Microplastics in equatorial coasts: Pollution hotspots and spatiotemporal variations associated with tropical monsoons

Mui-Choo Jong; Xuneng Tong; Junnan Li; Zichen Xu; Shannae Hui Qing Chng; Yiliang He; Karina Yew-Hoong Gin

doi:10.1016/j.jhazmat.2021.127626

Microplastics in equatorial coasts: Pollution hotspots and spatiotemporal variations associated with tropical monsoons

J Hazard Mater. 2022 Feb 15;424(Pt C):127626. doi: 10.1016/j.jhazmat.2021.127626. Epub 2021 Oct 29.

Authors

Mui-Choo Jong¹, Xuneng Tong², Junnan Li³, Zichen Xu², Shannae Hui Qing Chng², Yiliang He⁴, Karina Yew-Hoong Gin⁵

Affiliations

¹ National University of Singapore Environment Research Institute, National University of Singapore, 1 Create Way, #15-02, Singapore 138602, Singapore.
² Department of Civil and Environmental Engineering, National University of Singapore, Block E1A-07-03, 1 Engineering Drive 2, Singapore 117576, Singapore.
³ School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
⁴ School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China; E2S2-CREATE, NUS Environmental Research Institute, National University of Singapore, 1 Create way, Create Tower, #15-02, Singapore 138602, Singapore. Electronic address: ylhe@sjtu.edu.cn.
⁵ National University of Singapore Environment Research Institute, National University of Singapore, 1 Create Way, #15-02, Singapore 138602, Singapore; Department of Civil and Environmental Engineering, National University of Singapore, Block E1A-07-03, 1 Engineering Drive 2, Singapore 117576, Singapore; E2S2-CREATE, NUS Environmental Research Institute, National University of Singapore, 1 Create way, Create Tower, #15-02, Singapore 138602, Singapore. Electronic address: ceeginyh@nus.edu.sg.

PMID: 34741937
DOI: 10.1016/j.jhazmat.2021.127626

Abstract

Microplastics (MP < 5 mm) are eroding oceanic health and coastal development at a planetary scale. Coastlines in Southeast Asia (SEA) are plagued with plastic litters, but how MP are dispersed within SEA region is poorly understood, which can vary dramatically under the tropical climate. We systematically quantified MP in equatorial Singapore, to assess how prevailing Monsoons and other factors impact MP distributions in beaches and mangroves. Data highlighted spatial preponderance differed broadly by seasons (p < 0.05) and were strongly modulated by wind speediness (p < 0.05; r = 0.6-0.7) and promoted transboundary migrations of MP. Conversely, an inverse relationship existed between sediment MP and rainfall (r = -0.54) possibly due to re-entrainment of surficial MP. Elevated concentrations in mangrove's compartments (p < 0.05) suggest effective repository hotspots. Coastal MP consisted assorted morphologies and commonest polymers including 34% polypropylene (PP), 26% polyethelene (PE), and 23% Low Density PE. Further comparisons revealed coastal MP in Singapore accelerated by two orders of magnitude since 2014, implying cumulative pollution which is not reversible. We synthesized the first seasonal coastal MP report in SEA which is useful for source apportionment, prediction study, and mitigation planning under tropical circumstances.

Keywords: Coastal; Mangrove; Microplastics; Monsoon; Tropical.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Environmental Monitoring
Environmental Pollution
Microplastics*
Plastics
Water Pollutants, Chemical* / analysis

Substances

Microplastics
Plastics
Water Pollutants, Chemical