Studies on the occurrence of emerging pesticides in surface and drinking water in Vietnam are limited. In this study, lake water (n = 7), river water (n = 1), tap water (n = 46), and bottled water ...(n = 3) collected from Hanoi and other four provinces in northern Vietnam were analyzed for selected pesticides (including insecticides such as neonicotinoids, fipronil, and chlorpyrifos; fungicide carbendazim; herbicides such as atrazine, terbuthylazine, simazine, 2,4-dichlorophenoxyacetic acid, 2-methyl-4-chlorophenoxyacetic acid, and bentazon) and some of their degradates by liquid chromatography-tandem mass spectrometry. Carbendazim (median: 86.7 ng/L) and triazines (49.3 ng/L) were the major pesticides found in lake water samples, followed by neonicotinoids and their degradation products (15.1 ng/L), chlorpyrifos and its degradate (13.4 ng/L), fipronil and its degradates (3.76 ng/L), chlorophenoxy acid herbicides (2.10 ng/L), and bentazon (0.62 ng/L). Triazines (164 ng/L) were the major pesticides in river water. Higher concentrations (median: 39.3 ng/L; range: 1.20–127) of selected pesticides were found in tap water from Hanoi than those from four other provinces studied (5.49 ng/L; 4.73–66.8 ng/L). Bottled water samples collected from Hanoi contained lower concentrations of pesticide residues (median: 3.54 ng/L, range: 2.18–8.09) than those of tap water samples. The calculated risks from pesticide exposure through ingestion of tap water by the general populations were low. However, fipronil concentrations in lake water exceeded the benchmark value recommended for freshwater in the United States or the Netherlands. Degradation of acetamiprid into desmethyl-acetamiprid was found in lake water.
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•Lake water had lower herbicide levels and higher insecticide levels than river water.•Degradation product of acetamiprid was found in lake water.•Fipronil in lake water exceeded the threshold value set in the USA or the Netherlands.•Terbuthylazine level in a lake exceeded the predicted no effect concentration (PNEC).•Chlorpyrifos and carbendazim concentrations in lake water exceeded the PNECs.
Phthalate diesters are used as plasticizers in a wide range of consumer products. Because phthalates have been shown in laboratory animal studies to be toxic, human exposure to these chemicals is a ...matter of concern. Nevertheless, little is known about inhalation exposure to phthalates in the United States. In this study, occurrence of nine phthalates was determined in 60 indoor air samples collected in 2014 in Albany, New York, USA. Airborne particulate and vapor phase samples were collected from various sampling locations by use of a low-volume air sampler. The median concentrations of nine phthalates in air samples collected from homes, offices, laboratories, schools, salons (hair and nail salons), and public places were 732, 143, 170, 371, 2600, and 354 ng/m
3
, respectively. Diethyl phthalate (DEP) was found at the highest concentrations, which ranged from 4.83 to 2250 ng/m
3
(median 152) followed by di-
n
-butyl phthalate, which ranged from 4.05 to 1170 ng/m
3
(median 63.3). The median inhalation exposure dose to phthalates was estimated at 0.845, 0.423, 0.203, 0.089, and 0.070 µg/kg-bw/d for infants, toddlers, children, teenagers, and adults, respectively. Inhalation is an important pathway of human exposure to DEP.
Cyclic and linear siloxanes are used in a wide variety of household and consumer products. Nevertheless, very few studies have reported the occurrence of these compounds in indoor air or inhalation ...exposure to these compounds. In this study, five cyclic (D3–D7) and nine linear siloxanes (L3–L11) were determined in 60 indoor air samples collected in Albany, New York, USA. The mean concentrations of individual siloxanes in particulate and vapor phases ranged from <12μgg−1 (for octamethyltrisiloxane L3, decamethyltetrasiloxane L4) to 2420μgg−1 (for decamethylcyclopentasiloxane D5) and from 1.05ngm−3 to 543ngm−3, respectively. The mean concentrations of individual siloxanes in combined particulate and vapor phases of bulk indoor air ranged from 1.41ngm−3 (for L4) to 721ngm−3 (for D5). Cyclic siloxanes hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), D5, dodecamethylcyclohexasiloxane (D6), and octadecamethylcycloheptasiloxane (D7) were found in all indoor air samples. The mean concentrations of total siloxanes (i.e., sum of cyclic and linear siloxanes) ranged from 249ngm−3 in laboratories to 6210ngm−3 in salons, with an overall mean concentration of 1470ngm−3 in bulk indoor air samples. The calculated mean daily inhalation exposure doses of total siloxanes (sum of 14 siloxanes) for infants, toddlers, children, teenagers, and adults were 3.18, 1.59, 0.76, 0.34, and 0.27μg/kg-bw/day, respectively.
•Cyclic and linear siloxanes were determined in 60 indoor air samples.•Concentrations of 14 siloxanes ranged from 249 to 6210ng/m3 with the highest levels in salons.•High molecular weight siloxanes were preferably sorbed in particulate phase of indoor air.•Inhalation exposure dose to siloxanes ranged from 0.27 to 3.18μg/kg-bw/d.
Contamination status, potential emission sources, environmental fate, and human exposure risk of polybrominated diphenyl ethers (PBDEs) are reviewed for indoor and outdoor dust from Southeast Asian ...countries, under an international comparison point of view. PBDEs have been widely detected in house, workplace, car, and road dust samples collected from Indonesia, Philippines, Singapore, Thailand, and Vietnam. The highest PBDE levels up to hundreds of μg/g were found in settled dust from some e-waste processing areas in Thailand and Vietnam. Concentrations of PBDEs in house, car, and road dust from this region were generally lower than those reported in China and Western developed countries. BDE-209 was the most predominant congener in almost all analyzed samples, reflecting the widespread application of materials and products treated with commercial deca-BDE mixtures in this region. The market demand and application rate of commercial PBDE mixtures in Southeast Asia were lower than those documented for other regions in the world. As a result, PBDE contamination levels in the environments (e.g., indoor and outdoor dust) and associated risks in these countries were not significantly high. However, more attention should be paid to informal processing activities and management strategies for modern wastes such as e-waste, plastics, and end-of-life vehicles. There exist several knowledge gaps about spatiotemporal trends, potential sources, risk assessment, inventory, management, and legislation regarding PBDEs in dust from this region, which should be filled by additional comprehensive, detailed studies with relevant inter-country/regional monitoring schemes.
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•PBDEs have been found in workplace, house, car, and road dust in Southeast Asia.•PBDE concentrations in dust from this region were at the lower end of global range.•BDE-209 was the most dominant congener, indicating extensive deca-BDE applications.•Informal waste processing activities are critical PBDE sources in dust.•Research and management efforts are needed to control PBDE emissions and risks.
Capsule: The occurrence, sources, and human exposure risks of PBDEs in dust are reviewed for Southeast Asian countries, addressing the current pollution status and future perspectives.
Phthalate diesters (phthalates), esters of p-hydroxybenzoic acid (parabens), and bisphenol A diglycidyl ether (BADGE) are used in personal care products, food packages, household products, or ...pharmaceuticals. These compounds possess endocrine-disrupting potentials and have been reported to occur in the environment. Nevertheless, no previous studies have reported the occurrence of these compounds in indoor dust from Vietnam. In this study, nine phthalates, six parabens, and four BADGEs were determined in indoor dust samples collected from Hanoi, Hatinh, Hungyen, and Thaibinh, in Vietnam. Total concentrations of phthalates, parabens, and BADGEs in indoor dust ranged from 3440 to 106,000 ng/g (median: 22,600 ng/g), 40–840 ng/g (median: 123 ng/g), and 23 to 1750 ng/g (median: 184 ng/g), respectively. Based on the measured median concentration of phthalates, parabens, and BADGEs in indoor dust, we estimated human exposure doses to these compounds through indoor dust ingestion for various age groups. The exposure doses to phthalates, parabens, and BADGEs decreased with age and ranged from 19.4 to 90.4 ng/kg-bw/d, 0.113–0.528 ng/kg-bw/d, and 0.158–0.736 ng/kg-bw/d, respectively. This is the first study on the occurrence and human exposure of phthalates, parabens, and BADGEs in indoor dust from Vietnam.
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•Phthalates, parabens, and BADGEs were found widely in indoor dust from Vietnam.•Median concentration of phthalates and parabens was 22,600 and 123 ng/g, respectively.•Median concentration of BADGEs in dust was 184 ng/g.•Median exposure to phthalates through dust ingestion by toddlers was 90 ng/kg-bw/d.
Concentrations of unsubstituted and methylated polycyclic aromatic hydrocarbons (PAHs and Me-PAHs) were examined in road dusts from some representative areas with different land-use types in northern ...Vietnam, providing updated information about the occurrence, sources, and risks of these pollutants in Southeast Asian region. The Vietnamese road dusts were contaminated with low to moderate levels of PAHs and Me-PAHs as compared to those from other countries in the world. Concentrations of PAHs and Me-PAHs (Σ34PAHs) decreased in the order: urban (median 1800; range 1100–5500) ≈ industrial (1300; 550–10,000) > suburban (450; 310–1300) ≈ rural road dust (330; 210–2300 ng g−1), suggesting an urban-rural declining trend and effects of urbanization-industrialization processes in PAH emission extent in Vietnam. The profiles and diagnostic ratios of PAHs and Me-PAHs in our samples revealed that these compounds were mainly derived from pyrogenic sources rather than petrogenic sources. Traffic emissions (e.g., vehicle exhaust, tire debris, and possible leaks of fuels, oils, and lubricants) were estimated as principal sources of PAHs and Me-PAHs, especially in the urban and industrial areas. Other pyrogenic sources (e.g., coal, wood, and biomass combustion) were also existed in the industrial, suburban, and rural areas, reflecting PAH origins from thermal industrial processes, open burning of agricultural by-products, and domestic energy utilization. Persons working outdoors and children in the urban and industrial areas were estimated to receive higher intake doses of PAHs and Me-PAHs, which were one to two orders of magnitude higher than those estimated for other groups. Except for potential cancer risk estimated for the occupational groups in the industrial area under the worst exposure scenarios, the non-cancer and cancer risk levels were generally acceptable; however, more comprehensive risk assessment considering other exposure pathways (e.g., inhalation and diet) is needed.
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•PAH concentrations in Vietnamese road dust fall in low to moderate global range.•Total PAH levels were higher in urban/industrial than suburban/rural road dust.•Pyrogenic sources dominated PAH patterns in almost all the samples.•Traffic emissions were principal PAH sources, especially in urban/industrial areas.•Road dust-bound PAHs/Me-PAHs of this study exhibited acceptable levels of risk.
The moderate levels of PAHs and Me-PAHs detected in road dust from northern Vietnam were derived from mixed sources with significant contribution of traffic emission.
Siloxanes are organo-silicon compounds containing Si-O-Si linkages and methyl branches. Depending on the structure, siloxanes can be divided into cyclic and linear compounds. Methyl siloxanes with ...small and medium molecular weights (molecular weights less than 500 g mol−1), are volatile under normal conditions, and hence are referred to as volatile methyl siloxanes (VMSs). VMSs are additive ingredients in many products such as plastics, rubber, personal care products, and household items. This review provides information on the distribution of VMSs in consumer products, indoor air and dust, and their implications for human exposure. VMSs have been used in personal care products and household items at concentrations on the order of hundreds to thousands of micrograms per gram which are the main sources of contamination in the indoor environments. VMSs have been found widely in indoor air and dust. A significant correlation existed between VMS concentrations in indoor air and dust. Among typical VMSs, dodecamethylcylcopentasiloxane (D5) is the major compound found in indoor environments. The human exposure doses to VMSs through dermal absorption, dust ingestion, and inhalation were compiled; Inhalation is a dominant pathway of exposure to VMSs, especially in indoor environments of occupational settings like hair salons. The human exposure doses were higher in children than in adults.
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•Using PCPs containing VMSs is the main released source into the indoor environments.•A significant correlation existed between VMS concentrations in indoor air and dust.•Specific occupational settings contain elevated levels of VMSs in air and dust.•Inhalation is the major exposure pathway to VMSs in indoor environments.
A total of 20 organophosphate triesters (OPEs), including seven alkyl-OPEs, three chlorinated (Cl)-OPEs, seven aryl-OPEs, and three oligomeric-OPEs were measured in 341 house dust samples collected ...from 12 countries during the period 2010–2014. OPEs were ubiquitous in indoor dust, and the total concentrations of OPEs (∑OPEs; sum of 20 OPEs) ranged from 49.4 to 249,000 ng/g dry weight (dw). Generally, Cl-OPEs were the predominant compounds (51% of total) in indoor dust samples, with a median concentration of 800 ng/g, followed by alkyl-OPEs (31%), aryl-OPEs (17%), and oligomeric-OPEs (1%), with median concentrations of 480, 270, and 21.9 ng/g, respectively. ∑OPE concentrations in indoor dust from more industrialized countries (South Korea: median, 31,300; Japan: 29,800; and the United States: 26,500 ng/g dw) were one or two orders of magnitude higher than those from less industrialized countries (Greece: 7140, Saudi Arabia: 5310, Kuwait: 4420, Romania: 4110, Vietnam: 1190, China: 1120, Colombia: 374, India: 276, and Pakistan: 138 ng/g dw). Statistically significant positive correlations (0.114 < r < 0.748, p < 0.05) were found among the concentrations of 16 OPEs in dust samples, indicating similar sources of these compounds. The median estimated daily intakes of ΣOPEs via dust ingestion for children and adults were in the ranges of 0.29–64.8 and 0.07–14.9 ng/kg bw/day, respectively.
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•OPEs are ubiquitous in house dust samples collected from 12 countries.•Cl-OPEs were the predominant compounds in indoor dust samples.•∑OPEs in dust from industrialized countries were higher than those from less industrialized countries.•Indoor dust ingestion is an important route of human exposure to OPEs.
Phthalates are used as plasticizers to impart flexibility of plastics. Because of their toxicity, human exposure to phthalates is a concern. Little is known on the occurrence of and inhalation ...exposure to phthalates in indoor air. In this study, ten phthalates were measured in 97 indoor air samples collected from Northern Vietnam during September 2016 to January 2017. The mean concentrations of total phthalates (i.e., sum of ten phthalates) in particulate and gas phases ranged from 95.2 to 13,100μgg−1 and from 57.0 to 14,900ngm−3, respectively. In bulk indoor air samples (i.e., gas plus particulate phase), the mean concentration of total phthalates ranged from 106 to 16,000ngm−3 (mean: 1040ngm−3). Diethyl phthalate (DEP) was found at the highest concentration in indoor air at a concentration range of below the method quantitation limit (MQL) to 12,400ngm−3 (mean: 376). Among various microenvironments, indoor air collected from hair salons contained the highest concentrations of phthalates (range: 596 to 16,000ngm−3). Among the four northern Vietnamese cities studied, the highest concentrations of phthalates were found in indoor air samples from Hanoi. The calculated mean inhalation exposure doses to phthalates for infants, toddlers, children, teenagers, and adults were 780, 485, 416, 292, and 213ngkg-bw−1d−1, respectively.
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•Ten phthalate diesters were determined in 97 indoor air samples.•Concentrations of phthalates ranged from 106 to 16,000ng/m3 with the highest levels in hair salons.•Diethyl phthalate accounted for >38% of phthalate concentrations in indoor air.•Inhalation exposure to phthalates is higher than that from dust ingestion.
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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