Quantification and characterization of airborne microplastics in the coastal area of Terengganu, Malaysia.

Microplastics (MPs) pose a threat to ecosystems due to their capacity to bind with toxic chemicals. While the occurrence of MPs in aquatic environmental matrices like water, sediments, and biota is well studied, their presence in the atmosphere remains less understood. This study aimed to determine the presence of airborne MPs and their characteristics through ground-based sampling in the coastal city of Kuala Nerus, Terengganu, Malaysia. Airborne MP samples were collected using passive sampling technique in December 2019. MPs were manually counted and identified using a stereomicroscope based on their colour and shape. The average deposition rate of airborne MPs during the sampling period was 5476 ± 3796 particles/m2/day, ranging from 576 to 15,562 particles/m2/day. Various colours such as transparent (38%), blue (25%), black (20%), red (13%), and others (4%) were observed. The predominant shape of airborne MPs was fibres (> 99%). The morphology structure of MPs observed using a scanning electron microscope (SEM) showed a cracked surface on MPs, suggesting weathering and irregular fragmentation. Further elemental analysis using energy dispersive X-ray spectroscopy (EDS) showed the presence of heavy metals such as aluminium (Al) and cadmium (Cd) on the surface of MPs, attributed to the adsorption capacities of MPs. Polymer types of airborne MPs were analysed using attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), which revealed particles composed of polyester (PES), polyethylene (PE), and polypropylene (PP). The preliminary findings could provide additional information for further investigations of MPs, especially in the atmosphere, to better understand their sources and potential human exposure.

A multidimensional approach for microplastics monitoring in two major tropical river basins, Malaysia.

Microplastics (MPs) with the size of 1 µm-5 mm are pollutants of great concern ubiquitously found in the environment. Existing efforts have found that most of the MPs present in the seas mainly originated from land via riverine inputs. Asian rivers are known to be among the top in microplastic emissions. However, field data are scarce, especially in Malaysia. This study presents the distribution and characteristics of MPs in the surface water of two major river basins of Malaysia, namely Langat River (West Coast/Straits of Malacca) and Kelantan River (East Coast/South China Sea). Water samples were collected at 21-22 locations in Kelantan and Langat rivers, covering the river, estuary and sea. MPs were physically classified based on sizes, shapes, colours and surface morphology (SEM-EDS). The average of 179.6 items/L and 1464.8 items/L of MPs had been quantified from Kelantan and Langat rivers, respectively. Fibre (91.90%) was highly recorded at Kelantan, compared to Langat whereby both fibre (59.21%) and fragment (38.87%) were prevalence. Anthropogenic activities and urbanised areas contribute to high microplastic abundance, especially in the Langat River. Micro-FTIR analysis identified 14 polymers in Kelantan River, whereas 20 polymers were found in Langat River. Polypropylene, polyethylene, polyethylene terephthalate, nylon, phenoxy resins, poly(methyl acrylate), poly(methyl methacrylate), polystyrene, polytetrafluoroethylene, polyurethane and rayon were discovered in both rivers, although only polyethylene was significant (>1 ppm) when further analysed using pyrolysis-GC/MS. Correlation analysis and multiple linear regression were used to explain the relationship between water quality and MP abundance, suggesting only turbidity was positively significant to the microplastic occurrence. This comprehensive study is first to suggest a full-scale monitoring protocol for MPs in Malaysian riverine system and is significant in understanding MPs abundance in correlation to in-situ environmental factors. Consequently, this will allow the right authorities to develop mitigation strategies to address riverine plastic pollution in major river basins in Malaysia and the South East Asia.

Occurrence of octylphenol and nonylphenol in the sediment of South China Sea and Malacca Strait, Peninsular Malaysia.

Sediment is the ultimate reservoir of effluent from landmasses. This includes octylphenol (OP) and nonylphenol (NP), two chemical compounds which are known with the ability to disrupt the normal functions of hormones in the organism. To our knowledge, no study of these compounds in the marine sediment of Malaysia has been published to date. Hence, this study presents the level of OP and NP in the sediment of the South China Sea and Malacca Strait, Malaysia. The extraction of compounds was done using the liquid-liquid extraction method and followed by clean-up using solid-phase extraction cartridges. The range of OP in Malacca Strait (1.00-27.16 ng/g dw) was greater than in the South China Sea (5.12-14.16 ng/g dw) whereas a similar range of NP was found in the South China Sea (1.32-23.76 ng/g dw) and Malacca Strait (0.79-27.59 ng/g dw). The concentration of both compounds was consistently high near Redang Island (E2A) and Penang (W32 and W43) suggesting continuous input of these chemicals from this nearby land. Risk quotient (RQ) values of OP showed the potential risk to benthic communities in 4/7 and 21/47 sampling points of the respective South China Sea and Malacca Strait. Both water bodies are located far from the wastewater effluent and yet able to retain these chemicals in their sediment. This suggests that the wastewater treatment system as well as dilution effects do not prevent these chemicals to be ended up in the marine environment.

A raw data on the physico-chemical water parameters and sedimentation rates of two different aquatic macrophytes in Tasik Berombak, Malaysia.

The excessive growth of aquatic macrophytes in a water system has a negative effect on the lake ecosystem. This article presents data on water parameters and sedimentation rates from sites that include different aquatic macrophytes at Tasik Berombak, a freshwater lake on Peninsular Malaysia's eastern coast. Areas with Hanguana malayana and Pandanus helicopus were selected for sampling, while an area without aquatic macrophytes served as the control. At the lake's surface and bottom, temperature, conductivity, total dissolved solids, dissolved oxygen (D.O.), and pH were measured in situ. The surface water was sampled for chemical analysis in the laboratory (chlorophyll-a, total suspended solids, total carbon, total organic carbon, inorganic carbon, total dissolved nitrogen, total dissolved phosphorus). Settling sediment was collected using cylinder traps deployed under the macrophytes at the bottom of the lake. The presented data includes the water parameters according to plant-base area, depth differentiation (top versus bottom), and variable correlation analysis. Understanding the impact of excessive aquatic plants on the lake ecosystem in a tropical environment requires information on water parameters and sedimentation rates from the aquatic plants. Therefore, these data can be used to monitor the impact of land use change on the aquatic plant community and, ultimately, the lake ecosystem.

First evidence of microplastic pollution in the surface water of Malaysian Marine Park islands, South China Sea during COVID-19.

Malaysia is bounded by the South China Sea with many islands that support species megadiversity and coral reef ecosystems. This study investigates the distribution of microplastics (MPs) in the surface water around the four marine park islands (Perhentian, Redang, Kapas, and Tenggol) during COVID-19. The global pandemic has reset human activities, impacting the environment while possibly reducing anthropogenic contributions of microplastic pollution near the South China Sea islands. It was found that Pulau Perhentian recorded the most abundance of MPs (588.33 ± 111.77 items/L), followed by Pulau Redang (314.67 ± 58.08 items/L), Pulau Kapas (359.8 ± 87.70 items/L) and Pulau Tenggol (294.33 ± 101.64 items/L). Kruskal-Wallis analysis indicates a significant difference in total MPs abundance between islands. There are moderate correlations between salinity, pH, temperature and MPs variability. Among these parameters, only temperature is significant (p < 0.05) as proven by the principal component analysis and multiple linear regression analysis. Nearly 99 % of MPs are fiber type, with the majority of them being black and transparent. Micro-FTIR spectroscopy revealed polyethylene, polypropylene, polyvinyl methyl ether, polyamide, phenoxy-resins and polyurethane-acrylic are associated with MPs. The findings provide a new baseline reference for the MPs distribution on Malaysian islands, which contributes to a potential future direction regarding marine sustainability.

Utilizing Pyrolysis-Gas Chromatography/Mass Spectrometry for Monitoring and Analytical Characterization of Microplastics in Polychaete Worms.

Microplastics (the term for plastics at sizes of <5 mm) might be introduced into the environment from domestic or agricultural activities or from the breakdown of plastic pieces, particles, and debris that are bigger in size. Their presence in the aquatic environment has caused accumulation problems, as microplastics do not easily break down and can be digested by some aquatic organisms. This study was conducted to screen and monitor the level of microplastic pollution in polychaete worms using pyrolysis−gas chromatography/mass spectrometry (Py-GC/MS). The study was conducted in Setiu Wetlands, Malaysia from November 2015 to January 2017 at five-month intervals and covered all monsoon changes. Results from physical and visual analyses indicated that a total number of 371.4 ± 20.2 items/g microplastics were retrieved from polychaete for all seasons, in which, the majority comprised transparent microplastics (49.87%), followed by brown with 138.3 ± 13.6 items/g (37.24%), 21.7 ± 1.9 items/g for blue (5.84%), and 12.9 ± 1.1 items/g for black (3.47%), while the remaining were green and grey-red colors. Statistical analysis using Kruskal−Wallis showed insignificant differences (p > 0.05) between the sampling station and period for the presence of a microplastics amount. Most of the microplastics were found in fiber form (81.5%), whereas the remaining comprised fragment (18.31%) and film (0.19%) forms. Further analysis with Py-GC/MS under a selective ion monitoring mode indicated that pyrolytic products and fragment ions for a variety of polymers, such as polyvinyl chloride, polypropylene, polyethylene, polyethylene terephthalate, polyamide, and polymethylmethacrylate, were detected. This study provides an insightful application of Py-GC/MS techniques for microplastics monitoring, especially when dealing with analytical amounts of samples.