Impact of Seasonal Variation of Heavy Metal Concentrations in Abattoir Effluents on Groundwater Quality in Port Harcourt Metropolis, Rivers State

This study investigates the impact of seasonal variation of heavy metal concentrations in abattoir effluents on groundwater quality in Port Harcourt metropolis, Rivers State, over 12 months. Forty-nine water samples (48 groundwater and 1 surface water) were collected from four abattoirs and a control site between May 2023 and April 2024 for this study. Heavy metals like Chromium, Cadmium, Zinc, Copper, Iron, and Lead were analyzed in the lab and compared with the Control using an experimental design and a completely randomized block design. The study revealed that Eagle Island had the highest chromium level (0.52 mg/l) during the wet season, which exceeded NSDWQ limits, and may pose risks of skin irritation and long-term organ damage. Copper levels exceeded the 0.004 mg/l NSDWQ limit at all sites during the wet season, and elevated copper in drinking water may, over time, lead to liver and kidney damage. Similarly, zinc levels far exceeded the NSDWQ limit (0.01 mg/l) at all sites during the dry season, indicating significant contamination. Lead levels at the control (36 mg/l) during the dry season exceeded the NSDWQ limit, as well as expected environmental and regulatory thresholds. The study recommended, amongst others, that the Ministries of Health, Environment, and Agriculture, in collaboration with Veterinary and environmental professionals, should establish continuous groundwater monitoring and enforce best management practices (BMPs) at all abattoir locations to mitigate the long-term accumulation of toxic metals such as lead and iron in nearby water sources.