Organotin compounds are used as pesticides and fungicides as well as additives in plastics. This study identifies the de novo generation of novel volatile organotins in municipal waste deposits and their release via landfill gas. Besides tetramethyltin (Me(4)Sn), a strong neurotoxin, and 5 previously reported organotins, 13 novel ethylated, propylated, and butylated tetraalkyltin compounds were identified. A concentration of 2-4 μg of Sn m(-3) landfill gas was estimated for two landfill sites in Scotland. The atmospheric stability of Me(4)Sn and methylated tin hydrides was determined empirically in a static atmosphere in the dark and under UV light to simulate night- and daytime conditions. Theoretical calculations were carried out to help predict the experimentally obtained stabilities and to estimate the relative stabilities of other alkylated species. Assuming first-order kinetics, the atmospheric half-life for Me(3)SnH was found to be 33 ± 16 and 1311 ± 111 h during day- and nighttime conditions, respectively. Polyalkylation and larger alkyl substitutes tend to reduce the atmospheric stability. These results show that substantial concentrations of neurotoxic organotin compounds can be released from landfill sites and are sufficiently stable in the atmosphere to travel over large distances in night- and daytime conditions to populated areas.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/es102512u | DOI Listing |
This study explores the propagation dynamics of Bessel-Gaussian (BG) beams, focusing on vortex-splitting behavior under short-range atmospheric conditions with varying disturbances. Using the split-step beam propagation method, the research reveals that greater atmospheric turbulence and longer transmission distances enhance both the average vortex splitting distance and its variance while reducing the average topological charge of the received OAM mode. Conversely, laminar conditions promote beam stability.
View Article and Find Full Text PDFMetal halide perovskites have unique luminescent properties that make them an attractive alternative for high quality light-emitting devices. However, the poor stability of perovskites with many defects and the long cycle time for the preparation of perovskite nanocomposites have hindered their production and application. Here, we prepared the perovskite mesostructures by embedding MAPbBr nanocrystals in the mesopores on the surface of silica nanospheres and mixing the nanospheres with silver nanowires and poly(methyl methacrylate) (PMMA), and further explored their optical properties.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, PR China. Electronic address:
The synthesis of highly efficient and environmentally friendly flame retardants through the synergistic interaction of boron, phosphorus and nitrogen is becoming a new research direction. In this study, N-DBSPA, a flame retardant with high flame retardancy, high thermal stability and high efficiency, was prepared by the reaction between pentaerythritol borate and amino trimethylene phosphate, and the limiting oxygen index (LOI) of the modified cotton fabric increased from 18 % to 44.7 % at a weight gain (WG) of 20.
View Article and Find Full Text PDFMed Phys
January 2025
OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany.
Background: Previous studies have shown that in-beam magnetic resonance imaging (MRI) can be used to visualize a proton beam during the irradiation of liquid-filled phantoms. The beam energy- and current-dependent local image contrast observed in water was identified to be predominantly caused by beam-induced buoyant convection and associated flow effects. Besides this flow dependency, the MR signal change was found to be characterized by a change in the relaxation time of water, hinting at a radiochemical contribution, which was hypothesized to lie in oxygen depletion-evoked relaxation time lengthening.
View Article and Find Full Text PDFEnviron Monit Assess
January 2025
Faculty of Resources Management, Thai Nguyen University of Agriculture and Forestry, Mo Bach Str, Thai Nguyen City, Thai Nguyen Province, 250000, Vietnam.
Drought is a reoccurring natural phenomenon that presents significant challenges to agricultural production, ecosystem stability, and water resource management. The Central Highlands of Vietnam, a major region of industrial crops and vegetation ecosystems, has become increasingly vulnerable to drought impacts. Despite this vulnerability, limited research has explored the specific characteristics of drought and its seasonal effects on vegetation ecosystems in the region.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!