Management consequences and diseases transmission potentials of dredge sediments from Nworie River, Owerri, Eastern Nigeria

Improper disposal of Nworie River dredge sediments can serve as source of pathogenic organisms to the inhabitants of Owerri, eastern Nigeria. This study aimed at determining the bacterial quality of the sediments to help ascertain its diseases transmission potentials to the environment. Five grams of 20 sediment samples (10 at each side and each about 400m apart, along the River bank) were collected and subjected to standard physical treatment and microbiological analysis. The Total Heterotrophic Bacterial Count (THBC) ranged from 6.9 x 105 to 3.2 x 103 cfu/ml while the Total Coliform Bacterial Count (TCBC) ranged from 6.3 x 103 to 2.8 x 102 cfu/ml. The following organisms were isolated from all the sediment samples: Escherichia coli, Klebsiella mobilis, Shigella dysenteriae, Salmonella typhi, Proteus vulgaris, Enterobacter cloacae, and Citrobacter freundii. The high THBC may be an indicator of poor general biological quality of the dredge sediments or spoils. The TCBC is a reliable indication of the possible presence of fecal contamination and is consequently, correlated with pathogens in the dredge spoils. Some of the isolates are responsible for diarrheal, typhoid and gastroenteritis, bacillary dysentery, colonization of the intestinal, urinary, or respiratory tract to fatal septicemia, and meningitis with high morbidity and mortality potentials. Proper disposal of dredge sediments and inclusion of the determination of potential pathogens in its management will assist in controlling environmental consequences of dredging.