Thi Yen Nhi Tran

Diagram showing PFAS occurrence in tap water in Ho Chi Minh City and their contribution to cumulative human health risk, with PFOS, PFOA, and PFBS identified as dominant contributors. Per- and polyfluoroalkyl substances (PFAS) are persistent and bioaccumulative contaminants of emerging concern in drinking water, posing potential risks to human health. This study evaluated the occurrence, concentration levels, and health risks of 12 PFAS compounds in household tap water from 24 districts in Ho Chi Minh City (HCMC), Vietnam, along with influent water from three major water supply plants. Between May and August 2022, a total of 72 tap water and 12 influent samples were collected and analyzed using solid-phase extraction and UPLC-MS/MS. Eight PFAS compounds were detected, with PFOS, PFBS, and PFOA found in all tap water samples. Total PFAS concentrations ranged from 0.74 to 6.01 ng/L (mean: 1.79 ± 1.41 ng/L). In several cases, treated water showed higher PFAS levels than influent water, suggesting contamination during treatment or distribution. Estimated daily intake (EDI) and hazard index (HI) calculations indicated PFOS as the dominant contributor to health risk, though HI values were below 1. Descriptive HQi-based contribution analysis identified PFBS, PFOS, and PFOA as the major contributors to cumulative non-carcinogenic risk. This study emphasizes the need for continued monitoring, regulatory action, and improved treatment processes to reduce PFAS exposure through tap water in urban environments.

Background/Objectives: Dioscorea batatas Decne (yam), which contains various bioactive compounds, has been utilized in the cosmetics industry, while most of the peel of D. batatas (DBP) is discarded without further use. Recent studies have shown that DBP contains higher levels of bioactive substances than the rhizome flesh. The aim of this study was to evaluate the skin biological activities of DBP extracts obtained using 70% ethanol (70% EtOH DBP), 95% ethanol (95% EtOH DBP), and ethyl acetate (EA DBP), with particular attention to their antioxidant-associated protective effects. Methods: Skin-related bioactivities of DBP extracts prepared using ultrasonic extraction were evaluated using in vitro tyrosinase and matrix metalloproteinase-1 (MMP-1) assays, alpha-melanocyte-stimulating hormone (α-MSH)-induced melanogenesis in B16F10 cells, ultraviolet B (UVB)-irradiated HaCaT viability assays, and Western blot analysis of pro-collagen type I alpha 1(Pro-COL1A1) and MMP-1 in HDF cells. In addition, the ABTS and DPPH radical scavenging activities of DBP extracts and representative DBP derivatives were assessed. Results: DBP extracts inhibited tyrosinase activity in vitro and reduced melanogenesis in B16F10 cells. DBP extracts also protected skin cells from UVB by increasing the viability of UVB-irradiated HaCaT cells. In UVB-irradiated HDF cells, DBP extracts restored Pro-COL1A1 expression and suppressed MMP-1 levels. Additionally, DBP extracts inhibited MMP-1 activity in a concentration-dependent manner. The DBP extracts themselves exhibited ABTS and DPPH radical scavenging activities, with EA DBP showing the highest vitamin C equivalent antioxidant capacity among the tested extracts. Representative DBP-derived phenanthrene compounds also showed radical scavenging activities, supporting the antioxidant potential of peel-derived phytochemicals. Conclusions: These findings indicate that DBP extracts possess skin-whitening and anti-photoaging effects and suggest that these protective activities may be associated with the antioxidant potential of both DBP extracts and DBP derivatives.

Tires are a significant source of environmental contaminants, releasing a range of emerging chemical contaminants into surrounding ecosystems. In this study, we developed and optimized a highly sensitive analytical method using liquid chromatography‐tandem mass spectrometry to detect seven specific tire related compounds: 1 H ‐benzotriazole (BTR), 5‐methyl‐1 H ‐benzotriazole (5‐MBTR), 2‐aminobenzothiazole, 2‐(methylthio)benzothiazole (2‐Me BTH), 1,3‐diphenylurea, 1,3‐diethyl‐1,3‐diphenylurea, and 1,3‐diphenylguanidine. The method demonstrated excellent sensitivity, with limits of quantification (LOQs) ranging from 0.8 to 5.6 ng/L and recovery rates between 79.8% and 90.7% near the LOQ. This technique was applied to tap water and surface river water samples from Ho Chi Minh City, revealing that 5‐MBTR, 2‐Me BTH, and BTR were the most prevalent contaminants, with concentrations ranging from 0.8 to 19.8 ng/L.