Review of marine hazardous and noxious substance spills: current trends and future research directions

The transportation of hazardous and noxious substances (HNS) is an important component of maritime transport. However, accidental HNS spills into the ocean, which negatively impact human and ecosystem health and can also lead to international disputes, are difficult to manage. In this study, we aimed to review research trends on marine HNS spill incidents and identify existing research gaps. After searching relevant databases, studies on marine HNS spills were identified and categorized into technical response, HNS characterization and toxicity evaluation, risk assessment and management, and legal response and policy studies. Toxicity assessment for marine life was identified as the most researched area under the risk assessment and management category. Further, in terms of the diversity of HNS, the number of HNS components that have been studied thus far is limited and research focusing on HNS leak responses and monitoring methods are lacking. Therefore, considering past leak cases, there is an urgent need to strengthen technical response efforts and international collaboration to the end of preventing the recurrence of similar incidents and developing more effective mitigation strategies. This review provides an overview of the state of research on maritime HNS spills and highlights avenues for further research to ensure human and ecosystem safety.