Temporal trends of risks in consumption of wild and farmed mussels in 2013-2019 in the Saldanha Bay area (South Africa)

The levels of 24 macro- and microelements in mussels were determined by the instrumental neutron activation analysis. The samples were collected during the period of 2013-2019 on three sites with different natural features in the Saldanha Bay area. The safety of mussel consumption was calculated using several different approaches: considering maximum permissible levels for seafood, maximum tolerable consumption rates, target hazard quotients and hazard indices. In general, the wild and farmed mussels demonstrated low levels of risk for human health during the entire studied period, except for intakes of such elements as Fe and Zn in several cases. Based on the applied approaches, Cr, Fe, Ni, Zn, As and I in wild mussels can pose possible health risks to potential consumers in several cases during 2013-2019. It was concluded that the safe level of weekly consumption rate should be less than 100g/week per person, according to the highest calculated values of concentrations. Possible symptoms of deficiency and excess of elements and their levels and significance for human health are considered. The content of wild and farmed mussels from the Saldanha Bay is influenced by the seasonal natural and anthropogenic factors, including sea disturbance, coastal runoff, and harbor traffic.