Modelling Exposure from Airborne Hazardous Short-Duration Releases in Urban Environments

When considering accidental or/and deliberate releases of airborne hazardous substances the release duration is often short and in most cases not precisely known. The downstream exposure in those cases is stochastic due to ambient turbulence and strongly dependent on the release duration. Depending on the adopted modelling approach, a relatively large number of dispersion simulations may be required to assess exposure and its statistical behaviour. The present study introduces a novel approach aiming to replace the large number of the abovementioned simulation scenarios by only one simulation of a corresponding continuous release scenario and to derive the exposure-related quantities for each finite-duration release scenario by simple relationships. The present analysis was concentrated on dosages and peak concentrations as the primary parameters of concern for human health. The experimental and theoretical analysis supports the hypothesis that the dosage statistics for short releases can be correlated with the corresponding continuous release concentration statistics. The analysis shows also that the peak concentration statistics for short-duration releases in terms of ensemble average and standard deviation are well correlated with the corresponding dosage statistics. However, for more reliable quantification of the associated correlation coefficients further experimental and theoretical research is needed. The probability/cumulative density function for dosage and peak concentration can be approximated by the beta function proposed in an earlier work by the authors for continuous releases.

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Development and Validation of a LC-MS/MS Method for the Determination of Nitrofuran Metabolites in Soft-Shell Turtle Powder Health Food Supplement

International Journal of Analytical Chemistry ◽

10.1155/2021/8822448 ◽

2021 ◽

Vol 2021 ◽

pp. 1-11

Author(s):

EunChae Ryu ◽

Ji Sung Park ◽

Sib Sankar Giri ◽

Se Chang Park

Keyword(s):

Correlation Coefficients ◽

Accurate Method ◽

Food Supplement ◽

Hazardous Substances ◽

The European Union ◽

Health Food ◽

Quick Method ◽

Soft Shell ◽

Time Required ◽

Nitrofuran Metabolites

Soft-shell turtle (SST; freshwater terrapin or tortoise) is a popular and important health functional food (HFF) product in many Asian countries. HFFs containing SST must be safe, but several HFFs have been found to be contaminated with dangerous substances, such as nitrofuran metabolites (NFMs). This finding suggests that the consumption of HFFs results in the regular exposure of vulnerable individuals to hazardous substances. Importantly, nitrofuran antibiotics have been banned for use in food-producing animals since the 1990s by the European Union. Thus, in this study, we propose a reliable and quick method to reduce the time required for the detection of four NFMs in SST powder that conventional methods are unable to quantify. Our method involves the derivatization and hydrolysis of SST powder and was validated in accordance with the requirements of European Commission Decision 2002/657/EC. The method achieves an apparent mean recovery of 82.2–108.1%, repeatability of 1.5–3.8%, and reproducibility of 2.2–4.8% for 0.5–10.0 μg kg−1 of 1-aminohydantoin, semicarbazide, 3-amino-2-oxazolidinone, and 3-amino-5-morpholinomethyl-2-oxazolidinone. In addition, linearity was achieved with correlation coefficients of 0.999, and the detection capability (CCβ) and decision limit (CCα) were found to be reliable, indicating that this is a fast and accurate method for the analysis of SST powder. The validated method was successfully applied to detect NFMs in SST powder in commercial HHFs.

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High-resolution urban air quality monitoring using sentinel satellite images and low-cost ground-based sensor networks

E3S Web of Conferences ◽

10.1051/e3sconf/202017102002 ◽

2020 ◽

Vol 171 ◽

pp. 02002

Author(s):

Joseph Gitahi ◽

Michael Hahn

Keyword(s):

Satellite Images ◽

Meteorological Data ◽

Low Cost ◽

Correlation Coefficients ◽

Urban Environments ◽

Average Correlation ◽

Second Stage ◽

Aerosol Distribution ◽

Level Monitoring ◽

Sentinel 2

Satellite remote sensing aerosol monitoring products are readily available but limited to regional and global scales due to low spatial resolutions making them unsuitable for city-level monitoring. Freely available satellite images such as Sentinel -2 at relatively high spatial (10m) and temporal (5 days) resolutions offer the chance to map aerosol distribution at local scales. In the first stage of this study, we retrieve Aerosol Optical Depth (AOD) from Sentinel -2 imagery for the Munich region and assess the accuracy against ground AOD measurements obtained from two Aerosol Robotic Network (AERONET) stations. Sen2Cor, iCOR and MAJA algorithms which retrieve AOD using Look-up-Tables (LUT) pre-calculated using radiative transfer (RT) equations and SARA algorithm that applies RT equations directly to satellite images were used in the study. Sen2Cor, iCOR and MAJA retrieved AOD at 550nm show strong consistency with AERONET measurements with average correlation coefficients of 0.91, 0.89 and 0.73 respectively. However, MAJA algorithm gives better and detailed variations of AOD at 10m spatial resolution which is suitable for identifying varying aerosol conditions over urban environments at a local scale. In the second stage, we performed multiple linear regression to estimate surface Particulate Matter (PM2.5) concentrations using the satellite retrieved AOD and meteorological data as independent variables and ground-measured PM2.5 data as the dependent variable. The predicted PM2.5 concentrations exhibited agreement with ground measurements, with an overall coefficient (R2) of 0.59.

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Integrating RELAX with PS-InSAR Technique to Improve Identification of Persistent Scatterers for Land Subsidence Monitoring

Remote Sensing ◽

10.3390/rs12172730 ◽

2020 ◽

Vol 12 (17) ◽

pp. 2730

Author(s):

Di Zhou ◽

Anita Simic-Milas ◽

Jie Yu ◽

Lin Zhu ◽

Beibei Chen ◽

...

Keyword(s):

Land Subsidence ◽

Correlation Coefficients ◽

Joint Modeling ◽

Urban Environments ◽

Persistent Scatterers ◽

Persistent Scatterer ◽

Monitoring Accuracy ◽

Value Decomposition ◽

Subsidence Monitoring ◽

Beijing China

Identifying Persistent Scatterers (PSs) is one of the key processing steps of the Persistent Scatterer Interferometric Synthetic Aperture Radar (PS-InSAR) technique. The number, density, and reliability of identified PSs directly affect the monitoring accuracy of land subsidence, especially in higher density urban environments. As a result of the side-looking viewing geometry of SAR, the layover effect poses a major challenge to the PS identification. This research proposes joint modeling of the PS-InSAR technique and RELAX algorithm for SAR tomography (PS-InSAR+RELAX) to detect single and double scatterers and to improve the identification and reliability of PSs. It has been demonstrated that RELAX improves separation of the scatterers when compared to two other spectral analysis methods for SAR tomography, Beam-Forming (BF) and Singular Value Decomposition (SVD). RELAX exhibits the least noise when the number of baseline changes from 15 to 30, and it can separate the scatterers at a lower Normal-Slant-Range (NSR) height than the two other methods. As RELAX can better identify, separate, and then filter out layover scatterers, the number and density of PSs identified by PS-InSAR+RELAX is reduced and visually simplified, suggesting that the method can effectively reduce the influence of the layover effect on the PS identification. Also, the PSs identified by PS-InSAR+RELAX are more coherent than those identified by the traditional PS-InSAR technique. The proposed technique has been applied to Sentinel-1A data acquired from 2014 to 2016, to monitor land subsidence in the city of Beijing, China. When evaluated against the leveling measurements, PS-InSAR+RELAX performs better than the traditional PS-InSAR technique, with the correlation coefficients (r) of r = 0.98 and r = 0.95, respectively.

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Ensemble CNN to Detect Drowsy Driving with In-Vehicle Sensor Data

Sensors ◽

10.3390/s21072372 ◽

2021 ◽

Vol 21 (7) ◽

pp. 2372

Author(s):

Yongsu Jeon ◽

Beomjun Kim ◽

Yunju Baek

Keyword(s):

Short Duration ◽

Road Traffic ◽

Imbalanced Data ◽

Urban Environments ◽

Sensor Data ◽

Steering Wheel ◽

Drowsy Driving ◽

Detection Technology ◽

Long Duration ◽

Vehicle Sensor

Drowsy driving is a major threat to the safety of drivers and road traffic. Accurate and reliable drowsy driving detection technology can reduce accidents caused by drowsy driving. In this study, we present a new method to detect drowsy driving with vehicle sensor data obtained from the steering wheel and pedal pressure. From our empirical study, we categorized drowsy driving into long-duration drowsy driving and short-duration drowsy driving. Furthermore, we propose an ensemble network model composed of convolution neural networks that can detect each type of drowsy driving. Each subnetwork is specialized to detect long- or short-duration drowsy driving using a fusion of features, obtained through time series analysis. To efficiently train the proposed network, we propose an imbalanced data-handling method that adjusts the ratio of normal driving data and drowsy driving data in the dataset by partially removing normal driving data. A dataset comprising 198.3 h of in-vehicle sensor data was acquired through a driving simulation that includes a variety of road environments such as urban environments and highways. The performance of the proposed model was evaluated with a dataset. This study achieved the detection of drowsy driving with an accuracy of up to 94.2%.

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Ecological co-inhabitance index (ECI) as a management tool for ecosystem preservation in rivers

Water Science & Technology ◽

10.2166/wst.2001.0086 ◽

2001 ◽

Vol 43 (2) ◽

pp. 161-170 ◽

Cited By ~ 3

Author(s):

C. Yoshimura ◽

Y. Kumagai ◽

K. Fukushi ◽

T. Omura

Keyword(s):

Water Quality ◽

Diversity Index ◽

Correlation Coefficients ◽

Pollution Index ◽

Hazardous Substances ◽

Management Tool ◽

Biotic Index ◽

River Ecosystem ◽

Significance Level ◽

Benthic Animals

The number of novel man-made hazardous substances produced by industries is increasing year after year, resulting in conventional discharge standards ineffective to preserve the natural ecological environment. A novel index, ecological co-inhabitance index (ECI), was proposed in order to evaluate the river ecosystem sensitively. The river benthic community with a high value of ECI is formed in the healthy ecosystem where benthic animals can share resources in the river environment efficiently, keep the ecosystem functioning, and give the least adverse effect to lower reaches of the river. In order to clarify the characteristic of ECI, the relationship between ECI and water quality in the river was investigated using the data on benthic animals obtained from 17 various rivers. Results of this investigation indicated that ECI could synthetically evaluate the river environment without a bias toward a specific water quality. Moreover, ECI had the significant correlation coefficients with diversity index, biotic index and pollution index at significance level 0.05, respectively. Therefore, ECI is a promising index for managing the river ecosystem.

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Interaction relationship between urban domestic energy consumption and water use – a case study of Beijing and Shanghai

Water Policy ◽

10.2166/wp.2015.090 ◽

2015 ◽

Vol 18 (3) ◽

pp. 670-684 ◽

Cited By ~ 1

Author(s):

Silan Chen ◽

Jiahong Liu ◽

Hao Wang ◽

Jinyue Yan ◽

Pietro Elia Campana ◽

...

Keyword(s):

Energy Consumption ◽

Correlation Coefficient ◽

Water Use ◽

Correlation Coefficients ◽

Scientific Basis ◽

Urban Environments ◽

Water Supply Systems ◽

Urban Context ◽

Per Capita ◽

Domestic Energy

Energy consumption and water use are inextricably linked. Combining research on energy consumption and water use in an urban context provides a scientific basis for the integrated planning of energy and water supply systems. Domestic energy and water are among the most consumed resources in urban environments. Furthermore, domestic resources represent an increasing proportion of the total resources consumed. This paper explores four key indicators of urban energy consumption (UEC) and water use in Beijing and Shanghai for the period of 2000 to 2011. Using correlation analysis, this study establishes the intrinsic relationship between UEC and water use. It also offers an analysis of the consumption trends of these two resources as well as their interactive relationship. The results show that urban domestic energy consumption (UDEC) and water use have a significant linear correlation: UDEC is positively correlated with water use, and the correlation coefficients of Beijing and Shanghai are 0.81 and 0.97, respectively. In Beijing, urban domestic energy and water use per capita are negatively correlated, with the high correlation coefficient of 0.93. In Shanghai, urban domestic energy and water use per capita are positively correlated, with the correlation coefficient of 0.90.

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The Threat of Environmental Pollution with Harmful Substances, on the Example of Uncontrolled Fires in Landfills and Actions Aimed at Reducing it

Safety & Fire Technology ◽

10.12845/sft.57.1.2021.6 ◽

2021 ◽

Vol 57 (1) ◽

pp. 80-98

Author(s):

Krzysztof Cygańczuk ◽

Paweł Janik

Keyword(s):

Waste Management ◽

Point Of View ◽

Hazardous Substances ◽

Theoretical Research ◽

Volatile Phenols ◽

Free Disposal ◽

Harmful Substances ◽

Copper Aluminum ◽

The Eu

Aim: This article attempts to bring closer the issues related to the emission of harmful substances to the environment. The example of two fires that occurred in Poland in 2018 was used – in the former “Boruta” plant in Zgierz and in a landfill in Trzebinia. By presenting the results of measurements and tests available in this field, attention was drawn to the need to improve the methods of detecting and measuring hazardous substances, in particular with regard to their dispersion in the atmosphere. Introduction: The threat to the environment resulting from improper management, including waste disposal, remains a serious challenge for many societies, also for the EU countries, which are among the richest countries in the world. Increased waste generation, high costs related to waste management, i.e. landfilling and recycling, generate the risk of deliberately causing fires in landfills as a method of free disposal. It is cost-free only from the point of view of the dishonest owner of this waste, because the direct costs of long-term rescue and firefighting activities and the effects of the emission of hazardous substances to the environment are borne by the society. In addition, in the last of the aspects mentioned above, the price for this method of disposal is paid primarily by people living in the vicinity of the facilities in question. But not only. In the event of the penetration of the substances mentioned above into the soil and watercourses via e.g. firefighting waters, their impact – also delayed in time – may also affect many other people, e.g. consumers of agricultural products manufactured in the contaminated areas. Methodology: In the article, mainly theoretical research methods were used, including the analysis of literature. Also research reports of specialized research units involved in extinguishing the mentioned fires were analysed. The legal instruments were reviewed against the background of economic conditions and their impact on the efficiency of waste management in Poland was determined. Conclusions: Despite measurement imperfections mentioned above, the presence of the compounds such as toluene, benzene, ethylbenzene, styrene, methylstyrene, sulfur dioxide and o-xylene, which are characteristic substances released during the combustion of plastics, was found in the fire areas. The analysis of surface water samples showed exceeding the standard levels of metals such as copper, aluminum and antimony, as well as petroleum substances such as anthracene, fluoranthene, benzo (b) fluoranthene, benzo (k) fluoranthene, benzo (g, h, i) fluoranthene, petroleum hydrocarbons and volatile phenols. Moreover, elevated values of heavy metals were found in the soil. The above data fully justify the formulation of a thesis on the need to undertake increased, systemic actions aimed at reducing the number and size of fires in landfills. The description of some activities in the field of fire protection of the considered facilities undertaken in Poland will also constitute one of the issues of this article. Keywords: hazardous waste materials, environmental hazard, waste management, uncontrolled fires, legal regulations in waste management Type of article: review article

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Bimolecular Reactive Transport Experiments and Simulations in Porous Media

Water ◽

10.3390/w12071931 ◽

2020 ◽

Vol 12 (7) ◽

pp. 1931

Author(s):

Qian Wang ◽

Jianmin Bian ◽

Yihan Li ◽

Chunpeng Zhang ◽

Fei Ding

Keyword(s):

Particle Size ◽

Porous Media ◽

Reactive Transport ◽

Peak Concentration ◽

Correlation Coefficients ◽

Breakthrough Curves ◽

Peak Time ◽

Average Pore ◽

Fem Model ◽

Relationship Model

For reactive transport process in porous media, limited mixing and non-Fickian behavior are difficult to understand and predict. To explore the effects of anomalous diffusion and limited mixing, the column-based experiments of bimolecular reactive migration were performed and simulated by the CTRW-FEM model (continuous time random walk-finite element method). Simulated parameters were calibrated and the correlation coefficients between modeled and observed BTCs (breakthrough curves) were greater than 0.9, indicating that CTRW-FEM can solve over-prediction and tailing problems effectively. Porous media with coarser particle size show enhanced mixing and the non-Fickian behavior is not affected by particle size. β (a parameter of CTRW-FEM) and Da (Damköhler number) of CTRW-FEM under different Pe (Péclet number) values showed logarithmic linear relationship. Model sensitivity analysis of the CTRW-FEM model show that the peak concentration is most sensitive to the average pore velocity and the arriving peak time of peak concentration is most sensitive to β. These findings provide a theoretical basis for handling mixing and non-Fickian behavior patterns under actual environmental conditions.

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CFD-RANS prediction of individual exposure from continuous release of hazardous airborne materials in complex urban environments

Journal of Turbulence ◽

10.1080/14685248.2016.1246736 ◽

2016 ◽

Vol 18 (2) ◽

pp. 115-137 ◽

Cited By ~ 7

Author(s):

G. C. Efthimiou ◽

S. Andronopoulos ◽

J. G. Bartzis ◽

E. Berbekar ◽

F. Harms ◽

...

Keyword(s):

Urban Environments ◽

Individual Exposure ◽

Continuous Release

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A study of cometary eruptions through OH radio-lines

International Astronomical Union Colloquium ◽

10.1017/s025292110003150x ◽

1999 ◽

Vol 173 ◽

pp. 249-254

Author(s):

A.M. Silva ◽

R.D. Miró

Keyword(s):

Short Duration ◽

Growth Curves ◽

The Other ◽

Initial Mass ◽

Radio Lines ◽

Other Hand ◽

Sudden Rise

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.

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