm in order to increase the awareness of risk-benefit assessment in the academic environment, as well as to acquire valuable input from other experts. To promote cooperation on this subject in a Nordic setting we aim to host a workshop on risk-benefit assessment methods for Nordic countries during 2016. We are also open for collaboration in the risk-benefit assessment area within the EU. Conclusions The described working procedure is based on current best practices on how to perform risk-benefit assessments. The NFA working procedure share many features with for example the BEPRARIBEAN [4], BRAFO [5] and EFSA procedures [2]. Thus, our intention has been to incorporate experience and knowledge from previously published assessments and suggested procedures into a suitable in-house method. Our risk-benefit procedure is applied to relevant risk assessment questions at NFA. The case study regarding reduction of salt and nitrite content of processed meat helped us to identify critical points in the working procedure since it covered various aspects in microbiology, nutrition and toxicology. In our work and report we have identified several challenges associated with risk-benefit assessments. This emphasizes the need to develop a commonly accepted and feasible working procedure within the EU. The complete report can be downloaded free from: http://www.livsmedelsverket.se/globalassets/rapporter/2014/2014_livsmedelsverket_24_risk_benefit_assessment_procedures.pdf