Burial leakage: A human accustomed groundwater contaminant sources and health hazards study near cemeteries in Benin City, Nigeria.

This study was carried out to assess the levels of physico-chemical parameters that could be impacted by burial leakage and associated human health risks in Benin City, Nigeria. A total of thirty groundwater samples were collected from two cemeteries and analysed for pH, alkalinity, chloride, sulphate, nitrate, phosphate, ammonia- N, calcium, sodium, potassium, BOD5, COD, Mn, Cd, Cu, Ni, Pb, Zn and Fe. The concentrations of the parameters were compared to national and international standards. The results revealed that the groundwater is highly acidic in nature. Principal component analysis (PCA) revealed that except for alkalinity, all other parameters characterised contributed significantly to various principal components (PC) with eigenvalues ≥ 1. Moreover, the significance of the PC depicted decomposition of the body corpse and associated burial materials. Water quality index (WQI), heavy metal evaluation index (HEI) and Nemerov pollution index (NI) indicated that groundwater from the study area is of poor quality, and highly contaminated by heavy metals. We determined the Chronic health risk through exposure by calculating the hazard quotient (HQ) and hazard index (HI), for both children and adults. For the oral exposure, approximately 33% of samples suggest the high category of chronic risk for children while the medium category was indicated for adults. We found that oral exposure showed relatively higher risk than dermal exposure, and chronic risk for children and adults ranged from low to negligible. However, the carcinogenic risk of Ni and Pb via oral exposure route suggests, very high risk for Ni and medium risk for Pb. In consideration that long term exposure to low concentrations of some heavy metals (including Pb, Cd, and Ni) could result in different manifestations of cancer, we recommend that residents of these areas should find an alternative source of water for drinking and other domestic uses.

Another insight into the contamination levels at Ogoniland in Niger Delta, Nigeria, with focus on Goi Creek.

Environmental pollution arising from crude oil exploratory activities has adversely impacted both the living and non-living components of the ecosystem. An insight into the impact of such activities with focus on Goi Creek in Ogoniland was provided in this study. We generated reliable data for physicochemical, heavy metal, and total hydrocarbon levels in the creek via a total of 40 samples collected across 4 stations designated within the creek in a duration of 10 months. With the exception of temperature, total dissolve solid, dissolved oxygen, chloride, sulfate, nitrate, zinc, and vanadium, the levels of other regulated parameters in the samples were not compatible with the national and international guidelines and standards for surface water quality including Federal Ministry of Environment Guidelines and standards for water quality in Nigeria and Environmental Protection Agency National recommended water quality criteria, respectively. The principal components (PCs) 1 and 2 of principal component analysis biplot revealed that the concentrations of the physicochemical parameters showed a mixed distribution among the stations; however, the heavy metals were more localized to station 4. Moreover, the dataset was subjected to water quality index (WQI), contamination index (Cd), heavy metal evaluation index (HEI), trace element toxicity index (TETI), and environmental water quality index (EWQI) to determine the extent of contamination. The result showed poor WQI, high contamination for Cd, and low-to-medium contamination for HEI. Although, there were variations among the stations on the contamination level, uniform remediation method should be adopted due to the similarity of the contaminants in all the stations.