Microplastics contamination in coastal environment of Southeast Asia: A systematic review

The recurrent issue of microplastic (MP) pollution in Southeast Asia has become a major challenge with serious repercussions on biodiversity, economy, and public health. Despite efforts to address the problem, a lack of thorough research on the sources, and distribution in the region impedes effective policymaking and intervention measures. This study aims to provide a comprehensive overview of the state of research on MPs in the coastal environment of Southeast Asia. We specifically addressed the following questions: What is the current composition and abundance of MPs existing in Southeast Asia's coastal areas, and what information gaps exist in the studies conducted in the coastal environment? Articles were retrieved using the Web of Science and Scopus databases, with publication dates ranging from 2019 to 2022. Our systematic review of 39 studies on MP pollution in the coastal environment of Southeast Asia reveals that MPs are prevalent in the region, with concentrations of up to 238,000 particles L⁻¹, >200,000 particles kg⁻¹ and 40 particles m⁻² d⁻¹ in the coastal water, sediment and atmosphere, respectively. In addition, our study found that only a small proportion (n = 1) of all MP studies in the coastal environment addressed the composition of MPs in the atmosphere. Despite the significant abundance of MPs in the region, there has been a scarcity of comprehensive research on the sources and transport. Our findings highlight the critical need for more standardized sampling and more targeted research on the sources, distribution, and effect of MPs across Southeast Asia.