Abstract
Seasonal variation of the distribution pattern, enrichment and contamination of some heavy metals (Cd, Cr, Fe, Pb, Zn, Ni and Cu) in surface water of Qua Iboe river estuary and adjoining creeks were investigated using physicochemical parameters. The results of wet season mean concentrations (mg/l) were: Cd (0.09 ± 0.02), Cr (0.05 ± 0.02), Cu (0.05 ± 0.01), Fe (10.68 ± 1.91), Pb (0.06 ± 0.01), Zn (0.08 ± 0.03) and Ni (7.4 ± 1.31) while the dry season mean concentrations (mg/l) revealed Cd (0.06 ± 0.02), Cr (0.04 ± 0.02), Cu (0.02 ± 0.004), Fe (7.36 ± 1.94), Pb (0.03 ± 0.008), Zn (0.03 ± 0.01) and Ni (5.17 ± 1.73). The wet season mean concentration of heavy metals were higher than the dry season. Concentration data were processed using Pearson correlation matrix to identify the inter-relationships between physicochemical parameters as well as the sources of heavy metals. The results showed that salinity, pH and temperature among others played a significant role in the adsorption/desorption and dissolution of heavy metals in the surface water. The Enrichment factor (EF) calculated during the wet season in surface water ranged from 0.2 to 2.9 while the EF calculated during the dry season ranged from 0.2 to 1.9. During wet season, Cd, Cu, Fe, Pb and Zn showed minor surface enrichments while Cr and Ni showed no enrichment. During dry season, Cd, Fe and Zn were moderately enriched in surface water while Cr, Cu, Pb and Ni were not enriched. Surface enrichment was attributed to atmospheric deposition, released of sediment bound metals to the surface, dissolution/erosion of coastal sediments as well as anthropogenic input. The computed degree of contamination indicated that the river system was moderately contaminated during dry season but highly contaminated during wet season. The implication is that during flooding which is consequent upon climate change, there will be higher degree of contamination of Qua Iboe River estuary and adjoining creeks. Key words: Heavy metals, seasonal variations, surface enrichments and contamination, Qua Iboe estuary.
Highlights
Pollution refers to the introduction by man, directly or indirectly, of substances or energy into the marine environment resulting in deleterious effects such as harm to living resources, hazards to human health, hindrance to marine activities including fishing, impairment of quality for use of sea water and reduction of amenities (GESAMP, 1993).Estuarine pollution may be defined as the human introduction to an estuary of any substances such as chemicals and waste products that are hazardous orJ
In surface water studied at 8 locations during dry and wet season are presented in Tables 3 and 4, respectively
These results agrees with the results obtained by Godwin et al (2004) for seasonal variations of heavy metals concentration in the study area and was attributed mainly to surface runoffs and anthropogenic inputs
Summary
Pollution refers to the introduction by man, directly or indirectly, of substances or energy into the marine environment (including estuaries) resulting in deleterious effects such as harm to living resources, hazards to human health, hindrance to marine activities including fishing, impairment of quality for use of sea water and reduction of amenities (GESAMP, 1993).Estuarine pollution may be defined as the human introduction to an estuary of any substances such as chemicals and waste products that are hazardous orJ. Pollution refers to the introduction by man, directly or indirectly, of substances or energy into the marine environment (including estuaries) resulting in deleterious effects such as harm to living resources, hazards to human health, hindrance to marine activities including fishing, impairment of quality for use of sea water and reduction of amenities (GESAMP, 1993). Estuarine pollution may be defined as the human introduction to an estuary of any substances such as chemicals and waste products that are hazardous or. Potentially harmful to the estuarine ecosystem (Tomlinson et al, 1980). This includes pollutants that are directly toxic to plants and animals, as well as materials that overload the estuary's capacity to assimilate wastes and deplete essential oxygen (Tomlinson et al, 1980)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
