Trace elements risk assessment for consumption of wild mussels along South Africa coastline

•The levels of Na, Mn, Fe, Ni, Sr, Sb, U in mussels considered as safe.•Maximum consumption of mussels should be lower than 250 g per person per week.•The maximum concentrations of Cr, Zn, As and Se exceeded permissible levels.•The most risky zones are Port Nolloth, Waterfront, Hout Bay and Durban. The study aimed to contribute to the scarce data on concentrations in the soft tissue of wild mussels growing in coastal cities of South Africa. The intake of 26 micro and macroelements was estimated. The mass fractions of sample sets from 8 sites along the South African coast from the West (Port Nolloth) to the East (Durban) were studied by neutron activation analysis at the Joint Institute for Nuclear Research (Russia). The following elements were identified as potentially hazardous due to high consumption risks: Al, Cr, Co, Zn, As, and I at stations in the Cape Town area (Waterfront, Hout Bay) and Durban. The mean concentrations of these elements among all individuals were 208, 0.8, 0.46, 60, 2.6, and 11 ppm of wet weight, respectively. In the studied mussels, the concentrations of Cr, Zn, As, and Se (ranging between 0.2−2.8, 14–290, 1.6−4.6, and 0.31−2.4 ppm of wet weight, respectively) exceeded maximum permissible levels for fish products. The weekly consumption of more than 250 g of fresh mussels per person could increase the risk for human health by potential intake of such elements as Al, As, and I.