Marine plastic debris pollution in coastal areas of Ayeyarwady, Myanmar

ABSTRACT

Marine plastic debris (MPD) pollution is ubiquitous in Asian coastal areas; however, there is limited information on the types of polymers and quantification of MPD in the coastal regions of Myanmar. This study collected beach plastic debris samples from low- and high-tide strandlines across three coastal areas in the Ayeyarwady region to quantify and characterize the abundance of macroplastics (>25 mm) and mesoplastics (5–25 mm). The mean abundance values of plastic debris in the low-tide strandline were consistent: 1.7±0.5 pieces/m² in Ngayoke Kaung, 1.6±0.6 pieces/m² in Chaung Thar, and 1.1±0.7 pieces/m² in Ngwe Saung. In contrast, higher abundances of plastic debris were detected in the high-tide strandline, with 9.3±5.7 pieces/m² in Ngwe Saung, 7.0±4.4 pieces/m² in Chaung Thar, and 4.9±0.5 pieces/m² in Ngayoke Kaung. This variation may be attributed to the larger size of the MPD and its entanglement with the large driftwood. The dominant shapes of the MPD found in low- and high-tide strandlines were fragments, films, and foam, typically white or transparent. The types of polymers were analyzed using Fourier-transform infrared, revealing that polypropylene (PP) and polyethylene (PE) were the most abundant in all sampling sites. The primary sources of this plastic debris are likely consumer products such as food and drink packaging and aquaculture gear. The presence of plastic debris in Myanmar’s coastal areas may be linked to waste management practices, highlighting the need for enhanced environmental education within local communities to control plastic emissions into marine ecosystems.

INTRODUCTION

The ubiquitous distribution of marine plastic debris (MPD) from land-based sources has emerged as a critical environmental concern, particularly in the coastal areas of Asia. This region has experienced rapid urban growth since the late 1980s, driven by increasing population, economic growth, urbanization, and industrialization. These factors have led to changes in income and consumption patterns, resulting in a surge in solid waste generation (Ngoc and Schnitzer, 2009). Plastics are major commodities in today’s market and are found everywhere—from large shopping malls to small grocery stores, medical shops, to daily street food vendors (Law and Thompson, 2014; Zhao et al., 2022). Consequently, the rising demand for single-use packaging, such as carry bags, water bottles, cold drink bottles, plastic cups, nylon ropes, and other applications in construction, automotive, electronics, and agriculture, has led to a significant increase in plastic production, reaching 390.7 million metric tons globally since 2021 (Janssens, 2022). The extensive production and use of single-use plastics has resulted in their massive disposal in the environment (Hu et al., 2022).

Previous studies have reported that the quantity of mismanaged plastic waste was highest in China, at 8.82 million tonnes in 2010, and 11 of the top 20 waste-dumping countries, including Myanmar (Burma), are located in Asia (Jambeck et al., 2015). Additionally, 192 coastal countries generated 275 million metric tonnes of plastic waste in 2010 (Jambeck et al., 2015). Consequently, high densities of plastic debris have been observed, such as on the Skikda coast (northeast of Algeria) with a mean abundance value of 1,067.19±625.62 pieces/m² (Grini et al., 2022). In contrast, lower amounts of plastic debris have been found on the Caribbean coast (4.54 pieces/m²), Spain’s Alicante coast (0.12 pieces/m²), and Brazil’s Silver coast (2.0 pieces/m²) (Marin et al., 2019; Asensio-Montesinos et al., 2020; Rangel-Buitrago et al., 2021). Large quantities of used plastic debris eventually reach the ocean floor via rivers (Chiba et al., 2018; Nurlatifah et al., 2021). Rivers alone can transport approximately 0.47–2.75 million tons of plastic waste to the sea (Mani et al., 2019). Notably, Asian rivers, including the Ayeyarwady River in Myanmar, are among the top 20 most plastic-polluted rivers in the world (Lebreton et al., 2017).

Nearly 75% of marine debris consists of plastic products of various sizes, including microplastic (MP) particles. The vast quantities of plastic debris and MP particles directly affect marine life and indirectly affect human beings because of their high and long-term toxicity (Ding et al., 2022; Ita-Nagy et al., 2022). This is because plastic debris and MPs are linked to exposure to chemicals used as plastic additives. Tun et al. (2023) suggested that single-use plastic products, specifically polyethylene (PE) and polypropylene (PP) bags collected from Myanmar, contain high amounts of plastic additives, such as dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DiBP), dibutyl phthalate (DBP), di(2-ethylhexyl) phthalate (DEHP), and the antioxidant butylated hydroxytoluene (BHT). Plastic debris collected from the beaches contained benzotriazole UV stabilizers and brominated flame retardants (Tanaka et al., 2020). High concentrations of phthalate plasticizers and synthetic phenolic antioxidants have also been detected in plastic debris from the deep sea (Nurlatifah et al., 2021). These harmful chemicals are not easily released into seawater but can leach into the stomachs of organisms; brominated flame retardants and benzotriazole UV stabilizers have also been detected in seabirds (Tanaka et al., 2019; Yamashita et al., 2021). These findings strongly suggest that plastic debris transports toxic chemicals into the environment, leading to their bioaccumulation and harmful effects on marine ecosystems. Therefore, proper plastic waste collection is required to control and reduce the discharge of plastic waste into marine environment.

Implementing environmental education in schools is an effective strategy for reducing littering behaviors among the general population (Eastman et al., 2013). The socioeconomic and educational background of local communities plays a vital role in shaping how people interact with the environment (Akarsu et al., 2022). The ASEAN-Japan Eco-school Project, launched in 2022, introduced environmental education to address marine plastic pollution in ASEAN and Japan, following the Future Leaders’ Declaration on ASEAN-Japan Cooperation for International Marine Plastic Waste in 2021 (Antara Press, 2021). Understanding pollution at the boundary between terrestrial regions and oceans, such as in coastal zones, is essential for comprehending the mechanisms of MPD and for effectively implementing environmental education.

In Myanmar, limited information on environmental contamination has been reported, including studies on greenhouse gas emission potential in Yangon city (Tun and Juchelková, 2018), high concentrations of polycyclic aromatic hydrocarbons (PAHs) in urban road dust (Mon et al., 2020), artificial sweeteners such as acesulfame and sucralose in river water from Yangon and Pathein (Watanabe et al., 2016), elevated arsenic levels in groundwater from the Ayeyarwady region (Van Geen et al., 2014), heavy metals in soils near gold mining sites in the Sagaing Region (Tun et al., 2020), and metal concentrations and pollution assessment in bottom sediments from Inle Lake (Aung et al., 2019). Additionally, Tun et al. (2024) reported the highest abundance of microplastics in sediment samples from Myanmar. Furthermore, Mon et al. (2022) documented the occurrence of microplastics in road dust in Myanmar. However, there is currently no information available on the abundance and distribution of MPD pollution in Myanmar’s coastal areas.

Based on this background, the aim of this study was to determine the abundance and distribution of plastic debris in coastal areas and to identify the colors, shapes, size distributions, and polymer types of marine debris collected from coastal regions in the Ayeyarwady region of Myanmar.

MATERIALS AND METHODS

STUDY SITES AND SAMPLE COLLECTION

This study was conducted in three coastal areas of the Ayeyarwady region in Myanmar (Fig. 1). The sampling sites were located along the Andaman coast, and all target points were selected near rural areas to obtain original data on the occurrence of plastic debris in coastal environments. Sampling was performed at the strandlines of both low and high tides in each coastal area. We followed a previously reported method (Ospar, 2010) with slight modifications to estimate the level of plastic debris pollution, using a 30×1 m² transect for visual collection with large plastic garbage bags. MPD samples were collected from a total of 18 sampling points across three coastal areas: Kan Gyi village (n=3 for low tide, n=3 for high tide) from Chaung Thar, Ngayoke Kaung (n=3 for low tide, n=3 for high tide) from Ngaputaw township, and Thazin village (n=3 for low tide, n=3 for high tide) from Ngwe Saung between December 2022 and January 2023 (Figs. 2, S-1, S-2, and Table 1).

Fig. 1 Study sites of marine debris pollution in coastal areas from the Ayeyarwady region, Myanmar

Fig. 2 Map of the marine debris collection site in the coastal areas from the Ayeyarwady region, Myanmar

Table 1 Sampling sites of marine plastic debris collected from the Ayeyarwady Region, Myanmar (during 2022 and 2023)

Sample ID	Location	Year	Latitude	Longitude	Remark
CT-1	Chaung Thar	2022	16.93932	94.43708	Kan Gyi Village
CT-2	Chaung Thar	2022	16.93787	94.43704	Kan Gyi Village
CT-3	Chaung Thar	2022	16.93493	94.43633	Kan Gyi Village
NK-1	Ngayoke Kaung	2023	16.52776	94.30775	Ngayoke Kaung
NK-2	Ngayoke Kaung	2023	16.52635	94.30128	Ngayoke Kaung
NK-3	Ngayoke Kaung	2023	16.52616	94.29483	Ngayoke Kaung
NS-1	Ngwe Saung	2022	16.90745	94.39042	Thazin Village
NS-2	Ngwe Saung	2022	16.90408	94.39376	Thazin Village
NS-3	Ngwe Saung	2022	16.90192	94.39809	Thazin Village

All marine debris from the low-tide strandline, including plastic debris, leaves, shells, driftwood, and other materials, was collected, whereas only plastic debris was collected from the high-tide strandline. All collected marine debris was transported to the laboratory for further categorization and polymer identification analysis.

MPD MEASUREMENT AND POLYMER IDENTIFICATION

In this study, MPD was classified into two size categories: mesoplastics (5–25 mm) and macroplastics (>25 mm). The collected marine debris was dried at room temperature. After drying, the debris was brushed to remove adherent particles such as sand and dust. The size of each piece of debris was measured, counted, and sorted by morphology (e.g., fragment, film, foam, rope, mask, bottle, and cap) and color (white/transparent, black, blue, green, red, pink, orange, and purple). For polymer identification, we followed a previously reported procedure (Kitahara and Nakata, 2020) with slight modifications. The marine plastic waste samples were cut into pieces (1×1 cm), and only the external layer of each sample was analyzed using Fourier-transform infrared (FT-IR) spectroscopy in the attenuated total reflection mode (Perkin Elmer Spectrum Two FT-IR Spectrometer). Before analyzing the samples, the instrument detector was cleaned with isopropyl alcohol, and a background spectrum was obtained. The FT-IR wavenumber range was set from 400 to 4,000 cm⁻¹, and the quality threshold for the polymer measurement in the plastic debris was set at a minimum of 75% similarity to the reference libraries, and the identification ratios by FT-IR were 86.5% and 31.4% for low- and high-tide MPD, respectively. The occurrence of MPD, as identified by the polymer type, was expressed as the number of pieces per square meter (pieces/m²). To examine the differences in MPD abundances between low and high tides, nonparametric statistical analysis—U-test—was performed using the software of EXCEL STATISTICS (Esumi Co. Ltd., Japan).

RESULTS AND DISCUSSION

ABUNDANCE AND DISTRIBUTION OF THE PLASTIC DEBRIS

The marine debris samples collected from the low- and high-tide strandline areas were classified and counted into categories such as driftwood, leaves, plastic, shells, and feathers (Tables 2 and S-1). Plastic debris was observed at all sampling points at high detection frequencies (100%). A total of 401 pieces of plastic debris from the low-tide strandlines and 1,914 pieces from the high-tide strandlines were collected from the three beaches. The mean abundance of plastic debris in the low-tide strandline was 1.7±0.5 pieces/m² in Ngayoke Kaung, 1.6±0.6 pieces/m² in Chaung Thar, and 1.1±0.7 pieces/m² in Ngwe Saung (Fig. 3 and Table 2). In contrast, a high abundance of MPD in the high-tide strandline was found in Ngwe Saung (9.3±5.7 pieces/m²), followed by Chaung Thar (7.0±4.4 pieces/m²) and Ngayoke Kaung (4.9±0.5 pieces/m²) (Fig. 3 and Table 2). In Ngwe Saung, one sampling point recorded a high amount of MPD at 15.7 pieces/m². There was a significant difference in macroplastic abundance between the high and low tides collected from the three locations (Fig. 3) (p<0.01). However, due to the small number of samples analyzed, it was difficult to examine geographical differences in MPD abundances.

Table 2 Abundance of marine plastic debris (pieces/m²) in three coastal areas from the Ayeyarwady Region, Myanmar (during 2022 and 2023)

Low tide	Chaung Thar (n=3)				Ngayoke Kaung (n=3)				Ngwe Saung (n=3)
	DF	Median	Mean±STD	Min–Max	DF	Median	Mean±STD	Min–Max	DF	Median	Mean±STD	Min–Max
Driftwood	100	30.7	128.0±219.2	22.0–331.9	100	49.4	45.3±13.2	30.0–56.0	100	24.3	18.3±11.1	5.5–25.1
Leaves	100	34.6	32.1±37.0	4.7–57.0	100	5.1	5.2±2.7	2.5–8.0	100	2.7	2.4±1.1	1.1–3.2
Plastics debris	100	1.4	1.6±0.6	1.2–2.3	100	1.9	1.7±0.5	1.2–2.1	100	0.9	1.1±0.7	0.6–2.0
Feather	33	0	0.6±0.9	0.0–1.0	100	0.1	0.1±0.0	0.1–0.1	33	0.0	0.0±0.0	0.0–0.0
Shell	67	0.2	0.5±0.4	0–0.7	100	0.1	0.2±0.1	0.1–0.3	67	0.2	0.2±0.2	0.0–0.3

 

High tide	Chaung Thar (n=3)				Ngayoke Kaung (n=3)				Ngwe Saung (n=3)
	DF	Median	Mean±STD	Min–Max	DF	Median	Mean±STD	Min–Max	DF	Median	Mean±STD	Min–Max
Plastics debris	100	5	7.0±4.4	4.0–12.0	100	4.6	4.9±0.5	4.6–5.5	100	7.2	9.3±5.7	5.0–15.7

DF: Detection Frequency

Fig. 3 Boxplots show the variation of marine plastic debris quantities from low and high tide strandline of three coastal areas

The difference in the amount of plastic debris between the low- and high-tide strandlines may be attributed to the larger size and higher quantity of plastic debris, which can become entangled with large pieces of driftwood. The individual concentrations of the detected plastic debris are shown in Fig. S3. Recent studies have also reported the occurrence of MPD on beaches. For example, the mean concentration of mesoplastics was found to be 140.74±16.98 pieces/m² at Grande Plage and 292.59±150.03 pieces/m² at Titanic, both located in the northeast Algeria (Grini et al., 2022), and 37.7 pieces/m² in South Korea (Lee et al., 2015). These results are greater by an order of magnitude compared with our study findings, although the concentration of 5.50±4.46 pieces/m² in Istanbul (Turkey) (Akarsu et al., 2022) was lower than in our study.

Driftwood and leaves were found to be highly dominant at all sampling points, especially in Chaung Thar, where mangrove forests are widely distributed near the sampling sites. Consequently, dry branches and leaves from the mangroves were dispersed throughout the coastal areas. The driftwood composition exceeded 78% at all sampling points except CT-3, whereas plastic debris was observed in the range of 1%–8% at all low-tide strandline sites from the three coastal areas (Fig. 4). Tin and glass were also sporadically observed in the collected marine debris (Table S1). At the high-tide strandline, only plastics and other harmful debris were collected because the size and quantity of the driftwood were too large to transport to the laboratory. Therefore, the quantities of MPD were calculated to assess the environmental load of the high-tide strandline from the three coastal areas in the Ayeyarwady region of Myanmar, with a focus on categorizing the types of plastic debris and their polymer compositions.

Fig. 4 Composition of marine debris at low tide in the three coastal areas

CHARACTERIZATION OF PLASTIC DEBRIS

The collected plastic debris was classified into eight color categories. In the low-tide strandline, white/transparent plastic debris was the most dominant, accounting for 51% (n=401) of the study areas. The other color groups were ranked as follows: green>blue>yellow>red>black (Fig. 5 and Table S1). In the high-tide strandline, white/transparent plastic debris was also predominant among all collected plastic debris (n=1914), followed by green>blue>yellow>black (Fig. 5). White/transparent was the most dominant color in the collected plastic debris at each individual study site, with 50% (n=148) and 59% (n=637) in Chaung Thar, 46% (n=152) and 59% (n=443) in Ngayoke Kaung, and 57% (n=101) and 62% (n=834) in Ngwe Saung, respectively (Fig. S4). Previous reports have also indicated a high prevalence of white/transparent plastic in other studies (Grini et al., 2022). Tun et al. (2024) reported that white/transparent microplastics are highly dominant in Myanmar’s sediments. Additionally, white and blue plastic pieces could originate from fishing lines or nets commonly used around the world (Van Cauwenberghe and Janssen, 2014). Other possible sources of white plastic debris include single-use plastics such as bottles and carrier bags.

Fig. 5 Composition of color, shape, size and polymer types of collected marine plastic debris from three coastal areas

It is well-known that the extensive weathering of plastic materials can result in the loss of their original color (Veerasingam et al., 2016a, 2016b). Other colored plastics can be attributed to ropes, fishing nets, and clothing (Kumar et al., 2018). Several factors can cause color changes in plastics such as the discoloration of phenolic antioxidants, exposure to UV light, high-temperature polymerization, and oxidation. For example, yellowing often results from photo-oxidative weathering and the extended presence of plastics in the ocean environment (Pospíšil et al., 2002; Carson et al., 2011). Although plastics weathering primarily occurs on beaches, the sorption of persistent organic pollutants is largely observed in seawater (Endo et al., 2005). White MPs derived from plastic debris may be more concerning as harmful materials than other colors due to their likelihood of being ingested by plankton, fish, and other organisms, which can mistake them for prey (Anderson et al., 2016; Clark et al., 2016). This ingestion can lead to toxicity across multiple trophic levels (Yamashita and Tanimura, 2007; Wright et al., 2013; Steer et al., 2017; Scheurer and Bigalke, 2018).

The shapes of the observed plastics were sorted into eight categories: foam, fragment, film, rope, bottle, cap, slippers, and straw (Fig. 5). The fragment shape was the most dominant among the plastics collected from the low-tide strandline, comprising 31% of the total detected plastics (n=401), followed by film (26%) and rope (24%) (Fig. 5 and Table S1). In contrast, foam shape was significantly prevalent in the high-tide strandline, constituting 27% (n=1914) of the total plastic debris, followed by fragments and films (Fig. 5). Additionally, film-shaped debris was also prominent in the low-tide strandline of the Chaung Thar and Ngwe Saung coastal areas, but fragments were consistently found across all sampling points except Ngayoke Kaung (Fig. 5). Conversely, a large amount of rope debris was observed in the low-tide strandline of Ngayoke Kaung, and foam was consistently dominant in the high-tide strandline across the three coastal areas. However, bottle-shaped debris was not observed in the low-tide strandline at the Ngwe Saung sampling points (Fig. 5). Overall, fragments were the major shape of MPD collected from both the low- and high-tide strandlines of the three coastal areas (Fig. 5).

Recent studies suggest that fragments, films, foams, and lines are the dominant shapes in the collected debris (Thushari et al., 2023). Grini et al. (2022) reported that fragment, film, pellet, and foam shapes were prominent in MPD from the Skikda coast (northeast Algeria). These findings are consistent with the present study’s results. Fragment-shaped plastic debris may originate from the degradation (caused by chemical, physical, and biological factors) of larger plastic pieces that break down into smaller fragments (Veerasingam et al., 2016a, 2016b; Khatmullina and Isachenko, 2017). Fragment-shaped plastic debris is often composed of household plastic particles derived from urban runoff (Vidyasakar et al., 2020). The potential sources of foam-shaped debris include single-use food packaging and freezer boxes used for fishing, as polystyrene food boxes and freezer boxes are widely used in Myanmar.

The size distribution of the plastic debris collected from the low- and high-tide strandlines was grouped into eight categories: 0–25, 25–100, 100–200, 200–300, 300–400, 400–500, 500–600, and >600 mm (Fig. 5). The most common size of the plastic debris was 25–100 mm, representing 42% in the low tide and 49% in the high-tide strandlines, accounting for the total collected plastics (n=401; n=1,914, Fig. 5). This category was followed by the 100–200 mm category, which accounted for 23% at low tide and 25% at high tide, respectively (Fig. 5, S5, and Table S1). Additionally, the 25–100 mm size of plastic debris was the largest in all sampling locations, followed by the 100–200 mm size category (Fig. 5). The size distribution of marine plastic debris collected from the three coastal areas in this study revealed that macroplastics were prominent across the debris (Fig. 5). Thushari et al. (2023) suggested that plastic debris sized 0.45–1 mm was predominant around the Kuroshio current, which is contrary to the size distribution found in this study. However, Grini et al. (2022) reported that mesoplastic composition was the largest in the Skikda coast (Northeast Algeria). In contrast, this study found a high concentration of macroplastics. Therefore, the size distribution of the meso and macroplastics in this study inversely correlated with the results from the Kuroshio current and the Skikda coast. The size distribution of macroplastics in this study was >87% (Fig. 5). The amounts of mesoplastic particles are likely controlled by weathering macroplastic particles under tropical climatic conditions through transportation from urban runoff or source areas. Furthermore, the weathering of the mesoparticles can contribute to the formation of microparticles during breakdown.

The polymer types of the MPD were analyzed using FT-IR and compared with the standard spectra to identify the polymer types (Figs. S6, S7, S8, and Table S1). In the polymer analysis, polypropylene (PP), polyethylene (PE), polystyrene (PS), and polyethylene terephthalate/polyester (PET/PES) were the most prominent polymers found in all the collected MPDs (Fig. 5). Generally, the composition of PP was 49% in the low tide and 37% in the high-tide strandlines, followed by PE at 32% and 25% in the low and high-tide strandlines, respectively (Fig. 5). However, PS was the second most dominant polymer composition in the high-tide strandline at 26%. While PP was the most dominant polymer in all sampling points, the PS composition was consistently found in the high-tide strandline of the three coastal areas (Fig. S8). Images of the collected MPD are shown in Figs. S2 and S7. Previous studies have reported that PP is one of the most versatile polymers and is commonly used to make packaging, bottle caps, ropes, fishing gear, laboratory equipment, and drinking straws (Lawale and Jelkie, 2017). PE is also a primary polymer used to manufacture various plastic materials and is globally used for packaging materials or bottles. Tun et al. (2023) suggested that PE, PP, and PET are the dominant polymer types in single-use plastic products from Myanmar. Furthermore, PE, PP, PET, and PS were dominant in the sediment samples from Myanmar (Tun et al., 2024). Therefore, the polymer types of the MPD collected in this study are consistent with those of previous studies (Tun et al., 2023; Tun et al., 2024).

It is worth noting that European countries have a high demand for PE and PP polymers, which are primarily used in fishing gear and packaging (Bergmann et al., 2017). These polymers (PE, PP, and PS), which have a lower density than seawater, can travel long distances and are found far from their primary sources (Zhang et al., 2018). As a result, the PE and PP pieces can be transported by ocean currents over long distances. In contrast, polyvinyl chloride (PVC) polymer has a higher density than seawater and tends to sink; thus, it is usually concentrated in the bottom sediments (Vidyasakar et al., 2020). The polyamide (PA) polymers are mostly used in fishing lines and nets (Hongthong et al., 2021).

CONCLUSION

This study provides much-needed baseline information on MPD-induced anthropogenic environmental pollution in three coastal areas of the Ayeyarwady region, Myanmar. Plastic debris was observed in the low- and high-tide strandlines of the coastal areas of Chaung Thar, Ngayoke Kaung, and Ngwe Saung; however, the abundance was higher in the high-tide zone than in the low-tide zone. The dominant shape of the collected plastic debris in these study areas was fragments. Based on the polymer identification of the collected MPD, PP and PE were the most prominent polymers. This suggests that MPD pollution in these coastal areas may result from poor plastic waste management, improper disposal systems, and a lack of environmental education in the Ayeyarwady region, Myanmar.

This study highlights the need to implement environmental education in primary and secondary schools as an effective strategy to reduce littering behavior among the general population in Myanmar. Additionally, further studies should be conducted to better understand the abundance and occurrence of microplastics, including plastic additives, and their adverse effects on ecosystems along Myanmar’s coastal areas.

ACKNOWLEDGMENTS

We extend our gratitude to the academic staff of the Department of Chemistry at Pathein University for their assistance with marine debris collection in the coastal areas of the Ayeyarwady region, Myanmar. This study was partially supported by the ASEAN-Japan Center, Japan, through the ASEAN-Japan Ecoschool for Marine Plastic Waste Education Program (2022).

CREDIT AUTHORSHIP CONTRIBUTION STATEMENT

Yoon Nandar Lynn: Investigation, Data curation, Formal analysis, Writing manuscript. Cho Cho Than: Sampling. Myint Myint Khine: Sampling. Katrina Navallo: Review and editing. Haruhiko Nakata: Review and editing manuscript. Thant Zin Tun: Conceptualization, Investigation, Writing, Resources, Funding acquisition, Review and editing manuscript.

CONFLICT OF INTEREST

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

SUPPLEMENTARY MATERIAL

Fig. S-1, Sampling procedure (a), sampling locations (b), sampling pictures (c); Fig. S-2, Collected marine plastic debris; Fig. S-3, Marine plastic debris concentration between low and high tide strandline; Fig. S-4, Composition of color and shape of collected marine plastic debris from study locations; Fig. S-5, Size distribution of collected marine plastic debris from study locations; Fig. S-6, FT-IR spectra of collected marine plastic debris; Fig. S-7, Plastic debris and their polymer types; Fig. S-8, Polymer composition of collected marine plastic debris; Table S-1, Shape, color, size and polymer types of collected marine plastic debris (30 m²) from three coastal areas of Ayeyarwady Region, Myanmar (during 2022 and 2023).

This material is available on the Website at https://doi.org/10.5985/emcr.20240026.

REFERENCES

•  Akarsu,  C.,  Sönmez,  V.Z.,  Altay,  M.C.,  Pehlivan,  T.,  Sivri,  N., 2022. The spatial and temporal changes of beach litter on Istanbul (Turkey) beaches as measured by the clean-coast index. Mar. Pollut. Bull. 176, 113407. doi: 10.1016/j.marpolbul.2022.113407.
•  Anderson,  J.C.,  Park,  B.J.,  Palace,  V.P., 2016. Microplastics in aquatic environments: Implications for Canadian ecosystems. Environ. Pollut. 218, 269–280. doi: 10.1016/j.envpol.2016.06.074.
• Antara Press 2021. Declaration by 22 studnents from Japan and 10 ASEAN member countries studing in Japan: the launch ceremony to be held online on March 16. News/Antara/Indonesia.
•  Asensio-Montesinos,  F.,  Oliva Ramírez,  M.,  González-Leal,  J.M.,  Carrizo,  D.,  Anfuso,  G., 2020. Characterization of plastic beach litter by Raman spectroscopy in South-western Spain. Sci. Total Environ. 744, 140890. doi: 10.1016/j.scitotenv.2020.140890.
•  Aung,  P.P.,  Mao,  Y.,  Hu,  T.,  Qi,  S.,  Tian,  Q.,  Chen,  Z.,  Xing,  X., 2019. Metal concentrations and pollution assessment in bottom sediments from Inle Lake, Myanmar. J. Geochem. Explor. 207, 106357. doi: 10.1016/j.gexplo.2019.106357.
•  Bergmann,  M.,  Tekman,  M.B.,  Gutow,  L., 2017. Sea change for plastic pollution. Nature 544, 297–297. doi: 10.1038/544297a.
•  Carson,  H.S.,  Colbert,  S.L.,  Kaylor,  M.J.,  McDermid,  K.J., 2011. Small plastic debris changes water movement and heat transfer through beach sediments. Mar. Pollut. Bull. 62, 1708–1713. doi: 10.1016/j.marpolbul.2011.05.032.
•  Chiba,  S.,  Saito,  H.,  Fletcher,  R.,  Yogi,  T.,  Kayo,  M.,  Miyagi,  S.,  Ogido,  M.,  Fujikura,  K., 2018. Human footprint in the abyss: 30 year records of deep-sea plastic debris. Mar. Policy 96, 204–212. doi: 10.1016/j.marpol.2018.03.022.
•  Clark,  J.R.,  Cole,  M.,  Lindeque,  P.K.,  Fileman,  E.,  Blackford,  J.,  Lewis,  C.,  Lenton,  T.M.,  Galloway,  T.S., 2016. Marine microplastic debris: a targeted plan for understanding and quantifying interactions with marine life. Front. Ecol. Environ. 14, 317–324. doi: 10.1002/fee.1297.
•  Ding,  J.,  Sun,  C.,  He,  C.,  Zheng,  L.,  Dai,  D.,  Li,  F., 2022. Atmospheric microplastics in the Northwestern Pacific Ocean: distribution, source, and deposition. Sci. Total Environ. 829, 154337 doi: 10.1016/j.scitotenv.2022.154337.
•  Endo,  S.,  Takizawa,  R.,  Okuda,  K.,  Takada,  H.,  Chiba,  K.,  Kanehiro,  H.,  Ogi,  H.,  Yamashita,  R.,  Date,  T., 2005. Concentration of polychlorinated biphenyls (PCBs) in beached resin pellets: Variability among individual particles and regional differences. Mar. Pollut. Bull. 50, 1103–1114. doi: 10.1016/j.marpolbul.2005.04.030.
•  Eastman,  L.B.,  Núnez,  P.,  Crettier,  B.,  Thiel,  M., 2013. Identification of self-reported user behavior, education level, and preferences to reduce littering on beaches-a survey from the SE Pacific. Ocean Coast. Manag. 78, 18–24. doi: 10.1016/j.ocecoaman.2013.02.014.
•  Grini,  H.,  Metallaoui,  S.,  González-Fernández,  D.,  Bensouilah,  M., 2022. First evidence of plastic pollution in beach sediments of the Skikda coast (northeast of Algeria). Mar. Pollut. Bull. 181, 113831. doi: 10.1016/j.marpolbul.2022.113831.
•  Hongthong,  S.,  Leese,  H.S.,  Allen,  M.J.,  Chuck,  C.J., 2021. Assessing the conversion of various nylon polymers in the hydrothermal liquefaction of macroalgae. Environ.-MDPI 8, 1–17. doi: 10.3390/environment8040034.
•  Hu,  K.,  Yang,  Y.,  Zuo,  J.,  Tian,  W.,  Wang,  Y.,  Duan,  X.,  Wang,  S., 2022. Emerging microplastics in the environment: Properties, distributions, and impacts. Chemosphere 297, 134118. doi: 10.1016/j.chemosphere.2022.134118.
•  Ita-Nagy,  D.,  Vázquez-Rowe,  I.,  Kahhat,  R., 2022. Prevalence of microplastics in the ocean in Latin America and the Caribbean. J. Hazard. Mater. Adv. 5, 100037. doi: 10.1016/j.hazadv.2021.100037.
•  Jambeck  J.,  Geyer  R.,  Wilcox  C.,  Siegler  T.R.,  Perryman  M.,  Andrady  A.,  Narayan  R.,  Law  K.L. (2015) Plastic waste inputs from land into the ocean. Science 347(6223), 768–771. doi: 10.1126/science.1260352.
•  Janssens  V (2022) Plastics—the Facts 2022: 81. Plastics—the Facts 2022. Plastics Europe.
•  Khatmullina,  L.,  Isachenko,  I., 2017. Settling velocity of microplastic particles of regular shapes. Mar. Pollut. Bull. 114, 871–880. doi: 10.1016/j.marpolbul.2016.11.024.
•  Kitahara,  K.I.,  Nakata,  H., 2020. Plastic additives as tracers of microplastic sources in Japanese road dusts. Sci. Total Environ. 736, 139694. doi: 10.1016/j.scitotenv.2020.139694.
•  Kumar,  V.E.,  Ravikumar,  G.,  Jeyasanta,  K.I., 2018. Occurrence of microplastics in fishes from two landing sites in Tuticorin, South east coast of India. Mar. Pollut. Bull. 135, 889–894. doi: 10.1016/j.marpolbul.2018.08.023.
•  Law,  K.L.,  Thompson,  R.C., 2014. Microplastics in the seas. Science 345, 144–145. doi: 10.1126/science.1254065.
•  Lawale,  D.,  Jelkie,  N., 2017. Knowledge paper on plastic industry for infrastructure, 35 pp. In: 3rd National Conference of Sustainable Infrastructure with Plastics. Organized by Federation of Indian Chambers of Commerce Industry.
•  Lebreton,  L.C.M.,  Van Der Zwet,  J.,  Damsteeg,  J.W.,  Slat,  B.,  Andrady,  A.,  Reisser,  J., 2017. River plastic emissions to the world’s oceans. Nat. Commun. 8, 1–10. doi: 10.1038/ncomms15611.
•  Lee,  J.,  Lee,  J.S.,  Jang,  Y.C.,  Hong,  S.Y.,  Shim,  W.J.,  Song,  Y.K.,  Hong,  S.H.,  Jang,  M.,  Han,  G.M.,  Kang,  D.,  Hong,  S., 2015. Distribution and Size Relationships of Plastic Marine Debris on Beaches in South Korea. Arch. Environ. Contam. Toxicol. 69, 288–298. doi: 10.1007/s00244-015-0208-x.
•  Mani,  T.,  Primpke,  S.,  Lorenz,  C.,  Gerdts,  G.,  Burkhardt-holm,  P., 2019. Microplastic Pollution in Benthic Midstream Sediments of the Rhine River. Environ. Sci. Technol. 53(10), 6053–6062. doi: 10.1021/acs.est.9b01363.
•  Marin,  C.B.,  Niero,  H.,  Zinnke,  I.,  Pellizzetti,  M.A.,  Santos,  P.H.,  Rudolf,  A.C.,  Beltrão,  M.,  Waltrick,  D. de S.,  Polette,  M., 2019. Marine debris and pollution indexes on the beaches of Santa Catarina State, Brazil. Reg. Stud. Mar. Sci. 31, 100771. doi: 10.1016/j.rsma.2019.100771.
•  Mon,  E.E.,  Phay,  N.,  Agusa,  T.,  Bach,  L.T.,  Yeh,  H.M.,  Huang,  C.H.,  Nakata,  H., 2020. Polycyclic Aromatic Hydrocarbons (PAHs) in Road Dust Collected from Myanmar, Japan, Taiwan, and Vietnam. Arch. Environ. Contam. Toxicol. 78, 34–45. doi: 10.1007/s00244-019-00693-y.
•  Mon,  E.E.,  Tun,  T.Z.,  Agusa,  T.,  Yeh,  H.-M.,  Haung,  C.H.,  Nakata,  H., 2022. Monitoring of microplastics in road dust samples from Myanmar and Taiwan. Environ. Monit. Contam. Res. 2, 112–119. doi: 10.5985/emcr.20220008.
•  Ngoc,  U.N.,  Schnitzer,  H., 2009. Sustainable solutions for solid waste management in Southeast Asian countries. Waste Manag. 29, 1982–1995. doi: 10.1016/j.wasman.2008.08.031.
•  Nurlatifah,  Yamauchi, T., Nakajima, R., Tsuchiya, M., Yabuki, A., Kitahashi, T., Nagano, Y., Isobe, N., Nakata, H., 2021. Plastic additives in deep-sea debris collected from the western North Pacific and estimation for their environmental loads. Sci. Total Environ. 768, 144537. doi: 10.1016/j.scitotenv.2020.144537.
• Ospar, 2010. Guideline for monitoring marine litter on the beachs in the OSPAR Maritime Area. OSPAR Comm. 1, 84.
•  Pospíšil,  J.,  Habicher,  W.D.,  Pilař,  J.,  Nešpůrek,  S.,  Kuthan,  J.,  Piringer,  G.O.,  Zweifel,  H., 2002. Discoloration of polymers by phenolic antioxidants. Polym. Degrad. Stab. 77, 531–538. doi: 10.1016/S0141-3910(02)00112-X.
•  Rangel-Buitrago,  N.,  Mendoza,  A.V.,  Mantilla-Barbosa,  E.,  Arroyo-Olarte,  H.,  Arana,  V.A.,  Trilleras,  J.,  Gracia  C.A.,  Neal,  W.J.,  Williams,  A.T., 2021. Plastic pollution on the Colombian central Caribbean beaches. Mar. Pollut. Bull. 162, 111837. doi: 10.1016/j.marpolbul.2020.111837.
•  Scheurer,  M.,  Bigalke,  M., 2018. Microplastics in Swiss Floodplain Soils. Environ. Sci. Technol. 52, 3591–3598. doi: 10.1021/acs.est.7b06003.
•  Steer,  M.,  Cole,  M.,  Thompson,  R.C.,  Lindeque,  P.K., 2017. Microplastic ingestion in fish larvae in the western English Channel. Environ. Pollut. 226, 250–259. doi: 10.1016/j.envpol.2017.03.062.
•  Tanaka,  K.,  Franeker,  J.A. Van,  Deguchi,  T.,  Takada,  H., 2019. Piece-by-piece analysis of additives and manufacturing byproducts in plastics ingested by seabirds: Implication for risk of exposure to seabirds. Mar. Pollut. Bull. 145, 36–41. doi: 10.1016/j.marpolbul.2019.05.028.
•  Tanaka,  K.,  Takada,  H.,  Ikenaka,  Y.,  Nakayama,  S.M.M.,  Ishizuka,  M., 2020. Occurrence and concentrations of chemical additives in plastic fragments on a beach on the island of Kauai, Hawaii. Mar. Pollut. Bull. 150, 110732. doi: 10.1016/j.marpolbul.2019.110732.
•  Thushari,  G.G.N.,  Miyazono,  K.,  Sato,  T.,  Yamashita,  R.,  Takasuka,  A.,  Watai,  M.,  Yasuda,  T.,  Kuroda,  H.,  Takahashi,  K., 2023. Floating plastic accumulation and distribution around Kuroshio Current, western North Pacific. Mar. Pollut. Bull. 188, 114604. doi: 10.1016/j.marpolbul.2023.114604.
•  Tun,  A.Z.,  Wongsasuluk,  P.,  Siriwong,  W., 2020. Heavy metals in the soils of placer small-scale gold mining sites in Myanmar. J. Heal. Pollut. 10, 200911. doi: 10.5696/2156-9614-10.27.200911.
•  Tun,  M.M.,  Juchelková,  D., 2018. Assessment of solid waste generation and greenhouse gas emission potential in Yangon city, Myanmar. J. Mater. Cycles Waste Manag. 20, 1397–1408.
•  Tun,  T.Z.,  Mon,  E.E.,  Nakata,  H., 2024. Microplastics Distribution in Sediments Collected from Myanmar. Arch. Environ. Contam. Toxicol. 86, 1–12. doi: 10.1007/s00244-023-01042-w.
•  Tun,  T.Z., Nurlatifah, Htwe, A.T., Than, N.N., Khine, M.M., Chavanich, S., Viyakarn, V., Isobe, A., Nakata, H., 2023. Polymer types and additive concentrations in single-use plastic products collected from Indonesia, Japan, Myanmar, and Thailand. Sci. Total Environ. 889, 163983. doi: 10.1016/j.scitotenv.2023.163983.
•  Van Cauwenberghe,  L.,  Janssen,  C.R., 2014. Microplastics in bivalves cultured for human consumption. Environ. Pollut. 193, 65–70. doi: 10.1016/j.envpol.2014.06.010.
•  Van Geen,  A.,  Win,  K.H.,  Zaw,  T.,  Naing,  W.,  Mey,  J.L.,  Mailloux,  B., 2014. Confirmation of elevated arsenic levels in groundwater of Myanmar. Sci. Total Environ. 478, 21–24. doi: 10.1016/j.scitotenv.2014.01.073.
•  Veerasingam,  S.,  Mugilarasan,  M.,  Venkatachalapathy,  R.,  Vethamony,  P. (2016a) Influence of 2015 flood on the distribution and occurrence of microplastic pellets along the Chennai coast, India. Mar. Pollut. Bull. 109, 196–204. doi: 10.1016/j.marpolbul.2016.05.082.
•  Veerasingam,  S.,  Saha,  M.,  Suneel,  V.,  Vethamony,  P.,  Rodrigues,  A.C.,  Bhattacharyya,  S.,  Naik,  B.G. (2016b) Characteristics, seasonal distribution and surface degradation features of microplastic pellets along the Goa coast, India. Chemosphere 159, 496–505. doi: 10.1016/j.chemosphere.2016.06.056.
•  Vidyasakar,  A.,  Krishnakumar,  S.,  Kasilingam,  K.,  Neelavannan,  K.,  Bharathi,  V.A.,  Godson,  P.S.,  Prabha,  K.,  Magesh,  N.S., 2020. Characterization and distribution of microplastics and plastic debris along Silver Beach, Southern India. Mar. Pollut. Bull. 158, 111421. doi: 10.1016/j.marpolbul.2020.111421.
•  Watanabe,  Y.,  Tho,  L.,  Pham,  B.,  Maricar,  V.D., 2016. Ubiquitous Detection of Artificial Sweeteners and Iodinated X-ray Contrast Media in Aquatic Environmental and Wastewater Treatment Plant Samples from Vietnam, The Philippines, and Myanmar. Arch. Environ. Contam. Toxicol. 70, 671–681. doi: 10.1007/s00244-015-0220-1.
•  Wright,  S.L.,  Thompson,  R.C.,  Galloway,  T.S., 2013. The physical impacts of microplastics on marine organisms: a review. Environ. Pollut. 178, 483–492. doi: 10.1016/j.envpol.2013.02.031.
•  Yamashita,  R.,  Hiki,  N.,  Kashiwada,  F.,  Takada,  H.,  Mizukawa,  K.,  Hardesty,  B.D.,  Roman,  L.,  Hyrenbach,  D.,  Ryan,  P.G.,  Dilley,  B.J.,  Munozperez,  J.P.,  Valle,  C.A.,  Pham,  C.K.,  Frias,  J.,  Nishizawa,  B.,  Takahashi,  A.,  Thiebot,  J.-B.,  Will,  A.,  Kokubun,  N.,  Watanabe,  Y.Y.,  Yamamoto,  T.,  Shiomi,  K.,  Shimabukuro,  U.,  Watanuki,  Y., 2021. Plastic additives and legacy persistent organic pollutants in the preen gland oil of seabirds sampled across the globe. Environ. Monit. Contam. Res. 1: 97–112. doi: 10.5985/emcr.20210009.
•  Yamashita,  R.,  Tanimura,  A., 2007. Floating plastic in the Kuroshio Current area, western North Pacific Ocean 54. Mar. Pollut. Bull. 54(4), 485–488. doi: 10.1016/j.marpolbul.2006.11.016.
•  Zhao,  X.,  Yong,  Y.,  Du,  C.-S.,  Guo,  W.-G.,  Luo,  D.-P., 2022. Evaluation on production trend, compositions, and impact of plastic waste in Chengdu, southwestern China. J. Air Waste Manag. Assoc. 72, 1454–1462. doi: 10.1080/10962247.2022.2126558.
•  Zhang,  K.,  Shi,  H.,  Peng,  J.,  Wang,  Y.,  Xiong,  X.,  Wu,  C.,  Lam,  P.K.S., 2018. Microplastic pollution in China’s inland water systems: A review of findings, methods, characteristics, effects, and management. Sci. Total Environ. 630, 1641–1653. doi: 10.1016/j.scitotenv.2018.02.300.