Many Oil Wells, One Evil: Potentially toxic metals concentration, seasonal variation and Human Health Risk Assessment in Drinking Water Quality in Ebocha-Obrikom Oil and Gas Area of Rivers State, Nigeria
Authors: Raimi Olalekan Morufu , Sawyerr Olawale Henry , Ezekwe Clinton Ifeanyichukwu , Salako Gabriel 
Published: November 2021

Background

Oil and natural gas extraction have produced environmental pollution at levels that affect reproductive health of indigenous populations. Accordingly, polluted drinking water from physical, chemical and heavy metals can result in serious health problems, like anemia, kidney failure, immunosuppression, neurological impairments, gastrointestinal as well as respiratory irritation, skeletal system abnormalities, liver inflammation, liver cancer, cardiovascular diseases after chronic exposure and other cancer diseases with negative health effects. These diseases types remain associated to high amounts of heavy metal elements such as lead, chromium, zinc, copper, cadmium, manganese as well as nickel etc.

Objectives

Compare differences in water quality parameters in the study area (determine the level of pollutions in the different sites).

Methodology

The investigation made use of standard analytical procedures. All sampling, conservation, transportation and analysis followed standard procedures described in APHA (2012). To prevent degradation of the organic substances, all obtained samples were transferred to the laboratory, while keeping in an icebox.

Results

Result shows that during wet season, the mean values obtained for water quality parameters were significantly lower in site 9 compared with that obtained in other sites (p<0.05) with the exemptions of temperature, DO, BOD, COD, acidity, TH, TDS, K, Mg, Zn, Mn, Cd, Pb, Cu, Cr, NH3, NO2, NO3, Ni though slightly lower in most cases in site 9 were not significantly different (p>0.05) and both alkalinity and SO4which were significantly higher in site9than site 1 (p<0.05). Result obtained during dry season reveals that there is no remarkable difference in pH, acidity, Pb and Ni between the nine sites (p>0.05) while other water quality parameters were significantly lower in site 9 than other sites excluding Cl and Mg which were both significantly higher in site 9 than site 8 (p<0.05).

Conclusion

To guarantee quality groundwater supply for various purposes in Nigeria’s core Niger Delta region, extra efforts must be taken to fully understand hydrogeochemical features and its suitability. Thus, this study will aid in the development of a quantitative understanding of the effects of diverse causes on groundwater level fluctuations in any aquifer around the world. Also, this analysis reinforces a valuable resource for researchers, activists and public officials seeking to help enhance community awareness, planning and performance. The verdicts would remain a valuable guideline for policymakers, the Ministry of Water Resources and development practitioners, as this highlights the requirement for suitable approaches toward mitigating toxic element of water resources contamination in the core Niger Delta toward safeguarding health of the public from carcinogenic as well as non-carcinogenic risks.

HIGHLIGHTS

Many tropical countries are suffering from severe groundwater pollution. Governments at all levels are doing little or very little to provide clean and accessible water to citizens, especially in Nigeria’s Niger Delta region.

This study aims to determine the level of pollutions in the different sites.

Result depicts that during wet and dry season, the mean values obtained for water quality parameters were significantly lower in site 9 compared with that obtained in other sites.

Result reveals that groundwater at location 3, 4 and 7 were heavily polluted during wet and dry season. Hence, an alliance is needed to address the rising global health emergency threat caused by groundwater pollution in Nigeria’s core Niger Delta region, which is threatening millions of people. The situation will only get worse and faster unless there is a coordinated response to the problem through a worldwide alliance of organizations capable of bringing meaningful change.

The disease risk as well as illness to millions of individuals living in close proximity to gas flaring remain a cause for worry in its own right, the gases as well as toxins impact released into the atmosphere through continuously flaring gases has worldwide implications.

Regarding the environmental and social conditions of the area, gas flaring significantly increases the health hazards, first through releasing dangerous pollutants directly into the atmosphere as well as through pollutants transfer to the food chain.

Groundwater pollution has a financial cost that runs into billions of Naira, in addition to the human and environmental effect. Thus, there is need for tougher environmental regulations.

At present, no coordinated action being taken, real change will only occur if governments as well as key stakeholder organizations form a global alliance toward addressing the issue. Starting with a strategy to finance well closure as well as relocation of sites that are most dangerous (location 3, 4 & 7) as soon as possible, as well as providing support through capital and experience is required. Even though the cost will remain substantial, it will provide an opportunity toward investing in the Niger Delta infrastructure as well as economy. Furthermore, the expense of closing the most dangerous groundwater open wells will be a drop in the bucket compared to the cost of the health consequences.