# Occurrence and levels of industrial persistent organic pollutants under the Stockholm convention: A review of water resources in southeast Asian countries

Toan Khanh Vu, Vincent Fauvelle, Thi Thao Nguyen, Van Hoi Bui, Laure Malleret

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## To cite this version:

Toan Khanh Vu, Vincent Fauvelle, Thi Thao Nguyen, Van Hoi Bui, Laure Malleret. Occurrence and levels of industrial persistent organic pollutants under the Stockholm convention: A review of water resources in southeast Asian countries. Journal of Hazardous Materials Advances, 2025, 20, pp.100872. 10.1016/j.hazadv.2025.100872. hal-05489729

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# Occurrence and levels of industrial persistent organic pollutants under the Stockholm convention: A review of water resources in southeast Asian countries

Toan Khanh Vu<sup>a,b,c</sup>, Vincent Fauvelle<sup>c</sup>, Thi Thao Nguyen<sup>a,b</sup>, Van Hoi Bui<sup>b</sup>, Laure Malleret<sup>a,*</sup>

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## ARTICLE INFO

**Keywords:**

PCBs

PBDEs

PFAS

CPs

Southeast Asia

Aquatic environment

Water resources

## ABSTRACT

The Stockholm Convention (SC) on Persistent Organic Pollutants (POPs) aims to protect the environment and human health by regulating the production and the use of the so-called forever chemicals. Among the compounds listed under the SC, are 209 congeners of Polychlorinated biphenyls (PCBs) and Polybrominated biphenyl ethers (PBDEs), Chlorinated paraffins (CPs) and three molecules and related compounds of Poly- and Perfluoroalkyl substances (PFAS), representing four groups of industrial POPs gathering a huge number of molecules. These chemicals have been extensively used in various applications since the mid-20th century, resulting in their global dispersion as persistent and long-range-transport substances. Moreover, the rapid industrialization and economic development in Southeast Asian countries have heightened the vulnerability of their environments to such pollutants. The differences, both in the phases of economic development and in the history of practices and rulings, implies specific trends of POP concentrations in these developing countries. This articles reviews in sections three to five the occurrence and the reported concentrations of PCBs, PBDEs, and PFAS in the fresh and marine hydro-systems, gathering samples of water, sediment, and aquatic biota, studied across eight Southeast Asian countries over the past three decades. The summarized data provides in-depth information for the national policymakers to align with the objectives of the SC. It shows that these countries are paying increasing attention to document the quality status of the water resources, particularly in connection with the implementation of regulations, or with the edible resources. But the efforts need to be strengthened. Indeed, the review underscores in section 6, the urgent need for the regular environmental monitoring of these broad groups of POPs, points out the knowledge gaps in some countries and for some POPs, and highlights future directions for research to ensure the sustainability of water resources.

## 1. Introduction

Southeast Asia (SEA) is located in the Western Pacific region, and consists of 11 countries (Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, the Philippines, Singapore, Timor Leste, Thailand, and Vietnam). With a population of 680 million, of which 51.8 % are urban population (2023, Asian Development Bank), the region has been witnessing a high rate of urbanization and rapid growth in the economy (GDP growth rate at 4.6 % in July 2024, Asian Development Bank, 2024). The economic development and the increase in urban population lead to higher consumption, prompting greater importation of

commercial products in order to meet the population's need and that of the expanding markets. In addition to importation, the manufacturing industries in Southeast Asia are rapidly expanding in the response to the consumers' demand. The manufacturing industries accounted for 9.2 – 24.9 % of national GDP in 2023 in the region (Asian Development Bank, https://kidb.adb.org, accessed November 2024). Naturally, the increase in production rate leads to higher demand for chemicals used for various industrial purposes. The environment in SEA is thus vulnerable to anthropogenic contaminants, given the rise in importation and fast development in the industrial sectors in the region. To protect the environment, along with their own national regulations, Southeast

<footnote><sup>a</sup> Aix Marseille Univ, CNRS, LCE, Laboratoire Chimie Environnement, FR ECCOREV, ITEM, OCEAN, Aix-en-Provence, France</footnote>

<footnote><sup>b</sup> Department of Water-Environment-Oceanography, University of Science and Technology of Hanoi (USTH), Vietnam Academy of Science and Technology (VAST), 18 Hoang Quoc Viet, Cau Giay, Hanoi 100000, Vietnam</footnote>

<footnote><sup>c</sup> Université de Toulouse, LEGOS (IRD/CNES/CNRS/UT3), 31400 Toulouse, France</footnote>

<footnote>* Corresponding author.</footnote>

<footnote>E-mail address: laure.malleret@univ-amu.fr (L. Malleret).</footnote>
Asian countries have either signed or ratified the Stockholm Convention (Table S1) with the commitment to regulate the use of Persistent Organic Pollutants (POPs) and eliminate their discharge to the environment.

POPs are groups of organic substances with specific physical and chemical properties so that they i) remain highly persistent to degradation, ii) have the capacity for long-range transport in the environment and can iii) accumulate and become toxic in living organisms and human beings. The Annex D of the Stockholm Convention has defined the four criteria when identifying POPs (UNEP, 2023). To be considered persistent, a chemical's half-life must be greater than two months in water and six months in soils. A chemical is regarded as bio-accumulative if its bio-concentration factor or bio-accumulation factor in aquatic species is greater than 5000, or its Kow is greater than 5. The potential for long-range environmental transport refers to the measured levels of the chemical in locations distant from the sources of its release. The transport may occur via air, water or migratory species. And the toxicity includes adverse effects to human health and to the environment. There were, initially, 12 POPs in the Stockholm Convention, nine of which were pesticides, e.g. Aldrin, Chlordane, and Hexachlorobenzene. Throughout the year, more and more organic chemicals have been listed in the Convention, making the total number of 34 POPs (https://www.pops.int/TheConvention/ThePOPs/AllPOPs, assessed November 2024) identified as pesticides (20 POPs) and industrial (18 POPs) or unintentional chemicals (7 POPs). These 34 POPs are classified into three Annexes: Annex A (the production and use of chemicals must be eliminated), Annex B (the production and use of chemicals must be restricted), and Annex C (the unintentional releases of chemicals must be reduced). The majority of POPs are listed as individual contaminants. Among the industrial POPs, a few stand out as they are not just individual compounds but rather consist of a large number of molecules. This is in particular the case for the polychlorinated biphenyls (PCBs) and the polybrominated diphenyl ethers (PBDEs) gathering 209 congeners each; Chlorinated paraffins (CPs) and the three poly- and perfluoroalkyl substances (PFAS), their salts and related compounds, representing several thousands of molecules. If the occurrence, levels and distribution of these POPs were widely described in Europe, America and Japan or China, it is needed to zoom in countries, where the implementation of the Convention is difficult or where there is limited capacity to apply it. Indeed, the differences, both in the phases of economic development and in the history of practices and rulings, mean that the trends of concentrations of POPs measured in developed part of the world cannot be extrapolated to the developing countries (Mbusnum et al., 2020). According to the inventory reports from the Southeast Asian nations, even though there has been no recorded production of these four industrial POPs, they are still present in large quantity in the region due to the contaminated products and materials. It was estimated that there were approximately 30,000 tons of oil containing PCBs imported to Vietnam from the USSR, China and Romania (Kishida et al., 2007). The accumulative amount of PBDE impregnated in vehicles imported in Thailand was estimated to be 1.5 tons (UNEP, 2022). And several countries in the region have imported several tons of PFAS annually in form of firefighting foams and synthetic materials (UNEP, 2014, 2017, 2022).

POPs could be released into the environment from both point (e.g., production, usage, and waste disposal sites) and non-point sources (e.g., runoff and wastewater discharge, atmospheric deposition sources); and may distribute unevenly across environmental compartments, influenced by their physicochemical properties. PCBs, PBDEs and PFAS have been detected in fresh and marine surface water and sediment (Kwan et al., 2014; Lam et al., 2017; Wang & Kelly, 2017), ground- and drinking water (Hongkachok et al., 2017, 2023), and biota from low to high trophic levels (Falahudin et al., 2023; Yudhistira Azis et al., 2021). Water is regarded as a transport vector for contaminants. Industrial wastewater, urban and agricultural runoff, or leachate from waste disposal sites can introduce organic chemicals into the environment via discharge points, often stemming from inadequate treatment efficiency

(Guardian et al., 2020; Lertassavakorn et al., 2021). Besides water, sediment has been considered a sink and a source of POPs in the aquatic environment. On the one hand, the sediment is increasingly considered a sink accumulating contaminants through various sorption mechanisms related to chemical, physical and biological processes (Lampert, 2018). This phenomenon can be further enhanced by the dam-induced trapping of sediment. Dam construction has been proven to increase the retention time of sediment in the reservoirs, thus enhancing the accumulation and pollutant loads (Guo et al., 2023). Ang et al. (2024) reported that there were 1055 dams in the Mekong River basin, designating the region as a potential storage hotspot for POPs and more broadly, organic contaminants. On the other hand, sediment is subjected to disturbance caused by extreme events and bioturbation. In this case, the sediment becomes a source releasing the contaminants back into the water column. Moreover, sediment is a crucial component in the hydro-system, hosting numerous species, e.g., benthic invertebrates. These invertebrates could take up and accumulate the anthropogenic contaminants that are gradually biomagnified in the food chains, along the trophic levels (Bayen et al., 2005; Brandsma et al., 2015). The Southeast Asian countries are well connected via several river systems (e.g., Mekong River, Irrawaddy River and Chao Phraya River) and marine waterways (e.g., East Sea, Strait of Malacca, Gulf of Thailand and Celebes Sea). Given the long-range-transport capability of POPs, the transboundary contamination among Southeast Asian countries is possible. As other actual sources, PCBs, PBDEs or PFAS may be vectored by or released from microplastics (Bouhoum et al., 2019; Yeo et al., 2020; F. Yu et al., 2024), the presence of which has been highly reported in recent years in Southeast Asian countries (Curren et al., 2021; Gabisa et al., 2022; T. T. Nguyen et al., 2024). Extreme weather events (e.g., flooding, seas level rise, and typhoons) driven by climate change impact the remobilization and redistribution of contaminants in the environments (Bolan et al., 2024; Crawford et al., 2022). Southeast Asia is one of the most vulnerable regions to climate change and expected to be exposed to more severe rainfall and higher sea level rise by the middle of the 21st century (Intergovernmental Panel on Climate Change (IPCC), 2023). Therefore, it is necessary to investigate the presence of POPs in Southeast Asian aquatic compartments to better evaluate their potential sources and fate in the ecosystem.

For the last decade, a few review articles on PCBs, PBDEs and PFAS in this region were published. These reviews either generally covered emerging POPs in selected matrices (Bhagat et al., 2024) or focused on specific groups of contaminants at smaller geographical scales (Kaw & Kannan, 2017; Mackintosh et al., 2015). Hence, the present work aims to comprehensively review the scientific discoveries on the contamination of the aquatic environment, i.e. water, sediment, and biota samples, by PCBs, PBDEs, CPs, and PFAS in the 11 Southeast Asian countries, that are hydro-geographically connected and therefore relevant to study together.

This review highlights also research gaps and suggests future directions to make progress in the study of POP analysis and dispersion, particularly in the context of development and climate change in Southeast Asia

## 2. Methodology

This review covers the occurrence of four groups of industrial POPs namely PCBs, PBDE, CPs, and PFAS in three aquatic matrices, i.e., in sediment, waters (fresh and marine surface water, ground water, drinking water) and aquatic biota in SEA. "Occurrence", "environment", "contamination", the names of the groups of organic contaminants and the name of each Southeast Asian country (Fig. 1 and Table S1) were the keywords used as "Web of Science" queries. The review only took into account the research articles and papers written in English. The preliminary results, totaling 1642 items, revealed the following geographical distribution: 9 articles in Brunei, 27 in Cambodia, 152 in Indonesia, 92 in Laos, 318 in Malaysia, 7 in Myanmar, 96 in the Philippines, 396 in
<figure><img src="image_5.png" /><figcaption>**Fig. 1.** Map of the Southeast Asian countries covered by the review, and for each country the number of articles published from 1990 to 2024 and dealing with at least one of the three studied groups of POPs.</figcaption></figure>

Singapore, 228 in Thailand and 317 in Vietnam. A more comprehensive search was necessary to identify articles that investigated at least one group of target compounds in at least one relevant environmental matrix (i.e., water, sediment, and biota) within one or more of the 11 Southeast Asian countries. To filter the results, the authors carefully reviewed the title and abstract of each article. Articles were excluded if they did not study any of the contaminants of interest, focused on unrelated topics (e. g., politics, social welfare) or covered outside the target geographic re- gion. For example, because the acronym “PCBs” is also used to refer to “Printed circuit boards”, several studies related to electronics were initially included in the search results but were later excluded during screening. After this comprehensive search, a smaller set of relevant articles remained. Finally, 6 articles were reported in Cambodia, 17 in Indonesia, 3 in Laos, 14 in Malaysia, 15 in the Philippines, 20 in Singapore, 23 in Thailand and 61 in Vietnam (Fig. 1). No articles were found regarding Brunei, Myanmar, and Timor-Leste. Moreover, no ar- ticles were found investigating the occurrence of CPs in the region in the environmental matrices of interest. As a result, this article reviews the occurrence and levels of three groups of POPs, namely PCBs, PBDEs and PFAS, in eight Southeast Asian countries (i.e. Cambodia, Indonesia, Laos, Malaysia, Philippines, Singapore, Thailand and Vietnam).

The total number of 121 articles (as reported in SI references) were reviewed and compiled (Table S2), covering 35 years from 1990 to the 1st of April 2024. The trend of the number of articles published per year on PCB, PBDE, PFAS occurrence, in Southeast Asia, over the period, is presented on Fig. 2, which clearly shows a real beginning of the research studies from 2003 (enter in force of the Stockholm Convention) and an average of 8 papers per year since. The sum of articles in individual

countries (Fig. 1) was higher than the sum which can be calculated from Fig. 2 because one article might work on samples from multiple countries and could be counted several times. Sixteen review articles were published during this period and excluded from our review, but the data, if it matched our focus, was retrieved from the primary publication.

All the data compiled in the present review are summarized in Table S2. The data used for the graphical presentations were the average values of the reported data in the reviewed articles. The units of data in sediments and water were standardized as ng.g⁻¹ and ng.L⁻¹, respectively

### 3. Polychlorinated biphenyls

#### 3.1. General information

PCBs are a group of aromatic chemicals that consist of a biphenyl structure bound to hydrogen and chlorine atoms. According to the number of hydrogen atoms substituted by chlorine atoms and their position on the biphenyl structure, the International Union of Pure and Applied Chemistry (IUPAC) has identified 209 congeners of PCBs (ATSDR, 2000). Being first synthesized by Oskar Gustav Doebner, a German chemist in 1876 and commercialized since the 1920s (Ngoubeyou et al., 2022), PCBs have been proven to possess several crucial characteristics: having dielectric and electrical insulating prop- erties, being resistant to chemical and thermal decomposition and non-flammable. Therefore, they had been used in electronics and hy- draulic equipment, as plasticizers in paints, pigments, dyes, and rubber products (De & Pereira, 2004; Tue et al., 2013; Zhu et al., 2021). Due to
<figure><img src="image_6.png" /><figcaption>Fig. 2. Number of publications reporting PCBs, PBDEs and/or PFAS concentrations in water, sediment, and aquatic biota samples in eight Southeast Asian countries from 1990 to 2024.</figcaption></figure>

their outstanding properties that were well served for industrial purposes, it was reported that from 1 to 1.5 million tons of PCBs had been produced globally since the 1920s, resulting in 17 million tons of products containing this group of chemicals (Othman et al., 2022). Little information could be found on the production of PCBs in Southeast Asia. PCBs were never produced in Indonesia, Laos or Vietnam (Falahudin et al., 2023; Kishida et al., 2007; Sudaryanto et al., 2011). In other Southeast Asian countries, while domestic production of PCBs has never reported, the widespread importation of PCB-containing equipment has significantly contributed to the regional contamination. Although most countries have implemented import ban on PCBs during the late 1990s to early 2000s, it was not until in 2016 did Indonesia last record the import of waste oil and electronics containing PCBs to the country (UNEP, 2021b). As of 2017, an inventory survey in Vietnam reported the presence of over 1300 tons of PCBs-contaminated oil; along with 26,537 discarded capacitors and 35,948 other pieces of equipment suspected to contain PCBs (UNEP, 2017). Overall, it is estimated that hundreds and thousands tons of PCB-related materials remain across Southeast Asia, either in storage, still in use, or awaiting disposal.

Because of their wide applications, PCBs have been released into the environment through anthropogenic activities and detected in water, soil, sediment, air, aquatic species and human fluids due to their high resistance to degradation, bio-accumulative and persistent nature (Anh et al., 2020; Ikemoto et al., 2008; Minh et al., 2004; Ngoubeyou et al., 2022; Thao et al., 1993). Early studies in the region reported the concentration of PCBs as equivalents to the commercial industrial mixtures of PCBs such as Aroclor 1254, Aroclor 1260 and Kanechlor (Duch Nhan et al., 1998; Viet et al., 2000). Later research used the sum of quantified PCBs congeners, especially 7 indicators PCBs (PCB 28, 52, 101, 118, 138, 153, and 180) suggested by the International Council for the

Exploration of the Sea (7 ICES congeners) and 12 dioxin-like PCBs (PCB 77, 81, 105, 114, 118, 123, 126, 156, 157, 167, 169 and 189) suggested by World Health Organization (WHO).

This chlorinated group of chemicals exhibits many toxicological risks to both organisms and human health when accumulating in the trophic levels such as acting as carcinogens, disrupting reproductive function, causing dermatological adverse effects and developmental deficits, affecting the endocrine systems and hormonal levels (ATSDR, 2014). Given those potential effects on human bodies, the Stockholm Convention on Persistent Organic Pollutants listed, in 2004, PCBs as one of the twelve initial POPs and put them in Annex A (Elimination) suggesting that all member parties ban the production and new uses of PCBs. Furthermore, the Convention expects its members to implement waste management of all liquid waste and PCBs-contaminated products no later than 2028. Despite the efforts of governments, the United Nations Environment Program (UNEP) estimated, in January 2016, that only 17 % (equivalent to 3 million tons) of PCB-containing materials and products have been eliminated resulting in more than 80 % still in the environment on the global scale (UNEP, 2016a). Even though PCBs, as well as organochlorinated pesticides, had been phased out for years and regulated since the start of the Stockholm Convention, traces of them are still found in fresh and coastal waters in European countries (Castro-Jiménez et al., 2008; Kanzari et al., 2012; Liber et al., 2019), even though these countries are ranked as having the capacity to apply the convention in full. This implies that PCBs continue to leach into the environment and pose ecological and epidemiological threats.
## 3.2. Occurrence, concentrations and distribution in the abiotic aquatic compartment

While scientific research on the presence of PCBs in the region dates to the early 1990s, it was not until 2004 when the Stockholm convention included this group of chlorinated chemicals on the list of industrial POPs, and in the late 2000s, when the Southeast Asian countries signed the Convention, that comprehensive monitoring of PCBs in the Asian environment gained more attention (Fig. 3). For these monitoring programs, sediment samples from freshwater, estuarine and marine water bodies received more attention than water samples. Regardless of the ban from Southeast Asian countries since the early 2000s and the efforts of the Convention to identify and manage the PCB-containing products by 2028, the concentration ranges in environmental samples remained quite elevated and showed no sign of decline throughout the studied period (Fig. 3). This trend may imply the continuous release of PCBs to different environmental matrices, especially from the storage sites for PCBs-containing fluids and equipment.

Fig. 4 shows that in the Southeast Asian region, the occurrence of PCBs in environmental aquatic compartments, especially in sediment, was mostly investigated in Vietnam, followed by Singapore and then other countries like Laos, Indonesia, the Philippines, and Thailand. For water samples (Fig. 4a), the PCB levels reported in Singapore were lower when compared to those observed in other countries in the region. In contrast, the PCB concentrations in sediment (Fig. 4b) appeared to be relatively consistent across the investigated nations. Under the time frame of this review, the earliest scientific research was conducted on water samples from the Klang River in Malaysia (Tan et al., 1991). The average concentration of PCBs in seven sampling stations reached up to 1970 ng.L⁻¹. Iwata et al (1994) carried out extensive research to investigate the occurrence of PCBs in water and sediment samples collected from sewage systems, canals, lakes, and rivers located in agricultural, urban, and industrial areas in Vietnam, Thailand Indonesia, and Malaysia. The total concentration of PCB isomers and congeners in sediment samples from Vietnam (n=18), Thailand (n=4) and Indonesia (n=4) could reach up to 630, 520 and 220 ng.g⁻¹, dry weight (dw), respectively. The concentrations in water had a similar pattern to those of sediment with an average value of 2.4 ng.L⁻¹ for Vietnam (n=7), 1.77

for Thailand (n=5), 1.26 for Indonesia (n=3) and 0.45 for Malaysia (n=1).

Metropolitan areas constantly suffer from anthropogenic pollutions. The concentration of PCBs in the urban canals in Vientiane, the capital city of Laos (840,000 inhabitants in 2023) was in the range of 11 – 300 ng.g⁻¹, dw (Sudaryanto et al., 2011). A series of research focused on the densely populated areas of Hanoi, the capital city of Vietnam (4 million urban inhabitants in 2021). A large network of canals and urban rivers, including the Nhue River, To Lich River, Lu River, Set River, and Kim Nguu River received wastewater mainly coming from residential areas in the city. The contamination of PCBs in sediments from these rivers has been documented since the early 2000s with the concentration ranging from 0.3 to 96 ng.g⁻¹, dw (Duc Nhan et al., 2001; Hoai et al., 2010; Hoang, Takahashi, et al., 2021). Furthermore, Kim Nguu River was investigated for the seasonal impact on the occurrence of PCBs in water and sediment samples (Quynh & Toan, 2019; Toan et al., 2020). It was pointed out that PCBs' concentrations were lower in the rainy season than in the dry season, implying that the rising rainfall could explain the dilution of contaminant burden in both water and sediment. Similarly, Minh et al. in 2007 reported the contamination of PCBs in sediment samples collected in urban canals and rivers in Ho Chi Minh City, another major city in Vietnam (7.2 million urban inhabitants in 2021). PCBs' concentrations were more elevated upstream with densely populated areas (average concentration of 81 ng.g⁻¹, dw in city canals and 6.9 ng.g⁻¹, dw in upstream river) and tended to decrease downstream, towards the ocean (average concentration of 0.9 ng.g⁻¹, dw in estuary zone). This conclusion on the spatial distribution in Sai Gon – Dong Nai River was in agreement with the Mekong River (Sudaryanto et al., 2011) and Kali Mas River (Ilyas et al., 2013). Nonetheless, 16 sediment samples and 183 water samples collected in an urbanized watershed in Singapore (5.9 million urban inhabitants in 2023) were reported with relatively lower concentrations of PCBs when compared to big cities in Vietnam (Hanoi and Ho Chi Minh City) or Laos (Vientiane), with an average value of 23.81 ng.g⁻¹, dw and 0.15 ng.L⁻¹ respectively (Wang & Kelly, 2017).

Compared to the highly populated zones above, marine waters appear to be less contaminated. PCBs were detected in several Singaporean marine waters but at lower concentrations than in urban waters,

<figure><img src="image_7.png" /><figcaption>**Fig. 3.** Average PCBs concentrations in freshwater sediment (n=46), estuarine/marine sediment (n=40), fresh water (n=13) and estuarine/marine water (n=10) over the studied period (1990–2024).</figcaption></figure>
<figure><img src="image_8.png" /><figcaption>**Fig. 4.** Reported average PCBs, PBDEs, and PFAS concentration in a) water and b) sediment samples in Southeast Asian countries.</figcaption></figure>

from less than 0.1 to just over 60 ng.L⁻¹ (Basheer et al., 2003; Bayen et al., 2003; Wurl & Obbard, 2005, 2006). Despite its proximity to metropolitan Manila, home to over 14 million inhabitants in 2023, the average concentration of PCBs found in 14 sediment samples from Manila Bay was less than 1 ng.g⁻¹, dw (Carvalho et al., 2009; Villeneuve et al., 2010). Moreover, Yudhistira Azis et al. (2021) detected only PCB 28, 51 and 101 with an average concentration of 0.72 ng.g⁻¹, dw in seven sediment samples collected in the coastal mangrove forest of Indonesia. Even lower concentrations (36 -158 pg.g⁻¹, dw) were reported in surface sediments sampled from the offshore waters in the central region of Vietnam (Manh Tri et al., 2016). However, the case was not the same for Vietnam's coastal areas. When measuring PCBs in water from Cua Dai estuary, central Vietnam, Nguyen et al. (2019) detected high concentrations of 7 indicator PCBs with a maximum value of 1050 ng.L⁻¹. PCBs were also found at high concentrations in sediment collected from the estuaries of Cua Hoi, Nhat Le and Lang Co Lagoon (the average values were 820, 799 and 121 ng.g⁻¹, dw, respectively) in the same region (Tham et al., 2019).

The PCBs concentrations in freshwater samples reported in Southeast Asia satisfied the water quality guideline (14 ng.L⁻¹) proposed by the United States Environmental Protection Agency (US-EPA, 2024b). But

the levels of PCBs in marine waters were higher than the US-EPA standard for seawater, which is set at 3 ng.L⁻¹. Some countries in the region also have certain regulations regarding PCBs in water. DENR Administrative Order 2016-08 of the Philippines government defined the classification of fresh water supplies and set the limit of PCBs in water for public use to be less than 100 ng.L⁻¹. The concentration of PCBs has to be less than 500 ng.L⁻¹ in drinking water in Cambodia and in surface water in Vietnam (regulations listed in Table S1).

### 3.3. Occurrence and concentrations in the aquatic trophic chain

Mollusks, i.e., filter feeders, are highly capable of accumulating contaminants in their tissues. Bayen et al. (2007) designed an experiment in the marine area of Singapore investigating the accumulation rate of oysters in an environment contaminated with PCBs, PBDEs, and DDT and chlordane pesticides in 2007. The oysters were cultivated for 230 days, and the oyster samples were analyzed for PCBs on the 0th, 126th and 230th day. Oysters raised in the uncontaminated sites witnessed better growth and higher tissue yield and lower levels of organic contaminants than those in contaminated sites. This finding signaled threats to the cultivation of oysters and other species in general, and it
also represented the threat to humans when consuming contaminated aquacultural products.

The Asian Mussel Watch Program revealed an elevated level of PCBs in mussels collected in the urban and industrialized zones, reaching up to 1400 and 1900 ng.g⁻¹, lipid weight in samples from Indonesia and the Philippines, respectively (Ramu et al., 2007).

Additionally, signs of bioaccumulation and biomagnification were observed according to the detection of PCBs organisms of higher trophic levels than the filter feeders (Table 1), for example fish (Duc et al., 2024; Wang & Kelly, 2018); green turtle eggs (van de Merwe et al., 2009), and

<table><caption>**Table 1**
Concentrations of PCBs (ng.g⁻¹) measured in aquatic biota samples of the Southeast Asian region tabulated from lower to higher trophic levels.</caption><thead><tr><th>Samples</th><th>Countries</th><th>Average concentration</th><th>Analytes</th><th>References</th></tr></thead><tbody><tr><td>Plankton (Planktothricoides spp and Synechococcus)</td><td>Urban catchment in Singapore</td><td>826.5 ng.g⁻¹, lipid weight</td><td>28 PCBs</td><td>(Wang & Kelly, 2018)</td></tr><tr><td>Apple snail (Ampullariidae)</td><td></td><td>420.6 ng.g⁻¹, lipid weight</td><td></td><td></td></tr><tr><td>Clam (Meretrix lusoriameretrix)</td><td>Coastal zone, Northern Vietnam</td><td>7.88 ng.g⁻¹, dry weight</td><td>6 PCBs</td><td>(Duc Nhan et al., 1999)</td></tr><tr><td>Green mussels (Perna viridis) and blue mussels (Mytilus edulis)</td><td>Vietnam</td><td>76.32 ng.g⁻¹, lipid weight</td><td>62 PCBs</td><td>(Ramu et al., 2007)</td></tr><tr><td>Oysters (Crassostrea gigas)</td><td>Cambodia</td><td>250 ng.g⁻¹, lipid weight</td><td></td><td></td></tr><tr><td></td><td>Indonesia</td><td>792.5 ng.g⁻¹, lipid weight</td><td></td><td></td></tr><tr><td></td><td>Malaysia</td><td>88.8 ng.g⁻¹, lipid weight</td><td></td><td></td></tr><tr><td></td><td>The Philippines</td><td>1500 ng.g⁻¹, lipid weight</td><td></td><td></td></tr><tr><td></td><td>Manila Bay, the Philippines</td><td>19.89 ng.g⁻¹, dry weight</td><td>13 PCBs</td><td>(Carvalho, Villeneuve, Cattini, Tolosa, et al., 2009)</td></tr><tr><td>Clams</td><td>Mekong River</td><td>6.98 ng.g⁻¹, dry weight</td><td>13 PCBs</td><td>(Carvalho, Villeneuve, Cattini, Thuan, et al., 2009)</td></tr><tr><td>Skipjack Tuna (Katsuwonus pelamis)</td><td>The Philippines</td><td>190 ng.g⁻¹, lipid weight</td><td>117 PCBs</td><td>(Ueno et al., 2003)</td></tr><tr><td>Peacock bass (Cichla orinocensis)</td><td>Urban catchment in Singapore</td><td>50 ng.g⁻¹, lipid weight</td><td></td><td></td></tr><tr><td>Tilapia (Oreochromis mossambicus)</td><td></td><td>3309 ng.g⁻¹, lipid weight</td><td>28 PCBs</td><td>(Wang & Kelly, 2018)</td></tr><tr><td>6 species of fish</td><td>Lagoon, Central Vietnam</td><td>1238.2 ng.g⁻¹, lipid weight</td><td></td><td></td></tr><tr><td>Various species of marine fish</td><td>Central-northern Vietnam</td><td>124 ng.g⁻¹, lipid weight</td><td>7 PCBs</td><td>(T. A. M. Tran et al., 2019)</td></tr><tr><td>Green turtle (Chelonia mydas) eggs</td><td>Malaysia</td><td>0.47 ng.g⁻¹, lipid weight</td><td>83 PCBs</td><td>(Duc et al., 2024)</td></tr><tr><td>Cetaceans</td><td>The Philippines</td><td>3600 ng.g⁻¹, lipid weight</td><td>62 PCBs</td><td>(van de Merwe et al., 2009)</td></tr><tr><td>Short-finned pilot whale (Globicephala macrorhynchus)</td><td>Indonesia</td><td>237.9 ng.g⁻¹, lipid weight</td><td>209 PCBs</td><td>(Kajiwara et al., 2006) (Falahudin et al., 2023)</td></tr></tbody></table>

whale and other cetaceans (Falahudin et al., 2023; Kajiwara et al., 2006). Monirith et al. (1999) reported the PCBs daily intake of Cam-bodians from fish to be 14 ng.person⁻¹.day⁻¹ in 1999, which was significantly lower than the acceptable daily intake set Food and Agri-culture Organization (FAO) and WHO in 1986 (60,000 ng.person⁻¹. day⁻¹). In 2003, WHO set a new tolerable daily intake of PBCs at 20 ng. kg⁻¹ body weight.day⁻¹ (WHO, 2003). Villeneuve et al. (2010) est-mated the intake of 8.5 ng PCBs per kg body weight per day through the consumption of oysters by the Manila population in the Philippines. The consumption of marine fish in Vietnam would result in the intake of 3.04 to 6.92 ng PCBs per kg body weight per day, as calculated by Tran-Lam et al. (2023). The levels of PCBs in organisms from lower trophic levels (mussels, oysters, fish) do not pose significant health risks, as the est-mated intake through their consumption remains below the acceptable daily intake thresholds (Monirith et al., 2000; Tran-Lam et al., 2023; Villeneuve et al., 2010). However, van de Merwe et al. (2009) warned that the consumption of a single turtle egg could result in an intake of coplanar PCBs (0.6 ng.kg body weight⁻¹.day⁻¹) up to 300 times higher than the acceptable daily intake (ADI) established by the FAO/WHO in 2007 for coplanar PCBs (0.002 ng.kg body weight⁻¹.day⁻¹). This highlights a significant potential health risk associated with the con- sumption of contaminated products from wild animals, which is believed to have medicinal qualities by the local people in Malaysia. This would imply the growing concerning health risk with higher tro- phic levels, as biomagnification can lead to increased concentrations of PCBs in top predators exposed to human through consumption.

### 3.4. General profile of PCBs in environmental samples

The seven indicator PCBs (PCB 28, 52, 101, 118, 138, 158, and 180) have been widely detected in water, sediment and biota samples in the region. These congeners are often chosen as target analytes due to their presence in the technical mixture used in various industrial applications. Correlation tests and cluster analysis were performed to determine the relation between the congeners detected in samples and the components of the historically used commercial mixtures. Hoang et al. (2021) indi-cated that the profile of PCBs in sediment samples highly related to those in the commercial mixtures such as Sovol, Aroclor 1254, and Kanechlor 500. The pattern of Aroclor PCBs (PCB 101, 118, 153, and 138) was also found to be predominant in aquatic organisms in highly urbanized catchment in Singapore (Wang & Kelly, 2018). As shown in Fig. 3, despite the implementation of the Stockholm Convention and the ban on importation of PCBs in the Southeast Asian nations, the concentrations of PCBs in aquatic compartments show no decreasing trend. Given the quantity of PCBs inventoried in each country, the remaining stock of this chlorinated POPs remains significant and continues to be released into the environment.

## 4. Polybrominated diphenyl ethers

### 4.1. General information

Polybrominated Diphenyl Ethers (PBDEs) are a group of organic chemicals consisting of a diphenyl ether structure bound to bromine atoms. Similarly to PCBs, depending on the numbers of bromine atoms and their positions on the aromatic rings, IUPAC has identified 209 congeners categorized into 10 groups from mono- to deca-bromodiphenyl ethers (ATSDR, 2017). There had been about 1.5 million tons of PBDEs produced globally since the 1970s (Motamedi et al., 2022). Being highly resistant to physical and chemical degradation, PBDEs had been widely used as flame retardants in various products such as electronics, furniture, and textiles (Costa & Giordano, 2014; Tue et al., 2013). Three major commercialized PBDE mixtures are pentaBDE (composed of BDE 47, 99 and 100), octaBDE (BDE-183 and other octa-congeners) and decaBDE (mostly composed of BDE-209) (Kefeni et al., 2011). By 2005, the historical productions of penta-, octa-, and
decaBDE mixtures were approximately estimated to be 0.175, 0.13, and 1.1 million tons, respectively (Abbasi et al., 2019; T. Meng et al., 2021). Similarly to PCBs, inventory efforts on PBDEs have been carried out the Southeast Asian countries and reported under the framework of the Stockholm Convention. While no domestic production was recorded in these countries, the importation of electronics and electrical equipment (EEE) has emerged as a significant source of PBDE contamination. Laos reported in 2016 a stockpile of approximately 5.8 tons of commercial octa-BDE associated with imported household EEE (UNEP, 2016b). In Thailand, an estimated 920 to 1500 tons commercial deca-BDE were identified in 2022 in imported television sets, along with an additional 3 tons of deca-BDE found in flame-retardants fabrics (UNEP, 2022). In addition to EEE, imported vehicles have also been identified as potential sources for PBDE contamination. In 2014, the Philippines recorded 2.2 tons of commercial penta-BDE on imported vehicles as well as additional 2 tons found in cars, trucks, and buses that are classified as end-of-life vehicles (UNEP, 2014). In parallel, in 2017, Vietnam reported more than 6 tons of PBDEs found in polymer components of vehicles that were still in use (UNEP, 2017).

These flame retardants are additive compounds, or in other words, they are only physically bonded to the products. Consequently, they can easily escape and leach into the environment (Costa & Giordano, 2014; Darnerud et al., 2001). Similarly to PCBs, PBDEs have been shown to exhibit severe toxicity towards humans; being endocrine disruptors and carcinogens, causing DNA damage and inducing neurotoxicity (Couderc et al., 2016; Motamedi et al., 2022; Renzelli et al., 2023). Because of the potential health impact on humans, the US and Europe banned the production of these brominated chemicals in the 2000s (Abbasi et al., 2019). According to Directive 2013/39/EU under the European Water Framework Directive (WFD), the maximum allowable concentration for six PBDEs (BDE 28, 47, 99, 100, 153, and 154) was 140 ng.L⁻¹ for inland surface waters (lakes, rivers and other artificial and heavily modified water bodies). In addition, the Stockholm Convention listed penta- and octaBDE mixtures in Annex A (Elimination) in 2009. And 8 years later in 2017, the Convention also added the decaBDE mixture to Annex A, banning its production and use, with specific exemptions for certain applications (e.g. textile productions requiring anti-flammable characteristics, additives in plastic housings and parts at concentrations lower

than 10 % by weight of the part, and certain vehicles and aircrafts, Decision UNEP/POPS/COP.8/10, https://chm.pops.int/Convention/COP/COPDecisions/tabid/208/Default.aspx, accessed March 2025). Besides the allowable limit of PBDEs content in electrical and electric products (0.1 % by weight) set by Singaporean and Vietnamese governments, no other regulations on PBDEs-containing products were documented in other Southeast Asian nations (Hoang et al., 2021).

## 4.2. Occurrence, concentrations and distribution in the abiotic aquatic compartment

PBDEs have received more attention after they were identified as POPs by the Stockholm Convention in 2009 for tetra- and pentaBDE and in 2017 for decaBDE. Throughout the years, PBDEs have been progressively searched for and detected in environmental samples with a wide concentration range in sediment and water (Fig. 5). Quite similarly to PCBs, PBDE levels in sediment remain highly variable and show no clear signs of decline, despite existing regulatory measures. This persistent presence suggests that regulatory actions may not have made considerable impact, possibly due to the continued release from existing sources and the nature of high resistance to degradation of these compounds. For water, the PBDE levels appeared to be decreasing toward the late 2010s and early 2020s. However, the limited data on the levels of PBDE in water samples prevents making a definitive conclusion on the overall temporal trend.

Generally, the reported data on studies in this region was the sum of different PBDEs congeners detected in environmental samples. As the three major mixtures consist mostly of BDE-28, -47, -99, -100, -153, -154, -183 and -209 (Salvadó et al., 2012), these eight representative congeners are frequently measured for environmental monitoring.

Being hydrophobic with low water solubility and high n-octanol-water partition coefficient (4.3–9.9), PBDEs preferentially partition into particulate matter and gradually accumulate in sediment (Darnerud et al., 2001; Kwan et al., 2013). Therefore, it might explain why the occurrence of PBDE is better documented in sediment than in water for Southeast Asian countries (Fig. 4). High urbanization and industrialization rates might lead to higher production of wastes, especially electronic waste, or e-waste, which contribute significantly to the presence

<figure><img src="image_9.png" /><figcaption>**Fig. 5.** Average PBDE concentrations in freshwater sediment (n=35), estuarine/marine sediment (n=16), fresh water (n=10) and estuarine/marine water (n=3) over the studied period (1990–2024).</figcaption></figure>
of PBDEs in the environment. It was estimated that in 2019, Southeast Asian countries had generated three and a half megaton e-wastes (Forti et al., 2020). Although recycling e-wastes is considered a sound strategy for disposal and may bring economic benefits (Matsukami et al., 2015, 2022), the recycling sites where e-wastes are gathered could become significant sources of PBDEs released into the environment. Sediments collected from drainage canals in Trieu Khuc e-waste recycling village (Vietnam) were found to be contaminated with the eight PBDEs (BDE 28, 47, 99, 100, 153, 154, 183 and 209), whose average sum concentration reached up to 434 ng.g⁻¹, dw (Anh et al., 2017). The authors also reported a contamination by the eight congeners not only in sediment but also in fish found in nearby ponds and canals of Bui Dau recycling village (Vietnam). More alarmingly, Matsukami et al (2005), who worked on the samples from the Bui Dau e-waste recycling village, recorded an increase in the concentration of PBDEs in sediment throughout a 3-year period. This highlights that even though PBDEs are no longer produced, the risk of environmental contamination remains high unless efficient treatment processes of e-waste are developed and followed to reduce the accidental release of PBDEs into the environment.

The screening of PBDEs in water was less common in the studied countries. Kwan et al. in 2013 conducted a screening of 46 PBDEs in leachates from municipal waste dumping sites in seven countries in the region. The leachates from dumping sites in the industrialized city of Bangkok (Thailand) showed extremely high concentrations, reaching up to 133,000 ng.L⁻¹. The values were one to three orders of magnitude lower for other less industrialized countries such as Laos, Cambodia and the Philippines. On the contrary, Wang & Kelly (2017) reported no further inputs of PBDEs to the environment, as they detected very low concentrations in water samples (average values of 0.046 and 0.057 ng. L⁻¹ in open water bodies (n=32) and in catchment channels (n=24), respectively) collected in an urban watershed in Singapore, which stands as the only developed country in Southeast Asia. This finding was consistent with the clear trend shown in Figure 4 where PBDE levels in both water and sediment samples from Singapore were significantly lower than those reported in other developing Southeast Asian countries.

### 4.3. Occurrence and concentrations in the aquatic trophic chain

Having a lipophilic nature, PBDEs can gradually accumulate into living organisms (Darnerud et al., 2001; Falahudin et al., 2022). The earliest studies on the occurrence of PBDEs investigated, in the early 2000s, their presence in mussels (8.85 ng.g⁻¹, dw, Bayen et al., 2003) in skipjack tunas (14 ng.g⁻¹, lipid weight, Ueno et al., 2004) and in freshwater fish captured near dumping sites in the Mekong river delta (36 ng.g⁻¹, lipid weight, Hung Minh et al., 2006). Later studies alerted on the risk of bioaccumulation and biomagnification of PBDEs in aquatic organisms from low trophic levels (plankton, barnacles, mussels) to higher ones (turtles, dolphins) (Table 2). The marine traffic and the industrial activities in the coastal areas could be responsible for the contamination of PBDEs in marine organisms (Ramu et al., 2007). US-EPA has derived the oral reference doses (RfD) for PBDEs as follows: 7000 ng.body weight⁻¹.day⁻¹ for decaBDE (BDE 209), 3000 ng.body weight⁻¹.day⁻¹ for octaBDE, 2000 ng.body weight⁻¹.day⁻¹ for pentaBDE, 100 ng.body weight⁻¹.day⁻¹ for both BDE 47 and 99, and 200 ng.body weight⁻¹.day⁻¹ for BDE 153 (ATSDR, 2017). People living in coastal areas in northern Vietnam could up take from 9.06 to 33.5 ng of 8 PBDEs.body weight⁻¹.day⁻¹ via fish consumption (BDE 28, 47, 99, 100, 153, 154, 183, and 209, Duc et al., 2024). Furthermore, elevated levels of PBDEs found in fish caught in the waterbodies near e-waste recycling sites in Vietnam (Anh et al., 2017), once again, emphasized the significant source of contaminants due to improper handling of PBDEs-containing e-waste and called for the attention of authorities on the recycling and disposal activities. The daily intake of eight PBDE congeners (BDE 28, 47, 99, 100, 153, 154, 183, and 209) among residents of e-waste recycling sites was 154 ng.person⁻¹.day⁻¹ for children

<caption>**Table 2**</caption>

Concentrations of PBDEs (ng.g⁻¹) measured in aquatic biota samples of the Southeast Asian region tabulated from lower to higher trophic levels.

<table><thead><tr><th>Sample</th><th>Countries</th><th>Average concentration</th><th>Analytes</th><th>References</th></tr></thead><tbody><tr><td>Green mussels (Perna viridis)</td><td>Singapore</td><td>8.85 ng.g⁻¹, dry weight</td><td>7 PBDEs</td><td>(Bayen et al., 2003)</td></tr><tr><td>Mussels (Perna viridis, Mytilus edulis)</td><td>Cambodia</td><td>3.81 ng.g⁻¹, lipid weight</td><td>9 PBDEs</td><td>(Ramu et al., 2007)</td></tr><tr><td></td><td>Indonesia</td><td>13.2 ng.g⁻¹, lipid weight</td><td></td><td></td></tr><tr><td></td><td>Malaysia</td><td>6.7 ng.g⁻¹, lipid weight</td><td></td><td></td></tr><tr><td></td><td>The Philippines</td><td>103.8 ng.g⁻¹, lipid weight</td><td></td><td></td></tr><tr><td></td><td>Vietnam</td><td>2 ng.g⁻¹, lipid weight</td><td></td><td></td></tr><tr><td>Barnacles</td><td></td><td>51.2 ng.g⁻¹, lipid weight</td><td>44 PBDEs</td><td>(Vaezzadeh et al., 2021)</td></tr><tr><td>Green mussels</td><td></td><td>60.5 ng.g⁻¹, lipid weight</td><td></td><td></td></tr><tr><td>Green mussels (Perna viridis)</td><td>Vietnam</td><td>8.63 ng.g⁻¹, dry weight</td><td>5 PBDEs</td><td>(D. T. Nguyen et al., 2024)</td></tr><tr><td>Catfish (Pangasianodon hypophthalmus)</td><td>Mekong river delta, Vietnam</td><td>2.7 ng.g⁻¹, lipid weight</td><td>6 PBDEs</td><td>(Hung Minh et al., 2006)</td></tr><tr><td>Three species of carps</td><td>Vietnam</td><td>160 – 1380 ng. g⁻¹, lipid weight</td><td>8 PBDEs</td><td>(Anh et al., 2017)</td></tr><tr><td>Various freshwater species</td><td>Urban catching in Singapore</td><td>48.4 – 474.5 ng. g⁻¹, lipid weight</td><td>7 PBDEs</td><td>(Wang & Kelly, 2018)</td></tr><tr><td>Marine fish</td><td>Vietnam</td><td>67.7 ng.g⁻¹, lipid weight</td><td>8 PBDEs</td><td>(Duc et al., 2024)</td></tr><tr><td>Skipjack Tuna (Katsuwonus pelamis)</td><td>Philippines</td><td>14 ng.g⁻¹, lipid weight</td><td>11 PBDEs</td><td>(Ueno et al., 2004)</td></tr><tr><td>Green turtle (Chelonia mydas) eggs</td><td>Malaysia</td><td>21.4 pg.g⁻¹, wet weight</td><td>19 PBDEs</td><td>(van de Merwe et al., 2009)</td></tr><tr><td>Spinner dolphins (Stenella longirostris)</td><td>Philippines</td><td>36 ng.g⁻¹, lipid weight</td><td>10 PBDE</td><td>(Kajiwara et al., 2006)</td></tr></tbody></table>

and 730 ng.person⁻¹.day⁻¹ for adults. BDE 209 contributed to more than 80 % of total daily PBDEs intake in both groups.

### 4.4. General profile of PBDEs in environmental samples

Overall, the PBDE profiles in samples from aquatic compartment in Southeast Asia saw a predominance of congeners that are the most prevalent in the technical mixtures (i.e BDE 47, 99, 100, 153, 154, 183, and especially BDE 209). BDE 209 is the main component of the commercial deca-BDE mixture, which accounted for nearly 80 % of the historical production of PBDE mixture. Consequently, the widespread presence of imported products contaminated with PBDEs has significantly contributed to the environmental burden of these brominated POPs in the region. Furthermore, the detection of nona-BDE congeners (e.g., BDE 206, 207, and 208) in sediment, leachate, and biota samples has prompted further discussion on the debromination of PBDEs (Ilyas et al., 2011; Kwan et al., 2013). Higher-brominated PBDEs, particularly BDE 209, could be transformed under anaerobic conditions or through metabolic processes in organisms, leading to the formation of lower-brominated PBDEs (Ilyas et al., 2013; Wang & Kelly, 2017). This debromination process may explain the presence of certain nona-BDE congeners in environmental samples, even though these are not commonly found in technical BDE mixtures.
# 5. Poly- and Perfluoroalkyl substances

## 5.1. General information

PFAS are a group of synthetic chemicals including carbon atoms and fluorine atoms covalently bonded to the alkyl chain (Buck et al., 2011) and different functional groups. It is estimated that over 8000 chemicals of known structures have been identified as PFAS (Evich et al., 2022). Because PFAS are highly resistant to extreme heat and repellent to oil and water, they are used in a variety of consumer products, for example in cookware, food packaging, paint, textile, and aqueous firefighting foam (Buck et al., 2011; Phong Vo et al., 2020; Schmidt et al., 2019).

Several countries in Southeast Asia have conducted inventory work for Perfluorooctane sulfonic acid (PFOS). Quite similarly to the chlorinated and brominated POPs, PFOS was not produced in Southeast Asia but instead introduced into the region through the importation of finished products. Laos, until 2016, imported 366 tons of PFOS used in synthetic materials whereas the Philippines reported over 500 tons of PFOS incorporated in imported articles (i.e. synthetic carpets, fire resistant textiles, chrome metal-plating pigments and food packaging) only in 5-year period from 2008 to 2012 (UNEP, 2016b, 2022). The presence of PFOS in firefighting foams is significant. In 2019, Thailand was estimated to have between 3.7 and 5.5 tons of PFOS contained in 925,000 liters of firefighting foams held in stock. The Vietnamese inventory report in 2017 suggested the importation between 10 and 15 tons of PFOS in firefighting foams during the period from 1998 to 2013. Annual PFOS imports for other applications were comparable in the same time period, ranging from 0.11 to 3.45 tons for textiles and upholstery, and from 0.2 to 4.8 tons for paper and paperboard products. (UNEP, 2017).

Because of their wide applications, PFAS have become ubiquitous in the environment.

Toxic effects of PFAS are mostly attributed to endocrine disruption mechanisms leading to health outcomes (Braun, 2017) including epigenetic changes and a number of autoimmune diseases (e.g., leukaemia, breast cancer, diabetes, multiple sclerosis) and other health problems (e.g., early puberty, reduced fertility (S. Kim et al., 2021). PFAS also exhibits toxicity, e.g., immunotoxic, dyslipidemic, neurotoxic effects (Bonato et al., 2020; Fenton et al., 2021). Of note, PFAS have been found in blood samples of almost all human population (Fenton et al., 2021), and induce oxidative stress, autophagy as well as apoptosis at cell level in human (Zeng et al., 2021). Bioaccumulation have been highlighted for many organisms, including both PFAAs and few precursors (Alfaro Garcia et al., 2022; Evich et al., 2022; Herzke et al., 2023; Jouanneau et al., 2020; Macorps et al., 2022). PFAS biomagnification has also been evidenced for longer chain Perfluoroalkyl acids (PFAAs), whereas several precursors were not found to be magnified along trophic levels, due to potential metabolization (Simonnet-Laprade et al., 2019). Cell toxicity and endocrine disruption has also been shown for aquatic species (Hu et al., 2003; Shi et al., 2019). Another issue is the apparent multigenerational effects of PFAAs exposure (Li et al., 2020). Remarkably, most studies focus on PFAAs effects, and the literature on precursors effects is still scarce (Macorps et al., 2022; McDonough et al., 2022; Panieri et al., 2022). Moreover, PFAS occur as a mixture of PFAAs and precursors in the environment, and these mixture effects have even less been investigated (Dickman & Aga, 2022).

Perfluorooctanoic acid (PFOA) and PFOS are the most regulated PFAS. The Stockholm Convention has listed PFOS in 2009 in Annex B (Restriction) and PFOA, in 2019, in Annex A (Elimination). Moreover, in 2019, the Convention banned the production of PFOS, its salts and perfluorooctane sulfonyl fluoride; and set specific exemptions on their usage on metal plating and fire-fighting foam (Decision UNEP/POPS/COP.9/4, https://chm.pops.int/Convention/COP/COPDecisions/tabid/208/Default.aspx, accessed March 2025). Perfluorohexane sulfonic acid (PFHxS) and its salts were added into the same Annex as PFOA in 2022. Furthermore, the European Commission, in Directive 2013/39/

EU, set the annual average environmental quality standard (AA-EQS) for PFOS and its derivatives at 0.65 and 0.13 ng L⁻¹ for inland and other surface waters, respectively. Regulatory agencies worldwide have established restrictions for PFAS levels in drinking water. The Drinking Water Directive (DWD-EU) 2020/2184 of the European Parliament introduced a limit for the sum concentration of 20 PFAS (10 perfluoroalkyl carboxylic acids and 10 perfluoroalkyl sulfonic acids) at 100 ng.L⁻¹. More recently in April 2024, the US-EPA announced the National Primary Drinking Water Regulation (NPDWR) for several PFAS, three of which are listed in the Stockholm Convention (PFOA, PFOS and PFHxS). The NPDWR indicates the limits for PFOA and PFOS each at 4 ng.L⁻¹ and for PFHxS at 10 ng.L⁻¹ in drinking water (US-EPA, 2024a).

## 5.2. An emerging concern in South-East Asia

Similarly to PCBs and PBDEs, the 2010s witnessed an increase in PFAS research articles conducted in Southeast Asia (Figure S1). While only one article on PFAS could be found before PFOS was listed in the Stockholm Convention, 18 new articles were found 10 years after the regulations on PFOS and 15 more were published during a four-year period after the listing of PFOA. The number of PFAS research in Southeast Asia is comparable to that of Japan (27 articles) and Korea (37 articles) in East Asia, but it is approximately 5 times lower than in China (163 articles) (Tang et al., 2023).

Fig. 6 presents the data on PFAS in water and sediment samples in Southeast Asia. The observed concentrations span a wide range, reflecting the variability across sites and sample types. Despite the implementation of PFAS regulations, there is no evident decreasing trend in environmental concentrations. This may be explained by the fact that monitoring activities in the region only began after the introduction of these regulations. Besides the regulations established by the Stockholm Convention, the Southeast Asian nations have not yet introduced their own national limits for PFAS concentration in various matrices. Efforts to establish comprehensive inventory and identify the PFAS occurrence are relatively recent, which may be limitations for the investigations of long-term trends.

## 5.3. Occurrence and concentrations in waters and edible aquatic species

The studies on PFAS in the environment were only conducted in the Philippines, Singapore, Thailand, Vietnam, and Malaysia and mostly focused on the water samples (Table 3 and Figure 4). The early 2010s marked the pioneering studies on PFAS in the region. The Langat River in Malaysia was reported with important levels of PFOA and PFOS (respective maximum concentrations at 5940 and 43,500 ng.L⁻¹) at sampling stations of a landfill area and a creational camping site. The results were coherent with the detection of PFOA and PFOS in the leachate samples collected in landfills in Hanoi (J. W. Kim et al., 2013; Ngoc et al., 2021) and in Singapore (Yin et al., 2017). Therefore, it is of importance to apply proper and efficient treatment methods for leachate, and wastewater in general, to prevent the dissemination of PFAS through water transport. However, not only might the conventional methods in wastewater treatment plants be ineffective in completely removing PFAS, but the total concentration of PFAS in effluents may also increase, likely due to the degradation of precursors forming new PFAS, particularly PFOA and PFOS (Kunacheva et al., 2010, 2011). On the contrary, Tabtong et al. (2015) concluded on the removal rate of 86 % of PFAAs when advanced treatment methods using granular activated carbon filter and reverse osmosis are applied.

The presence of PFAS was recorded in sediment samples collected in urban water bodies in Singapore (T. V. Nguyen et al., 2016; V. T. Nguyen et al., 2012) and in large cities in Vietnam (Babut et al., 2019; Ngoc et al., 2021; H. Le Tran et al., 2022) with the average concentrations ranging from less than 1 up to 15 ng.g⁻¹, dry weight (Figure 4).

More alarmingly, PFAS have been detected in drinking water, bottled water, and biota samples (Table 3 and 4). The presence of PFAS in
<figure><img src="image_10.png" /><figcaption>Fig. 6. Average PFAS concentrations in freshwater sediment (n=13), estuarine/marine sediment (n=2), fresh water (n=70) over the studied period (1990–2024).</figcaption></figure>

<caption>**Table 3**</caption>

Concentrations of PFAS (ng.L⁻¹) measured in tap, ground, drinking and bottled waters of the Southeast Asian region.

<table><thead><tr><th>Country</th><th>Sample type</th><th>Concentration (ng.L<sup>-1</sup>)</th><th>Analytes</th><th>Reference</th></tr></thead><tbody><tr><td rowspan="2">Philippines</td><td>Drinking water</td><td>9.08 – 11.63</td><td>12 PFAS</td><td>(Guardian et al., 2020)</td></tr><tr><td>Thailand</td><td>Tap water<br>Tap water<br>Bottled water<br>Tap water<br>Bottled water<br>Drinking water<br>Tap water<br>Bottled water<br>Groundwater</td><td>10*<br>6.03 *<br>11.64 *<br>0.4*<br>0.5*<br>7.16 – 59.49<br>54.2 **<br>0.45<br>0.62<br>13.4 *</td><td>8 PFAS<br>5 PFAS detected<br>• PFOS<br>12 PFAS<br>PFOS<br>PFOS<br>PFOA<br>6 PFAS detected<br>7 PFAS detected<br>Groundwater<br>Tap water<br>Well water<br>Drinking water</td><td>(Kunacheva et al., 2009)<br>(Kunacheva et al., 2010)<br>(Boontanon et al., 2013)<br>(Guardian et al., 2020)<br>(Lertassavakorn et al., 2021)<br>(Hongkachok et al., 2023)<br>(Duong et al., 2015)<br>(Lam et al., 2017)<br>13 PFAS<br>PFOA<br>PFHpA<br>PFNA</td></tr><tr><td>Vietnam</td><td>Groundwater</td><td>0.54–5.56</td><td></td><td>(Tröger et al., 2021)</td></tr></tbody></table>

bottled water in Thailand highlighted the inefficiency of the treatment methods (Kunacheva et al., 2010; Lertassavakorn et al., 2021). This emphasizes the potential exposure risk for humans to these organic contaminants. Other than contact with PFAS-containing products (for example, cookware and food packaging), the potential consumption of contaminated water or food indicates a direct exposure route via the digestive system, thus making it significantly dangerous for human health. The levels of PFAS in drinking water samples collected in the Philippines, Thailand and Vietnam were well below European and

American limits (Table 3). Table 4 signals the accumulation of PFAS in aquatic organisms, especially species usually served as food. The European Food Safety Authority established the tolerable weekly intake (TWI) of four PFAS (PFOA, PFNA, PFHxS, and PFOS) to be 4.4 ng.kg body weight⁻¹. week⁻¹ (Schrenk et al., 2020). Murakami et al. (2011) reported the daily intake of both PFOS and PFOA to be 0.51 ng.kg body weight⁻¹. day⁻¹ for population in some Asian countries, including Malaysia and Vietnam. The maximum weekly intake of PFOA, PFNA, PFHxS, and PFOS for population in the Red River delta (Vietnam) was calculated to be 3.7 ng.kg body weight⁻¹. week⁻¹, which was still lower than the European limit (Hoa et al., 2022). On the other hand, study

<caption>**Table 4**</caption>

Concentrations of PFAS (ng.g⁻¹) measured in aquatic biota samples of the Southeast Asian region.

<table><thead><tr><th>Samples</th><th>Countries</th><th>Concentration (ng.g<sup>-1</sup>, wet weight)</th><th>Analytes</th><th>References</th></tr></thead><tbody><tr><td>Snakehead (scientific name not identified)</td><td>Malay (n=2)<br>Vietnam (n=4)</td><td>Liver: 4.6 *<br>Muscle: 0.4 *<br>Liver: 23.18 *<br>Muscle: 0.33 *</td><td>10 PFAS</td><td>(Murakami et al., 2011)</td></tr><tr><td>Various aquatic species</td><td>Vietnam</td><td>0.33 - 2.81</td><td>13 PFAS</td><td>(Lam et al., 2017)</td></tr><tr><td>Four common food fish species (Hypophthalmichthys nobilis, Cyprinus carpio, Labeo rohita, and Tilapia spp.)</td><td>Vietnam</td><td>Blood: 5.2 – 29 ng.mL<sup>-1</sup><br>Liver: 2.7 – 6.6<br>Muscle: 0.51 – 2.6</td><td>17 PFAS</td><td>(Hoa et al., 2022)</td></tr><tr><td>Freshwater fish</td><td>Vietnam</td><td>0.08 – 8.06</td><td>9 PFAS</td><td>(Vi et al., 2022)</td></tr><tr><td>Marine fish</td><td>Vietnam</td><td>0.22 – 3.62</td><td></td><td></td></tr><tr><td>Various marine species</td><td>Thailand</td><td>&lt; LOD – 6.724</td><td>PFOS, PFOA</td><td>(Lertassavakorn et al., 2021)</td></tr><tr><td>Marine fish</td><td>Vietnam</td><td>9 – 28.6</td><td>23 PFAS</td><td>(Vu-Duc et al., 2023)</td></tr></tbody></table>

<footnote>*: average values, **: maximum values</footnote>

<footnote>*: average values</footnote>
carried out by Lertassavakorn et al. (2021) showed that the intake of only PFOS was 1.9 ng.kg body weight⁻¹.week⁻¹ for general population but could reach up to 37.42 ng.kg body weight⁻¹.week⁻¹ for the consumers of seafood living close to a coastal industrial zone in Thailand. The authors even advised against the regular consumption of squid and spotted babylon to avoid the potential health risks related to PFAS exposure. Even if some of the reviewed studies on biota samples in Southeast Asia alarmed no immediate risks with fish consumption, as the daily intake lied under the acceptable thresholds, long-term exposure to PFAS, accumulating from both drinking water and seafood, would still pose significant health concerns.

## 5.4. PFAS and the analytical trends

PFOA and PFOS are the first two PFAS to be listed as POPs in the Stockholm Convention. During the 2000s and 2010s, PFAS research in Southeast Asia primarily focused on these two compounds, along with other PFAAs. The inventory work done in this time period included only PFOS, given its widespread use in textiles and firefighting foams across the region. Following the implementation of new regulations on the production and use of PFOA, PFOS, PFHxS, alternative PFAS compounds began to emerge as replacements for the restricted substances in industrial processes. For example, 6:2 fluorotelomer sulfonic acid (6:2-FTS) is used as substitutes for PFOS in metal electroplating, and N-Methyl Perfluorooctane sulfonamidoethanol (N-MeFOSE) and N-Ethyl Perfluorooctane sulfonamidoethanol (N-EtFOSE) are used paper, packaging and textile products (Brunn et al., 2023; Göckener et al., 2021). As a result, more recent researches have also taken these emerging PFAS into account. 6:2-FTS, N-Methyl Perfluorooctane sulfonamidoacetic acid (N-MeFOSAA), and N-Ethyl Perfluorooctane sulfonamidoacetic acid (N-EtFOSAA) have been included in the list of targeted analytes and detected in surface water, sediment and fish samples (Chen et al., 2019; Vu-Duc et al., 2023). Chen et al., 2017 even reported the dominance of EtFOSAA over legacy PFAS (i.e. PFOS, PFOA) in the surface sediment samples collected in 2017 in Singapore. Although the regulatory framework for PFAS management in Southeast Asia is still under development and has not yet been comprehensively established, the region's scientific community has demonstrated a proactive approach in responding to emerging PFAS challenges. Research groups have kept pace with evolving trends in PFAS usage, including the shift towards alternative compounds, and have been adapting monitoring strategies accordingly.

# 6. Research gaps and future directions

## 6.1. Economic growth and extreme climate events

Studies of PCBs and PBDEs have been carried out since the 1990s in eight Southeast Asian countries. They have received much more attention since 2004 and 2010, after the regulatory agencies, not only regional but also worldwide, take effective measures to mitigate their negative impacts. The levels of PCBs and PBDEs in the SEA environment were comparable to those in the Bohai Sea and Yellow Sea in China and South Korea (J. Meng et al., 2017; H. Yu et al., 2023), in the Mediterranean Sea in Southern Europe (Kanzari et al., 2012, 2014), and in North America environment (Hale et al., 2003). Although PCBs and PBDEs have been successively banned, their replacement has involved the marketing of products with similar potential applications. This gives currently rise to the production of very diverse brominated and chlorinated molecules, some of which have characteristics similar to POPs and merit specific attention from the scientific community (Rigal et al., 2024; Vénisseau et al., 2018). In comparison to PCBs and PBDEs, PFAS were poorly investigated in South-East Asia. Hence further research is required to have a more comprehensive understanding of PFAS contamination in this region. This is of high human health concern, since PFAS have been detected in drinking waters and various aquatic species.

Moreover, it is utmost important to conduct regular monitoring of POPs to gain a better understanding on the change in quality status of the water resources, owing to two cumulative factors taking place in the region (Zhang et al., 2019). On the one's hand, the rapid economic growth is likely to intensify the use of chemicals and the consumption of consumer goods. The rapid economic and population growth act driving factors for the increased rate of production and consumption. The PBDEs emission is proven to be correlated with population growth, urbanization and industrialization (Kwan et al., 2014). A higher GDP per capita often reflects increased purchasing power and higher living standard, which can eventually lead to greater demand for goods and services. Majority of these products, such as electronics, vehicles, textiles, and household appliances, as indicated in the inventory reports, contain POPs. The region with fast economic development, therefore, may exhibit increased potential for POP emissions and accumulation in the environment. In addition, climate change will lead to more frequent extreme events, which should result in the remobilization of sedimentary pollutants and long-range transport to remote areas (Nadal et al., 2015; Pizzini et al., 2022; Teran et al., 2012). Santiago & Rivas (2012) reported higher PCBs levels in water after typhoon due to the overflow from river and runoff from surrounding areas. Similarly, Lertassavakorn et al., (2021) suggested that the heavy precipitation events could contribute to the repartition of PFOA and PFOS, leading to more elevated concentration in environmental samples. These conclusions were further supported by the results from climate models, which suggested that the increase in precipitation would lead to higher levels of POPs in environmental compartments (Noyes et al., 2025). Moreover, climate change affects not only abiotic environmental matrices but also has significant impacts on biotic components. Living organisms, including wildlife, are becoming more vulnerable to the change in climate patterns, which can eventually influence their exposure to and accumulation of organic contaminants. Foster et al., (2019) showed clear correlations between rainfall and concentrations of organochlorine pollutant in seabirds. The study pointed out that increased concentrations of PCBs in seabird eggs were associated with higher rainfall. This emphasizes once again the link between the intensified precipitation and the enhancement of mobilization and bioavailability of POPs. The findings of climate models highlight the complex interactions between the extreme events caused by climate changes and the dynamics of POPs in environmental systems. In this context, the fate of POPs must be followed more systematically in Southeast Asia, given the region's vulnerability to climate change. The scientific findings would be helpful for policy makers to set national standards in water, sediment, and biota samples and to prevent potential ecological and human health risks. On the other hand, the development of proper treatment protocols for the discharge or recycling of POPs-containing products, like e-product or plastic, is needed to limit POP uncontrolled dispersion into the aquatic resources and to achieve the goals and provisions of the Stockholm Convention.

## 6.2. Forgotten countries

As earlier mentioned, no studies could be found concerning the occurrence of PCBs, PBDEs and PFAS in Brunei and Timor-Leste nor any information on their consumption in these two countries. According to PCB inventory conducted in 2016–2017, 119 out of 592 inventoried transformers contained PCBs at concentration higher than the 50-ppm threshold set by the Stockholm Convention and there remained more than 319 tons of PCB-containing oil in Myanmar (UNEP, 2020). Moreover, in 2016, Myanmar imported more than 56,000 liters of firefighting foam, only 2.4 % of which were used and the remains stayed in stockage. Nevertheless, there is no record of scientific article working on the presence of PCBs, PBDEs and PFAS in Myanmar's aquatic environment. Myanmar, formerly known as Burma, has experience prolonged periods of military rule and political unrest (Stokke et al., 2022). The most recent military coup d'état, which took place in February 2021, further
destabilized the nation, sparking widespread armed conflicts and resistance as well as a humanitarian crisis (Andrews, 2022; Manurung, 2021). Hence, the political turmoil within Myanmar may have hindered and limited the monitoring activities despite the potential risks of contamination from POPs, which have been mentioned during the POPs inventory and the national implementation plan for the Stockholm Convention published in 2020 (UNEP, 2020). For the case of Timor-Leste, the country obtained its independence and was recognized as a sovereign nation by the United Nations only 23 years ago, on May 20, 2002. As a newly independent nation, though Timor Leste understands the importance of environmental monitoring, it has not yet to develop a fully structured environmental management system including legislation, regulation, and adequately resourced institutions (World Bank, 2009). This knowledge gap should be due to the lack of environmental monitoring strategies linked to limited governmental and population concern and capacity of local facilities (e.g., analytical laboratories). Despite being the signatory of the Stockholm Convention since 2002, Brunei has never ratified the Convention and has no national restriction on the production and usage of POPs (Sharkey et al., 2020). Effectively, no National Implementation Plan of Brunei has been submitted to the Stockholm Convention.

Gong et al. (2018) reported however the long-range transport of organochlorine compounds (including PCBs) by air masses coming from Myanmar, inferring thus the atmospheric contamination in this country. These three countries are drained by several large river systems (the Irrawaddy River and the Salween in Myanmar, the Belait River and Tutong River in Brunei, and the Loes River and Laclo River in Timor-Leste) and are well connected to other Southeast Asian countries via maritime routes. This implies that the dissemination of POPs by water ways are highly possible. Given their participation and commitment to the Stockholm Convention, it is required to conduct the industrial POPs inventories and monitoring in Brunei, Myanmar and Timor Leste, especially in aquatic compartments. To facilitate the international cooperation on environment in the region, the Association of Southeast Asian Nations (ASEAN) has been making efforts by establishing ASEAN Environmental Cooperation Framework. The Association hosts biannually the ASEAN Ministerial Meeting on Environment (AMME) assisted by the ASEAN Senior Officials on Environment (ASOEN) with specific working groups to cover all priority areas in environmental cooperation.

### 6.3. Chlorinated paraffins, an orphan broad group of industrial POPs

Similarly to the three previously reviewed groups of contaminants, the chlorinated paraffins (CPs) are a POPs-like group of compounds, estimated to gather more than 30,000 homologues and isomers (South et al., 2022). CPs are complex mixtures of polychlorinated alkanes with different degrees of chlorination and the chlorine content varying from 30 % to 72 % (w/w). Based on the length of the carbon chains, CPs are classified into three groups: short-chain CPs (SCCPs, $C_{10}$-$C_{13}$), medium-chain CPs (MCCPs, $C_{14}$-$C_{17}$) and long-chain CPs (LCCPs, $> C_{18}$) having 18 or more carbon atoms (Bayen et al., 2006). Since CPs have high chemical stability, flame retardancy and low volatility, they have been used as additives in metal cutting fluids, plasticizers, flame retardants in rubber, paints, and textiles (Huang et al., 2020; van Mourik et al., 2015). It was estimated that during the period from 1930 to 2020, 32.5 million tons of CPs were produced, of which 28 % were SCCPs (Mu et al., 2023). The global cumulative emissions of CPs by 2020 have reached an alarming figure of 5.2 million metric tons (C. Chen et al., 2022). Nevertheless, CPs can be carcinogenic and SCCPs were categorized in Group 2B as possibly carcinogenic to humans from the International Agency for Research on Cancer. CPs can induce several other toxicities, disrupt endocrine systems, and cause developmental problems (S. Chen et al., 2023). SCCPs have been considered as POPs by the Stockholm Convention when they were listed in Annex A (Elimination) in 2017. SCCPs have persistent, bio-accumulable and toxic (PBT) and very persistent, very bio-accumulable (vPvB) properties and they were

added to the Candidate List of substances of very high concern for Authorization under REACH Regulation. Furthermore, MCCPs are now being under consideration for the listing under the Convention (UNEP, 2021a) were added to the Candidate List of Substances of Very High Concern (SVHC) under the REACH Regulation in 2021 and are planned to be added to the ROHS restricted substances list (Commission, 2022; ROHS Directive 2011/65/EU for electronic devices).

In national implementation plans submitted to the Stockholm Convention by the Southeast Asian nations, little information was reported on the inventory of CPs. Indonesia recorded an imported amount of 13,521 tons of CPs between 2014 and 2016 and suggested that Thailand was an exporting country with the cumulative amount of 1143 tons (UNEP, 2021b). However, Indonesia, Thailand and Vietnam have taken important steps by initiating plans to include SCCPs in their national inventories and regulatory frameworks, as indicated in their implementation plans.

Despite their utmost concern in term of toxicity and production tonnage, this huge group of POPs could not be added to our review article, because there were no scientific article reporting the presence of CPs in the aquatic environment of any of the 11 South-East Asian countries. Nonetheless, the presence of CPs in the region has been recorded in other environmental samples as well as in human serum samples collected in China, Korea and Japan (van Mourik et al., 2020). Thus, McGrath et al. (2023) investigated the presence of CPs in indoor dust in Thailand and three other countries (Japan, Australia, and Colombia). In general, the concentrations of CPs in samples from Thailand were higher than those from other three countries with the median values being $29 \mu g \cdot g^{-1}$ (SCCPs), $120 \mu g \cdot g^{-1}$ (MCCPs) and $12 \mu g \cdot g^{-1}$ (LCCPs). Moreover, CPs were detected in ambient air in Vietnam, China, and Australia (He et al., 2023). While the concentrations of SCCPs were comparable between air samples collected in Vietnam and China, the levels of MCCPs were two times lower in samples from Vietnam. The vicinity of China and India, which are both the two biggest CP producers in the world, the increase in the production rate of MCCPs in China (452,000 tons compared to 236,400 tons of SCCPs produced in 2019, (S. Chen et al., 2023) and CP detection in air samples in the region, are all arguments in favor of the relevance of including these molecules in the regular environmental monitoring strategies of South-East Asia, besides PCBs, PBDEs and PFAS.

### 6.4. Analytical challenges

The industrial group of POPs on which this review article focuses gather, in the case of PCBs or PBDEs, 209 congeners, but can amount to thousands of molecules in the case of PFAS or CPs. In both latter cases, given i) the huge number of compounds identified, ii) the intrinsic limitations of the target-based approach to dozens of molecules, iii) and the unavailability of analytical standards, alternative analytical strategies for measuring a total content have recently been developed.

Among them, for PFAS, the Total Oxidizable Precursors Assay (TOPA) accounting for PFAAs precursors such as Fluorotelomer sulfonic acids (FTS), the Extractable Organically bound Fluorine (EOF), and the Non-Target Screening (NTS) represent the current trend in environmental monitoring of PFAS (Bugsel et al., 2023; Houtz & Sedlak, 2012; Simon et al., 2023). But, few laboratories have their analysis in hand worldwide.

Fifteen years ago, the analysis of CPs in environmental matrices was qualified as “the ultimate challenge of the analytical chemist” by Tomy, as these complex mixtures (i) cannot be separated by chromatography, (ii) cannot be classically quantified by using analytical standards, and their signal can be interfered by a lot of chlorinated pollutants (Tomy, 2009). Since then, many sophisticated analytical methods have been applied to resolve this inextricable issue and were recently reviewed for environmental and food matrices (van Mourik et al., 2018; X. Yu et al., 2022; Yuan et al., 2019). Currently, the method most widely accepted by the scientific community, even if it is only partially satisfactory, relies on
the latest generation of instruments and a complex quantification method based on recording the signal from mixtures with different degrees of chlorination (van Mourik, Lava, et al., 2020). This analytical sophistication is undoubtedly one of the reasons for the lack of data generated in South-East Asia as well as the paucity of data generated worldwide, in comparison with PBDEs, which were produced, used and regulated at fairly similar times and purposes. Moreover, the compliance with the actual regulation trend requires analytical optimization for the accurate determination of MCCPs (Schinkel et al., 2018). The development of a simple and rapid qualitative method (presence/absence) could constitute a first step and a sustainable approach for the elucidation of this group of compounds in developing countries.

On the other hand, owing to their physico-chemical properties, POPs are prone to accumulate in sediment and biota and are rather present at trace levels in water. This explains why very few data are available on fresh or marine waters, with the exception of PFAS, some of which being quite polar. However, for bio-accessibility and toxicity purpose, the dissolved fraction of pollutants can be more relevant. But this is hampered by the ultra-trace concentrations of hydrophobic organic compounds in the dissolved phase, the fleeting nature of aqueous discharges, and the problems of glass sorption and sample preservation, all the more so when the field can be a long way from the analysis laboratory. To overcome these limitations for POPs, the development and progress of water passive sampling has emerged over the last ten years as a powerful tool, having been the subject of methodological guidelines and interlaboratory validation trials for PCB and PBDE congeners with silicone and low-density polyethylene (Booij et al., 2024; Smedes et al., 2012; Vrana et al., 2015). In addition, very recently, analytical developments were proposed for the water passive sampling of SCCPs (Godéré et al., 2021, 2022) and regulated PFAS (Fang et al., 2021; Kaltenberg et al., 2022).

However, none of the data collected in the South-Asia waters over even the most recent period is the result of passive sampling. Yet thanks to high polymer-water partition coefficients, the equivalent volume of water sampled can range up to thousands of liters (Vrana et al., 2020). These tools provide a time-weighted average concentration of dissolved POPs, reducing the frequency of spot sampling needed to achieve reliable analysis, and the pre-concentration of POPs directly in situ, enabling to achieve the sensitivity requirement (LOQs) (Godéré et al., 2022). The advantage also lies in the fact that flows and risks can be assessed. It would therefore be judicious to apply these tools, which have already been widely used in other parts of the world for POPs, to better estimate the dissolved phase fraction of POPs in these regions.

## 7. Conclusion

Among the compounds listed under the SC, the 209 congeners of PCBS and PBDEs, as well as PFAS and CPs form four groups of industrial POPs comprising a vast number of molecules. Their worldwide environmental dispersion, the rapid industrialization and economic development in Southeast Asian countries as well as their proximity to major producers such as China and India and the massive importation of the contaminated products in the past, have heightened the vulnerability of ASEAN environments to such persistent pollutants. The differences, both in the phases of economic development and in the history of practices and rulings, implies specific trends of POP concentrations.

Over the past three decades, 121 research papers were addressing the occurrence of PCBs, PBDEs, and PFAS in the fresh and marine hydro systems (water, sediment, and aquatic biota) across eight Southeast Asian countries. It shows that these countries are paying increasing attention since 2004, to document the quality status of the water resources, particularly in connection with the implementation of regulations, or with the edible resources. The summarized data provides in-depth information for the national policymakers to align with the objectives of the SC. But the efforts need to be strengthened. Indeed, this review suggests that despite the national and international regulations,

the concentrations of these POPs in environment has shown no sign of decline for the past 35 years. The review also underscores the urgent need for the regular environmental monitoring of these broad groups of POPs, points out the knowledge gaps in some countries, such as Brunei, Myanmar and Timor Leste, and the data lack concerning chlorinated paraffins. The development of sum or qualitative methods and the implementation of passive sampling technologies are advised as future analytical developments, to help in intensifying the monitoring.

## Financial support

We are grateful to the French Embassy in Vietnam for their granting support towards the PhD thesis of Toan Khanh VU. This work received support from the French government under the France 2030 investment plan, as part of the Initiative d'Excellence d'Aix-Marseille Université-A*MIDEX - Institute for Ocean Sciences (no AMX-21-IET-016). The French National Research Institute for Sustainable Development (IRD) is acknowledged for their granting support towards the PhD thesis of Thi Thao NGUYEN.

## CRediT authorship contribution statement

**Toan Khanh Vu:** Writing – original draft, Visualization, Investigation, Formal analysis, Data curation. **Vincent Fauvelle:** Writing – review & editing, Supervision, Project administration, Funding acquisition, Conceptualization. **Thi Thao Nguyen:** Visualization, Methodology. **Van Hoi Bui:** Writing – review & editing, Supervision, Project administration, Funding acquisition. **Laure Malleret:** Writing – review & editing, Writing – original draft, Validation, Supervision, Resources, Project administration, Methodology, Funding acquisition, Conceptualization.

## Declaration of competing 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.

## Acknowledgments

We are grateful to the French Embassy in Vietnam for their granting support towards the PhD thesis of Toan Khanh VU. We would like to extend our sincere gratitude to the AM\*idex foundation and the Institute of Ocean Sciences (OCEAN) as well as to the French National Research Institute for Sustainable Development (IRD) for their granting support towards the PhD thesis of Thi Thao NGUYEN.

## Supplementary materials

Supplementary material associated with this article can be found, in the online version, at doi:10.1016/j.hazadv.2025.100872.

## Data availability

Data given in SI

## References

Abbasi, G., Li, L., Breivik, K., 2019. Global Historical Stocks and Emissions of PBDEs. Environmental Science and Technology 53 (11), 6330–6340. https://doi.org/10.1021/ACS.8B07032/ASSET/IMAGES/LARGE/ES-2018-07032Z.0006.JPEG.

Alfaro Garcia, L.A., Descamps, S., Herzke, D., Chastel, O., Carravieri, A., Cherel, Y., Labadie, P., Budzinski, H., Munoz, G., Bustamante, P., Polder, A., Gabrielsen, G.W., Bustnes, J.O., Borgå, K., 2022. Bioaccumulation of Per and Polyfluoroalkyl Substances in Antarctic Breeding South Polar Skuas (Catharacta maccormicki) and Their Prey. Front. Mar. Sci. 9, 819525. https://doi.org/10.3389/FMARS.2022.819525/BIBTEX.
Andrews, T.H., 2022. Report of the Special Rapporteur on the situation of human rights in Myanmar (A/HRC/49/76). https://www.ohchr.org/en/documents/thematic-reports/ahrc49crp1-conference-room-paper.

Ang, W.J., Park, E., Pokhrel, Y., Tran, D.D., Loc, H.H., 2024. Dams in the Mekong: a comprehensive database, spatiotemporal distribution, and hydropower potentials. Earth. Syst. Sci. Data 16 (3), 1209–1228. https://doi.org/10.5194/essd-16-2029-2024.

Anh, H.Q., Nam, V.D., Tri, T.M., Ha, N.M., Ngoc, N.T., Mai, P.T.N., Anh, D.H., Minh, N. H., Tuan, N.A., Minh, T.B., 2017. Polybrominated diphenyl ethers in plastic products, indoor dust, sediment and fish from informal e-waste recycling sites in Vietnam: a comprehensive assessment of contamination, accumulation pattern, emissions, and human exposure. Environ. Geochem. Health 39 (4), 935–954. https://doi.org/10.1007/s10653-016-9865-6.

Anh, H.Q., Watanabe, I., Tue, N.M., Tuyen, L.H., Viet, P.H., Chi, N.K., Minh, T.B., Takahashi, S., 2020. Polyurethane foam-based passive air sampling for simultaneous determination of POP- and PAH-related compounds: A case study in informal waste processing and urban areas, northern Vietnam. Chemosphere 247. https://doi.org/10.1016/j.chemosphere.2020.125991.

Asian Development Bank. (2024). Asian Development Outlook (ADO) July 2024: Steady Growth, Slowing Inflation. 10.22617/FLS240353-3.

ATSDR, 2000. Toxicological Profile for Polychlorinated Biphenyls (PCBs). https://www.atsdr.cdc.gov/toxprofiles/tp17.pdf.

ATSDR, 2014. Agency for Toxic Substances and Disease Registry Case Studies in Environmental Medicine Polychlorinated Biphenyls (PCBs) Toxicity. http://www.atsdr.cdc.gov/csem/coneduc.html.

ATSDR, 2017. Toxicological Profile for Polybrominated Diphenyl Ethers (PBDEs). https://www.atsdr.cdc.gov/toxprofiles/tp207.pdf.

Babut, M., Mourier, B., Desmet, M., Simonnet-Laprade, C., Labadie, P., Budzinski, H., De Alencastro, L.F., Tu, T.A., Strady, E., Gratiot, N., 2019. Where has the pollution gone? A survey of organic contaminants in Ho Chi Minh city /Saigon River (Vietnam) bed sediments. Chemosphere 217, 261–269. https://doi.org/10.1016/j.chemosphere.2018.11.008.

Basheer, C., Philip Obbard, J., Lee, H.K., 2003. Persistent Organic Pollutants in Singapore's coastal marine environment: Part I, Seawater. Water, Air and Soil Pollution 149 (1–4), 295–313.

Bayen, S., Kee Lee, H., Philip Obbard, J., 2007. Exposure and response of aquacultured oysters, Crassostrea gigas, to marine contaminants. Environ. Res. 103 (3), 375–382. https://doi.org/10.1016/j.envres.2006.06.012.

Bayen, S., Obbard, J.P., Thomas, G.O., 2006. Chlorinated paraffins: A review of analysis and environmental occurrence. Environ. Int. 32 (7), 915–929. https://doi.org/10.1016/j.envint.2006.05.009.

Bayen, S., Thomas, G.O., Lee, H.K., Obbard, J.P., 2003. Occurrence of Polychlorinated Biphenyls and Polybrominated Diphenyl Ethers in Green Mussels (Perna Viridis) from Singapore, Southeast Asia. Environ. Toxicol. Chem. 22 (10), 2432–2437. http://www.singstat.gov.sg.

Bayen, S., Wurl, O., Karuppiah, S., Sivasothi, N., Hian, K.L., Obbard, J.P., 2005. Persistent organic pollutants in mgrove food webs in Singapore. Chemosphere 61 (3), 303–313. https://doi.org/10.1016/j.chemosphere.2005.02.097.

Bhatag, J., Singh, N., Shimada, Y., 2024. Southeast Asia's environmental challenges: emergence of new contaminants and advancements in testing methods. Front. Toxicol. 6. https://doi.org/10.3389/ftox.2024.1322386.

Bolan, S., Padhye, L.P., Jazemised, T., Govarchanan, M., Karmegam, N., Wijesekara, H., Amarasiri, D., Hou, D., Zhou, P., Biswal, B.K., Balasubramanian, R., Wang, H., Siddique, K.H.M., Rinklebe, J., Kirkham, M.B., Bolan, N., 2024. Impacts of climate change on the fate of contaminants through extreme weather events. Science of The Total Environment 909, 168388. https://doi.org/10.1016/j.SUSTOTENV.2023.168388.

Bonato, M., Corrà, F., Bellio, M., Guidolin, L., Tallandini, L., Irato, P., Savitov, G., 2020. PFAS Environmental Pollution and Antioxidant Responses: An Overview of the Impact on Human Field. International Journal of Environmental Research and Public Health 2020, Vol. 17, Page 8020 17 (21), 8020. https://doi.org/10.3390/IJERPH17218020.

Booj, K., Crum, S., Vrana, B., Grabic, R., Morin, N.A.O., Parmentier, K., Kech, C., Krystek, P., Noro, K., Becker, B., Lohmann, R., Malleret, L., Kaserzon, S.L., Miège, C., Alliot, F., Pfeiffer, F., Crowley, D., Rakowska, M., Ocelka, T., Röhler, L., 2024. Ongoing Laboratory Performance Study on Chemical Analysis of Hydrophobic and Hydrophilic Compounds in Three Aquatic Passive Samplers. Environmental Science and Technology 58 (15), 6772–6780. https://doi.org/10.1021/ACS.EST.3C10272/SUPPL_FILE/ES3C10272_S1_001.pdf.

Boontanon, S.K., Kunacheva, C., Boontanon, N., Musirat, N., Fujii, S., Tanaka, S., 2013. Occurrence of Perfluorooctane Sulfonate in the Water Environment of Bangkok, Thailand. Journal of Environmental Engineering 139 (4), 588–593. https://doi.org/10.1061/(asce)ee.1943-7870.0000603.

Bouhoum, R., Boulkamh, A., Asia, L., Lebarillier, S., ter Halle, A., Syakti, A., Doumenq, P., Malleret, L., Wong-Wah-Chung, P., Halle, T.A., 2019. Concentrations and fingerprints of PAHs and PCBs adsorbed onto marine plastic debris from the Indonesian Cilacap coast and the North Atlantic gyre. Reg. Stud. Mar. Sci. 29, 100611. https://doi.org/10.1016/j.rsma.2019.100611i.

Brandsma, S.H., Leonards, P.E.G., Leslie, H.A., de Boer, J., 2015. Tracing organophosphorus and brominated flame retardants and plasticizers in an estuarine food web. Science of the Total Environment 505, 22–31. https://doi.org/10.1016/j.SCRITOTENV.2014.08.072.

Braun, J.M., 2017. Early-life exposure to EDCs: role in childhood obesity and neurodevelopment. Nature Reviews. Endocrinology 13 (3), 161–173. https://doi.org/10.1038/NRENDO.2016.186.

Brunn, H., Arnold, G., Körner, W., Rippen, G., Steinhäuser, K.G., Valentin, I., 2023. PFAS: forever chemicals persistent, bioaccumulative and mobile. Reviewing the status and the need for their phase out and remediation of contaminated sites. Environ. Sci. Eur. 35 (1), 20. https://doi.org/10.1186/s12302-023-00721-8.

Buck, R.C., Franklin, J., Berger, U., Conder, J.M., Cousins, I.T., Voogt, P.De, Jensen, A.A., Kannan, K., Mabury, S.A., van Leeuwen, S.P.J., 2011. Perfluoroalkyl and polyfluoroalkyl substances in the environment: Terminology, classification, and origins. Integr. Environ. Assess. Manage 7 (4), 513–541. https://doi.org/10.1002/IEAM.258.

Bugel, B., Zweigle, J., Zwiener, C., 2023. Nontarget screening strategies for PFAS prioritization and identification by high resolution mass spectrometry: A review. Trends in Environmental Analytical Chemistry 40, e00216. https://doi.org/10.1016/J.TEAC.2023.E00216.

Carvalho, F.P., Villeneuve, J.P., Cattini, C., Thuan, D.D., Nhan, D.D., 2009. Polychlorinated biphenyl congeners in the aquatic environment of the Mekong River, South of Vietnam. Bull. Environ. Contam. Toxicol. 83 (6), 892–898. https://doi.org/10.1007/s00128-009-9862-x.

Carvalho, F.P., Villeneuve, J.P., Cattini, C., Tolosa, I., Bajet, C.M., Navarro-Calingacion, M., 2009. Organic contaminants in the marine environment of Manila Bay, Philippines. Arch. Environ. Contam. Toxicol. 57 (2), 348–358. https://doi.org/10.1007/s00244-008-9271-x.

Castro-Jiménez, J., Mariani, G., Eisenreich, S.J., Christoph, E.H., Hanke, G., Canuti, E., Skejo, H., Umlauf, G., 2008. Atmospheric input of POPs into Lake Maggiorne (Northern Italy): PCDD/F and dioxin-like PCB profiles and fluxes in the atmosphere and aquatic system. Chemosphere 73 (1), S122–S130. https://doi.org/10.1016/J.CHEMOSPHERE.2007.06.097.

Chen, C., Chen, A., Zhan, F., Wania, F., Zhang, S., Li, L., Liu, J., 2023. Global Historical Production, Use, In-Use Stocks, and Emissions of Short-, Medium-, and Long-Chain Chlorinated Paraffins. Environmental Science and Technology 56 (12), 7895–7904. https://doi.org/10.1021/ACS.EST.2C00264.

Chen, H., Reinhard, M., Nguyen, T.V., You, L., He, Y., Gin, K.Y.H., 2017. Characterization of occurrence, sources and sinks of perfluoroalkyl and polyfluoroalkyl substances (PFASs) in a tropical urban catchment. Environmental Pollution 227, 397–405. https://doi.org/10.1016/j.envpol.2017.04.091.

Chen, H., Reinhard, M., Yin, T., Nguyen, T.V., Tran, N.H., Yew-Hoong Gin, K., 2019. Multi-compartment distribution of perfluoroalkyl and polyfluoroalkyl substances (PFASs) in an urban catchment system. Water. Res. 154, 227–237. https://doi.org/10.1016/j.watres.2019.02.009.

Chen, S., Gong, Y., Luo, Y., Cao, R., Yang, J., Cheng, L., Gao, Y., Zhang, H., Chen, J., Geng, N., 2023. Toxic effects and toxicological mechanisms of chlorinated paraffins: A review for insight into species sensitivity and toxicity difference. Environ. Int. 178, 108020. https://doi.org/10.1016/j.JENVINT.2023.108020.

Costa, L.G., Giordano, G., 2014. Polybrominated Diphenyl Ethers. Encyclopedia of Toxicology: Third Edition. Elsevier, pp. 1032–1034. https://doi.org/10.1016/B978-0-12-386454-3.00422-X.

Crawford, S.E., Brinkmann, M., Ouellet, J.D., Lehmkuhl, F., Reichertner, K., Schwarzbauer, J., Bellanova, P., Letmathe, P., Blank, L.M., Weber, R., Brack, W., van Dongen, J.T., Menzel, L., Hecker, M., Schüttrumpf, H., Hollert, H., 2022. Remobilization of pollutants during extreme flood events poses severe risks to human and environmental health. J. Hazard. Mater. 421, 126691. https://doi.org/10.1016/J.JHAZMAT.2021.126691.

Darnerud, P.O., Eriksen, G.S., Jóhannesson, T., Larsen, P.B., Viluksela, M., 2001. Polychlorinated Diphenyl Ethers: Occurrence, Dietary Exposure, and Toxicology. Health Perspect. 109, 49–68. https://about.jstor.org/terms.

De, M., Pereira, S., 2004. Polychlorinated Dibenzo-P-Dioxins (PCDD), Dibenzofurans (PCDF) and Polychlorinated Biphenyls (PCB): Main sources, environmental behavior and risk to man and biota. Quim. Nova 27 (6), 934–943.

Dickman, R.A., Aga, D.S., 2022. A review of recent studies on toxicity, sequestration, and degradation of per- and polyfluoroalkyl substances (PFAS). J. Hazard. Mater. 436, 129120. https://doi.org/10.1016/J.JHAZMAT.2022.129120.

Duc, N.V., Minh, T.Le, Nguyen, H.T., Dam, D.A., Thi, X.N., Chu, D.B., Hoi, B.Van, Hoang, A.Q., Manh, T.T., Pham, T.N.M, 2024. Halogenated organic pollutants (HOPs) in marine fish collected from central-northern coastal waters in Vietnam. Int. J. Environ. Anal. Chem. https://doi.org/10.1080/03067319.2023.2299740.

Duc Nhan, D., Carvalho, F., Manh Am, N., Quoc Tuan, N., Thi Hai Yen, N., Villeneuve, J., Cattini, C., Quoc Viet, H., Giay, C., Nam, V., 2001. Chlorinated pesticides and PCBs in sediments and molluscs from freshwater canals in the Hanoi region 112, 311–320. www.elsevier.com/locate/envpol.

Duc Nhan, D., Manh Am, N., Carvalho, F., Villeneuve, J., Cattini, C., 1999. Organochlorine pesticides and PCBs along the coast of north Vietnam. The Science of the Total Environment, 237/238 363–371.

Duch Nhan, D., Manh N.A., Chu Hoi, N., Van Dieu, L., Carvalho, F.P., Villeneuve, J., Cattini, C., 1998. Organochlorine pesticides and PCBs in the Red River Delta, North Vietnam. Mar. Pollut. Bull. 36 (9), 742–749.

Duong, H.T., Kadokami, K., Shirasaka, H., Hidaka, R., Chau, H.T.C., Kong, L., Nguyen, T. Q., Nguyen, T.T., 2015. Occurrence of perfluoroalkyl acids in environmental waters in Vietnam. Chemosphere 122, 115–124. https://doi.org/10.1016/J.CHEMOSPHERE.2014.11.023.

Evich, M.G., Davis, M.J.B., McCord, J.P., Acrey, B., Awkerman, J.A., Knappe, D.R.U., Lindstrom, A.B., Speth, T.F., Tebes-Stevens, C., Strynar, M.J., Wang, Z., Weber, E.J., Henderson, W.M., Washington, J.W., 2022. Per- and polyfluoroalkyl substances in the environment. Science (1979) (6580), 375. https://doi.org/10.1126/science.abg9065.

Falahudin, D., Herandarudewi, S.M.C., Hukom, F.D., Arifin, Z., Wulandari, I., Sudaryanto, A., Hoang, A.Q., Watanabe, I., Takahashi, S., 2023. The first full-congener analysis of 209 polychlorinated biphenyls (PCBs) in the blubber of short-
finned pilot whales (Globicephala macrorhynchus) stranded along the coast of Savo Island, Indonesia. Science of the Total Environment 879. https://doi.org/10.1016/j.scitotenv.2023.163008.

Falahudin, D., Quoc Hoang, A., Watanabe, I., Kenkyuka Nogakubu Shin Takahashi, N., Kenkyuka Nogakubu, N., 2022. First insight into accumulation of characteristics and tissues distribution of PCBs, PBDEs, and other BFRs in the living Indonesian coelacanth (Latimeria menadoensis). Environmental Science and Pollution Research 30, 49368–49380. https://doi.org/10.21203/rs.3.rs-2091749/v1.

Fang, Z., Li, Y., Li, Y., Yang, D., Zhang, H., Jones, K.C., Gu, C., Luo, J., 2021. Development and Applications of Novel DGT Passive Samplers for Measuring 12 Per-And Polyfluoroalkyl Substances in Natural Waters and Wastewaters. Environmental Science and Technology 55 (14), 9548–9556. https://doi.org/10.1021/ACS.EST.0C08092 SUPPL_FILE/ES0C08092_S1.001 PDF.

Fenton, S.E., Ducatman, A., Boobis, A., DeWitt, J.C., Lau, C., Ng, C., Smith, J.S., Roberts, S.M., 2021. Per- and Polyfluoroalkyl Substance Toxicity and Human Health Review: Current State of Knowledge and Strategies for Informing Future Research. Environ. Toxicol. Chem. 40 (3), 606–630. https://doi.org/10.1002/ETC.4890.

Forti, V., Baldé, C.P., Kuehr, R., Bel, G., 2020. The Global E-waste Monitor 2020: Quantities, flows, and the circular economy potential. United Nations University (UNU)/United Nations Institute for Training and Research (UNITAR) – co-hosted SCYCLE Programme, International Telecommunication Union (ITU) & International Solid Waste Association (ISWA), Bonn/Geneva/Rotterdam.

Foster, K.L., Braune, B.M., Gaston, A.J., Mallory, M.L., 2019. Climate Influence on Legacy Organochlorine Pollutants in Arctic Seabirds. Environmental Science and Technology 53 (5), 2518–2528. https://doi.org/10.1021/ACS.EST.8B07106/ASSET/IMAGES/LARGE/ES-2018-07106N_0005 JPEG.

Göckener, B., Fliedner, A., Rüdel, H., Fettig, I., Koschvorreck, J., 2021. Exploring unknown per- and polyfluoroalkyl substances in the German environment – The total oxidizable precursor assay as helpful tool in research and regulation. Science of The Total Environment 782, 146825. https://doi.org/10.1016/J.SCITOTENV.2021.146825.

Godéré, M., Malleret, L., Höhener, P., Doumenq, P., 2022. Passive sampling of chlorinated paraffins by silicone: Focus on diffusion and silicone-water partition coefficients. Chemosphere 287, 132201. https://doi.org/10.1016/J.CHEMOSPHERE.2021.132201.

Godéré, M., Mondange, S., Doumenq, P., Gonzalez, C., Malleret, L., 2021. First study of passive sampling to monitor short-chain chlorinated paraffins in water: Comparing capabilities of Chemcatcher® and silicone rubber samplers. Talanta 224, 121920. https://doi.org/10.1016/j.talanta.2020.121920i.

Gong, P., Wang, X., Sheng, J., Wang, H., Yuan, X., He, Y., Qian, Y., Yao, T., 2018. Seasonal variations and sources of atmospheric polycyclic aromatic hydrocarbons and organochlorine compounds in a high-altitude area: Evidence from four-year observations. Environmental Pollution 233, 1188–1197. https://doi.org/10.1016/J.ENVPOL.2017.10.064.

Guardian, M.G.E., Boongaling, E.G., Bernardo-Boongaling, V.R.R., Gamonchuang, J., Boontongto, T., Burakham, R., Arnnok, P., Aga, D.S., 2020. Prevalence of per- and polyfluoroalkyl substances (PFASs) in drinking and source water from two Asian countries. Chemosphere 256. https://doi.org/10.1016/j.chemosphere.2020.127115.

Guo, J., Xie, Y., Guan, A., Qi, W., Cao, X., Peng, J., Liu, H., Wu, X., Li, C., Wang, D., Qu, J., 2023. Dam construction reshares sedimentary pollutant distribution along the Yangtze River by regulating sediment composition. Environmental Pollution 316, 120659. https://doi.org/10.1016/j.ENVPOL.2022.120659.

Hale, R.C., Alaeem, M., Manchester-Neesvig, J.B., Stapleton, H.M., Ikonomou, M.G., 2003. Polybrominated diphenyl ether flame retardants in the North American environment. Environ. Int. 29 (6), 771–779. https://doi.org/10.1016/S0160-4120 (03)00113-2.

He, C., Thai, P.K., Bertrand, L., Jayarathne, A., van Mourik, L., Phuc, D.H., Banks, A., Mueller, J.F., Wang, X.F., 2023. Calibration and Application of PUF Disk Passive Air Samplers To Assess Chlorinated Paraffins in Ambient Air in Australia, China, and Vietnam. Environmental Science and Technology 57 (50), 21061–21070. https://doi.org/10.1021/acs.est.3c06703.

Herzke, D., Nikiforov, V., Yeung, L.W.Y., Moe, B., Routti, H., Nygård, T., Gabrielsen, G. W., Hanssen, L., 2023. Targeted PFAS analyses and extractable organofluorine – Enhancing our understanding of the presence of unknown PFAS in Norwegian wildlife. Environ. Int. 171, 107640. https://doi.org/10.1016/J.ENVINT.2022.107640.

Hoa, N.T.Q., Lieu, T.T., Anh, H.Q., Huong, N.T.A., Nghia, N.T., Chuc, N.T., Quang, P.D., Vi, P.T., Tuyen, L.H., 2022. Perfluoroalkyl substances (PFAS) in freshwater fish from rural lakes in Hanoi, Vietnam: concentrations, tissue distribution, and implication for risk assessment. Environmental Science and Pollution Research 29 (34), 52057–52069. https://doi.org/10.1007/s11356-022-19532-0.

Hoai, P.M., Ngoc, N.T., Minh, N.H., Viet, P.H., Berg, M., Alder, A.C., Giger, W., 2010. Recent levels of organochlorine pesticides and polychlorinated biphenyls in sediments of the sewer system in Hanoi, Vietnam. Environmental Pollution 158 (3), 913–920. https://doi.org/10.1016/j.envpol.2009.09.018.

Hoang, A.Q., Takahashi, S., Da Le, N., Duong, T.T., Huong Pham, T.M., Mai Pham, T.N., Huong Nguyen, T.A., Tran, T.M., Tu, M.B., Quynh Le, T.P., 2021. Comprehensive determination of polychlorinated biphenyls and brominated flame retardants in surface sediment samples from Hanoi urban area, Vietnam: Contamination status, accumulation profiles, and potential ecological risks. Environ. Res. 197. https://doi.org/10.1016/j.envres.2021.111158.

Hoang, A.Q., Tran, T.M., Tu, M.B., Takahashi, S., 2021. Polybrominated diphenyl ethers in indoor and outdoor dust from Southeast Asia: An updated review on contamination status, human exposure, and future perspectives. In: Environmental Pollution, Vol. 272. Elsevier Ltd. https://doi.org/10.1016/j.envpol.2020.116012.

Hongkachok, C., Boontanon, S.K., Boontanon, N., Fujii, S., Tanaka, S., Suzuki, Y., 2017. Levels of perfluorinated compounds (PFCs) in groundwater around improper municipal and industrial waste disposal sites in Thailand and health risk assessment. Water Science and Technology 2017 (2), 457–466. https://doi.org/10.2166/wst.2018.168.

Hongkachok, C., Boontanon, S.K., Boontanon, N., Sukeesan, W., Polprasert, C., Fujii, S., 2023. Per- and polyfluoroalkyl substances in groundwater in Thailand: occurrence, source identification and spatial distribution. International Journal of Environmental Science and Technology 20 (11), 12437–12448. https://doi.org/10.1007/s13762- 023-04894-w.

Houtz, E.F., Sedlak, D.L., 2012. Oxidative conversion as a means of detecting precursors to perfluoroalkyl acids in urban runoff. Environmental Science and Technology 46 (17), 9342–9349. https://doi.org/10.1021/es302274g.

Hu, W.yue, Jones, P.D., DeCoen, W., King, L., Fraker, P., Newsted, J., Giesy, J.P., 2003. Alterations in cell membrane properties caused by perfluorinated compounds. Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology 135 (1), 77–88. https://doi.org/10.1016/S1532-0456(03)00043-7.

Huang, D., Gao, L., Qiao, L., Cui, L., Xu, C., Wang, K., Zheng, M., 2020. Concentrations of and risks posed by short-chain and medium-chain chlorinated paraffins in soil at a chemical industrial park on the southeast coast of China. Environmental Pollution 258. https://doi.org/10.1016/j.envpol.2019.113704.

Hung Minh, N., Binh Minh, T., Kajiwara, N., Kunisue, T., Iwata, H., Hung Viet, P., Phuc Cam, N.T., Cach Tuyen, B., Tanabe, S., Trai Str, N., Xuan District, T., 2006. Contamination by Polybrominated Diphenyl Ethers and Persistent Organochlorines in catfish and feed from Mekong River Delta, Vietnam. Environ. Toxicol. Chem. 25 (10), 2700–2709. http://www.eco-web.com/register/02769.html.

Ikemoto, T., Tu, N.P.C., Watanabe, M.X., Okuda, N., Omori, K., Tanabe, S., Tuyen, B.C., Takeuchi, I., 2008. Analysis of biomagnification of persistent organic pollutants in the aquatic food web of the Mekong Delta, South Vietnam using stable carbon and nitrogen isotopes. Chemosphere 72 (1), 104–114. https://doi.org/10.1016/j.chemosphere.2008.01.011.

Ilyas, M., Sudaryanto, A., Setiawan, I.E., Riyadi, A.S., Isobe, T., Takahashi, S., Tanabe, S., 2011. Characterization of polychlorinated biphenyls and brominated flame retardants in sediments from riverine and coastal waters of Surabaya, Indonesia. Mar. Pollut. Bull. 62 (1), 89–98. https://doi.org/10.1016/j.marpolbul.2010.09.006.

Ilyas, M., Sudaryanto, A., Setiawan, I.E., Riyadi, A.S., Isobe, T., Tanabe, S., 2013. Characterization of polychlorinated biphenyls and brominated flame retardants in sludge, sediment and fish from municipal dumpsite at Surabaya, Indonesia. Chemosphere 93 (8), 1500–1510. https://doi.org/10.1016/j.chemosphere.2013.07.048.

Intergovernmental Panel on Climate Change (IPCC), 2023. Asia. In Climate Change 2022 – Impacts, Adaptation and Vulnerability: Working Group II Contribution to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, pp. 1457–1580. https://doi.org/10.1017/9781009325844.012.

Iwata, H., Tanabe, S., Sakai, N., Nishimura, A., Tatsukawa, R., 1994. Geographical distribution of Persistent Organic Organochlorines in Air, Water and Sediments from Asia and Oceania, and their implications for global redistribution from lower latitudes. Environmental Pollution 85, 15–33.

Jouanneau, W., Bärdsen, B.J., Herzke, D., Johnsen, T.V., Eulaers, I., Bustnes, J.O., 2020. Spatiotemporal Analysis of Perfluoroalkyl Substances in White-Tailed Eagle (Haliaeetus albicilla) Nestlings from Northern Norway-A Ten-Year Study. Environ. Sci. Technol. 54 (8), 5011–5020. https://doi.org/10.1021/ACS.EST.9B06818/ASSET/IMAGES/LARGE/ES9B06818_0001 JPEG.

Kajiwara, N., Kamikawa, S., Ramu, K., Ueno, D., Yamada, T.K., Subramanian, A., Lam, P. K.S., Jefferson, T.A., Prudente, M., Chung, K.H., Tanabe, S., 2006. Geographical distribution of polybrominated diphenyl ethers (PBDEs) and organochlorines in small cetaceans from Asian waters. Chemosphere 64 (2), 287–295. https://doi.org/10.1016/j.chemosphere.2005.12.013.

Kaltenberg, E.M., Dasu, K., Lefkovitz, L.F., Thorn, J., Schumitz, D., 2022. Sampling of freely dissolved per-and polyfluoroalkyl substances (PFAS) in surface water and groundwater using a newly developed passive sampler ☆ https://doi.org/10.1016/j.envpol.2022.120904.

Kanzari, F., Syakti, A.D., Asia, L., Malleret, L., Mille, G., Jouamussi, B., Abderrabba, M., Doumenq, P., 2012. Aliphatic hydrocarbons, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, organochlorine, and organophosphorous pesticides in surface sediments from the Arc river and the Berre lagoon, France. Environmental Science and Pollution Research 19 (2), 559–576. https://doi.org/10.1007/s11356-011-0582-5.

Kanzari, F., Syakti, A.D., Asia, L., Malleret, L., Piram, A., Mille, G., Doumenq, P., 2014. Distributions and sources of persistent organic pollutants (aliphatic hydrocarbons, PAHs, PCBs and pesticides) in surface sediments of an industrialized urban river (Huveaune), France. Science of the Total Environment 478, 141–151. https://doi.org/10.1016/j.scitotenv.2014.01.065.

Kaw, H.Y., Kannan, N., 2017. A review on polychlorinated biphenyls (PCBs) and Polybrominated diphenyl ethers (PBDEs) in South Asia with a focus on Malaysia. Rev. Environ. Contam. Toxicol. 242, 153–181. https://doi.org/10.1007/398_2016_14.

Kefeni, K.K., Okonkwo, J.O., Olukunle, O.I., Botha, B.M., 2011. Brominated flame retardants: Sources, distribution, exposure pathways, and toxicity. Environmental Reviews 19 (1), 238–253. https://doi.org/10.1139/a11-010.

Kim, J.W., Tue, N.M., Isobe, T., Misaki, K., Takahashi, S., Viet, P.H., Tanabe, S., 2013. Contamination by perfluorinated compounds in water near waste recycling and disposal sites in Vietnam. Environ. Monit. Assess. 185 (4), 2909–2919. https://doi.org/10.1007/s10661-012-2759-x.
Kim, S., Thapar, I., Brooks, B.W., 2021. Epigenetic changes by per- and polyfluoroalkyl substances (PFAS). Environmental Pollution 279, 116929. https://doi.org/10.1016/
J.ENVPOL.2021.116929.

Kishida, M., Imamura, K., Maeda, Y., Lan, T.T.N., Thao, N.T.P., Pham, H.V., 2007.
Distribution of Persistent Organic Pollutants and Poly cyclic Aromatic Hydrocarbons
in Sediment Samples from Vietnam. Journal of Health Science 53 (3), 291–301.
https://doi.org/10.1248/JHS.53.291.

Kunacheva, C., Boontanon, S.K., Fujii, S., Tanaka, S., Musirat, C., Artsalee, C.,
Wongwattana, T., 2009. Contamination of perfluorinated compounds (PFCs) in Chao
Phraya River and Bangpakong River, Thailand. Water Science and Technology 60
(4), 975-982. https://doi.org/10.2166/wst.2009.462.

Kunacheva, C., Fujii, S., Tanaka, S., Boontanon, S.K., Poothong, S., Wongresthana, T.,
Shivakoti, B.R., 2010. Perfluorinated compounds contamination in tap water and
bottled water in Bangkok, Thailand. Journal of Water Supply: Research and
Technology - AQUA 59 (5), 345-354. https://doi.org/10.2166/aqua.2010.063.

Kunacheva, C., Tanaka, S., Fujii, S., Boontanon, S.K., Musirat, C., Wongwattana, T.,
Shivakoti, B.R., 2011. Mass flows of perfluorinated compounds (PFCs) in central
wastewater treatment plants of industrial zones in Thailand. Chemosphere 83 (6),
737-744. https://doi.org/10.1016/j.chemosphere.2011.02.059.

Kwan, C.S., Takada, H., Boonyatumanond, R., Kato, Y., Mizukawa, K., Ito, M., Dung, L.
Q., Zakaria, M.P., Santiago, E.C., 2014. Historical occurrences of polybrominated
diphenyl ethers and polychlorinated biphenyls in Manila Bay, Philippines, and in the
upper Gulf of Thailand. Science of the Total Environment, 470-471 427-437.
https://doi.org/10.1016/j.scitotenv.2013.09.076.

Kwan, C.S., Takada, H., Mizukawa, K., Torii, M., Koike, T., Yamashita, R., Rinawati,
Saha, M., Santiago, E.C, 2013. PBDEs in leachates from municipal solid waste
dumping sites in tropical Asian countries: Phase distribution and deamination.
Environmental Science and Pollution Research 20 (6), 4188-4204. https://doi.org/
10.1007/s11356-012-1365-3.

Lam, N.H., Cho, C.R., Kannan, K., Cho, H.S., 2017. A nationwide survey of perfluorinated
alkyl substances in waters, sediment and biota collected from aquatic environment
in Vietnam: Distributions and bioconcentration profiles. J. Hazard. Mater. 323,
116-127. https://doi.org/10.1016/J.JHAZMAT.2016.04.010.

Lampert, D.J., 2018. Emerging Research Needs for Assessment and Remediation of
Sediments Contaminated with Per- and Poly-fluoroalkyl Substances. Curr. Pollut.
Rep. 4 (4), 277-279. https://doi.org/10.1007/S40726-018-0098-4.

Lertassavakorn, T., Pholphana, N., Rangkadilok, N., Suriyo, T., Satayavad, J., 2021.
Determination of perfluorooctanoate sulphonate and perfluorooctanoic acid in seafood
and water from Map Ta Phut Industrial Estate area, Thailand. Food Additives
and Contaminants - Part A Chemistry. Analysis, Control, Exposure and Risk Assessment
38 (8), 1400-1415. https://doi.org/10.1080/19440049.2021.1921281.

Li, Z., Yu, Z., Gao, P., Yin, D., 2020. Multigenerational effects of perfluorooctanoic acid
on lipid metabolism of Caenorhabditis elegans and its potential mechanism. Science
of The Total Environment 703, 134762. https://doi.org/10.1016/J.
SCITOTENV.2019.134762.

Liber, Y., Mourier, B., Marchand, P., Bichon, E., Perrodin, Y., Bedell, J.P., 2019. Past and recent state of sediment contamination by persistent organic pollutants (POPs) in the Rhône River: Overview of ecotoxicological implications. Science of The Total Environment 646, 1037-1046. https://doi.org/10.1016/J.
SCITOTENV.2018.07.340.

Mackintosh, S.A., Wallace, J.S., Gross, M.S., Navarro, D.D., Pérez-Fuentetaja, A.,
Alaea, M., Montecastro, D., Aga, D.S., 2015. Review on the occurrence and profiles
of polybrominated diphenyl ethers in the Philippines. In: Environment International,
85. Elsevier Ltd, pp. 314-326. https://doi.org/10.1016/j.envint.2015.09.006.

Macorps, N., Le Menach, K., Pardon, P., Guérin-Rechdaoui, S., Rocher, V., Budzinski, H.,
Labadie, P., 2022. Bioaccumulation of per- and polyfluoroalkyl substance in fish
from an urban river: Occurrence, patterns and investigation of potential ecological
drivers. Environmental Pollution 303, 119165. https://doi.org/10.1016/J.
ENVPOL.2022.119165.

Manurung, H., 2021. Myanmar Political Instability: A Threat to Southeast Asia Stability.

Jurnal Asia Pacific Studies 5 (1) https://doi.org/10.33541/JAPS.V5I1.2671.

Matsukami, H., Tue, N.M., Suzuki, G., Someya, M., Tuyen, L.H., Viet, P.H., Takahashi, S.,
Tanabe, S., Takigami, H., 2015. Flame retardant emission from e-waste recycling
operation in northern Vietnam: Environmental occurrence of emerging
organophosphorus esters used as alternatives for PBDEs. Science of the Total
Environment 514, 492-499. https://doi.org/10.1016/j.scitotenv.2015.02.008.

Matsukami, H., Wannomai, T., Uchida, N., Tue, N.M., Hoang, A.Q., Tuyen, L.H., Viet, P.
H., Takahashi, S., Kunisue, T., Suzuki, G., 2022. Silicone wristband- and handwipe-
based assessment of exposure to flame retardants for informal electronic-waste and
end-of-life-vehicle recycling workers and their children in Vietnam. Science of the
Total Environment 853. https://doi.org/10.1016/j.scitotenv.2022.158669.

Mbusnum, K.G., Malleret, L., Deschamps, P., Khabouchi, I., Asia, L., Lebarillier, S.,
Menot, G., Onguene, R., Doumenq, P., 2020. Persistent organic pollutants in
sediments of the Wouri Estuary Mangrove, Cameroon: Levels, patterns and
ecotoxicological significance. Mar. Pollut. Bull. 160, 111542. https://doi.org/
10.1016/J.MARPOLBUL.2020.111542.

McDonough, C.A., Li, W., Bischel, H.N., De Silva, A.O., DeWitt, J.C., 2022. Widening the
Lens on PFASs: Direct Human Exposure to Perfluoroalkyl Precursors (pre-
PFASs). Environmental Science and Technology 56 (10), 6004-6013. https://doi.
org/10.1021/ACS.EST.2C00254/ASSET/IMAGES/LARGE/ES2C00254_0001.JPEG.

McGrath, T.J., Poma, G., Hutinet, S., Fujii, Y., Dodson, R.E., Johnson-Restrepo, B.,
Muenhor, D., Dervilly, G., Cariou, R., Covaci, A., 2023. An international
investigation of chlorinated paraffin concentrations and homologue distributions in
indoor dust. Environmental Pollution 333. https://doi.org/10.1016/j.
envpol.2023.121994.

Meng, J., Hong, S., Wang, T., Li, Q., Yoon, S.J., Lu, Y., Giesy, J.P., Khim, J.S., 2017.
Traditional and new POPs in environments along the Bohai and Yellow Seas: An
overview of China and South Korea. Chemosphere 169, 503-515. https://doi.org/
10.1016/J.CHEMOSPHERE.2016.11.108.

Meng, T., Cheng, J., Tang, Z., Yin, H., Zhang, M., 2021. Global distribution and trends of
polybrominated diphenyl ethers in human blood and breast milk: A quantitative
meta-analysis of studies published in the period 2000-2019. J. Environ. Manage
280, 111696. https://doi.org/10.1016/J.JENVMAN.2020.111696.

Minh, N.H., Minh, T.B., Iwata, H., Kajiwara, N., Kunisue, T., Takahashi, S., Viet, P.H.,
Tuyen, B.C., Tanabe, S., 2007. Persistent organic pollutants in sediments from Sai
Gon-Dong Nai River basin, Vietnam: Levels and temporal trends. Arch. Environ.
Contam. Toxicol. 52 (4), 458-465. https://doi.org/10.1007/s00244-006-0157-5.

Minh, N.H., Someya, M., Minh, T.B., Kunisue, T., Iwata, H., Watanabe, M., Tanabe, S.,
Viet, P.H., Tuyen, B.C., 2004. Persistent organochlorine residues in human breast
milk from Hanoi and Hochiminh city, Vietnam: Contamination, accumulation
kinetics and risk assessment for infants. Environmental Pollution 129 (3), 431-441.
https://doi.org/10.1016/j.envpol.2003.11.012.

Monirith, I., Nakata, H., Tanabe, S., Tana, T.S., 1999. Persistent Organochlorine Residues
in Marine and Freshwater Fish in Cambodia.

Monirith, I., Nakata, H., Watanabe, M., Takahashi, S., Tanabe, S., Tana, T.S., 2000.
Organochlorine contamination in fish and mussels from Cambodia and other Asian
countries. http://iwaponline.com/wst-article/pdf/42/7-8/241/29251/241.pdf.

Motamedi, M., Yerushalmi, L., Haghighat, F., Chen, Z., 2022. A critical review of water
contamination by polybrominated diphenyl ethers (PBDE) and main degradation
techniques. J. Environ. Chem. Eng. 10 (4). https://doi.org/10.1016/j.
jece.2022.108196.

Mu, Y.W., Cheng, D., Zhang, C.L., Zhao, X.L., Zeng, T., 2023. The potential health risks of
short-chain chlorinated paraffin: A mini-review from a toxicological perspective.
Science of The Total Environment 872, 162187. https://doi.org/10.1016/J.
SCITOTENV.2023.162187.

Murakami, M., Adachi, N., Saha, M., Chiaki, Morita, Takada, H., 2011. Levels, Temporal
Trends, and Tissue Distribution of Perfluorinated Surfactants in Freshwater Fish
from Asian Countries. Arch. Environ. Contam. Toxicol. 61, 631-641. https://doi.
org/10.1007/s00244-011-9660-4.

Nadal, M., Marquès, M., Mari, M., Domingo, J.L., 2015. Climate change and
environmental concentrations of POPs: A review. Environ. Res. 143, 177-185.
https://doi.org/10.1016/J.ENVRES.2015.10.012.

Ngoc, N.T., Vi, P.T., Viet, P.H., Anh, D.H., 2021. Occurrence of perfluorinated chemicals
(PFCs) in leachate, surface water and sediment collected from Tay Mo landfill and
surrounding areas. Vietnam Journal of Chemistry 59 (2), 239-246. https://doi.org/
10.1002/VJCH.202000157.

Ngoubeyou, P.S.K., Wolkersdorfer, C., Ndibewu, P.P., Augustyn, W., 2022. Toxicity of
polychlorinated biphenyls in aquatic environments - A review. Aquatic Toxicology
251. https://doi.org/10.1016/j.aquatox.2022.106284.

Nguyen, D.T., Thao Le, X.T., Van Trinh, T., Van Do, M., 2024. Evaluation of chemical
exposure to the sediment and green mussels (Perna viridis) at some coastal sites in
Northern Vietnam. Reg. Stud. Mar. Sci. 71. https://doi.org/10.1016/j.
rsma.2024.103413.

Nguyen, T.T., Bui, V.H., Lebarillier, S., Vu, T.K., Wong-Wah-Chung, P., Fauvelle, V.,
Malleret, L., 2024. Spatial and seasonal abundance and characteristics of
microplastics along the Red River to the Gulf of Tonkin, Vietnam. Science of The
Total Environment 957 (2024), 177778. https://doi.org/10.1016/J.
SCITOTENV.2024.177778.

Nguyen, T.X., Nguyen, B.T., Tran, H.T.T., Le, T.T., Trinh, T.T., Trinh, T.T., Tu, M.B.,
Cao, N.D.T., Vo, H.D.T., 2019. The interactive effect of the season and estuary
position on the concentration of persistent organic pollutants in water and sediment
from the Cua Dai estuary in Vietnam. Environmental Science and Pollution Research
26 (11), 10756-10766. https://doi.org/10.1007/s11356-019-04238-7.

Nguyen, V.T., Gin, K.Y.H., Reinhard, M., Liu, C., 2012. Occurrence, fate, and fluxes of
perfluorochemicals (PFCs) in an urban catchment: Marina Reservoir, Singapore.
Water Science and Technology 66 (11), 2439-2446. https://doi.org/10.2166/
wst.2012.475.

Nguyen, T.V., Reinhard, M., Chen, H., Gin, K.Y.H., 2016. Fate and transport of perfluoro-
and polyfluoroalkyl substances including perfluorooctane sulfonamides in a
managed urban water body. Environmental Science and Pollution Research 23 (11),
10382-10392. https://doi.org/10.1007/s11356-016-6788-9.

Noyes, P.D., Miranda, D., Oliveira de Carvalho, G., Perfetti-Bolaño, A., Guida, Y., Barbosa
Machado Torres, F., Paulo Machado Torres, J., Miglioranza, K.S.B., Hatje, V.,
Barro, R.O. 2025. Climate change drives persistent organic pollutant dynamics in
marine environments. Communications Earth & Environment 2025 6:1 6 (1), 1-21.
https://doi.org/10.1038/s43247-025-02348-4.

Othman, N., Ismail, Z., Selamat, M.I., Sheikh Abdul Kadir, S.H., Shibraumalisi, N.A.,
2022. A Review of Polychlorinated Biphenyls (PCBs) Pollution in the Air: Where and
How Much Are We Exposed to? Int. J. Environ. Res. Public Health 19 (21), 13923.
https://doi.org/10.3390/JERPH192113923/S1.

Panieri, E., Baralic, K., Djukic-Cosic, D., Djordjevic, A.B., Saso, L., 2022. PFAS Molecules:
A Major Concern for the Human Health and the Environment. Toxics 2022, Vol. 10,
Page 44 10 (2), 44. https://doi.org/10.3390/TOXICS10020044.

Phong Vo, H.N., Ngo, H.H., Guo, W., Hong Nguyen, T.M., Li, J., Liang, H., Deng, L.,
Chen, Z., Hang Nguyen, T.A., 2020. Poly- and perfluoroalkyl substances in water and
wastewater: A comprehensive review from sources to remediation. J. Water. Process.
Eng. 36, 101393. https://doi.org/10.1016/J.JWPE.2020.101393.

Pizzini, S., Giuliani, S., Polonia, A., Piazza, R., Bellucci, L.G., Gambaro, A., Gasperini, L.,
2022. PAHs, PCBs, PBDEs, and OCPs trapped and remobilized in the Lake of Cavazzo
(NE Italy) sediments: Temporal trends, quality, and sources in an area prone to
anthropogenic and natural stressors. Environ. Res. 213, 113573. https://doi.org/10.1016/J.ENVRES.2022.113573.

Quynh, T.X., Toan, V.D., 2019. Endocrine Disrupting Compounds (EDCs) in Surface Waters of the KimNguu River, Vietnam. Bull. Environ. Contam. Toxicol. 103 (5), 734-738. https://doi.org/10.1007/s00128-019-02710-1.

Ramu, K., Kajiwara, N., Sudaryanto, A., Isobe, T., Takahashi, S., Subramanian, A., Ueno, D., Zheng, G.J., Lam, P.K.S., Takada, H., Zakaria, M.P., Viet, P.H., Prudente, M., Tana, T.S., Tanabe, S., 2007. Asian mussel watch program: Contamination status of polybrominated diphenyl ethers and organochlorines in coastal waters of Asian countries. Environmental Science and Technology 41 (13), 4580-4586. https://doi.org/10.1021/es070380p.

Renzelli, V., Gallo, M., Morviducci, L., Marino, G., Ragni, A., Tuveri, E., Faggiano, A., Mazzilli, R., Natalicchio, A., Zatelli, M.C., Montagnani, M., Fogli, S., Giuffrida, D., Silvestris, N., 2023. Polybrominated Diphenyl Ethers (PBDEs) and Human Health: Effects on Metabolism, Diabetes and Cancer. Cancers. (Basel) 15 (17), 4237. https://doi.org/10.3390/CANCERS15174237.

Rigal, C., Asia, L., Lebarillier, S., Doumenq, P., Mirleau, P., Malleret, L., 2024. Novel brominated flame retardants relevant for European aquatic environments: ranking of analytes to monitor and focus on the French Eastern Mediterranean coastline. Environmental Science and Pollution Research 1–17. https://doi.org/10.1007/S11356-024-34607-W/METRICS.

Salvadó, J.A., Grimalt, J.O., López, J.F., Durrieu De Madron, X., Heussner, S., Canals, M., 2012. Transformation of PBDE mixtures during sediment transport and resuspension in marine environments (Gulf of Lion, NW Mediterranean Sea). Environmental Pollution 168, 87–95. https://doi.org/10.1016/j.envpol.2012.04.019.

Santiago, E.C., Rivas, F., 2012. Polychlorinated biphenyls in selected sites in Pasig river and Laguna lake in the Philippines before and after a big flood event investigated under the UNU East Asia regional POPs monitoring project. Bull. Environ. Contam. Toxicol. 89 (2), 407–411. https://doi.org/10.1007/s00128-012-0677-9.

Schinkel, L., Bogdal, C., Canonica, E., Cariou, R., Bleiner, D., McNeill, K., Heeb, N.V., 2018. Analysis of Medium-Chain and Long-Chain Chlorinated Paraffins: The Urgent Need for More Specific Analytical Standards. Environmental Science and Technology Letters 5 (12), 708–717. https://doi.org/10.1021/ACS.ESTLETT.8B00537_SUPPL_FILE/EZ8B00537_S1_001.PDF.

Schmidt, N., Fauvelle, V., Castro-Jiménez, J., Lajaunie-Salla, K., Pinazo, C., Yohia, C., Sempéré, R., 2019. Occurrence of perfluoroalkyl substances in the Bay of Marseille (NW Mediterranean Sea) and the Rhône River. Mar. Pollut. Bull. 149, 110491. https://doi.org/10.1016/j.MARPOLBUL.2019.110491.

Schrenk, D., Bignami, M., Bodin, L., Chipman, J.K., del Mazo, J., Grasl-Kraupp, B., Hogstrand, C., Hoogenboom, L., Leblanc, J.C., Nebbia, C.S., Nielsen, E., Ntzani, E., Petersen, A., Sand, S., Vlemminckx, C., Wallace, H., Barregård, L., Ceccatelli, S., Cravedi, J.P., Schwerdtle, T., 2020. Risk to human health related to the presence of perfluoroalkyl substances in food. EFSA Journal 18 (9), e06223. https://doi.org/10.2903/J.EFSA.2020.6223.WGROUP-STRING:PUBLICATION.

Sharkey, P., Harrad, R., Abou-Elwafa Abdallah, M., Drage, D.S., Berresheim, H., 2020. Phasing-out of legacy brominated flame retardants: The UNEP Stockholm Convention and other legislative action worldwide. Environ. Int. 144, 106041. https://doi.org/10.1016/j.envint.2020.106041.

Shi, G., Cui, Q., Zhang, H., Cui, R., Guo, Y., Dai, J., 2019. Accumulation, Biotransformation, and Endocrine Disruption Effects of Fluorotelomer Surfactant Mixtures on Zebrafish. Chem. Res. Toxicol. 32 (7), 1432–1440. https://doi.org/10.1021/ACS.CHEMRESTOX.9B00127/ASSET/IMAGES/LARGE/TX-2019-00127H_0006.JPEG.

Simon, F., Gehrenkemper, L., Becher, S., Dierkes, G., Langhammer, N., Cossmer, A., von der Au, M., Göckener, B., Fliedner, A., Rüdel, H., Koschorreck, J., Meermann, B., 2023. Quantification and characterization of PFASs in suspended particulate matter (SPM) of German rivers using EOF, dTOPA, (non-)target HRMS. Science of the Total Environment 885. https://doi.org/10.1016/j.scitotenv.2023.163753.

Simonnet-Laprade, C., Budzinski, H., Maciejewski, K., Le Menach, K., Alliot, F., Goutte, A., Labadie, P., Santos, R., 2019. Biomagnification of perfluoroalkyl acids (PFAAs) in the food web of an urban river: assessment of the trophic transfer of targeted and unknown precursors and implications. Environmental Science: Processes & Impacts. https://doi.org/10.1039/C9EM00322Ci.

Smedes, F., Booij, K., Andersens, H.C., 2012. Guidelines for passive sampling of hydrophobic contaminants in water using silicone rubber samplers. https://doi.org/10.25607/OBP.236.

South, L., Saini, A., Harner, T., Niu, S., Parnis, J.M., Mastin, A., 2022. Medium- and long-chain chlorinated paraffins in air: A review of levels, physicochemical properties, and analytical considerations. In: Science of the Total Environment, Vol. 843. Elsevier B.V. https://doi.org/10.1016/j.scitotenv.2022.157094.

Stokke, K., Moo Kham, K.K., Nge, N.K.L., Kvanvik, S.H., 2022. Illiberal peacebuilding in a hybrid regime. Authoritarian strategies for conflict containment in Myanmar. Polit. Geogr. 93, 102551. https://doi.org/10.1016/j.POLGEO.2021.102551.

Sudaryanto, A., Isobe, T., Takahashi, S., Tanabe, S., 2011. Assessment of persistent organic pollutants in sediments from Lower Mekong River Basin. Chemosphere 82 (5), 679–686. https://doi.org/10.1016/j.chemosphere.2010.11.004.

Tabtong, W., Boontanon, S.K., Boontanon, N., 2015. Fate and Risk Assessment of Perfluoroalkyl Substances (PFASs) in Water Treatment Plants and Tap Water in Bangkok, Thailand. Procedia Environ. Sci. 28, 750–757. https://doi.org/10.1016/j.proenv.2015.07.088.

Tan, G.H., Vijayalethchy, K., Chong, C.L., 1991. Trace determination of waterborne organic pollutants in the Klang river basin. Analytical Sciences 7, 1069–1072.

Tang, Z.W., Shahul Hamid, F., Yusoff, I., Chan, V., 2023. A review of PFAS research in Asia and occurrence of PFOA and PFOS in groundwater, surface water and coastal

water in Asia. In: Groundwater for Sustainable Development, Vol. 22. Elsevier B.V. https://doi.org/10.1016/j.gsd.2023.100947.

Teran, T., Lamon, L., Marcomini, A., 2012. Climate change effects on POPs' environmental behaviour: a scientific perspective for future regulatory actions. Atmos. Pollut. Res. 3 (4), 466–476. https://doi.org/10.5094/APR.2012.054.

Tham, T.T., Anh, H.Q., Trinh, L.T., Lan, V.M., Truong, N.X., Yen, N.T.H., Anh, N.L., Tri, T.M., Minh, T.B., 2019. Distributions and seasonal variations of organochlorine pesticides, polychlorinated biphenyls, and polybrominated diphenyl ethers in surface sediment from coastal areas of central Vietnam. Mar. Pollut. Bull. 144, 28–35. https://doi.org/10.1016/j.marpolbul.2019.05.009.

Thao, V.D., Kawano, M., Tatsukawa, R., 1993. Persistent organochlorine residues in soils from tropical and sub-tropical Asian countries. Environmental Pollution 81 (1), 61–71. https://doi.org/10.1016/0269-7491(93)90029-N.

Toan, V.D., Quynh, T.X., Huang, N.T.L., 2020. Endocrine disrupting compounds in sediment from KimNguu river, Northern area of Vietnam: a comprehensive assessment of seasonal variation, accumulation pattern and ecological risk. Environ. Geochem. Health 42 (2), 647–659. https://doi.org/10.1007/s10653-019-00399-z.

Tomy, G. T. (2009). Analysis of Chlorinated Paraffins in Environmental Matrices: The Ultimate Challenge for the Analytical Chemist. 83–106. https://doi.org/10.1007/69_8_2009_39.

Tran, H.Le, Van, D.A., Vu, D.T., Huynh, T.H, 2022. Contamination of perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) in sediment of the Cau River, Vietnam. Environ. Monit. Assess. 194. https://doi.org/10.1007/s10661-022-10031-w.

Tran, T.A.M., Malarvannan, G., Hoang, T.L., Nguyen, V.H., Covaci, A., Elskens, M., 2019. Occurrence of organochlorine pesticides and polychlorinated biphenyls in sediment and fish in Cau Hai lagoon of Central Vietnam: Human health risk assessment. Mar. Pollut. Bull. 141, 521–528. https://doi.org/10.1016/j.marpolbul.2019.03.006.

Tran-Lam, T.T., Quan, T.C., Pham, P.T., Phung, A.T.T., Bui, M.Q., Dao, Y.H., 2023. Occurrence, distribution, and risk assessment of halogenated organic pollutants (HOPs) in marine fish muscle: The case study of Vietnam. Mar. Pollut. Bull. 192, 114986. https://doi.org/10.1016/j.MARPOLBUL.2023.114986.

Tri, T.M., Anh, H.Q., Tham, T.T., Quy, T.Van, Long, N.Q., Nhung, D.T., Nakamura, M., Nishida, M., Maeda, Y., Boi, L.Van, Minh, T.B, 2016. Distribution and Depth Profiles of Polychlorinated Dibenzo-p-Dioxins, Polychlorinated Dibenzofurans, and Polychlorinated Biphenyls in Sediment Collected from Offshore Waters of Central Vietnam. Mar. Pollut. Bull. https://doi.org/10.1016/j.marpolbul.2016.03.013.

Tröger, R., Ren, H., Yin, D., Postigo, C., Nguyen, P.D., Baduel, C., Golovko, O., Been, F., Joerss, H., Boleda, M.R., Polesello, S., Roncoroni, M., Taniyasu, S., Menger, F., Ahrens, L., Lai, F.Y., Wiberg, K., 2021. What's in the water? – Target and suspect screening of contaminants of emerging concern in raw water and drinking water from Europe and Asia. Water. Res. 198. https://doi.org/10.1016/jwatres.2021.117099.

Tue, N.M., Takahashi, S., Suzuki, G., Isobe, T., Viet, P.H., Kobara, Y., Seikei, N., Zhang, G., Sudaryanto, A., Tanabe, S., 2013. Contamination of indoor dust and air by polychlorinated biphenyls and brominated flame retardants and relevance of non-dietary exposure in Vietnamese informal e-waste recycling sites. Environ. Int. 51, 160–167. https://doi.org/10.1016/j.envint.2012.11.006.

Ueno, D., Kajiwara, N., Tanaka, H., Subramanian, A., Fillmann, G., Lam, P.K.S., Zheng, G. J., Muchitar, M., Razak, H., Prudente, M., Chung, K.H., Tanabe, S., 2004. Global Pollution Monitoring of Polybrominated Diphenyl Ethers Using Skipjack Tuna as a Bioindicator. Environmental Science and Technology 38 (2), 2312–2316. https://doi.org/10.1021/es035323k.

Ueno, D., Takahashi, S., Tanaka, H., Subramanian, A.N., Fillmann, G., Nakata, H., Lam, P.K.S., Zheng, J., Muchtar, M., Prudente, M., Chung, K.H., Tanabe, S., 2003. Global pollution monitoring of PCBs and organochlorine pesticides using skipjack tuna as a bioindicator. Arch. Environ. Contam. Toxicol. 45 (3), 378–389. https://doi.org/10.1007/s00244-002-0131-9.

UNEP, 2014. National Implementation Plan for the Stockholm Convention on Persistent Organic Pollutants (UNEP/POPS/NIP/Philippines/COP4).

UNEP, 2016a. Consolidated Assessment of Efforts made toward the Elimination of Polychlorinated Biphenyls.

UNEP, 2016b. Lao People's Democratic Republic National Implementation Plan Under Stockholm Convention (UNEP/POPS/NIP/LAOS/COP4). https://chm.pops.int/Countries/CountryProfiles/tabid/4501/Default.aspx.

UNEP, 2017. National Implementation Plan for Stockholm Convention on Persistent Organic Pollutants (UNEP/POPS/NIP/VietNam/COP8). https://chm.pops.int/Countries/CountryProfiles/tabid/4501/Default.aspx.

UNEP, 2020. National Implementation Plan of Myanmar for the Stockholm Convention on Persistent Organic Pollutants (UNEP/POPS/NIP/Myanmar/COP6). https://chm.pops.int/Countries/CountryProfiles/tabid/4501/Default.aspx.

UNEP, 2021a. Proposal to list chlorinated paraffins with carbon chain lengths in the range C14-17 and chlorination levels at or exceeding 45 per cent chlorine by weight in Annexes A, B and/or C to the Stockholm Convention on Persistent Organic Pollutants (UNEP/POPS/POPRC.17/6).

UNEP, 2021a. Review and Update of National Implementation Plan (NIP) for the Stockholm Convention on Persistent Organic Pollutants (UNEP/POPS/NIP/Indonesia/COP8).

UNEP, 2022. Thailand's The Second National Implementation Plan under the Stockholm Convention on Persistent Organic Pollutants (2023-2027)(UNEP/POPS/NIP/Thailand/COP9). https://chm.pops.int/Countries/CountryProfiles/tabid/4501/Default.aspx.

UNEP, 2023. Stockholm Convention on Persistent Organic Pollutants (POPs): Text and Annexes.

US-EPA, 2024a. Final PFAS National Primary Drinking Water Regulation. https://www.epa.gov/sdwa/and-polyfluoroalkyl-substances-pfas.
US-EPA, 2024b. National Recommended Water Quality Criteria - Aquatic Life Criteria Table. https://www.epa.gov/wqc/national-recommended-water-quality-criteria-a-quatic-life-criteria-table.

Vaezzadeh, V., Thomes, M.W., Kunisue, T., Tue, N.M., Zhang, G., Zakaria, M.P., Affendi, Y.A., Yap, F.C., Chew, L.L., Teoh, H.W., Lee, C.W., Bong, C.W., 2021. Examination of barnacles' potential to be used as bioindicators of persistent organic pollutants in coastal ecosystem: A Malaysia case study. Chemosphere 263. https://doi.org/10.1016/j.chemosphere.2020.128272.

van de Merwe, J.P., Hodge, M., Olszowy, H.A., Whittier, J.M., Ibrahim, K., Lee, S.Y., 2009. Chemical Contamination of Green Turtle (Chelonia mydas) Eggs in Peninsular Malaysia: Implications for Conservation and Public Health. Environ. Health Perspect. 117 (9), 1397-1401.

van Mourik, L.M., Lava, R., O'Brien, J., Leonards, P.E.G., De Boer, J., Ricci, M., 2020. The underlying challenges that arise when analysing short-chain chlorinated paraffins in environmental matrices. Journal of Chromatography A, 1610, 460550. https://doi.org/10.1016/j.chroma.2019.460550.

van Mourik, L.M., Leonards, P.E.G., Gaus, C., De Boer, J., 2015. Recent developments in capabilities for analysing chlorinated paraffins in environmental matrices: A review. In: Chemosphere, 136. Elsevier Ltd, pp. 259-272. https://doi.org/10.1016/j.chemosphere.2015.05.045.

van Mourik, L.M., Toms, L.M.L., He, C., Banks, A., Hobson, P., Leonards, P.E.G., de Boer, J., Mueller, J.F., 2020. Evaluating age and temporal trends of chlorinated paraffins in pooled serum collected from males in Australia between 2004 and 2015. Chemosphere 244. https://doi.org/10.1016/j.chemosphere.2019.125574.

van Mourik, L.M., van der Veen, I., Crum, S., de Boer, J., 2018. Developments and interlaboratory study of the analysis of short-chain chlorinated paraffins. TrAC Trends in Analytical Chemistry 102, 32-40. https://doi.org/10.1016/J.TRAC.2018.01.004.

Vénisseau, A., Bichon, E., Brosseaud, A., Vaccher, V., Lesquin, E., Larvor, F., Durand, S., Dervilly-Pinel, G., Marchand, P., Le Bizec, B., 2018. Occurence of legacy and novel brominated flame retardants in food and feed in France for the period 2014 to 2016. Chemosphere 207, 497-506. https://doi.org/10.1016/J.CHEMOSPHERE.2018.05.122.

Vi, P.T., Ngoc, N.T., Quang, P.D., Dam, N.T., Tue, N.M., Tuyen, L.H., Viet, P.H., Anh, D. H., 2022. Perfluoroalkyl substances in freshwater and marine fish from northern Vietnam: Accumulation levels, profiles, and implications for human consumption. Mar. Pollut. Bull. 182. https://doi.org/10.1016/j.marpolbul.2022.113995.

Viet, P.H., Hoai, P.M., Minh, N.H., Ngoc, N.T., Hung, P.T., 2000. Persistent organochlorine pesticides and polychlorinated biphenyls in some agricultural and industrial areas in Northern Vietnam. Water Science and Technology 42 (7-8), 223-229. https://iwaponline.com/wst/article-pdf/42/7-8/223/29225/223.pdf.

Villeneuve, J.P., Cattini, C., Bajet, C.M., Navarro-Calingacion, M.F., Carvalho, F.P., 2010. PCBs in sediments and oysters of Manila Bay, the Philippines. Int. J. Environ. Health Res. 20 (4), 259-269. https://doi.org/10.1080/09603121003624299.

Vrana, B., Smedes, F., Hilscherová, K., 2020. Passive Sampling of Waterborne Contaminants. Methods in Pharmacology and Toxicology 29-63. https://doi.org/10.1007/7653_2020_43.

Vrana, B., Smedes, F., Rusina, T., Okonski, K., Allan, I., Grung, M., Hilscherova, K., Novak, J., Tarabek, P., Slobodnik, J., 2015. Passive sampling: chemical analysis and toxicological profiling. Joint Danube Survey 3. A Comprehensive Analysis of Danube Water Quality, pp. 304-315. International Commission for the Protection of the Danube River. https://www.researchgate.net/publication/274193677.

Vu-Duc, N., Duong-Thi, Q.M., Bui, V.H., Vu-Cam, T., Nguyen, T.T., Nguyen, T.T., Le, M. T., Nguyen, H.T., Nguyen, H.A., Chu, D.B., 2023. Analysis of perfluoroalkyl

compounds in marine fish muscle samples by liquid chromatography tandem mass spectrometry. Int. J. Environ. Anal. Chem. https://doi.org/10.1080/03067319.2023.2285377.

Wang, Q., Kelly, B.C., 2017. Occurrence and distribution of halogenated flame retardants in an urban watershed: Comparison to polychlorinated biphenyls and organochlorine pesticides. Environmental Pollution 231, 252-261. https://doi.org/10.1016/j.envpol.2017.07.092.

Wang, Q., Kelly, B.C., 2018. Assessing bioaccumulation behaviour of hydrophobic organic contaminants in a tropical urban catchment. J. Hazard. Mater. 358, 366-375. https://doi.org/10.1016/j.jhazmat.2018.06.070.

WHO, 2003. Polychlorinated Biphenyls: Human Health Aspects. World Health Organization.

World Bank. (2009). Timor-Leste: Country Environmental Analysis.

Wurl, O., Obbard, J.P., 2005. Chlorinated pesticides and PCBs in the sea-surface microlayer and seawater samples of Singapore. Mar. Pollut. Bull. 50 (11), 1233-1243. https://doi.org/10.1016/j.marpolbul.2005.04.022.

Wurl, O., Obbard, J.P., 2006. Distribution of organochlorine compounds in the sea-surface microlayer, water column and sediment of Singapore's coastal environment. Chemosphere 62 (7), 1105-1115. https://doi.org/10.1016/j.chemosphere.2005.06.002.

Yin, T., Chen, H., Reinhard, M., Yi, X., He, Y., Gin, K.Y.H., 2017. Perfluoroalkyl and polyfluoroalkyl substances removal in a full-scale tropical constructed wetland system treating landfill leachate. Water. Res. 125, 418-426. https://doi.org/10.1016/j.watres.2017.08.071.

Yu, F., Wu, J., Wang, H., Bao, Y., Xing, H., Ye, W., Li, X., Huang, M., 2024. Interaction of microplastics with perfluoroalkyl and polyfluoroalkyl substances in water: A review of the fate, mechanisms and toxicity. Science of The Total Environment 948, 175000. https://doi.org/10.1016/J.SCITOTENV.2024.175000.

Yu, H., Lin, T., Hu, L., Lammel, G., Zhao, S., Sun, X., Wu, X., Guo, Z., 2023. Sources of polychlorinated biphenyls (PCBs) in sediments of the East China marginal seas: Role of unintentionally-produced PCBs. Environmental Pollution 338, 122707. https://doi.org/10.1016/j.envPOL.2023.122707.

Yu, X., Mcphedran, K.N., Huang, R., 2022. Chlorinated paraffins: A review of sample preparation, instrumental analysis, and occurrence and distribution in food samples ☆ https://doi.org/10.1016/j.envpol.2022.120875.

Yuan, B., Muir, D., MacLeod, M., 2019. Methods for trace analysis of short-, medium-, and long-chain chlorinated paraffins: Critical review and recommendations. Anal. Chim. Acta 1074, 16-32. https://doi.org/10.1016/JACA.2019.02.051.

Yudhistira Azis, M., Setiyanto, H., Salim, A., Vita Hidayati, N., Asia, L., Piram, A., Doumenq, P., Dhamar Syakti, A., 2021. Evidence of Micropollutants in Sediment and Mud Clams (Polymesoda erosa) from One of Mangrove Biodiversity Hotspots in Indonesia. Polycycl. Aromat. Compd. 1-18. https://doi.org/10.1080/10406638.2021.1901127i.

Zeng, H.C., Zhu, B.Q., Wang, Y.Q., He, Q.Z., 2021. ROS-Triggered Autophagy Is Involved in PFOS-Induced Apoptosis of Human Embryo Liver L-02 Cells. Biomed. Res. Int. 2021 (1), 6625952. https://doi.org/10.1155/2021/6625952.

Zhang, H., Huo, S., Yeager, K.M., Li, C., Xi, B., Zhang, J., He, Z., Ma, C., 2019. Apparent relationships between anthropogenic factors and climate change indicators and POPs deposition in a lacustrine system. https://doi.org/10.1016/j.jes.2019.03.024.

Zhu, M., Yuan, Y., Yin, H., Guo, Z., Wei, X., Qi, X., Liu, H., Dang, Z., 2021. Environmental contamination and human exposure of polychlorinated biphenyls (PCBs) in China: A review. https://doi.org/10.1016/j.scitotenv.2021.150270.