Widespread occurrence of volatile methyl siloxanes in settled dust from three regions in Vietnam: Geographical variations, indoor-outdoor differences, and human exposure assessment.
Non-methane volatile organic compounds (NMVOCs) in the atmosphere have garnered considerable attention worldwide because of their significance in atmospheric chemistry and their usefulness in identifying emission sources and chemical sinks. Despite the importance of VOCs, their routine measurement in the UK and across Europe is somewhat limited, and as such, there is limited information available regarding their sources, particularly in sensitive locations such as densely populated urban areas. In this study, hourly NMVOC concentration data measured between January 2015 and December 2023 were analyzed across four monitoring sites spanning an urban-to-rural gradient in England. The Marylebone and Eltham sites showed significantly higher concentrations of alkanes, alkenes, and aromatic hydrocarbons compared to the rural sites of Chilbolton and Auchencorth, with highest recorded VOC values of 29.9 ± 9.1 and 15.3 ± 4.3 µg m−3, respectively. Ethane (C2H6) and propane (C3H8) showed their highest ozone formation potential (OFP) levels at Marylebone Road, with the contribution of ethane to ozone formation ranging from 4% in Eltham to 8% in Chilbolton. This indicates that the emissions from vehicles and industries have a greater impact on the reactivity of these compounds. The potential source contribution function (PSCF) showed that the Marylebone and Eltham sites are mainly impacted by local traffic sources, while Chilbolton and Auchencorth receive VOC emissions from wider geographical areas. The COVID-19 lockdowns caused significant reductions in VOC concentrations at urban sites, which resulted in total VOCs declining by 26% at Marylebone Road and 11% in Eltham, while rural sites remained unaffected. The study results demonstrate new insights into NMVOC long-term temporal patterns and source identification across different UK environments, with important implications for air quality management and emission control policies.
Ibrahim Ouchen, S. Hama, Kevin P. Wyche et al.· Atmosphere· 0 citations
Organophosphate flame retardants (OPFRs) are additive chemicals that migrate from indoor materials and accumulate in settled dust. This study retrospectively characterized eight OPFRs in floor dust collected in Shanghai during 2016 to establish a seasonally resolved historical reference. A total of 136 residential dust samples were obtained from a convenience panel of 26 homes sampled at approximately two-month intervals; five office and four dormitory composite samples were included only for exploratory microenvironmental comparisons. Sampling, extraction, and LC-MS/MS determination were all completed in 2016. OPFRs were detected in all samples. Median (mean) Σ8OPFR concentrations were 1.51 × 103 (4.35 × 103), 2.48 × 103 (3.36 × 103), and 673 (963) ng·g−1 in residential, office, and dormitory dust, respectively, and chlorinated OPFRs—particularly tris(2-chloroisopropyl) phosphate and tris(2-chloroethyl) phosphate—dominated. Mixed-effects models accounting for repeated sampling confirmed significant season effects for Σ8OPFRs and all frequently detected congeners, with autumn generally lower than spring or winter. Under the mean 2016 concentration scenario, uptake-adjusted total estimated daily intakes were 3.3 ng·kg−1·day−1 for infants and 0.65 ng·kg−1·day−1 for adults. Oral administered-dose screening values did not exceed the selected non-cancer or cancer benchmarks. These measurements do not represent current exposure but provide a historical benchmark for method-matched follow-up monitoring.
Jiajun Chang, Li Li, Bing-Hong Cheng et al.· Toxics· 0 citations
Per- and polyfluoroalkyl substances (PFAS) have attracted attention because of their persistence and widespread occurrence in indoor environments. This study investigated the occurrence, distribution, and exposure risks of PFAS in indoor dust from different university environments. The associations between indoor dust and hair PFAS concentrations were explored. The average ∑PFAS concentration in dust from unrenovated dormitories (Type Ⅱ, 126.61 ng/g) exceeded that in renovated dormitories (Types Ⅰ and Ⅲ, 63.81 and 54.65 ng/g, respectively). Hair samples from students across all three dormitory types showed PFAS accumulation, with perfluorooctanoic acid (PFOA) as the dominant compound (75.46%, average: 1.15 ng/g). PFAS burdens in hair varied markedly across dormitory types, with average ∑PFAS concentrations of 4.67 ng/g for Type Ⅰ (renovated), 1.00 ng/g for Type Ⅲ (renovated), and 0.49 ng/g for Type Ⅱ (unrenovated). Significant positive correlations between ∑PFAS concentrations in dust and hair (r = 0.77, p < 0.01) suggest that indoor dust may represent a potential contributor to PFAS accumulation in human hair, highlighting the potential of hair as a non-invasive biomonitoring matrix for long-term PFAS exposure. Although the estimated exposure risks were relatively low, the widespread occurrence of PFAS highlights indoor environments as a potential source of chronic human exposure.
Yuan-Hang Zhang, Shunzhe Wei, Wanru Yang et al.· Journal of Hazardous Materia...· 0 citations
Polycyclic aromatic compounds (PACs) are common constituents of crude oil and its refined products, and they can be released into the ambient environment during oil exploitation activities, potentially adversely affecting environmental and human health. Herein, forehead (n=76) and hand wipes (n=76) and urine samples (n=102) from oilfield workers as well as indoor dust samples (n=19) (not individually paired with skin wipe and urine samples) in the oil exploitation area were collected, and 45 PACs and 15 PAC metabolites (mPACs) in these matrices were comparably determined. The median concentrations of ∑PACs in forehead and hand wipes and ∑mPACs in urine were 1.2-4.3 times higher in frontline workers than those in office administrators. Significant differences in PAC profiles were observed between different matrices, with relatively hydrophilic PACs being least in indoor dust, intermediate in hand wipes, and most abundant in forehead wipes. Furthermore, five PACs in forehead and hand wipes and their corresponding mPACs in urine exhibited significant positive correlations. Exposure assessment indicated that dermal uptake of low molecular weight (LMW) PACs contributed dominantly to internal exposure (20.2%-67.4%) compared to dust ingestion (< 2%). The quantile g-computation model revealed that hydroxynaphthalene (∑OH-Nap), 1-OH-pyrene, and 2-OH-dibenzofuran were the major contributors to the mPAC mixture's effect on lipid peroxidation, and dermal exposure may represent a potential pathway by which LMW PACs, particularly Nap, were associated with lipid peroxidation based on multiple linear regression. This study enhances understanding of less well-studied PAC exposure and supports oil exploitation contamination control.
Ping Lu, Qiao-Ying Chen, Meng-Meng Wang et al.· Environmental Research· 0 citations
Polybrominated diphenyl ethers (PBDEs) constitute a class of widespread environmental contaminants that pose significant health risks. Therefore, this study investigated the distribution, risks and sources of PBDEs in dusts from power generation plants in Nigeria. A total of 24 dust samples were collected from four power plants. Samples were collected for six months covering both wet and dry seasons. Dusts were extracted for PBDEs following the United State Environmental Protection Agency Method 3550C using a 1:1 mixture of dichloromethane and n-hexane. Thereafter, the extracts were cleaned-up and analyzed for PBDEs using a gas chromatograph-mass spectrometer. The results indicated that the mean concentrations of ∑39 PBDEs in the dusts ranged from 17.5 to 54.6 ng g-1 for wet season and 55.4 to 157 ng g-1 for dry season. There were significant spatio-temporal variations in the concentrations of PBDEs in the dust. The PBDEs have higher concentrations during the dry season than the wet season. The hazard index and total cancer risk values indicated that there is neither adverse non-carcinogenic risk nor carcinogenic risk from exposure to PBDEs in these dusts. Source apportionment indicated that the PBDEs in the dusts were from the use of deca- and penta-BDE commercial formulations used for dielectric insulating fluids for transformers, capacitors, cable insulators etc. It is hereby recommended that the Federal Ministry of Environment should establish environmental policy and enforceable regulatory frameworks for the control of PBDEs in order to minimize the levels environmental PBDEs and the risk to human and ecosystems.
J. N. Tesi, I. Agbozu, O. Edjere et al.· FUDMA Journal of Sciences· 0 citations
Despite extensive research on the environmental contamination of per- and polyfluoroalkyl substances (PFAS), their occurrence across diverse indoor microenvironments remains insufficiently characterized. In this study, we analyzed a broad spectrum of PFAS in dust samples collected from residential settings (n = 14) and six types of public environments in South China between July and September 2022, using ultra-performance liquid chromatography coupled with triple-quadrupole mass spectrometry (UPLC-MS/MS). Of the 35 target compounds, 19 PFAS were detected with detection frequencies exceeding 50%. Ultrashort-chain perfluoroalkyl acids (PFAAs) and their precursors emerged as the dominant species, with concentrations substantially higher than those of legacy compounds such as perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA). PFAS concentrations varied by microenvironment, with offices exhibiting the highest levels (median 516 ng/g), likely attributable to the widespread use of PFAS-containing materials and confined space. Estimated exposure via dust ingestion revealed that toddlers experienced the highest intake (0.692 ng/kg/day) among all age groups in household environments, due to greater dust ingestion rates. Our study highlights the widespread occurrence of emerging PFAS, including ultrashort- and short-chain PFAAs and PFAA precursors, in indoor environments in South China and emphasizes the importance of ongoing surveillance and regulatory measures for these substances.
Yu-Ge Liang, Xiaoyuan Guo, Chenglin Liu et al.· Environmental Pollution· 0 citations
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