Based on the analytical results of samples on the Austrian market (period 2016 to 2022), the present report evaluated the occurrence of total mercury in food, estimated the exposure of the Austrian population and calculated the exhaustion of the EFSA-derived TWI for inorganic mercury and methylmercury in the context of risk characterization.
The data evaluation of the 5380 samples used for the exposure estimation showed that especially fish fillets as well as processed fish products (canned food, spread, fish sticks) with an average total mercury content of 86 μg/kg and 56 μg/kg, respectively, had a comparatively high content of total mercury. For exposure estimation, the content of inorganic mercury and methylmercury was calculated from the analyzed total mercury content based on conversion factors.
While Austrian adults consumed between 0.09 and 0.9 μg inorganic mercury/kg bw/w (LB - UB), the intake of inorganic mercury in children was on average 0.1 - 1.5 μg/kg bw/w (LB - UB). At high consumption levels (P95), total inorganic mercury intake for adults was 0.4 - 2.8 μg/kg bw/w (LB - UB) and for children 0.5 - 3.7 μg/kg bw/w (LB - UB). It was found that dietary intake of inorganic mercury alone did not result in TWI depletion, however, all other sources of exposure (e.g., amalgam fillings) must be considered here.
The intake of methylmercury from fish and seafood consumption was 0.12 μg/kg bw/w in the case of Austrian adults and 0.31 μg/kg bw/w for children. At high consumption levels (P95), the average intake of methylmercury was significantly higher for adults at 0.96 μg/kg bw/w and children at 2.11 μg/kg bw/w, respectively. In children, on the other hand, a significant exceedance of the TWI occurred at high consumption levels. The largest contribution to exposure to methylmercury was from fish fillets, while the contribution from processed fish (e.g., canned) was significantly lower at both average and high consumption levels.
These results indicate that for certain fish species, consumption of even one serving of fish fillets can result in exhaustion of the TWI for methylmercury. This is particularly true for fatty predatory fish (e.g., swordfish, tuna, and buttermackerel). Therefore, attention should be paid to a varied diet, including the type of fish, in order to benefit from the positive health effects of fish while preventing possible negative health effects due to increased intake of methylmercury. Due to the neurotoxic effects of methylmercury, particularly in the unborn and in infants and young children, pregnant women, nursing mothers, infants and children are advised not to consume fatty marine fish.
Ulrike Mayerhofer, Kristina Marchart, Karin Manner, Gerhard Liftinger, Johann Steinwider, Daniela Hofstädter