Contamination levels and distribution patterns of ten typical phthalic acid esters (PAEs) were investigated in various types of water samples collected from Hanoi metropolitan area in Vietnam. ...Concentrations of 10 PAEs in bottled water, tap water, lake water, and wastewater samples were measured in the ranges of 1640–15,700 ng/L (mean/median: 6400/5820 ng/L), 2100–18,000 ng/L (mean/median: 11,200/9270 ng/L), 19,600–127,000 ng/L (mean/median: 51,800/49,300 ng/L), and 20,700–405,000 ng/L (mean/median: 121,000/115,000 ng/L), respectively. Among PAEs, di-(2-ethylhexyl) phthalate (DEHP) accounted for a major proportion of total concentrations (45%) in wastewater, followed by diisobutyl phthalate (DiBP, 10.3%), and dibutyl phthalate (DBP, 9.53%). Concentrations of PAEs in wastewater decreased significantly with distance from the wastewater treatment plants (WWTPs). Concentrations of PAEs in surface water samples did not vary greatly between locations. PAEs were found in bottled water in the following order: DBP (22.4%), DiBP (22.3%), benzylbutyl phthalate (BzBP, 20.1%), and DEHP (15.5%). The estimated mean exposure doses of 10 PAEs through consumption of drinking water for adults and children in Vietnam were 254 and 256 ng/kg-bw/day, respectively.
Capsule: Highest concentrations of PAEs were measured in wastewater, followed by lake water, tap water, and bottled water.
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•Elevated concentrations of PAEs were measured in wastewater samples from Vietnam.•DEHP was a major compound found in tap water, lake water and wastewater samples.•DiBP and DBP were the dominant PAEs in bottled water.•PAE concentrations in drinking water and associated exposure doses were below the reference values.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Very little information on the occurrence and risk assessment of antibiotics in the aquatic environment is reported for Vietnam, where antibiotics are assumed to be omnipresent in urban canals and ...lakes at high concentrations due to the easy accessibility of antibiotics without doctor prescription. This study provides comprehensive analysis of the occurrence of 23 antibiotics in urban canals (To Lich and Kim Nguu) and lakes (West Lake, Hoan Kiem, and Yen So) in Hanoi, Vietnam. Of these 23 antibiotics, 18 were detected in urban canals at above 67.9% detection frequency (DF). The concentrations of detected antibiotics were in the range from below quantification limit (MQL) to almost 50,000 ng/L, depending on the compound and sampling site. In urban canals, median concentration of amoxicillin, erythromycin, and sulfamethoxazole was >1000 ng/L while other antibiotics such as ampicillin, chloramphenicol, clindamycin, sulfamethazine, tetracycline, tylosin and vancomycin were detected at median concentrations of <100 ng/L. Similarly, 16 target antibiotics were also detected in urban lakes. Macrolides (azithromycin, clarithromycin, and erythromycin-H2O), fluoroquinolones (enrofloxacin and ofloxacin), lincosamides (clindamycin and lincomycin), and trimethoprim were ubiquitously detected in urban lakes (DF = 100%). In this study, potential risks of antibiotics in the investigated urban canals and lakes were assessed based on the predicted no-effect concentration (PNEC) from the existing literature for antibiotic resistance selection (PNECARM) and ecological toxicity to aquatic organisms (PNECEcotox). Ampicillin, amoxicillin, azithromycin, ciprofloxacin, clarithromycin, enrofloxacin, erythromycin, ofloxacin, tetracycline, and trimethoprim were found in the investigated urban canals at concentrations exceeding their PNECARM and PNECEcotox. Similarly, most of the target antibiotics (i.e. amoxicillin, ciprofloxacin, clarithromycin, clindamycin, enrofloxacin, erythromycin, lincomycin, ofloxacin, sulfamethoxazole, tetracycline, trimethoprim and tylosin) were detected in the investigated urban lakes at concentrations close to or exceeding PNECEcotox for aquatic organisms. Further investigations on the occurrence and fate of antibiotic residues and antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in surface waters are recommended.
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•Comprehensive data on the occurrence of 23 antibiotics in surface water was provided.•Median concentration of AMX, ERY, and SMX in urban canals was >1000 ng/L.•Macrolides, fluoroquinolones and lincosamides were ubiquitously detected in urban lakes.•β-lactam, macrolides, fluoroquinolones in canals posed a possible risk for resistance selection.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Contamination status and distribution characteristics of ten phthalic acid esters (PAEs) and three cyclic volatile methyl siloxanes (CSs) were determined in the air (gas and particle) samples ...collected from indoor and outdoor spaces of several chemistry laboratories, offices, and homes from urban area of Hanoi, the capital city of Vietnam. Air concentrations of Σ10PAEs (median 688; range 142–2390 ng m−3) and Σ3CSs (171; not detected–1100 ng m−3) in the indoor air samples were significantly higher than those measured in the outdoor ones (Σ10PAEs: 161; 34.1–515 ng m−3 and Σ3CSs: 43.2; not detected–258 ng m−3), partly suggesting the predominance of indoor emission sources of these substances. There were significant positive correlations in total air concentrations of phthalates and siloxanes between the indoor and outdoor air samples. The most predominant phthalates were diethyl-, di-n-butyl-, diisobutyl-, and di(2-ethylhexyl) phthalate. For siloxanes, D5 and D6 were more abundant than D4 in most samples. Except for di(2-ethylhexyl)- and di-n-octyl phthalate in some locations, almost all the compounds were likely associated with gas phase than particle phase. Daily intake doses of airborne phthalates and siloxanes, and non-cancer and cancer risks of selected phthalates were estimated for different exposure groups such as adults, children, and university subjects (e.g., laboratory staff and students), indicating relatively low levels of risk.
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•Phthalates and cyclic siloxanes were analyzed in indoor/outdoor air of Hanoi, Vietnam.•Concentrations of phthalates and siloxanes in indoor air were higher than in outdoor air.•DEP, DnBP, DiBP, DEHP, D5, and D6 were major compounds detected.•Most compounds were abundant in the gas phase than in particulate phase.•Non-cancer and cancer risks of airborne phthalates were relatively low.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Comprehensive studies on emerging contaminants like volatile methyl siloxanes in settled dust from different micro-environments are still limited. In this study, concentrations and distribution of ...cyclic volatile methyl siloxanes (CVMSs) including
D
3,
D
4,
D
5, and
D
6 were examined in indoor dust samples collected from various micro-environments in northern and central Vietnam. Concentrations of total CVMSs in the dust samples ranged from 86.0 to 5890 (median 755) ng/g and decreased in the order: waste processing workshops (median 1560; range 329–5890) > common houses (650; 115–1680) > university classrooms (480; 86.0–1540) > vehicle repair shops (295; 126–1950) ng/g. This observation suggests that informal waste processing activities are sources of CVMSs. Among the studied CVMSs,
D
5 was the most predominant compound (41 ± 14%), followed by
D
6 (26 ± 13%),
D
4 (23 ± 12%), and
D
3 (11 ± 11%). Moderate positive correlations between
D
3/
D
4,
D
4/
D
5, and
D
5/
D
6 were found. Median daily intake doses of
D
3,
D
4,
D
5, and
D
6 through dust ingestion were 0.016, 0.051, 0.11, and 0.054 ng/kg/d, respectively, which were comparable to water consumption and markedly lower than the air inhalation pathway.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The occurrence of nine phthalic acid esters (PAEs) were determined in indoor dust samples collected from vehicle repair shops, waste processing workshops, and homes in Vietnam. Concentrations of ...total PAEs ranged from 585 to 153,000 (median 33,400 ng/g), which fall in the lower end of global range. The PAE levels in workplace dust (median 49,100; range 9210–153,000 ng/g) were significantly higher than those in house dust (median 23,700; range 585–83,700 ng/g), indicating waste processing activities as potential PAE sources. The most predominant compound was di-(2-ethyl)hexyl phthalate (DEHP), accounting for 62 ± 18% of total PAEs. Other major compounds were benzyl butyl phthalate (BzBP) (10 ± 12%), di-
n
-butyl phthalate (DnBP) (9.7 ± 7.7%), di-
n
-octyl phthalate (DnOP) (7.9 ± 8.1%), and diisobutyl phthalate (DiBP) (6.9 ± 5.0%). Proportions of BzBP and DnBP in some workplace dust samples were markedly greater than in common house dust, suggesting specific emission sources. Daily intake doses of selected PAEs (e.g., DnBP, DiBP, BzBP, and DEHP) through dust ingestion were much lower than reference doses, implying acceptable levels of risk.
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CEKLJ, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
In this report, four cVMSs including hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) were determined in ...85 sediment samples collected from three rivers in northern Vietnam during the period from May to November 2020. Total mean concentrations of cVMSs ranged from 75.4 to 15,000 ng/g-dw. The highest levels of cVMS were found in sediment samples collected from the To Lich River (range, 260–15,000 ng/g-dw; median, 2840 ng/g-dw), followed by the Nhue River (range, 188–6800 ng/g-dw; median, 1370 ng/g-dw), and the Day River (range, 75.4–4600 ng/g-dw; median, 666 ng/g-dw). Among cVMSs, decamethylcyclopentasiloxane (D5) was found at the highest levels in all samples and ranged from 9.00 to 11,000 ng/g-dw. Significant correlations exist between the concentrations of D4/D6 and D5/D6 pairs in river sediment samples. Although the calculated ecological risk was not high, the presence of cVMSs in the sediment raises concerns about the impact on aquatic life because of their long-term accumulation capacity.
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CEKLJ, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The occurrence of seven typical parabens was investigated in several types of personal care products (PCPs) sold at supermarkets and in indoor dust samples collected from houses, laboratories, and ...medical stores in Hanoi, Vietnam. Parabens were frequently detected in PCPs regardless of the paraben indication in their ingredient labels. However, concentrations of parabens in labeled products (median 3280; range 1370–5610 μg/g) were much higher than those found in non-labeled products (69.4; not detected – 356 μg/g). Parabens were also measured in indoor dust samples of this study at elevated concentrations, ranging from not detected to 1650 (median 286 ng/g). Levels of parabens in the indoor dust samples collected in 2019 decreased in the order: house > medical store > laboratory dust, however, the difference was not statistically significant. Interestingly, levels of parabens in Vietnamese house dust exhibited an increasing trend over time, for example, mean/median concentrations of parabens in house dust samples collected in 2014, 2017, and 2019 were 245/205, 310/264, and 505/379 ng/g, respectively. Methylparaben was found at the highest frequency and concentrations in both PCPs and indoor dust samples. Mean exposure doses of total parabens through dust ingestion were estimated to be 2.02, 1.61, 0.968, 0.504, and 0.192 ng/kg-bw/d for infants, toddlers, children, teenagers, and adults, respectively. Further studies on the distribution, emission behavior, potential sources, and negative impacts of parabens in different environmental media in Vietnam are needed.
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•Paraben concentrations in labeled PCPs were much higher than in non-labeled PCPs.•MeP was a major compound measured in both labeled and non-labeled PCPs.•Paraben concentrations in Hanoi house dust showed an increasing trend over time.•MeP was found at the highest frequency and concentrations in indoor dust samples.•Exposure doses to parabens via dust ingestion decreased with increasing age.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The noble metal-based nanoparticles (NPs) have been considered as potential antimicrobial agents because of their good antibacterial and antifungal activities as well as biocompatible nature. In this ...study, we have introduced a simple and fast route to synthesize silver, gold, and silver-gold bimetallic NP-decorated dextran. The as-synthesized noble metal-based NPs with spherical geometry showed high dispersity in dextran. The antibacterial and antifungal of obtained nanomaterials were tested with Xanthomonas oryzae pv. oryzae (Xoo) bacteria and Magnaporthe grisea (M. grisea) fungi. The silver NPs and bimetallic NPs with high silver content in dextran exhibited excellent activity to inhibited the growth of the bacteria and fungi, whereas the gold/dextran has weak antimicrobial effects. The antibacterial and antifungal properties of silver-gold bimetallic NPs in dextran biopolymer can be tuned according to the content of silver in the bimetallic NPs. The obtained nanomaterials could open an entry to a new class of antibiotics.
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FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
In this study, four cyclic volatile methylsiloxanes (cVMSs) were determined in drinking water, tap water, surface water, and wastewater samples collected from Hanoi metropolitan area, Vietnam, during ...August to December 2020 (dry season) by using solid phase extraction combined with gas chromatography tandem mass spectrometry. Highest concentrations of cVMSs in the range of 63–7400 ng/L (mean/median: 1840/1310 ng/L) were found in wastewater samples. A significant difference existed in the concentrations of cVMSs between influent and effluent of a wastewater treatment plant. The sum concentrations of four cVMSs in lake water, tap water, and bottled water samples were in the ranges of 67.0–1100 ng/L (mean/median: 350/282 ng/L), 19.8–350 ng/L (12.6/12.3 ng/L), and 2.31–28.1 ng/L (10.3/8.23 ng/L), respectively. Among the four cVMSs, decamethylcyclopentasiloxane (D5) was found at the highest concentrations in all water samples analyzed. The mean exposure doses of cVMSs calculated for adults and children through the consumption of drinking were 0.409 and 0.412 ng/kg-bw/day, respectively. Human exposure to cVMSs calculated through drinking water consumption was significantly lower than that reported for inhalation.
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•cVMSs were found in bottled, tap, lake and wastewater samples from Vietnam.•D5 was a major compound found in all water samples.•Wastewater samples contained elevated levels of cVMSs.•cVMSs levels in wastewater influent were an order of magnitude higher than in effluent.
Concentrations of four cyclic volatile methylsiloxanes (D3, D4, D5, and D6) decreased in the order: influent wastewater ≫ effluent wastewater ≈ lake water > tap water ≈ bottled water.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Pollution status and distribution characteristics of ten typical phthalic acid esters (PAEs) were investigated in 36 sediment samples collected from three rivers in Northern Vietnam from June to ...October 2020. The total concentrations of PAEs in sediment samples collected from the To Lich River (n = 9), the Nhue River (n = 12), and the Day River (n = 15) were in ranges of 11,000–125,000 ng/g-dwt (mean/median: 50,000/42,200 ng/g-dwt), 2140–89,900 ng/g-dwt (mean/median: 29,300/20,700 ng/g-dwt), and 1140–43,100 ng/g-dwt (mean/median: 13,800/10,400 ng/g-dwt), respectively. Among ten PAEs studied, di-(2-ethylhexyl) phthalate (DEHP) was found at the highest levels in all samples meanwhile dimethyl phthalate (DMP), diethyl phthalate (DEP), and dipropyl phthalate (DPP) were detected at low frequency and concentration. Significant correlations have existed between the median-chain (C4–C7) PAE pairs in sediment samples. Due to the high accumulation in the sediments, the median-chain PAEs had a higher ecological risk than the short-chain (C1–C3) PAEs. These contaminants may present a longstanding influence on organisms and ecosystems.
•Elevated PAE concentrations in surface sediments of three rivers in Northern Vietnam.•DEHP was a major substance measured in all sediment samples.•Significant correlations existed between the concentrations of the medium-chain PAE pairs.•The ecological risk of the medium-chain PAEs was higher than the short-chain PAEs.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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