Trace Metals in Water, Bottom Sediment, Shrimp and Dependent Human Blood in Ukwuani Local Government Area of Delta State, Nigeria

Abstract

Trace metals (Fe, Mn, Zn, Cu, Pb, Cd and Cr) levels were investigated in the water, bottom sediment, shrimp (Macrobrachium vollenhovenii) of Okumeshi River using Atomic Absorption Spectrophotometer (ASS);and blood of individuals that feed on the shrimps using an Inductively Coupled Plasma Mass Spectrometer (ICP-MS).The descriptive statistics such as the mean, range and standard error were for significant differences in the heavy metals, nutrients and total hydrocarbons in water and sediment samples was done using ANOVA (P < 0.05). Duncan Multiple Range (DMR) test was used to identify the source of variance using SPSS version 19.1.The order of accumulation in the matrices studied was bottom sediment > shrimp > water > human blood. High level of zinc and copper in human blood can be attributed to their high concentrations in all environmental matrices. It can also be attributed to the high biological accumulation factors of the metals in the shrimp. Copper also has a high essentiality in the respiratory pigment haemocyanin of shrimps. These facts are buttressed by the significant correlations of copper and zinc concentrations in the shrimp with their concentrations in human blood. The observed insalubrity of the shrimps is a prognostic of chronic health hazards to the consumers; which is also a function of the predominant oil exploration activities. Copper had an uninterrupted transit into the blood of the consumers from the aqueous phase. While zinc showed some significant level of biomagnification. The study provided an early signal of likely impending catastrophe; necessitating a proactive regulation of trace metals released into the aquatic system through the prevalent anthropogenic activities; mainly oil exploration.