Microplastics and its impacts

One area of my research focuses on comprehending the pervasive issue of microplastic pollution, particularly within aquatic ecosystems. Over the years, my work has encompassed various aspects of microplastics, from their detection and characterization to their ecological impacts. For instance, I have investigated the presence of microplastics in human feaces, elucidating their potential health risks. My investigations have also extended to numerous marine organisms, such as the Indo-Pacific humpback dolphins, green-lipped mussels, and edible oysters, where I have employed advanced techniques like Raman microspectroscopy and optical photothermal infrared to identify and assess microplastic ingestion. Furthermore, I have contributed to the development of innovative methodologies for microplastic detection, including high-throughput polarization holographic imaging.

My research also explores the environmental dynamics of microplastics, investigating their distribution in remote areas such as the Tibetan Plateau and their presence in natural rivers and urban stormwater runoff in Hong Kong. Through these studies, I have sought to underscore the widespread nature of microplastic pollution, its potential health risks to humans, and its impacts on marine and freshwater ecosystems. My ongoing projects continue to focus on these critical issues, with the objective of advancing our understanding of microplastic pollution and informing strategies for mitigating its effects.

Projects:

1. Contract Study: Comprehensive study of microplastics in Hong Kong’s river and streams - Environmental Protection Department, Hong Kong SAR.
2. Contract Study: China’s Third Marine Pollution Baseline Survey - Environmental Protection Department, Hong Kong SAR.
3. Optical and Computational Technologies To Combat Microplastics and Nanoplastics Pollution
   • with Prof Edmond Lam’s group, The University of Hong Kong (RIF R7003-21), RGC-HK, 2022-2027
4. Ecological roles of the plasticsphere on microplastics in urban rivers of Hong Kong
   • with Prof Patrick Lee’s group, The City University of Hong Kong
5. Nano-bubble assisted flotation of microplastics removal
   • with Prof Alicia An’s group, The City University of Hong Kong

Microplastics Ingestion in Humpback dolphins

This study investigates the critical issue of microplastic ingestion in coastal cetaceans, specifically focusing on humpback dolphins stranded in Hong Kong between 2014 and 2023. By analyzing the stomach contents, we sought to comprehensively understand the extent of small-sized plastic particle ingestion. Utilizing μ-Raman spectroscopy with automated mapping analysis, we characterized the size and quantity of microplastics discovered. This approach significantly enhances our knowledge of microplastic ingestion in coastal cetaceans.

Among the various polymers detected, low-density materials such as polystyrene (PS), polypropylene (PP), and polyethylene (PE) accounted for 92.1% of all identified plastics. Our analysis, employing a hierarchical Bayesian model, revealed that the number of microplastic particles with a size smaller than 113.6μm may have been substantially underestimated in previous studies. Although significant variations were observed among individuals, our study’s advanced methodologies and application of Bayesian modeling techniques provide compelling evidence that previous estimates of microplastic ingestion in coastal cetaceans worldwide are likely to have been considerably underestimated.