A preliminary assessment of microplastic occurrence and their potential risk as pollutant transport vectors: A case study in Phu Ly, Ha Nam, Vietnam

doi:10.21203/rs.3.rs-2431881/v1

Download PDF

Research Article

A preliminary assessment of microplastic occurrence and their potential risk as pollutant transport vectors: A case study in Phu Ly, Ha Nam, Vietnam

https://doi.org/10.21203/rs.3.rs-2431881/v1

This work is licensed under a CC BY 4.0 License

Version 1

posted

You are reading this latest preprint version

Nowadays, microplastics are a global concern due to their potential environmental risks. However, there is currently a scarcity of data on the presence and health risks of microplastics in Southeast Asia, especially in Vietnam. This study investigated the levels of microplastics (MPs) in surface waters and sediments in Phu Ly, Ha Nam, Vietnam. MP concentrations range from 0.17 to 6.2 µg L^− 1 in surface water and 3.74 to 31.23 mg kg^− 1 wet-weight of sediment, respectively. Nine trace metals (TMs), including Cd, Pb, Co, Ni, Mn, Cr, As, Cu, and Zn, were detected to associate with MPs in surface water in a concentration range of 0.0004–42.75 mg/g. We hypothesized that the TMs adsorbed on the surface of MPs were strongly correlated with environmental pollution levels and hydrodynamic conditions. MPs can be viewed as transport vehicles for TMs in the aquatic environment. The link between AMR bacteria/ genes and MPs is weak, but the role of MPs in the transportation of those risks cannot be dismissed. Although the HQs of TMs associated with MPs in this study were less than 1, indicating low health risks from the pollutants, regular monitoring of MPs and other environmental concerns such as TMs and AMR are needed due to the high mobility of MPs in the ecological system.

Microplastics

Trace metals

antimicrobial resistance

health risk

transportation vehicle

The plastics industry increasingly produces roughly 9% yearly (Selvam et al., 2021). A large amount of plastic waste (approximately 8 million metric tons), mainly generated from terrestrial sources, has already been released into the ocean through inland waterways, industrial discharge, domestic wastewater outflows, as well as by winds or tides (Gao et al., 2019; Jambeck et al., 2015). Besides ecological impacts from large plastics, microplastics (MPs), generated from the degradation of plastic materials under environmental weathering, have been recognized as a global environmental problem (Sobhani et al., 2020). The main issues with MPs are their extreme durability in the environment, high potential risks of releasing plastic monomers and additives/chemicals, and remarkable capacity to adsorb/accumulate other environmental pollutants (Wright & Kelly, 2017).

Trace metals (TMs) are a common environmental hazard that can enter water bodies continually due to their inability to degrade. They are also recycled and enriched in the aqueous environment. In addition, trace metals and MPs also are offered as persistent and hazardous pollutants to the environment (Chen et al., 2022; Gao et al., 2019). MPs can adsorb hazardous contaminants like pollutant transport vehicles and concentrate them to a very high level because of their enormous surface area (Hildebrandt et al., 2021; Selvam et al., 2021; Zhou et al., 2020). When TMs carried by microplastics or attached to their surface can be transported easily on a global scale, transmitted further along the food chain, and cause potential health risks to the organisms (Rios Mendoza & Jones, 2015; Rochman et al., 2013)

Besides trace metals, the microbes in this ecosystem are also exposed to MP-related contaminants such as antimicrobial resistance (AMR). Plastic, an emerging pollutant, has the potential to increase AMR by supplying porous micro-ecosystems known as "plastisphere" (Kaur et al., 2022; Keswani et al., 2016). The plastisphere produces an environment that encourages microbial adhesion and subsequent biofilm development (Zettler et al., 2013). Antibiotic-resistant bacteria are thought to be the primary causes of AMR (Kraemer et al., 2019), and TMs contamination is associated with a higher frequency and quantity of antibiotic resistance genes, which also drives the selection for antibiotic resistance genes (ARGs) (Baker-Austin et al., 2006; Li et al., 2017; Nguyen et al., 2019).

Vietnam is one of Asian countries with highest rates of AMR due to the overuse of antimicrobial drugs, both in the animal health sector and in humans in both hospitals and the community. (Bui et al., 2018). As they are often used in hospitals and aquaculture, those emerging pollutants are present in high concentrations (ppm) in Vietnam's water environment. According to a recent assessment, there is a high prevalence of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae in Vietnam, including Escherichia coli, Klebsiella pneumoniae and nontyphoidal Salmonella as well as ESBL-encoding genes such as bla_CTX−M, bla_TEM and bla_SHV, in both community and nosocomial settings (Bui et al., 2018). Increasing levels of β-lactams, including cephalosporin, and colistin resistance, have been reported (Nguyen Nhung et al., 2016).

The Nhue – Day river is also one of the most contaminated rivers, ranking third overall in Vietnam. However, the Nhue River's contaminated water is mostly used for irrigation of significant paddy rice and vegetable crops in peri-urban regions and fishponds (Hanh et al., 2010). The pollution of TMs in the basin was reported in several studies, and it can result in severe potential threats to natural ecosystems due to its toxicity, persistence, and bioaccumulation (Ngo et al., 2021). Until now, no previous research has taken into account the connection between microplastic pollution of the water and sediment and other pollutants, including trace metals and antimicrobial microorganisms). The purpose of this study was to investigate the following issues: (1) the presence of MPs in different locations in the Nhue-Day river basin, including rivers and ponds; (2) the pollution status of trace metals (Cd, Pb, Co, Ni, Mn, Cr, As, Cu and Zn) and AMR associated with MPs; and (3) the potential health risks linked to pollutants that stick to the surface of MPs.

2.1. Study sites

The Nhue–Day River Basin and locations of sampling locations are illustrated in Fig. 1 and Table S1. The sampling areas include the Nhue river (Site 1, near Kim Binh industrial zone), Day River (site 2, after Chau Son and Thanh Liem industrial zones to Ha Nam Province), as well as after confluence of Day river with Nhue river (site 3). A total of six sediments and six water samples were collected in June 2022. For surface water, a certain volume of surface water per site was collected via the phytoplankton net with a 80 µm mesh size (Wildco 3-426-A37).

2.2. Chemicals

Calcium dichloride (CaCl₂), potassium chloride (KCl), sodium phosphate dibasic (Na₂HPO₄), potassium phosphate monobasic (KH₂PO₄), acid hydrochloric (HCl), sodium hydroxide (NaOH), nitric acid (HNO₃), Hydro peroxide (H₂O₂) 30% were purchased at analytical grade from Merck (Germany). The commercial MacConkey selective medium was purchased from Bimetech (Vietnam). EDTA and Tris – HCl (prepared for TE buffer), Cefotaxime and glucose were from Sigma (Germany). The other materials used in molecular experiments were purchased from Biotium (Hayward, CA).

2.3. Microplastic separation

2.3.1. Microplastic separation from sediments or water

The microplastic separation was followed previous study (Duong et al., 2022) with a minor modification. A certain amount of wet sediment sample was poured through a stainless-steel sieve with 5 different sieving sizes in the order of 10 mm, 7 mm; 5 mm; 0.25 mm (sieve diameter 200 mm) from top to bottom. The sediment was washed under running water gently to avoid losing microorganisms and contaminants on the surface. The remaining materials were collected on the 0.25 mm sieve and placed them in the saturated CaCl₂ solution for density separation. That solution was settled overnight at room temperature. The supernatant was poured through a 0.25mm sieve. The remaining materials were washed several times with RO water. The microplastics were collected under stereo microscope (Euromex, model SB.1902) and stored for further experiment.

For water samples, CaCl₂ was added directly until solutions were saturated. Then microplastic was separated similarly the sediment samples.

2.3.2. Microplastic separation for microorganism analysis

Sediments were prepared as section 2.3.1. Microplastics from the washed materials and surface water were collected directly under stereo microscope and stored in sterilized Phosphate buffer saline 0.2M and pH 7.4 at 4^oC for further experiment.

2.4 Trace metal extraction from MPs

1.5 ml of 30% HCl and 0.5 ml of 65% HNO₃ (v/v 3:1) were added each sample and samples were incubated at room temperature for 24 hours (in a fume hood). After that, 200 µl of H₂O₂ was added to each sample tube and kept at room temperature for 5 hrs before digested in microwave. For the controls, blank sample containing only 1.5 ml HCl 37% and 0.5 ml HNO₃ 65% and 1 reference sample for each set of samples were prepared. The samples were digested by microwave system (Speedwave entry, Berghof). After cooling to room temperature in a fume hood, samples were diluted with distilled water to 10 mL, filtered with a 0.45 µm cellulose membrane filter and analyzed by High Resolution Inductively Coupled Plasma Mass Spectrometer instrument (HR-ICP-MS, Thermo Finnigan Element II).

2.5 AMR bacteria and gene detection

Samples containing microplastics in PBS buffer were vortexed for 10 minutes and centrifuged to collect the supernatants. After that, 5µl of solution was spread on MacConkey selective medium containing 30 µg Cefotaxime antibiotic. The samples were incubated 37°C for 18 to 24 hrs. The E. coli suspected was selected via yellow colonies forming during glucose fermentation. Suspected colonies will be isolated for DNA and screening antibiotic resistant gene following previous study (Le et al., 2015). Genotypes of β-lactamases were assessed using multiplex PCR using primers specific to the TEM, SHV, CTX-M-1, CTX-M-2, CTX-M-8, CTX-M-9, and CTX-M-25 groups, as described in Table S2. PCR amplification was conducted with. the following conditions: initial denaturation at 95^oC for 5 min, followed by 25 cycles of denaturation at 95^oC for 30 s, annealing at 60^oC for 90 s, extension at 72^oC for 90 s, and a final cycle of amplification at 68^oC for 10 min. The amplified products were visualized using 1.5% agarose gel electrophoresis and staining with gel red (Biotium, Hayward, CA).

2.6. Health risk assessment of heavy metals

To evaluate the human health hazard of the eight heavy metals on microplastics, were assessed with the modified human health risk assessment (HHRA) model based on bioaccessibility (Chen et al., 2022; Zhou et al., 2020). For the risk assessment, the average daily intake (EDI, mg·kg^− 1·day^− 1) of heavy metals on microplastics was first calculated:

\(EDI= \frac{{M}_{c} x IR x EF x ED}{BW x AT} x {10}^{-6}\) [Eq. 1]

where M_c is the concentration of the TMs on microplastics (mg·kg^− 1); IR is the ingestion rate, which was estimated 583 ng x person^− 1x day^− 1 for adults, respectively; EF is the exposure frequency, which was set as 350 days; and ED is the exposure duration set as 24 years for adults; BW is the average body weight, which was set as 59.4 kg for male and 50.27 kg for female (Nutrition, 2012); AT is the averaging time (for noncarcinogenic risk: ED × 365 days; for carcinogenic risk: 70 × 365 days); and 1 × 10^− 6 is the conversion factor.

The noncarcinogenic risks due to ingestion of As, Cr, Cd, and Pb on microplastics were assessed based on the hazard quotient (HQ), which was calculated using Eq. (2):

\(HQ= \frac{EDI}{RfD} x {10}^{-3}\) [Eq. 2]

where EDI is the average daily intake of heavy metals on microplastics (mg kg^− 1 day^− 1); and RfD is the reference dose of daily intake. The RfDs for As, Cr, Cd, Ni, Mn-non diet, Cu and Zn are 3.0 × 10^− 4, 3.0 × 10^− 3, 1.0 × 10^− 3, 8.5 x 10^− 3_, 0.04 and 0.3 mg·(kg·day)⁻¹, respectively. As there is no RfD value for Pb, we use MRL representing for Pb, 0.2 mg·(kg·day)⁻¹. The THQ for Pb was calculated as follows:

\(THQ= \frac{{M}_{c} }{MRL}\) (Eq. 3)

Where: the MRL is the maximum limit of Pb in rice grains acquired by the Codex Alimentarius Commission

When the HQ value < 1, there is no noncarcinogenic risk to humans. The HQ value ≥ 1 indicates that the level of exposure is likely to cause chronic noncarcinogenic risks (USEPA, 2016).

2.7. Quality assurance and quality control

To minimize the risk of contamination, the usage of plastic materials was reduced. Before use, all equipment utilized for sampling and tests was thoroughly cleaned with distilled water. Aluminum foil was used to cover or wrap all exposed items were for analysis. The experiment-related liquids were filtered by 1.2 µm GF/C glass filters. Cotton jackets or lab coats were worn during the entirety of the research and sampling. The blank controls were present throughout the experiment and the existence of MPs in those samples was subtracted from the data's final calculation.

3.1. Occurrence of microplastics in surface water and sediment in Phu Ly - Ha Nam

In our study, MPs can be found in all investigated freshwater components, including surface water, sediments from rivers and ponds (Fig. 2). The colors of those debris were observed in black, red, blue and clear white. Two main shape groups of fiber and fragment were detected. The color variation reflects the different sources and components of microplastics released into the environment and represents their ability to carry more harmful substances such as heavy metals and organic pollutants (Gallagher et al., 2016; Lahijan zadeh et al., 2020). In the previous study (Naji et al., 2019) conducted in Bandar Abbas, the predominant color of the microplastics found in the sediment was white/clear, and black/gray, representing the sources of microplastic were mostly from man-made.

The high concentration of MPs in Phu Ly (Ha Nam) was observed and shown in Fig. 3. The MP concentrations in pond surface water were higher than those detected in river. In specific, concentrations of MP in WS1P1, WS1P2 and WS2P were 2.8, 2.3 and 6.2 µg L^− 1 of surface water, whereas the ones in WS1, WS2 and WS3 were in range from 0.17 to 1.1 µg L^− 1. Interestingly, a similar result trend was observed in pond sediments in which MP levels in SS1P1, SS1P2 and SS3 were 3.74, 16.48 and 31.23 mg kg^− 1 wet weight, respectively. It was from 1.5 to over 30 times higher than river sediments. Especially, MPs concentration of sediment in S₁P₂ was 38 times higher than those in S1. A similar observation was reported in previous study (Xiong et al., 2022) in which, the ponds received the major inland-sourced plastic wastes in the water system, and the microplastics they were in turn transported into the surrounding natural water bodies. Another study (Sukanya et al., 2020) showed that the accumulation of MPs in stagnant system such as pond is higher and he also mentioned that the condemnation in water is observed higher in riverine near industrial area as compared to the residential area. It was well correlated with our study’s results. Higher levels of MPs were distributed in sites 1 and 2 located near Kim Binh or Chau Son industrial zones than the one in site 3 closing to residential area.

There are several reports about MPs pollutions in rivers in Vietnam (Duong et al., 2022; Lahens et al., 2018; Le et al., 2022), however, the results were not considerably compared. The significant differences in MP levels among this study and others in Vietnam may be explained by the following reasons. Firstly, the sampling area in the current study is a suburban area where land is used for aquaculture, residential zones and several industrial factories. In contrast, other studies were conducted in densely populated areas such as Hanoi city or Red river Delta. The Nhue-Day river basin is location receiving water from Red river and wastewater from traditional craft villages and industrial zone in upstream areas. Seconds, different seasons for sampling in the studies might cause the variation of data. The study at Le collected samples in January/ February (Le et al., 2022) while our study and Duong’s reported the sampling work during June (Duong et al., 2022). Due to sampling at single seasonal period, it is difficult to make direct comparisons among the different studies as the MPs in river mobilizes via water flow and hydrodynamic conditions.

3.2. Trace metals extracted from MPs

As shown in Fig. 4 and Table S3, nine types of trace metals including Cd, Pb, Co, Ni, Mn, Cr, As, Cu and Zn were detected in the extracted solution of MPs. In surface water, Zn, Mn and Cu presented the highest level while Cd, Co and total As were the lowest pollutants. A similar observation was mentioned in the previous study (Ta & Babel, 2020); he observed that among six metals, Zn was found at the highest concentration in MPs while Cd was found at the lowest one. The MPs result from our study were detected from 0.0004–42.75 mg/g in surface water, whereas study of Ta et al. (2020), TMs were found in water samples with concentration from 3.52–39.22 µg/g. it is worthy noted that concentrations of the metals were normalized to the dry weight of MPs. The comparable concentrations of TMs extracted from MPs was also reported in the North Atlantic Gyre (Prunier et al., 2019) or the island of Vis, Adriatic Sea, Croatia (Maršić-Lučić et al., 2018).

The TM concentration detected in extract solution could be from various sources. It is possible for (1) the sorption of these metals from the water to MPs; (2) added stabilizers and pigments to increase the strength of plastics and create colors for plastic products (Brennecke et al., 2016; Hahladakis et al., 2018). The higher concentrations of trace metals in this report represented that a significant contamination level of the pollutants in the study sites were adsorbed on MPs. There is an evident (Rochman et al., 2014) indicating that the adsorption of metals doesn't significantly depend on a plastic type, it indicated that that the formation of biofilms, other environmental conditions such as pH and organic matter adsorption plays the most significant role when it comes to metal adsorption onto plastic surface (Coclet et al., 2021; Zettler et al., 2013).

Interestingly, the correlation of TM concentration between surface water and sediment or between pond and river were strongly observed. The trend of TM concentration extracted from MP were in the reverse order between surface water and sediment. In specific, the TM lelvel in surface water increased as the order of S2P < S3 < S1P2 < S1P1 < S2 < S1 while the one in sediment was S1P2 < S1 < S1P1 < S3 < S2P < S2. In addition, TM from MPs in pond water samples (WS1P2, WS1P2 and WS2P) showed similar patterns to the one in the river at the same sites. It can be explained that the water in aquaculture ponds is drawn from rivers, the metal levels in the pond fluctuate in accordance with the river water, exception Mn and Zn. It can prove for the hypothesis that MPs can easily absorbed trace metals and be their transporting vehicles in the environments.

3.3. The results of analysis for E. coli bacteria carrying the ESBL phenotype and detection of the ESBL encoding gene of the isolated strain E. coli

There was an evident that MPs could be microbial carrier but no AMR gene was detected from MP samples in this study. Among 18 samples analyzed, E. coli was found in 2 water samples (samples 7 and 11), in which sample no. 7 carried the CTX-M gene and no. 11 carried the TEM gene (Table 1). The suspected E. coli colonies in sample no.9, was identified negativly for E. coli, but found carrying the TEM gene when running multiplex PCR. Based on the above results, we find that the finding of two genes TEM and CTX-M (CTX-M: 94.1% and TEM: 45.3%) is consistent with many studies in Vietnam because the distribution of these genes is quite common in Vietnam and around the world recently. In addition, the suspected bacteria was found in MPs extracted solution but the AMR genes were detected from surface water in Site 1 (river and pond) and site 2 (river).

Table 1

ESBL-positive *E. coli* isolates and AMR gene found in MPs at the different sites
No	Coding samples	Type of samples	E. coli carrying ESBL (Mac/CTX)	CFU	AMR gene (PCR multiple primer)
1	WS₁P₁	Microplastic from separated from water	Neg	0	Neg
2	WS₁P₂		Neg	0	Neg
3	WS₁R		Neg	0	Neg
4	WS₂P		suspected	10²	Neg
5	WS₂R		suspected	10²	Neg
6	WS₃R		suspected	3	Neg
7	S₁P₁	Only Water	Pos	2	CTX-M
8	S₁P₂		Suspected	10⁶	Neg
9	S₁R		Suspected	10⁶	TEM
10	S₂P₁		Suspected	10³	Neg
11	S₂R		Pos	5	TEM
12	S₃R		Suspected	3	Neg
13	SS₁P₁	MPs separated fro Sediments	Suspected	10⁶	Neg
14	SS₁P₂		Suspected	10²	Neg
15	SS₁R		Suspected	5x10²	Neg
16	SS₂P₁		Suspected	10²	Neg
17	SS₂R		Suspected	10⁵	Neg
18	SS₃R		Suspected	10⁵	Neg
Neg: Negative
Pos: Positive

Several microbes have been reported to have the abilities of attaching them to the MPs, including Vibrio sp. (Kesy et al., 2020), Escherichia coli (Feng et al., 2022), Pseudomonas sp. (Metcalf et al., 2022), and Mycobacterium (Zhu et al., 2022) and are contributing to microplastic-associated AMR. AMR genes including sulphonamide resistance genes (sul1 and sul2), aminoglycoside resistance genes (strB), β-lactam resistance genes (bla_OXA and bla_TEM) were identified as abundance in the long-time exposed microplastic containing biofilms of Pseudomonas, Syntrophomonas, and Desulfotomaculum in wastewater landfill leachate with increasing environmental risks (J. J. Shi et al., 2020 (Shi et al., 2021)). Furthermore, other studies showed that TMs could induce the co-selection antibiotic resistance of microbe (Vats et al., 2022; Wang et al., 2020). Primarily via water environment, the transfer of ARGs across bacterial genera was observed to increase under subinhibitory concentrations of Cu and Ag nanoparticles as well as heavy metals ions, such as Cu (II), Cr (VI), Ag(I), Zn(II). This makes it easier for environmental as well as pathogenic bacteria to spread antibiotic resistance. If the MPs could carry both TMs and AMR on its surface, there might result in more complex environmental concerns to ecological system.

Because this result is only done on a small sample size, so to have more specific and accurate conclusions about the antibiotic resistance of bacteria, in the future, it is necessary to have studies with a large sample size. Moreover, the sample types are more diverse and studied on more bacterial agents, thereby showing the flexible and unpredictable and difficult to control variation of antibiotic resistance in bacteria.

3.4. Health risk assessment

In our study, the HQs for both male and female shown in Table 2 were much lower than the safe level (< 1.0), indicating that ingestion of microplastics containing those trace metals will not pose a noncarcinogenic risk to humans. The noncarcinogenic HQs of individual heavy metals based on the total heavy metal concentrations from microplastics decreased in the order Zn > Cu ≈ Mn > Cr > Ni ≈ Cd ≈ As (total) > Pb. Moreover, the highest HQ values were observed in most of samples from surface river water (WS1, WS2 and WS3).

Table 2

Hazard quotient of trace metals extracted from microplastics
		WS1	WS1P1	WS1P2	WS2	WS2P	WS3	SS1	SS1P1	SS1P2	SS2	SS2P	SS3
Cd	Male	5.2 x10^− 9	4.3 x10^− 11	1.1 x10^− 11	1.1 x10^− 9	1.3 x10^− 12	3.8 x10^− 11	5.5 x10^− 13	3.6 x10^− 12	2.3 x10^− 12	2.4 x10^− 13	1.3 x10^− 11	2.1 x10^− 12
Cd	Female	2.6 x10^− 6	2.2 x10^− 8	5.4 x10^− 9	5.3 x10^− 7	6.6 x10^− 10	1.9 x10^− 8	2.8 x10^− 10	1.9 x10^− 9	1.1 x10^− 9	1.2 x10^− 10	6.5 x10^− 9	1.1 x10^− 9
Pb	Male	7.3 x10^− 8	5.2 x10^− 9	4.1 x10^− 10	3.9 x10^− 8	1.6 x10^− 10	7.2 x10^− 10	1.5 x10^− 10	1.9 x10^− 10	1.8 x10^− 11	2.1 x10^− 10	8.6 x10^− 11	3.4 x10^− 11
Pb	Female	1.9 x10^− 7	1.3 x10^− 8	1.1 x10^− 9	9.8 x10^− 8	4.2 x10^− 10	1.8 x10^− 9	3.8 x10^− 10	4.9 x10^− 10	4.6 x10^− 11	5.4 x10^− 10	2.2 x10^− 10	8.7 x10^− 11
Cr	Male	6.3 x10^− 8	3.2 x10^− 9	4.6 x10^− 10	1.8 x10^− 8	3.3 x10^− 10	5.0 x10^− 10	4.0 x10^− 11	7.4 x10^− 11	1.1 x10^− 11	8.5 x10^− 11	3.2 x10^− 11	4.1 x10^− 11
Cr	Female	3.2 x10^− 5	1.6 x10^− 6	2.4 x10^− 7	9.0 x10^− 6	1.7 x10^− 7	2.5 x10^− 7	2.1 x10^− 8	3.8 x10^− 8	5.5 x10^− 9	4.3 x10^− 8	1.6 x10^− 8	2.1 x10^− 8
Mn	Male	1.4 x10^− 7	2.8 x10^− 9	1.2 x10^− 9	6.0 x10^− 8	8.2 x10^− 10	1.4 x10^− 9	1.7 x10^− 10	4.2 x10^− 10	2.7 x10^− 11	5.5 x10^− 10	5.2 x10^− 10	4.6 x10^− 10
Mn	Female	6.9 x10^− 5	1.4 x10^− 6	6.3 x10^− 7	3.0 x10^− 5	4.2 x10^− 7	7.0 x10^− 7	8.7 x10^− 8	2.1 x10^− 7	1.4 x10^− 8	2.8 x10^− 7	2.6 x10^− 7	2.4 x10^− 7
Ni	Male	4.8 x10^− 9	3.8 x10^− 9	4.8 x10^− 10	1.8 x10^− 8	2.8 x10^− 10	6.8 x10^− 10	1.8 x10^− 11	1.7 x10^− 11	4.9 x10^− 12	7.4 x10^− 12	2.1 x10^− 11	1.6 x10^− 11
Ni	Female	2.7 x10^− 5	2.0 x10^− 6	2.5 x10^− 7	9.0 x10^− 6	1.4 x10^− 7	3.5 x10^− 7	9.2 x10^− 9	8.7 x10^− 9	2.5 x10^− 9	3.8 x10^− 9	1.1 x10^− 8	7.9 x10^− 9
Cu	Male	1.4 x10^− 7	2.5 x10^− 8	6.0 x10^− 9	6.8 x10^− 8	6.3 x10^− 10	2.7 x10^− 9	1.2 x10^− 10	1.4 x10^− 10	2.7 x10^− 11	1.2 x10^− 10	5.5 x10^− 11	1.3 x10^− 10
Cu	Female	7.0 x10^− 5	1.3 x10^− 5	3.1 x10^− 6	3.5 x10^− 5	3.2 x10^− 7	1.4 x10^− 6	6.1 x10^− 8	7.0 x10^− 8	1.4 x10^− 8	6.1 x10^− 8	2.8 x10^− 8	6.7 x10^− 8
Zn	Male	3.2 x10^− 5	7.8 x10^− 7	4.3 x10^− 8	2.1 x10^− 6	1.6 x10^− 8	6.4 x10^− 8	1.2 x10^− 9	1.3 x10^− 7	8.4 x10^− 9	2.4 x10^− 8	3.3 x10^− 8	1.8 x10^− 8
Zn	Female	0.01607	0.000394	2.2 x10^− 5	0.001041	8.3 x10^− 6	3.3 x10^− 5	6.1 x10^− 7	6.7 x10^− 5	4.3 x10^− 6	1.2 x10^− 5	1.7 x10^− 5	8.9 x10^− 6
As	Male	9.8 x10^− 9	6.5 x10^− 10	2.1 x10^− 10	4.7 x10^− 9	4.4 x10^− 11	2.4 x10^− 10	2.7 x10^− 11	1.9 x10^− 11	1.0 x10^− 11	3.3 x10^− 11	2.2 x10^− 11	4.4 x10^− 11
As	Female	5.0 x10^− 6	3.3 x10^− 7	1.1 x10^− 7	2.4 x10^− 6	2.2 x10^− 8	1.2 x10^− 7	1.4 x10^− 8	9.4 x10^− 9	5.1 x10^− 9	1.7 x10^− 8	1.1 x10^− 8	2.2 x10^− 8

The main difference between plastic particles and TMs in terms of their environmental risk is that comparatively little is known about the actual risk posed by plastic contamination. In general, it should be clear that plastics, in contrast to TMs, do not have any benefit or use within the environment, as they are anthropogenic foreign objects in soils, sediments, or water. Currently, the toxic mechanisms of MPs toward ecological system are not clear. However, studies reported that MPs can act as vectors for carrying the metals into the ecosystem and human bodies (Brennecke et al., 2016). According to previous report (Akhbarizadeh et al., 2018), a strong relationship between the presence of MPs and toxic metals in fish species (i.e. A. djedaba and P. indicus) was confirmed. Thus, the consumption of high doses of fish may pose a health threat to consumers. Moreover, a study by Roman (Roman et al., 2020) found a correlation between plastic ingestion and increasing heavy-metal concentrations in seabirds. MPs found in the study can carry toxic metals and other pollutants from additives or surrounding environments into living organisms. In general, with a lack of robust data describing the tranferring pathway MPs and associated contaminants to food web, it implicates that the potential risk may exist for eating seafood but is insufficient to inform the ecolotoxicology of MPs in term of health risk assessment.

This work is a crucial beginning point for examining how microplastics might be a vehicle to harbor and transport environmental pollutants such as trace metals or antimicrobial resistence risks. This finding was the first assesment of MPs level in Nhue – Day river basin. Our study proposed that the sources of trace metals on MPs were mainly correlated with environmental conditions. Besides, we also demonstrated that a low connection between AMR and MPs but it roles in transportation of ESBL-bacteria cannot be dismissed. Rather, further studies are essential to allow for more solid results of seasonal variation of MPs distribution, roles of MPs in transportation of environmental issues and ecological risk assessment.

Acknowledgments

This work was funded by the SEAOHUN Small Grant Program with the generous support of the American people through US Agency for International Development (USAID) One Health Workforce - Next Generation (OHW-NG) Award 7200AA19CA00018. The contents and associated materials are the responsibility of the authors and do not necessarily reflect the views of USAID or the US Government.

Competing Interests

The authors have no relevant financial or non-financial interests to disclose.

Author Contributions

Le T. T. and Ngo T.T.H. contributed to the study conception and design. Material preparation, data collection and analysis were performed by all authors. The first draft of the manuscript was written by Le T.T.H and Ngo T.T.H. and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Data Availability

The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.

Akhbarizadeh, R., Moore, F., Keshavarzi, B. (2018) Investigating a probable relationship between microplastics and potentially toxic elements in fish muscles from northeast of Persian Gulf. Environ. Pol. 232 154-163. https://doi.org/10.1016/j.envpol.2017.09.028
Baker-Austin, C., Wright, M.S., Stepanauskas, R., McArthur, J.V. (2006) Co-selection of antibiotic and metal resistance. Trends Microbiol. 14 (4) 176-182. https://doi.org/10.1016/j.tim.2006.02.006
Brennecke, D., Duarte, B., Paiva, F., Caçador, I., Canning-Clode, J. (2016) Microplastics as vector for heavy metal contamination from the marine environment. Estuar. Coast. Shelf Sci. 178 189-195. https://doi.org/10.1016/j.ecss.2015.12.003
Bui, T.K.N., Bui, T.M.H., Ueda, S., Le, D.T., Yamamoto, Y., Hirai, I. (2018) Potential transmission opportunity of CTX-M-producing Escherichia coli on a large-scale chicken farm in Vietnam. J. Glob. Antimicrob. Resist. 13 1-6. https://doi.org/10.1016/j.jgar.2017.09.014
Chen, X.-j., Ma, J.-j., Yu, R.-l., Hu, G.-r., Yan, Y. (2022) Bioaccessibility of microplastic-associated heavy metals using an in vitro digestion model and its implications for human health risk assessment. Environ. Sci. Pollut. Res. 29 (51) 76983-76991. 10.1007/s11356-022-20983-8
Coclet, C., Garnier, C., D'Onofrio, S., Durrieu, G., Pasero, E., Le Poupon, C., Omanovic, D., Mullot, J.U., Misson, B., Briand, J.F. (2021) Trace Metal Contamination Impacts Predicted Functions More Than Structure of Marine Prokaryotic Biofilm Communities in an Anthropized Coastal Area. Front. Microbiol. 12 589948. 10.3389/fmicb.2021.589948
Duong, T.T., Le, P.T., Nguyen, T.N.H., Hoang, T.Q., Ngo, H.M., Doan, T.O., Le, T.P.Q., Bui, H.T., Bui, M.H., Trinh, V.T., Nguyen, T.L., Da Le, N., Vu, T.M., Tran, T.K.C., Ho, T.C., Phuong, N.N., Strady, E. (2022) Selection of a density separation solution to study microplastics in tropical riverine sediment. Environ. Monit. Assess. 194 (2) 65. 10.1007/s10661-021-09664-0
Feng, L.-J., Zhang, K.-X., Shi, Z.-L., Zhu, F.-P., Yuan, X.-Z., Zong, W.-S., Song, C. (2022) Aged microplastics enhance their interaction with ciprofloxacin and joint toxicity on Escherichia coli. Ecotoxicol Environ Saf 247 114218. https://doi.org/10.1016/j.ecoenv.2022.114218
Gallagher, A., Rees, A., Rowe, R., Stevens, J., Wright, P. (2016) Microplastics in the Solent estuarine complex, UK: An initial assessment. Mar. Pollut. Bull. 102 (2) 243-249. https://doi.org/10.1016/j.marpolbul.2015.04.002
Gao, F., Li, J., Sun, C., Zhang, L., Jiang, F., Cao, W., Zheng, L. (2019) Study on the capability and characteristics of heavy metals enriched on microplastics in marine environment. Mar. Pollut. Bull. 144 61-67. https://doi.org/10.1016/j.marpolbul.2019.04.039
Hahladakis, J.N., Velis, C.A., Weber, R., Iacovidou, E., Purnell, P. (2018) An overview of chemical additives present in plastics: Migration, release, fate and environmental impact during their use, disposal and recycling. J. Hazard. Mater. 344 179-199. https://doi.org/10.1016/j.jhazmat.2017.10.014
Hanh, P.T.M., Sthiannopkao, S., Kim, K.-W., Ba, D.T., Hung, N.Q. (2010) Anthropogenic influence on surface water quality of the Nhue and Day sub-river systems in Vietnam. Environ Geochem Health. 32 (3) 227-236. 10.1007/s10653-009-9279-9
Hildebrandt, L., Nack, F.L., Zimmermann, T., Pröfrock, D. (2021) Microplastics as a Trojan horse for trace metals. J. Hazard. Mater. Let. 2 100035. https://doi.org/10.1016/j.hazl.2021.100035
Jambeck, J.R., Geyer, R., Wilcox, C., Siegler, T.R., Perryman, M., Andrady, A., Narayan, R., Law, K.L. (2015) Plastic waste inputs from land into the ocean. Science 347 (6223) 768-771. 10.1126/science.1260352
Kaur, K., Reddy, S., Barathe, P., Oak, U., Shriram, V., Kharat, S.S., Govarthanan, M., Kumar, V. (2022) Microplastic-associated pathogens and antimicrobial resistance in environment. Chemosphere 291 133005. https://doi.org/10.1016/j.chemosphere.2021.133005
Keswani, A., Oliver, D.M., Gutierrez, T., Quilliam, R.S. (2016) Microbial hitchhikers on marine plastic debris: Human exposure risks at bathing waters and beach environments. Mar. Environ. Res. 118 10-19. https://doi.org/10.1016/j.marenvres.2016.04.006
Kesy, K., Labrenz, M., Scales, B.S., Kreikemeyer, B., Oberbeckmann, S. (2020) Vibrio Colonization Is Highly Dynamic in Early Microplastic-Associated Biofilms as Well as on Field-Collected Microplastics. Microorganisms 9 (1) 10.3390/microorganisms9010076
Kraemer, S.A., Ramachandran, A., Perron, G.G. 2019. Antibiotic Pollution in the Environment: From Microbial Ecology to Public Policy. in: Microorganisms, Vol. 7.
Lahens, L., Strady, E., Kieu-Le, T.-C., Dris, R., Boukerma, K., Rinnert, E., Gasperi, J., Tassin, B. (2018) Macroplastic and microplastic contamination assessment of a tropical river (Saigon River, Vietnam) transversed by a developing megacity. Environ. Pol. 236 661-671. https://doi.org/10.1016/j.envpol.2018.02.005
Lahijan zadeh, A., Mohammadi roozbahani, M., Sabzalipour, S., Nabavi, M. (2020) The Investigation of Microplastic Particles in Khor-e-Musa in Persian Gulf Sediments. JOC 11 (43) 17-25. 10.52547/joc.11.43.17
Le, N.D., Hoang, T.T.H., Duong, T.T., Lu, X., Pham, T.M.H., Phung, T.X.B., Le, T.M.H., Duong, T.H., Nguyen, T.D., Le, T.P.Q. (2022) First observation of microplastics in surface sediment of some aquaculture ponds in Hanoi city, Vietnam. J. Hazard. Mater. Adv. 6 100061. https://doi.org/10.1016/j.hazadv.2022.100061
Le, Q.P., Ueda, S., Nguyen, T.N.H., Dao, T.V.K., Van Hoang, T.A., Tran, T.T.N., Hirai, I., Nakayama, T., Kawahara, R., Do, T.H., Vien, Q.M., Yamamoto, Y. (2015) Characteristics of Extended-Spectrum β-Lactamase–Producing Escherichia coli in Retail Meats and Shrimp at a Local Market in Vietnam. Foodborne Pathog. Dis. 12 (8) 719-725. 10.1089/fpd.2015.1954
Li, L.-G., Xia, Y., Zhang, T. (2017) Co-occurrence of antibiotic and metal resistance genes revealed in complete genome collection. The ISME J. 11 (3) 651-662. 10.1038/ismej.2016.155
Maršić-Lučić, J., Lušić, J., Tutman, P., Bojanić Varezić, D., Šiljić, J., Pribudić, J. (2018) Levels of trace metals on microplastic particles in beach sediments of the island of Vis, Adriatic Sea, Croatia. Mar. Pollut. Bull. 137 231-236. https://doi.org/10.1016/j.marpolbul.2018.10.027
Metcalf, R., Oliver, D.M., Moresco, V., Quilliam, R.S. (2022) Quantifying the importance of plastic pollution for the dissemination of human pathogens: The challenges of choosing an appropriate ‘control’ material. Sci. Total Environ. 810 152292. https://doi.org/10.1016/j.scitotenv.2021.152292
Naji, A., Nuri, M., Amiri, P., Niyogi, S. (2019) Small microplastic particles (S-MPPs) in sediments of mangrove ecosystem on the northern coast of the Persian Gulf. Mar. Pollut. Bull. 146 305-311. https://doi.org/10.1016/j.marpolbul.2019.06.033
Ngo, H.T., Tran, L.A., Nguyen, D.Q., Nguyen, T.T., Le, T.T., Gao, Y. 2021. Metal Pollution and Bioaccumulation in the Nhue-Day River Basin, Vietnam: Potential Ecological and Human Health Risks. in: International Int. J. Environ. Res. Public Health, Vol. 18.
Nguyen, C.C., Hugie, C.N., Kile, M.L., Navab-Daneshmand, T. (2019) Association between heavy metals and antibiotic-resistant human pathogens in environmental reservoirs: A review. Front Environ Sci Eng. 13 (3) 46. 10.1007/s11783-019-1129-0
Nguyen Nhung, T., Nguyen Hoa, M., Nguyen Cuong, V., Nguyen Trung, V., Nguyen Men, T., Thai Hieu, Q., Ho Mai, H., Thwaites, G., Ngo Hoa, T., Baker, S., Carrique-Mas, J. (2016) Use of Colistin and Other Critical Antimicrobials on Pig and Chicken Farms in Southern Vietnam and Its Association with Resistance in Commensal Escherichia coli Bacteria. Appl. Environ. Microbiol. 82 (13) 3727-3735. 10.1128/AEM.00337-16
Nutrition, N.I.o. (2012) National Institute of Nutrition, UNICEF-Viet Nam, A review of the Nutrition situation in Vietnam 2009-2010. http://viendinhduong.vn/en/nutrition-database/a-review-of-the-nutrition-situation-in-vietnam-2009-2010.html. Accessed date: December 2022.
Prunier, J., Maurice, L., Perez, E., Gigault, J., Pierson Wickmann, A.-C., Davranche, M., Halle, A.t. (2019) Trace metals in polyethylene debris from the North Atlantic subtropical gyre. Environ. Pol. 245 371-379. https://doi.org/10.1016/j.envpol.2018.10.043
Rios Mendoza, L.M., Jones, P.R. (2015) Characterisation of microplastics and toxic chemicals extracted from microplastic samples from the North Pacific Gyre. Environ. Chem. 12 (5) 611-617.
Rochman, C.M., Hentschel, B.T., Teh, S.J. (2014) Long-Term Sorption of Metals Is Similar among Plastic Types: Implications for Plastic Debris in Aquatic Environments. PLOS ONE 9 (1) e85433. 10.1371/journal.pone.0085433
Rochman, C.M., Hoh, E., Kurobe, T., Teh, S.J. (2013) Ingested plastic transfers hazardous chemicals to fish and induces hepatic stress. Sci. Reports 3 (1) 3263. 10.1038/srep03263
Roman, L., Kastury, F., Petit, S., Aleman, R., Wilcox, C., Hardesty, B.D., Hindell, M.A. (2020) Plastic, nutrition and pollution; relationships between ingested plastic and metal concentrations in the livers of two Pachyptila seabirds. Sci. Reports 10 (1) 18023. 10.1038/s41598-020-75024-6
Selvam, S., Manisha, A., Roy, P.D., Venkatramanan, S., Chung, S.Y., Muthukumar, P., Jesuraja, K., Elgorban, A.M., Ahmed, B., Elzain, H.E. (2021) Microplastics and trace metals in fish species of the Gulf of Mannar (Indian Ocean) and evaluation of human health. Environ. Pol. 291 118089. https://doi.org/10.1016/j.envpol.2021.118089
Shi, J., Wu, D., Su, Y., Xie, B. (2021) Selective enrichment of antibiotic resistance genes and pathogens on polystyrene microplastics in landfill leachate. Sci. Total Environ. 765 142775. https://doi.org/10.1016/j.scitotenv.2020.142775
Sobhani, Z., Lei, Y., Tang, Y., Wu, L., Zhang, X., Naidu, R., Megharaj, M., Fang, C. (2020) Microplastics generated when opening plastic packaging. Sci. Reports 10 (1) 4841. 10.1038/s41598-020-61146-4
Sukanya, M., Khushboo, S., Geetika, S., Mandeep, S., Pooja, C. (2020) Sources, Fate, and Impact of Microplastics in Aquatic Environment. In: Emerging Contaminants, (Ed.) N. Aurel. IntechOpen. Rijeka, pp. Ch. 13.
Ta, A.T., Babel, S. (2020) Microplastics pollution with heavy metals in the aquaculture zone of the Chao Phraya River Estuary, Thailand. Mar. Pollut. Bull. 161 111747. https://doi.org/10.1016/j.marpolbul.2020.111747
USEPA (2016) Integrated Risk Information System-database. https://www.epa.gov/iris. December 2022
Vats, P., Kaur, U.J., Rishi, P. (2022) Heavy metal-induced selection and proliferation of antibiotic resistance: A review. J. Appl. Microbiol. 132 (6) 4058-4076. https://doi.org/10.1111/jam.15492
Wang, Q., Liu, L., Hou, Z., Wang, L., Ma, D., Yang, G., Guo, S., Luo, J., Qi, L., Luo, Y. (2020) Heavy metal copper accelerates the conjugative transfer of antibiotic resistance genes in freshwater microcosms. Sci. Total Environ. 717 137055. https://doi.org/10.1016/j.scitotenv.2020.137055
Wright, S.L., Kelly, F.J. (2017) Plastic and Human Health: A Micro Issue? Environ. Sci. Technol. 51 (12) 6634-6647. 10.1021/acs.est.7b00423
Xiong, X., Xie, S., Feng, K., Wang, Q. (2022) Occurrence of microplastics in a pond-river-lake connection water system: How does the aquaculture process affect microplastics in natural water bodies. J. Clean. Prod. 352 131632. https://doi.org/10.1016/j.jclepro.2022.131632
Zettler, E.R., Mincer, T.J., Amaral-Zettler, L.A. (2013) Life in the “Plastisphere”: Microbial Communities on Plastic Marine Debris. Environ. Sci. Technol. 47 (13) 7137-7146. 10.1021/es401288x
Zhou, Y., Yang, Y., Liu, G., He, G., Liu, W. (2020) Adsorption mechanism of cadmium on microplastics and their desorption behavior in sediment and gut environments: The roles of water pH, lead ions, natural organic matter and phenanthrene. Water Res. 184 116209. https://doi.org/10.1016/j.watres.2020.116209
Zhu, D., Ma, J., Li, G., Rillig, M.C., Zhu, Y.-G. (2022) Soil plastispheres as hotspots of antibiotic resistance genes and potential pathogens. The ISME J. 16 (2) 521-532. 10.1038/s41396-021-01103-9

Supportingmaterial.docx

Download PDF

Version 1

posted

You are reading this latest preprint version

A preliminary assessment of microplastic occurrence and their potential risk as pollutant transport vectors: A case study in Phu Ly, Ha Nam, Vietnam

Status:

Version 1

Abstract

Figures

1. Introduction

2. Material And Methods

2.1. Study sites

2.2. Chemicals

2.3. Microplastic separation

2.3.1. Microplastic separation from sediments or water

2.3.2. Microplastic separation for microorganism analysis

2.4 Trace metal extraction from MPs

2.5 AMR bacteria and gene detection

2.6. Health risk assessment of heavy metals

2.7. Quality assurance and quality control

3. Results And Discussion

3.1. Occurrence of microplastics in surface water and sediment in Phu Ly - Ha Nam

3.2. Trace metals extracted from MPs

3.3. The results of analysis for E. coli bacteria carrying the ESBL phenotype and detection of the ESBL encoding gene of the isolated strain E. coli

3.4. Health risk assessment

4. Conclusion

Declarations

References

Supplementary Files

Status:

Version 1