Assessment of Heavy Metal Pollution of the Iture Estuary in the Central Region of Ghana

Abstract

A detailed study has been presented on heavy metal content of the Iture Estuary. Waters of the Sorowie and Kakum rivers that supply water into the Estuary were investigated to ascertain heavy metal pollution levels due to anthropogenic activities. Concentration s of Cd, Zn, Se and Pb were measured. The study shows pre-occupying pollution levels that constitute a threat to both terrestrial and aquatic ecosystems. The abundance of metals in the Estuary is in the order Zn > Pb > Cd > Se. The level of Cd in the Iture Estuary ranged between 0.011 mg/l and 0.041 mg/l while Se was in the range 0.018 mg/l to 0.029 mg/l, Pb 0.020 mg/l to 0.075 mg/l and Zn 0.040 to 2.45 mg/l. The impact of contaminated water from the Sorowie River on the Iture Estuary was outstanding and the study points out the importance of the Sorowie River as a primary pollution source to the Iture Estuary. The pollution of the Iture Estuary was found to be connected to human activities in its catchments.

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“…This phenomenon indicates that the studied species D. trunculus has a bioavailability to accumulate Cd and Cu from the surrounding medium greater than other metals and can suggest using of D. trunculus as a good indicator for the presence of highly toxic metals such as Cd and as a bio-indicator for essential metals such as Cu. Increased Cd levels in the bivalve are worrying, especially considering the fact that it could be one of the most toxic heavy metals, even at relatively low concentrations (Fianko et al, 2007).…”

Current Levels of Heavy Metal Pollution in Africa

“…In Ghana (4 in Fig. 1), contamination (mg/l) of water in the Iture Estuary with Pb (0.020-0.075) and Cd (0.011-0.041) has been attributed to waste carried by the Sorowie and Kakum Rivers, which flow through a rapidly urbanized and industrialized central region [22]. Additionally, Kwandwo [28] recorded contamination (mg/kg) of Hg (up to 2.3  0.5) and As (up to 1.3  1.1) in streams and rivers in Tarkwa, a gold mining town in Ghana.…”

“…As observed by the United Nations Centre for Human Settlements (UNCHS) [56], only one-third of the solid waste generated in urban areas across Africa is collected, and of that, only 2% is recovered and recycled. Furthermore, use of leaded gasoline [36], fugitive dusts [13], indiscriminate dumping and burning of toxic waste, including nickel/cadmium-based batteries, due to weak pollution legislation has worsened heavy metal pollution on the continent [22].Recently, the United Nations Environment Program (UNEP) Global Environment Outlook (GEO) 4 [58] noted that Africa continues to be at risk from hazardous and electronic waste dumping due to inadequate monitoring capabilities and institutional mechanisms for managing such waste. There are limited resources for environmental management in most African countries, as most developmental programs are focused on economic growth and industrialization [52].…”

“…As observed by the United Nations Centre for Human Settlements (UNCHS) [56], only one-third of the solid waste generated in urban areas across Africa is collected, and of that, only 2% is recovered and recycled. Furthermore, use of leaded gasoline [36], fugitive dusts [13], indiscriminate dumping and burning of toxic waste, including nickel/cadmium-based batteries, due to weak pollution legislation has worsened heavy metal pollution on the continent [22].…”

Evaluation of impact of industrial effluents on intertidal sediments of a creek

“…As a result, large amounts of contaminants both organic as well as inorganic are being added to the coastal environments (Valette-Silver 1993;Williams et al 1994;Fianko et al 2007;Ip et al 2007). Creeks are low-energy environments and favor deposition of fine-grained sediments along with associated metals and organic matter.…”