Metal oxide nanoparticles in oil drilling: Aquatic toxicological concerns

The use of chemicals, surfactants, and polymers in improving the property of drilling fluid and enhancing the effectiveness of drilling process and in tertiary oil recovery is costly and ineffective in handling the challenges. Metal and metal oxide nanoparticles (MMO NPs) have gotten attention in recent time on their use in oil drilling processes. Lately, there are several articles suggesting the benefits, properties, and effectiveness of the use of MMO NPs in drilling mud. They propose and recommend the incorporation of MMO NPs in drilling fluids. MMO NPs of iron, copper, zinc, cerium, aluminium, nickel, zirconium, tin, magnesium, titanium, and silicon are used in oil drilling processes due to their benefits in achieving effective drilling. They perform better than conventional compounds in eliminating and mitigating the challenges caused by water-based mud. However, there is a concern of the eco-friendly property and aquatic toxicity, via improper disposals and runoffs. This review focuses on the aquatic toxicological concerns of these in-use and recommended for use MMO NPs on teleost fish which is a major aquatic organism with huge public health implications in humans. The findings from this review using experimental data prove the potentiality and possible aquatic toxicity of MMO NPs. Therefore, we recommend that their use should be monitored and strictly regulated until there is a standard monitoring technique and a detailed understanding of their effect, fate, and behaviour in aquatic environment.