Health Risk Assessment and Levels of Heavy Metals in Farmed Nile Tilapia (Oreochromis niloticus) from the Volta Basin of Ghana

Heavy metals (Pb, Cd, As, Mn, Fe, Zn, Cu, Ni, and Cr) are some of the most toxic elements that can bioaccumulate from sources linked to human activities, such as industry and agriculture. This study quantifies the concentrations of several heavy metals in caged tilapia found in Ghana’s Volta Basin and assesses the associated health risks. The levels of heavy metals in the tissues of Oreochromis niloticus from three cage farms (N = 52) were determined using Atomic Absorption Spectrometry (AAS). The implication for human health was assessed using several risk assessment techniques. Fe (50.11 ± 10.22 mg/kg) and Cr (0.31 ± 0.07 mg/kg) had the highest and lowest accumulated metal concentrations, respectively. Heavy metal concentrations in tilapia tissue from fish farms were ordered as follows: Fe > Mn > Zn > Ni > Cr (farm A), Fe > Zn > Ni > Mn (farm B), and Fe > Mn > Zn > Ni > Cr (farm C). All metals had an estimated daily intake (EDI) below the threshold, and mean differences between sample farms were not statistically significant. Similarly, the values of target hazard quotients (HQs) and hazard indices (HIs) were less than one. According to the risk assessment results, eating tilapia from farms posed no risk to human health. The presence of Mn, Fe, and Ni concentrations above the maximum level in the fish, on the other hand, suggests that they may affect fish health.

Levels of persistent organochlorine and polychlorinated biphenyls in Nile tilapia (Oreochromis niloticus) from three cage aquaculture farms on the Volta Basin of Ghana: Implications for human health

Increased agrochemical based agricultural activities along the Volta Basin and aquacultural practices from the cage farms have raised concerns about the potential ecological risk to the aquatic ecosystem. To assess this, caged tilapia samples were analysed for polychlorinated biphenyls (PCBs) and organochlorine pesticide (OCP).Fish samples in acetone/hexane (2:1v/v) solvent medium were sonicated on ultrasonic bath, shaken electronically, cleaned by solid-phase extraction and analysed by GC/ECD for OCPs and GC/MS for PCBs.The levels of OCPs reported in the fish ranged; ND – 2.310 µg/kg (fish farm A), <LOD – 4.260 µg/kg (fish farm B), <LOD – 6.109 µg/kg (fish farm C) and ND – 0.878µg/kg (control). The highest concentration of 6.109 µg/kg was encountered for δ-HCH in the muscles of Tilapia from fish farm C, whiles p,p'-DDE recorded the lowest in farm A. The levels of the OCPs detected in the cage tilapia were below the MRL proposed by the EU. Six PCBs congeners; PCB 18, PCB 28, PCB 52, PCB 101, PCB153 and PCB 180 were detected in the cage tilapia. The concentrations of the indicator congeners ranged from 0.288 ng/g to 0.931 ng/g dw, 0.042 ng/g to 1.321 ng/g dw, 0.260 ng/g to 10.657 ng/g, and ND-0.298ng/g dw in fish farm A, B, C and control respectively. The highest mean concentrations of PCB 153 (8.524 ± 1.5960ng/g) was found in farm Estimation of the EDIs and HQs for the pesticides do not present potential health risk to the consumers of the cage tilapia fish from the studied farms.

Factors influencing climate change adaptation strategies in North-Western Ghana: evidence of farmers in the Black Volta Basin in Upper West region

The erratic rainfall patterns and decline in crop production are due to the threat of climate change. The responses of farm households to climate change play a very essential role in addressing the risk of climate change. This study investigated factors influencing adaptation strategies to climate change in the Black Volta Basin of Ghana. Survey questions were administered to 450 households sampled from eight districts using a multistage sampling technique. Out of the six adaptation strategies, four major identified adaptation strategies were subsequently used as the dependent variable in the multivariate (MV) probit and binary logit models. The results revealed that factors such as gender, age, household size, farmer-based-organizations membership, farm income, years of education, districts of location of respondents, farm size and climate change awareness—statistically and significantly—influenced households’ adaptation to the changing climate. However, the positive correlation matrix from the MV probit model showed complementarities among all the adaptation strategies adopted by household heads. Priority should be given to improving household heads’ adaptive capacity. Also, governmental and non-governmental organizations should invest in climate-resilient programmes. Finally, programmes aimed at sensitizing household heads on climate change adaptation strategies such as changing planting time, changing farming methods, and planting early maturing and drought-resistant varieties through pieces of trainings and workshops may be duly supported by the Government; particularly, for household heads in the Black Volta Basin.

Northern Frontiers

This chapter recounts the early life and death of Gandah, a naa or 'chief', of Birifu, a dispersed settlement of traditional mud-walled compounds located near the bank of the Black Volta River in the northwestern corner of the Northern Territories of the Gold Coast. It narrates the final stages of Gandah's life as a renowned healer and accumulator of ritual 'medicines'. The chapter investigates how Gandah's story encapsulated key themes in the history of death and the dead in the Northern Territories in the first half of the twentieth century. This was a region that was in many ways quite distinct from the Akan forest and Gold Coast to the south. Historically, connections between the Akan world and the peoples of the middle Volta savannas did exist. Yet in terms of ecology, culture and political structure, the savanna, as the Akan perceived it, was another realm. The chapter outlines the emergence of a complex of kingdoms forged by horse-riding migrants who from the fifteenth century entered the savannas of the Volta basin straddling present-day Burkina Faso and northern Ghana.

Modelling Soil and Water Dynamics in the Black Volta Basin Using the Soil and Water Assessment Tool (SWAT) Model

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