Probabilistic modelling techniques in dietary exposure assessment: application on the risk assessment of cadmium for Austrian adults.

Probabilistic exposure and risk assessment of chemical hazards in the diet have increasingly gained ground in recent years as a pragmatic approach for the approximation of reality. This work presents the outcomes of a project which aimed at applying probabilistic techniques for basic modelling of chronic dietary exposure to food contaminants following EFSA guidance. These techniques, based on Monte Carlo Risk Assessment (MCRA) software and on the programming language R, were employed for the risk assessment of cadmium for Austrian adults, enabling the validation and the critical comparison of the two approaches. Harmonisation and optimisation of procedures, refinement of exposure assessment skills and confidence in the results were the main benefits. Data amount and validity were identified as critical parameters, influencing the precision of the results. Cadmium was selected as a case study due to its toxicological properties, its ubiquitous presence in food and the availability of Austrian occurrence data. Similar exposure and risk estimates were generated through MCRA and R in alternative optimistic and pessimistic exposure scenarios, suggesting low levels of concern, except for vegetarians, whose upper tail exposures are close to the established Tolerable Weekly Intake. However, as occurrence data gaps have been identified as the major element of uncertainty, the estimated exposure and risk levels are characterised as underestimated. Grains and grain-based products, potatoes and leafy vegetables are the main contributors to the intake. The results will contribute to risk management and to a future refinement of the assessment.

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).

Through our daily diet, we are exposed to a variety of food contaminants. Yet, assessing the cumulative health risk of chemical mixtures remains a challenge. Using a recently developed method, the modified Reference Point Index (mRPI), the cumulative risks posed by contaminant mixtures were assessed for their effects on reproduction and development. Since these effects can be quite diverse, a tiered approach was adopted to elucidate the risks at a more detailed level based on specific toxicological endpoints. An additional analysis was performed using the modified Maximum Cumulative Ratio (mMCR), which provides the determination of risk-dominating substances in the mixture. Our method represents a novel useful tool to screen and prioritise contaminant mixtures regarding their potential health risks. We found, that in the majority of the calculated scenarios a single substance dominates the cumulative risks. Lead was found to be the primary factor for adverse effects on reproduction and neuronal development of children. Perchlorate was identified as the most prominent risk factor for child development in generalCumulative risks of trichothecenes were dominated by deoxynivalenol. Concerning the impact on pre- and neonatal development, the co-exposure of several substances resulted in increased risks, with none of the considered contaminants dominating substantially.

Modified Reference Point Index (mRPI) and a decision tree for deriving uncertainty factors: A practical approach to cumulative risk assessment of food contaminant mixtures.

Risk assessment of chemical mixtures remains a challenging task in all areas of food and consumer safety. So far, no general method has been developed that is best suited to several subject areas (e.g. food contaminants, additives and supplements, plant protection products). Especially for mixtures of food contaminants sophisticated methods are typically not applicable due to a general lack of complete toxicological data sets. We developed a new approach, the modified Reference Point Index (mRPI), that combines the advantages of the Hazard Index and the Reference Point Index. Furthermore, we developed a decision tree for the determination of specific uncertainty factors that makes the mRPI an easy to use method for cumulative risk assessment even in a data poor field such as food contaminants. To further characterise the estimated cumulative risks, the Maximum Cumulative Ratio (MCR) was adapted to be applied on the mRPI, and the modified Maximum Cumulative Ratio (mMCR) was established to identify whether the risks are dominated by a single substance. We present two case studies assessing the nephrotoxic and neurotoxic risks for the Austrian population originating from food contaminant mixtures. Calculations could not rule out potential cumulative risks, yet, they seemed to be dominated by single substances.

Levels of estragole in fennel teas marketed in Austria and assessment of dietary exposure.

Levels of estragole in fennel teas (n = 42) on the Austrian market and the associated dietary exposure were assessed in this study. The estimated daily exposure from consumption of fennel teas ranged from 0.25 to 5.04 µg kg-1 d-1, 0.32 to 6.42 µg kg-1 d-1, and 0.15 to 2.93 µg kg-1 d-1 for children, women, and men, respectively. Daily estragole exposures for infants were 0.008-20.78 µg kg-1 d-1. Despite MOE values are above 10,000 for nearly half of the fennel teas analyzed, there are still MOEs below this value indicating a potential risk for human health and a priority for risk management. However, fennel teas are generally consumed only for short periods of gastrointestinal disorders. Estimated daily intakes may, therefore, be conservative and tend to overestimate the potential risk for human health.

Dietary exposure to non-dioxin-like PCBs of different population groups in Austria.

The dietary exposure to the sum of the six indicator PCBs (Σ6 PCBs; PCB 28, 52, 101, 138, 153, and 180) across different Austrian population groups was assessed in this study by combining data on occurrence from food of the Austrian market (n=157) analysed during 2006-2011 with national food consumption data. The most contaminated food group was meat, poultry, game and offal with average levels of ndl-PCBs of 5.20 ng g(-1) fat. In fish and fish products and eggs, mean concentrations of 3.89 ng g(-1) fresh weight (fw) and 4.00 ng g(-1) fat, respectively, were found. In milk and dairy products average concentrations ranged from 3.07 to 4.44 ng g(-1) fat. The mean dietary intake of Σ6 PCBs was estimated to be 3.37 ng kg(-1) bw d(-1) for children (6-15 years old), 3.19 ng kg(-1) bw d(-1) for women (19-65 years) and 2.64 ng kg(-1) bw d(-1) for men (19-65 years). In all three population groups, milk and dairy products was the major contributing food group to the total dietary intake (50-55%) followed by fish and fish products (23-27%). The exposure of all Austrian population groups is well below the tolerable daily intake (TDI) of 10 ng kg(-1) bw d(-1) proposed by WHO, accounting for 34% in children, 32% in women and 26% in men.