Heavy metal profiles in various matrices of the Bonny/New Calabar River Estuary, Niger delta, Nigeria

Abstract

A study of the concentrations of Ca, Mg, K, Zn, Pb, Cd, Co, Cr, Cu, Fe, Ni and Na in the sediment, sea water, fish and crab of the Bonny/New Calabar River Estuary in Niger Delta, Nigeria was carried out using atomic absorption spectrophotometer A-100 for two consecutive years. The contamination levels of the respective metals varied between 2011 and 2012and the range of mean values for all metals in mg/kg were presented along with variations at statistically significant level (P <0.05) between the two years studied. Only K, Zn and Co exhibited variation in their concentrations in water samples between the two years at a statistical significant level (P <0.05) probability. In sediment, only Cr varied between the two years at a statistically significant level (P = 0.05). All metals concentrations were higher in sediment than in water samples.Bioaccumulation factor (BF) indicated a more potent source of metals from sediment than water with organisms accumulating Zn, Fe and Ni in the magnitude of 10, 6 and 5 times more from sediment than from water. Some metals were more accumulated in fish than crab and vice versa. The evidence of elevated levels of heavy metals in sediment and bioaccumulation in biota in the studied area may poise a wanton threat to the health of inhabitants whose diet is predominantly fish. This calls for regular monitoring to avert potential public health problems arising from consumption of metals in seafood.

Risk Assessment of Poisonous Metals in Water and Soil at Two Abandoned Lead-Zinc Mines at Yonov, Benue State

“…The result of the present study is relatively higher than maximum permissible limit of 0.01mg/l for lead (Pb) in drinking water as stipulated by DPR, WHO and the NIS standard. These results are within the range reported by Babatunde et al [39] for Pb concentrations of 0.2-0.6 mg/kg in 2011 and 0.2-0.9 mg/kg in 2012 respectively, however, these results is higher than the results of Edori and Kpee [37] who reported mean concentration and standard error of lead in their study to be 0.970±0.00 mg kg and Ogbonnaya, et al [36] who reported low concentration of Pb in water samples, he claimed that the low levels recorded were as a result of poor or limited dispersion pattern of Pb, hence its anomalies were restricted to the mineralized zones, he, however, recorded high concentrations of lead (92 -≥1,700 mg kg −1…”

Determination of Pollution Intensity in the Soils of Stubbs Creek Forest Reserve, Akwa Ibom State, Nigeria

“…A good account of such studies in the Niger Delta Region is given in the work of Asonye et al (2007). Equally, heavy metal load of several rivers in Nigeria, mostly in sediments have been reported by Obiereet al (2003) and Davies et al (2006) on Elechi creek, Chindah et al (2004) on Bonny river, Omoigberale and Ogbeibu (2005) on Ase river and Babatunde et al (2013) on Bonny/New Calabar river estuary in which they advised on how most of the industrial activities should be conducted in this area.…”