A systematic review on microplastic contamination in marine sediment and water of Asia: Concentration, characterization, and polymeric risk assessment.

Abstract

Microplastics (MPs) are ubiquitous in the marine environment and harmful for biodiversity. This review was based on 311 studies published on various online platforms published between 2006 and 2024 on MP contamination in marine sediment and water in different countries of Asia. The research highlights an increasing trend in MP contamination studies, with China and India. Analytical techniques for sample collection, digestion, flotation, and polymer identification are discussed. Fourier transform infrared spectroscopy (FTIR) emerged as the preferred method for polymer identification. The maximum MP contamination in marine sediments was recorded at Taiwan and Indonesia, while the maximum MP contamination in marine water was recorded in China, Malaysia, and India. The fiber was the most dominant shape. The 1-2 mm and 500 μ-1 mm-sized MPs having blue color were found dominantly. The pollution indices revealed a very high risk of MP contamination in all the Asian countries. PRACTITIONER POINTS: China and India are the leading in publications on MP contamination studies. Common tools used are steel scoop/spatula/shovel for sediment, nets for water. FTIR is the preferred method for polymer identification. Highest MP in sediment of Indonesia and in water of China, Malaysia, and India. Dominant MP shape: fiber; size 1-2 mm and 500 μ-1 mm, blue color.