In many regions of China, very rapid economic growth has been accompanied by air pollution caused by vehicle emissions. In one of these regions, the Pearl River Delta, the variations of ground-level ozone and its precursors were investigated. Overall, the ambient concentrations of NO(2) increased quickly between 1995 and 1996, but then slightly decreased due to stringent nitrogen oxide (NO(x)) emission controls. Nonetheless, ambient NO(2) levels in the Pearl River Delta remained high. The regional average concentrations of volatile organic compounds (VOCs) were 290 ppbC in summer and 190 ppbC in autumn. Local emissions and long-distance transportation of pollutants play important roles in the regional distribution of VOCs. Ambient O(3) production is significant in urban areas and also downwind of cities. The relative incremental reactivities (RIRs), determined by an observation-based model, showed that ground-level ozone formation in the Guangzhou urban area is generally limited by the concentrations of VOCs, but there are also measurable impacts of NO(x).
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http://dx.doi.org/10.1016/j.jenvman.2007.12.008 | DOI Listing |
Nat Commun
December 2024
Earth Commons, Georgetown University, Washington, DC, USA.
Observationally-derived emissions of ozone depleting substances must be scrutinized to maintain the progress made by the Montreal Protocol in protecting the stratospheric ozone layer. Recent observations of three chlorofluorocarbons (CFCs), CFC-113, CFC-114, and CFC-115, suggest that emissions of these compounds have not decreased as expected given global reporting of their production. These emissions have been associated with hydrofluorocarbon (HFC) production, which can require CFCs as feedstocks or generate CFCs as by-products, yet emissions from these pathways have not been rigorously quantified.
View Article and Find Full Text PDFOpen Vet J
November 2024
Department of Nursing, Technical Institute of Suwaria, Middle Technical University, Baghdad, Iraq.
Background: Ozone (O) is a promising alternative antibacterial agent that has recently been used in meat processing. The understanding of the appropriate functional settings of O for addressing food safety problems is still insufficient.
Aim: The aim of this study was, therefore, to investigate the effects of exposure to O on the bacteriological quality of retail meat inoculated with at refrigeration temperatures.
Cureus
November 2024
Department of Plastic Surgery, Kobe University Graduate School of Medicine, Kobe, JPN.
Nanobubbles are studied for their unique properties and possible applications in wound healing processes. This study investigates the effects of hydrogen (H₂), oxygen (O₂), and ozone (O₃) nanobubbles on fibroblast migration and proliferation using scratch wound healing assays. Fibroblast cells were treated with Dulbecco's Modified Eagle Medium (DMEM) combined with nanobubble solutions, and cell density was measured at 24 and 48 hours.
View Article and Find Full Text PDFJ Infect Chemother
December 2024
Graduate School, International University of Health and Welfare, 2600-1 Kitakanemaru, Otawara, Tochigi 324-8501, Japan; School of Medicine, International University of Health and Welfare, 4-3 Kozunomori, Narita, Chiba 286-0048, Japan; Department of Infection Control, International University of Health and Welfare Narita Hospital, 852 Hatakeda, Narita, Chiba 286-0124, Japan.
Introduction: We aimed to determine the impact of prior antimicrobial treatment on recurrent Clostridioides difficile infection (CDI) based on days of antibiotic spectrum coverage (DASC) and predict the risk of recurrence to guide the selection of appropriate initial therapeutic agents.
Methods: We assessed the antimicrobial treatment administered to 195 patients with a history of CDI for 28 days before testing positive for C. difficile using DASC and illness severity using ATLAS scores.
J Hazard Mater
December 2024
School of Public Health, Guangzhou Medical University, Guangzhou 511436, China. Electronic address:
The burden of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) and its oxidized products on human health can no longer be ignored due to the detection types and concentrations in the environment continue to increase. Environmental ozone (O) and ultraviolet A (UVA) may induce ozonation and photoaging of 6PPD to produce toxic products. However, the impact of specific environmental conditions on the aging and toxic effects of 6PPD is unclear.
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