Toxic Heavy Metals of Public Health Importance in Surface Water from Nworie River, Owerri Imo State South East Nigeria

Assessment of the concentrations of toxic heavy metals of public health importance in Nworie River water samples in Owerri Imo State South East Nigeria. Aim of the study was to ascertain the variability in contamination by selected toxic heavy metals of public health importance in different parts of Nworie River and to compare the concentrations with WHO standards. The study design was analytical. The sampling sites were carefully selected to include upstream and downstream regions water samples were randomly collected from 20 cm below the water surface with 500 ml polypropylene plastic bottles. Two Samples were collected from each of the four strategic sampling points from Nworie River at Egbeada sampling point 1, Alvan/Fmc sampling point 2, Umezuruike Hospital sampling point 3, and Akanchawa sampling point 4.The Global Positioning System (GPS) was used to locate the coordinates of the sampling points. The samples were collected and labelled for easy identification and were deposited in an icebox to maintain the temperature of the samples. AAS model: FS 240 Varian Atomic Absorption Spectrophotometer connected to Nitrous oxidant and Acetylene gases was used for sample analysis. The results revealed that toxic heavy metals of public health importance were present in Nworie River at the following ranges of concentrations: (Hg (0.016 to 0.021), Cd (0.011 to 0.023), As (0.003 to 0.056), Cr (0.006 to 0.064), Ni (0.00 to 0.005), and Pb (0.041 to 0.082) mg/l, respectively. The presence at elevated levels of toxic heavy metals of public health importance, when compared to World Health Organisation (WHO) standards for surface water, which include mercury, arsenic, chromium, and lead, in the Nworie River poses significant public health hazards. Urgent action is required to identify and mitigate the sources of contamination and protect the well-being of the communities and ecosystems that depend on this water resource. Conduct a comprehensive source identification study to determine the origin of heavy metal contamination in the Nworie River. Take immediate action to address the high levels of mercury, arsenic, chromium, and lead. This may include implementing pollution control measures and potentially treating the water to remove or reduce these contaminants. Key words; toxic heavy metals, surface water, Nworie River, concentration.