Assessment of cyclic volatile methyl siloxanes (CVMSs) in indoor dust from different micro-environments in northern and central Vietnam.

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 D3, D4, D5, and D6 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.

Distribution and ecological risk assessment of phthalic acid esters in surface sediments of three rivers in Northern Vietnam.

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.

Assessment of distributional characteristics and ecological risks of cyclic volatile methylsiloxanes in sediments from urban rivers in northern Vietnam.

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.

Phthalic acid esters (PAEs) in workplace and house dust from Vietnam: concentrations, profiles, emission sources, and exposure risk.

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.

Profiles of phthalic acid esters (PAEs) in bottled water, tap water, lake water, and wastewater samples collected from Hanoi, Vietnam.

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.

Distribution of cyclic volatile methylsiloxanes in drinking water, tap water, surface water, and wastewater in Hanoi, Vietnam.

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.

Parabens in personal care products and indoor dust from Hanoi, Vietnam: Temporal trends, emission sources, and non-dietary exposure through dust ingestion.

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.

Air pollution caused by phthalates and cyclic siloxanes in Hanoi, Vietnam: Levels, distribution characteristics, and implications for inhalation exposure.

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) and Σ3CSs (171; not detected-1100 ng m) in the indoor air samples were significantly higher than those measured in the outdoor ones (Σ10PAEs: 161; 34.1-515 ng m and Σ3CSs: 43.