Evaluation of the effects of abattoir effluent on the physicochemical and bacteriological quality of River Benue, Nigeria.

This study investigated the impact of continual discharge of untreated abattoir effluents on the water quality of River Benue. Three major abattoirs (Wurukum, Wadata and Northbank) in Makurdi, Nigeria, and their polluting strength in river upstream and downstream were measured and compared. Two water quality parameters: physicochemical and bacteriological were investigated. Water quality index (WQI) was computed for all sampling sites. Results revealed that some of the physiochemical parameters were above recommended limits, especially in downstream river, in particular, the turbidity (24.0-55.5 mg/l), TSS (62.6-92.0 mg/l), DO (8.0 mg/l), and total hardness (160-240 mg/l). All sampling sites indicated an increased bacterial population while Salmonella spp. and Escherichia coli were the predominant bacteria among the ten genera identified in water upstream and downstream. Faecal coliforms increased from upstream to downstream in two sampling sites (Wurukum and Wadata). Strong positive correlations were observed between upstream and downstream samples for pH, EC, turbidity, TSS, DO, COD, SO42-, TC, and Shigella spp. WQI revealed that all sampling locations were heavily polluted and unsuitable for drinking purposes (WQI > 300) based on both the physicochemical and bacterial parameters. The sampling sites, however, showed excellent water quality based only on physicochemical properties especially upstream at both Wurukum and Northbank sampling sites (WQI < 50). It was suggested that anthropogenic activities around the river may be responsible for the high concentration of some physiochemical parameters and bacterial loads observed in the river downstream. Moreover, it was concluded that microbial loads should be fully considered in WQI computation in terms of water quality. Our results are useful for water resource and waste management in terms of practices and policy guidance, especially for developing countries.

Quantifying the exposure of humans and the environment to oil pollution in the Niger Delta using advanced geostatistical techniques.

The Niger Delta is one of the largest oil producing regions of the world. Large numbers and volumes of oil spills have been reported in this region. What has not been quantified is the putative exposure of humans and/or the environment to this hydrocarbon pollution. In this novel study, advanced geostatistical techniques were applied to an extensive database of oil spill incidents from 2007 to 2015. The aims were to (i) identify and analyse spill hotspots along the oil pipeline network and (ii) estimate the exposure of the hydrocarbon pollution to the human population and the environment within the Niger Delta. Over the study period almost 90millionlitres of oil were released. Approximately 29% of the human population living in proximity to the pipeline network has been potentially exposed to oil contamination, of which 565,000 people live within high or very high spill intensity sectors. Over 1000km2 of land has been contaminated by oil pollution, with broadleaved forest, mangroves and agricultural land the most heavily impacted land cover types. Proximity to the coast, roads and cities are the strongest spatial factors contributing to spill occurrence, which largely determine the accessibility of sites for pipeline sabotage and oil theft. Overall, the findings demonstrate the high levels of environmental and human exposure to hydrocarbon pollutants in the Niger Delta. These results provide evidence with which to spatially target interventions to reduce future spill incidents and mitigate the impacts of previous spills on human communities and ecosystem health.