Levels of Elements in Typical Mussels from the Southern Coast of Africa (Namibia, South Africa, Mozambique): Safety Aspect

Abstract

The soft tissues of mussels are often used as the main food source, especially in coastal areas. Neutron Activation Analysis was used to measure the content of 24 macro- and microelements in the soft tissues and 18 elements in the shells of selected sets of mussels of the species Mytilus galloprovincialis. The mussels were collected in 8 polluted and 4 pristine zones, which included Namibia, the west and east coasts of South Africa, and Mozambique. According to factor analysis Co, Ni, Zn, As, Se, Br, I, Sb could have anthropogenic origin. The concentrations of elements such as Cr, As, Se and partly Zn at polluted stations were above the maximum permissible levels for seafood. The concentrations of Sc, V, Cr, Mn, Co, Ni, Sb, Cs, Th, U in shells and soft tissues of the same mussels were at the close levels. Elements such as Al, Cr, Co, As (partly Zn, Se, and I) are considered to be harmful to human health at the levels of mussels consumption of 200 g/week per person and lower in such zones as Swakopmund, East London, Port Shepstone, Richards Bay, Xai-Xai according to calculated risk quotients and target hazard indices.

The Status of Marine Mussel Pollution Research in South Africa (2012–2022)

“…An Algerian study on the same species found a moderate human health risk from Fe and Cr and advised human consumers of wild mussels to eat no more than 500 g of mussel flesh per day [125]. To date, very little Southern African research has assessed the human health risk of consuming wild mussels via these indexes [16,113]. The two studies that were performed showed that recreational collectors should eat no more than 250 g of fresh mussels per week from South Africa (with even lower limits for Namibian and Mozambican mussels) to minimise their risk of negative health impacts from TEs [16,113].…”

“…To date, very little Southern African research has assessed the human health risk of consuming wild mussels via these indexes [16,113]. The two studies that were performed showed that recreational collectors should eat no more than 250 g of fresh mussels per week from South Africa (with even lower limits for Namibian and Mozambican mussels) to minimise their risk of negative health impacts from TEs [16,113]. More local, published research is needed to properly assess the benefits and risks of wild mussel consumption along the South African coastline.…”

“…The sharing of information, expertise, costs, and institutional facilities could be encouraged by the DFFE and would likely result in more comprehensive marine pollution research within the country. An example of the importance of involving multiple institutions within a contaminant analysis program can be seen in Table 2; two local studies analysed trace elements through Neutron Activation Analysis (NAA) and therefore did not determine concentrations of toxic Cd or Pb within the mussels [16,113], while another study was able to include these elements within mussel analyses due to the use of Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) [14]. These researchers had different equipment available to them for trace element analysis and, therefore, covered different contaminants.…”

Effects of Exposure to Urban Atmospheric Particulate Matter Suspended in Seawater on the Mussel Mytilus galloprovincialis

“…Mussels, as sessile filter-feeders, have been used as sentinels, indicating environmental pollution [16][17][18], which has led to an extensive monitoring program by the US EPA that is known as the Mussel Watch program [19]. This has also inspired other national and international monitoring programs worldwide.…”