Hodabalo Dheoulaba Solitoke^1,, Komlan Mawuli Afiademanyo^2,, Kamilou Ouro-Sama¹, Gnon Tanouayi¹, Tchaa Esso-Essinam Badassan¹, Kissao Gnandi¹

Trace element pollution in aquatic ecosystems is one of the most important threats of human health and food chain. In order to assess the concentration of trace element in soft tissues of Crasostrea gasar and the human health risk associated with its consumption, seven trace elements (As, Hg, Pb, Cd, Zn, Cu and Cr) were analyzed by Atomic Absorption Spectrometer coupled to a hydride and cold vapour generator. C. gasar were collected at Zowla and Zalivé in the Lake Zowla-Aného Lagoon hydrosystem. The results showed a significant inter-site variation of trace elements concentrations. The highest concentrations (mg kg⁻¹ dry weight) were obtained at Zalivé (0.69, 40.61, 246.47, 13.34, 10.13, 908.57 and 0.31) and lower concentration at Zowla (0.48, 34.26, 165.1, 10.4, 6.43, 766.3 and 0.2) respectively for As, Cd, Cu, Cr, Pb, Zn and Hg. The estimated daily intake (EDI) of each trace element in children is greater than the EDI for adults. The target hazard quotient (THQ) for children is higher than that for adults. For children, only Hg had a THQ < 1 at Zalivé, but at Zowla only As, Hg and Pb had THQ < 1. For adults, As, Hg, Pb, and Zn had THQ < 1 at Zalivé while in Zowla it was As, Cr, Hg, Pb and Zn which had THQ < 1. Considering the cumulative effect of all trace elements, these levels of trace elements in oysters can be toxic for consumers (TTHQ > 1). Also, the cancer risk (CR) for As and Cr were higher than 10^-4 indicating that the onset of carcinogenic effects related to As and Cr in children and adults is probable. This study, therefore, suggests that the current environmental levels of trace metals are potential threats to the health of regular consumers of C. gasar of this hydrosystem.

Cassostrea gasar, trace metals, oyster consumption, health risks, Aného Lagoon