Occurrence and risk of human exposure to organophosphate flame retardants in indoor air and dust in Hanoi, Vietnam.

The presence and distribution of thirteen organophosphate flame retardants (OPFRs) were investigated in indoor air and dust samples collected in Hanoi, Vietnam. The total OPFRs (Æ©OPFRs) concentrations in indoor air and dust samples were 42.3-358 ng m-3 (median 101 ng m-3) and 1290-17,500 ng g-1 (median 7580 ng g-1), respectively. The profile of OPFRs in both indoor air and dust indicated that tris(1-chloro-2-propyl) phosphate (TCIPP) was the most dominant compound with a median concentration of 75.3 ng m-3 and 3620 ng g-1, contributing 75.2% and 46.1% to Æ©OPFRs concentrations in indoor air and dust, respectively, followed by tris(2-butoxyethyl) phosphate (TBOEP), with a median concentration of 16.3 ng m-3 and 2500 ng g-1, contributing 14.1% and 33.6% to Æ©OPFRs concentrations in indoor air and dust, respectively. The levels of OPFRs in the indoor air samples and corresponding indoor dust samples showed a strong positive correlation. The total estimated daily intakes (EDItotal) of Æ©OPFRs (via air inhalation, dust ingestion, and dermal absorption) for adults and toddlers under the median and high exposure scenarios were 36.7 and 160 ng kg-1 d-1, and 266 and 1270 ng kg-1 d-1, respectively. Among the investigated exposure pathways, dermal absorption was a primary exposure pathway to OPFRs for both toddlers and adults. The hazard quotients (HQ) ranged from 5.31 × 10-8 to 6.47 × 10-2 (<1), and the lifetime cancer risks (LCR) were from 2.05 × 10-11 to 7.37 × 10-8 (<10-6), indicating that human health risks from exposure to OPFRs in indoor environments are not significant.

Occurrence and ecological risk assessment of organophosphate esters in surface water from rivers and lakes in urban Hanoi, Vietnam.

In this study, an investigation on the pollution status, distribution, and ecological risk to the aquatic organisms of six organophosphate tri-esters (tri-OPEs) and two organophosphate tri-esters (di-OPEs) in surface water in urban Hanoi, Vietnam were conducted. In 37 surveyed water samples (6 rivers and 17 lakes), all eight targeted OPEs were discovered with a detection frequency (DF) of 41-100% and the concentration varied largely from below the method detection limit (

Target screening analysis of 970 semi-volatile organic compounds adsorbed on atmospheric particulate matter in Hanoi, Vietnam.

Vietnam's rapid economic development has resulted in dramatic increases in construction and the number of transportation vehicles. There is now growing public concern regarding increasing air pollution, especially in big cities; however, little information is available on air quality, particularly regarding semi-volatile organic compounds (SVOCs) adsorbed on atmospheric particulate matter. Here, we determined the frequency and concentrations of 970 SVOCs in 48 air particle samples collected by means of high-volume air sampling in Hanoi, Vietnam, by using a target screening method and a gas chromatography-mass spectrometry database. A total of 118 compounds (12.2% of the target compounds) were detected at least once in the samples, and the number of chemicals detected in each sample ranged from 85 to 103 (median, 92). For samples collected near a heavily trafficked road, the concentrations of target compounds in the samples were higher in samples collected during the day than in those collected at night, whereas the opposite was true for samples collected in a highly populated residential area with industrial activities related to the production of fresh noodles. Sixteen PAHs were detected at high concentrations in nearly 100% of the samples. Eighteen pesticides were detected, with permethrin being detected the most frequently (>70% samples), which can be explained by the use of permethrin-based Permecide 50 EC for dengue fever control during the sampling period. Endocrine-disrupting chemicals (i.e., bisphenol A, 4-nitrophenol) and pharmaceuticals and personal care products (diethyltoluamide, caffeine) were detected in over 90% of the samples. Seven sterols, five phthalate compounds and five organophosphorus flame retardants were detected in the samples. This is the first comprehensive survey of SVOCs adsorbed on atmospheric particulate matter in Vietnam, and as such, this study provides important new information about the frequency and concentrations of atmospheric SVOC contamination. The variety of chemicals detected in this study implies an abundance of pollution sources; further investigations to determine these pollution sources and the risks posed by the detected SVOCs to human health are warranted.