Ecological Impact Analysis of Dispersants and Dispersed Oil: An Overview

Abstract

Soaring oil demand, as a result of industrial development, boosts oil exploration and production activities at sea, even into deeper and icier waters. The transportation of the oils, as well as the potential spill accidents and associated pollutions are thus increased. There is an urgent call for contingency planning with effective and eco-friendly oil spill cleanup responses. Dispersant applications can facilitate the breaking up of oil slicks into small oil droplets, allowing their rapid dispersion, dissolution, dilution and biodegradation in the water column. Dispersants have been recognized as effective oil treating agents and well adopted. Nearly 7 million liters of chemical dispersants, mostly Corexit® 9500A, were used after the Deepwater Horizon oil spill incident. However, debates over dispersants continued with major concerns about their environmental impacts and the ecological toxicity, which need to be well reviewed and tackled. Therefore, this study summarized the recent lab- and meso-scale studies and field trials on the ecological impact analysis of dispersants and the chemically dispersed oils. By providing an up-to-date review of the ecological toxicity and environmental impact assessment, this study would help to bridge the knowledge gaps in the field and facilitate future dispersant applications.