Metal Contamination of the Sediments from the Area II of the Ébrié System Following the Reopening of the Grand-Bassam Inlet

Abstract

This study aimed to assess the impact of the reopening of the Grand-Bassam inlet on the seasonal metal contamination of the superficial sediments of the area II of the Ébrié system by thirteen trace metals (Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sb, and Zn) and the associated ecological and human health risks. This study was conducted from May 2023 to April 2024. US-EPA sediment quality guidelines and four metal contamination indices (Contamination Factor, Geoaccumulation Index, Contamination Degree, and Mean Contamination Degree) were used to assess the metal contamination of these substrates. Their ecological risks were assessed using two sediment quality guidelines (SEQ-Eau V2 and CB-SQGs) and four indices (mHQ, PERI, mPEC-Q, and mERM-Q). Human health risks, primarily through dermal contact, were assessed using the non-carcinogenic dermal hazard index and lifetime carcinogenic risks index. The findings indicated that metal seasonal contamination of these substrates by trace metals ranged from low to moderate. Overall seasonal metal contamination of these sediments varied from moderate to considerable. Ecological risks were significant during some seasons. Generally, metal contamination and ecological risks were lower during the study period compared to before the reopening of this inlet. Short-term carcinogenic risks for humans were low, while lifetime carcinogenic risks were very high.