Source, dispersion and combustion modelling of an accidental release of hydrogen in an urban environment

Venetsanos, A.G.; Huld, Thomas; Adams, Paul; Bartzis, John G.

doi:10.1016/j.jhazmat.2003.05.001

Cited by 88 publications

(23 citation statements)

References 11 publications

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“…Molecular hydrogen is the smallest molecule in the universe and has the highest diffusibility 24. Inhaled hydrogen gas readily enters the blood stream through the alveoli 2025.…”

Section: Discussionmentioning

confidence: 99%

Inhalation of hydrogen gas elevates urinary 8-hydroxy-2′-deoxyguanine in Parkinson’s disease

et al. 2018

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Hyposmia is one of the earliest and the most common symptoms in Parkinson’s disease (PD). The benefits of hydrogen water on motor deficits have been reported in animal PD models and PD patients, but the effects of hydrogen gas on PD patients have not been studied. We evaluated the effect of inhalation of hydrogen gas on olfactory function, non-motor symptoms, activities of daily living, and urinary 8-hydroxy-2′-deoxyguanine (8-OHdG) levels by a randomized, double-blinded, placebo-controlled, crossover trial with an 8-week washout period in 20 patients with PD. Patients inhaled either ~1.2–1.4% hydrogen-air mixture or placebo for 10 minutes twice a day for 4 weeks. Inhalation of low dose hydrogen did not significantly influence the PD clinical parameters, but it did increase urinary 8-OHdG levels by 16%. This increase in 8-OHdG is markedly less than the over 300% increase in diabetes, and is more comparable to the increase after a bout of strenuous exercise. Although increased reactive oxygen species is often associated with toxicity and disease, they also play essential roles in mediating cytoprotective cellular adaptations in a process known as hormesis. Increases of oxidative stress by hydrogen have been previously reported, along with its ability to activate the Nrf2, NF-κB pathways, and heat shock responses. Although we did not observe any beneficial effect of hydrogen in our short trial, we propose that the increased 8-OHdG and other reported stress responses from hydrogen may indicate that its beneficial effects are partly or largely mediated by hormetic mechanisms. The study was approved by the ethics review committee of Nagoya University Graduate School of Medicine (approval number 2015-0295). The clinical trial was registered at the University Hospital Medical Information Network (identifier UMIN000019082).

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“…Molecular hydrogen is the smallest molecule in the universe and has the highest diffusibility 24. Inhaled hydrogen gas readily enters the blood stream through the alveoli 2025.…”

Section: Discussionmentioning

confidence: 99%

Inhalation of hydrogen gas elevates urinary 8-hydroxy-2′-deoxyguanine in Parkinson’s disease

et al. 2018

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“…It has been postulated that hydrogen reacts with reactive oxygen species causing a decreases in oxidative stress at the tissue level and thus decreasing the amount of blood brain barrier breakdown [ 7 ]. The decrease in blood brain barrier breakdown in turn results in the decreases vasogenic edema formation [ 14 ]. We measured lipid peroxidation, the final outcome of oxidative stress [ 15 ].…”

Section: Discussionmentioning

confidence: 99%

Hydrogen is neuroprotective against surgically induced brain injury

et al. 2011

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BackgroundNeurosurgical operations cause unavoidable damage to healthy brain tissues. Direct surgical injury as well as surgically induced oxidative stress contributes to the subsequent formation of brain edema. Therefore, we tested the neuroprotective effects of hydrogen (H2) in an established surgical brain injury (SBI) model in rats.Materials and methodsAdult male Sprague - Dawley rats (weight 300-350g) were divided into three groups to serve as sham operated, SBI without treatment, and SBI treated with H2 (2.9%). Brain water content, myeloperoxidase (MPO) assay, lipid peroxidation (LPO), and neurological function were measured at 24 hrs after SBI.ResultsSBI resulted in localized brain edema (p = < 0.001). Hydrogen (2.9%) administered concurrently with surgery significantly decreased the formation of cerebral edema (p = 0.028) and improved neurobehavioral score (p = 0.022). However, hydrogen treatment failed to reduce oxidative stress (LPO assay) or inflammation (MPO assay) in brain tissues.ConclusionsHydrogen appears to be promising as an effective, yet inexpensive way to reduce cerebral edema caused by surgical procedures. Hydrogen has the potential to improve clinical outcome, decrease hospital stay, and reduce overall cost to patients and the health care system.

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“…Such studies often describe the concentration field in a time-averaged sense. However, the mean concentration field alone is not sufficient for estimating the potential hazard risk in cases such as an accidental release of a highly toxic pollutant near a building [7], or a flammable gas leakage [8]. It is therefore necessary to estimate not only the mean concentration of a pollutant but also concentration fluctuations.…”

Section: Introductionmentioning

confidence: 99%

Analysis of concentration fluctuations in gas dispersion around high-rise building for different incident wind directions

Liu

Niu

Kwok

2011

Journal of Hazardous Materials

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This article presents experimental results that illustrate the unsteady characteristics of gas dispersion around a complex-shaped high-rise building for different incident wind directions. A series of wind tunnel experiments were conducted using a 1:30 scale model that represented the real structures under study. The objective of this paper is to study the behaviour of concentration fluctuations through transient analysis. Tracer gas was continuously released from a point source located at different positions, and a time series of fluctuating concentrations were recorded at a large number of points using fast flame ionization detectors. The experimental data were analysed to provide a comprehensive data set including variances and associated statistical quantities. Both the unsteady characteristics of the system and their potential practical impact are presented and discussed. Under crowd living conditions, the air pollutant exhausted from one household could probably re-enter into the neighbouring households, traveling with ambient airflow. Such pollutant dispersion process is defined as air cross-contamination in this study. The results indicate that the wind-induced cross-contamination around the studied type of high-rise building should not be overlooked, and the fluctuating concentrations should be paid attention to particularly during the evaluation of a potential contamination risk. This study can help deepen our understanding of the mechanisms of air cross-contamination, and will be useful for implementing optimization strategies to improve the built environments in metropolitan cities such as Hong Kong.

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Source, dispersion and combustion modelling of an accidental release of hydrogen in an urban environment

Cited by 88 publications

References 11 publications

Inhalation of hydrogen gas elevates urinary 8-hydroxy-2′-deoxyguanine in Parkinson’s disease

Inhalation of hydrogen gas elevates urinary 8-hydroxy-2′-deoxyguanine in Parkinson’s disease

Hydrogen is neuroprotective against surgically induced brain injury

Analysis of concentration fluctuations in gas dispersion around high-rise building for different incident wind directions

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