Contaminants are found in food due to unintentional inputs. Unlike pesticides, for example, contaminants are therefore not regulated by any approval procedures or the like. Consequently, little attention has been paid to date to chemical cocktails of food contaminants and associated health risks.
Aim and implementation
The aim of the project was to estimate cumulative risks of possible contaminant mixtures on the basis of occurrence data on food contaminants collected by AGES.
All food contaminants for which data were available were analyzed for their specific toxicological effects by means of research. For the purpose of joint risk assessment, the contaminants were assigned to assessment groups (CAG, cumulative assessment group) according to the target organs for adverse health effects. The following CAGs could be established: Reproductive and developmental effects, renal toxicity, neurotoxicity, liver toxicity, blood toxicity, thyroid effects.
Austrian consumption data, as available in the EFSA Comprehensive Food Consumption Database, were used to estimate population exposure to food contaminant mixtures.
A new method for cumulative risk assessment.
Risk assessment of chemical mixtures remains a challenge in diverse areas of food safety. To date, no general method has been developed for this purpose that would be most appropriate for diverse areas (e.g.: food contaminants, additives, pesticides). Especially for food contaminants, advanced methods are usually not applicable because toxicological data are usually incomplete.
With the modified reference point index (mRPI), we developed a new approach in which the advantages of two widely used methods, hazard index and reference point index, are combined. In addition, we developed a decision tree to derive substance- and effect-specific uncertainty factors. With this decision tree, the mRPI becomes a method for cumulative risk assessment that is easy to use, even in a data-poor area such as food contaminants.
For interpretation of the mRPI, one is guided by a value of 1. If the mRPI is below 1, the risk posed by the CAG is considered acceptable. mRPI values above 1 indicate that a more in-depth evaluation is needed to determine whether cumulative risks actually exist, or to characterize them more precisely.
Results
The mRPIs calculated for adults exceeded the comparative value of 1 in the CAG for renal toxicity in each exposure scenario. This CAG represented the greatest risk in adults, with cadmium contributing the most to the cumulative risk for renal toxicity. The mRPIs of the reproductive, blood toxicity, and thyroid CAGs did not exceed the comparison value in any scenario. For these CAGs, the cumulative risk is considered low.
For children, the comparative value in the CAGs for reproduction and development, developmental neurotoxicity, growth inhibition by trichothecenes, for nerve toxicity, and renal toxicity at least equaled or exceeded the comparative value in every scenario; these CAGs represented the greatest risk in children. Acrylamide, the sum of the Fusarium toxins deoxynivalenol, 3- and 15-acetyl-deoxynivalenol, and cadmium contributed most to the cumulative risk. The mRPIs of the CAGs for blood toxicity and for thyroid did not exceed the comparison value in any scenario; for these CAGs, the cumulative risk to children is considered low.
For all those scenarios for which a risk could not be excluded in this first cumulative risk assessment, a refinement of the risk assessment should be performed according to the WHO/IPCS tiered approach, especially in the collection of occurrence data and in the exposure assessment.
Original paper
Austrian Agency for Health and Food Safety (AGES); Federal Ministry of Social Affairs Health, Care and Consumer Protection (BMSGPK), 2020: CHEMCOCK - Assessment of the risk of chemical cocktails in food The studies were published in English:
Vejdovszky K., Mihats D., Griesbacher A., Wolf J., Steinwider J., Lueckl J., Jank B., Rauscher-Gabernig E., 2019: The modified Reference Point Index (mRPI) and a Decision Tree for deriving Uncertainty Factors: a Practical Approach for Cumulative Risk Assessment of Food Contaminant Mixtures. Journal of Food and Chemical Toxicology 2019, Volume 134: 110812. doi.org/10.1016/j.fct.2019.110812 Vejdovszky K., Mihats D., Griesbacher A., Wolf J., Steinwider J., Lueckl J., Jank B., Kppacka I., Rauscher-Gabernig E., 2021: A tiered approach to cumulative risk assessment for reproductive and developmental toxicity of food contaminants for the austrian population using the modified Reference Point Index (mRPI) . Food and Chemical Toxicology 147: 111861. https://doi.org/10.1016/j.fct.2020.111861
Katharina Vejdovszky