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International Journal of Environmental... Nov 2022Recently released hourly particular matter (PM:PM and PM) and gaseous pollutants (SO, NO, CO, and O) data observed in Qingdao, Hangzhou, and Xiamen from 2015 to 2019...
Recently released hourly particular matter (PM:PM and PM) and gaseous pollutants (SO, NO, CO, and O) data observed in Qingdao, Hangzhou, and Xiamen from 2015 to 2019 were utilized to reveal the current situation of air pollution over eastern coastal China. The PM pollution situation over the three metropolises ameliorated during studied period with the concentrations decreasing about 20-30%. Gas pollutants, excepting SO, generally exhibit no evident reduction tendencies, and a more rigorous control standard on gaseous pollutants is neededEven for the year 2018 with low pollution levels among the study period, these levels (<10% of PM, <6% of PM, and <15% of O) surpass the Grade II of the Chinese Ambient Air Quality Standard (CAAQS) over these metropolises of eastern coast China. No matter in which year, both SO and CO concentrations are always below the Grade-II standards. According to the comparative analysis of PM/PM and PM/CO during episode days and non-episode days, the formation of secondary aerosols associated with stagnant weather systems play an important role in the pollutant accumulation as haze episodes occurred. The stronger seasonal variations and higher magnitude occur in Qingdao and Hangzhou, while weaker seasonal variations and lower magnitudes occur in Xiamen. In Qingdao and Hangzhou, PM, NO, SO, and CO show relatively high levels in the cold wintertime and low levels in summer, whereas O shows a completely opposite pattern. Xiamen exhibits high levels of all air pollutants except O in spring due to its subtropical marine monsoon climate with mild winters. According to the back trajectory hierarchical clustering and concentration weighted trajectory (CWT) analysis, the regional transmission from adjacent cities has a significant impact on the atmospheric pollutant concentrations under the control of the prejudiced winds. Thus, besides local emission reduction, strengthening regional environmental cooperation and implementing joint prevention are effective measures to mitigate air pollution in the eastern coastal areas of China.
Topics: Air Pollutants; Nitrogen Dioxide; Environmental Pollutants; Gases; China; Wind; Particulate Matter
PubMed: 36430050
DOI: 10.3390/ijerph192215332 -
Environment International Sep 2019We review the major features of desert dust outbreaks that are relevant to the assessment of dust impacts upon human health. Our ultimate goal is to provide scientific... (Review)
Review
We review the major features of desert dust outbreaks that are relevant to the assessment of dust impacts upon human health. Our ultimate goal is to provide scientific guidance for the acquisition of relevant population exposure information for epidemiological studies tackling the short and long term health effects of desert dust. We first describe the source regions and the typical levels of dust particles in regions close and far away from the source areas, along with their size, composition, and bio-aerosol load. We then describe the processes by which dust may become mixed with anthropogenic particulate matter (PM) and/or alter its load in receptor areas. Short term health effects are found during desert dust episodes in different regions of the world, but in a number of cases the results differ when it comes to associate the effects to the bulk PM, the desert dust-PM, or non-desert dust-PM. These differences are likely due to the different monitoring strategies applied in the epidemiological studies, and to the differences on atmospheric and emission (natural and anthropogenic) patterns of desert dust around the world. We finally propose methods to allow the discrimination of health effects by PM fraction during dust outbreaks, and a strategy to implement desert dust alert and monitoring systems for health studies and air quality management.
Topics: Aerosols; Air Movements; Air Pollutants; Air Pollution; Dust; Environmental Monitoring
PubMed: 31207476
DOI: 10.1016/j.envint.2019.05.061 -
Sensors (Basel, Switzerland) Nov 2022Precise and accurate measurements of ambient HNO3 are crucial for understanding various atmospheric processes, but its ultra-low trace amounts and the high polarity of...
Precise and accurate measurements of ambient HNO3 are crucial for understanding various atmospheric processes, but its ultra-low trace amounts and the high polarity of HNO3 have strongly hindered routine, widespread, direct measurements of HNO3 and restricted field studies to mostly short-term, localized measurement campaigns. Here, we present a custom field-deployable direct absorption laser spectrometer and demonstrate its analytical capabilities for in situ atmospheric HNO3 measurements. Detailed laboratory characterizations with a particular focus on the instrument response under representative conditions for tropospheric measurements, i.e., the humidity, spectral interference, changing HNO3 amount fractions, and air-sampling-related artifacts, revealed the key aspects of our method: (i) a good linear response (R2 > 0.98) between 0 and 25 nmol·mol−1 in both dry and humid conditions with a limit of detection of 95 pmol·mol−1; (ii) a discrepancy of 20% between the spectroscopically derived amount fractions and indirect measurements using liquid trapping and ion chromatography; (iii) a systematic spectral bias due to water vapor. The spectrometer was deployed in a three-week field measurement campaign to continuously monitor the HNO3 amount fraction in ambient air. The measured values varied between 0.1 ppb and 0.8 ppb and correlated well with the daily total nitrates measured using a filter trapping method.
Topics: Air Pollutants; Air; Nitrates; Lasers
PubMed: 36501859
DOI: 10.3390/s22239158 -
PeerJ 2023Performing back trajectory and forward trajectory using the Hybrid Single-Particle Lagrangian Integrated Trajectory Model (HYSPLIT) is a reliable approach for assessing...
BACKGROUND
Performing back trajectory and forward trajectory using the Hybrid Single-Particle Lagrangian Integrated Trajectory Model (HYSPLIT) is a reliable approach for assessing particle transport after release among mid-field atmospheric models. HYSPLIT has an externally facing online interface that allows non-expert users to run the model trajectories without requiring extensive training or programming. However, the existing HYSPLIT interface is limited if simulations have a large amount of meteorological data and timesteps that are not coincident. The objective of this study is to design and develop a more robust tool to rapidly evaluate hazard transport conditions and to perform risk analysis, while still maintaining an intuitive and user-friendly interface.
METHODS
HYSPLIT calculates forward and backward trajectories of particles based on wind speed, wind direction, and the corresponding location, timestamp, and Pasquill stability classes of the regions of the atmosphere in terms of the wind speed, the amount of solar radiation, and the fractional cloud cover. The computed particle transport trajectories, combined with the online Proton Transfer Reaction-Mass Spectrometry (PTR-MS) data (https://figshare.com/articles/dataset/ARL_Data_from_PROS_station_at_Hanford_site/19993964), can be used to identify and quantify the sources and affected area of the hazardous chemicals' emission using the potential source distribution function (PSDF). PSDF is an improved statistical function based on the well-known potential source contribution function (PSCF) in establishing the air pollutant source and receptor relationship. Performing this analysis requires a range of meteorological and pollutant concentration measurements to be statistically meaningful. The existing HYSPLIT graphical user interface (GUI) does not easily permit computations of trajectories of a dataset of meteorological data in high temporal frequency. To improve the performance of HYSPLIT computations from a large dataset and enhance risk analysis of the accidental release of material at risk, a geospatial risk analysis tool (GRAT-GUI) is created to allow large data sets to be processed instantaneously and to provide ease of visualization.
RESULTS
The GRAT-GUI is a native desktop-based application and can be run in any Windows 10 system without any internet access requirements, thus providing a secure way to process large meteorological datasets even on a standalone computer. GRAT-GUI has features to import, integrate, and convert meteorological data with various formats for hazardous chemical emission source identification and risk analysis as a self-explanatory user interface. The tool is available at https://figshare.com/articles/software/GRAT/19426742.
Topics: Hazardous Substances; Air Pollutants; Wind; Risk Assessment; Atmosphere
PubMed: 36691483
DOI: 10.7717/peerj.14664 -
Parasitology Jun 2020Free-living amoebae (FLA) are widely dispersed in the environment, can cause opportunistic and non-opportunistic infections in humans and other animals. The aim of the...
Free-living amoebae (FLA) are widely dispersed in the environment, can cause opportunistic and non-opportunistic infections in humans and other animals. The aim of the present study was characterize FLA obtained from air-conditioners of a public hospital in the city of Florianópolis, SC, Brazil. Fifty-four dust samples were collected of air conditioners, and were inoculated on 1.5% non-nutrient agar, overlaid with layers of Escherichia coli. Subsequently the isolates were axenised in PYG growth medium. The morphological and molecular characterization of the isolates was performed, as well as the tolerance (physiological) assays were used to evaluate the pathogenic potential. The results revealed the presence of FLA in 42 (77.8%) of the collected samples. Of these, 39 (92.9%) axenic isolates of FLA were obtained for morphological and genotypic studies. All the isolates characterized belong to the genus Acanthamoeba. Nineteen (48.7%) isolates belong to the genotype T4, 16 (41.0%) to the T5 genotype and 4 (10.3%) to genotype T11. Seven (18.0%) isolates were considered potentially pathogenic in tolerance assays. These findings require attention, considering the isolation environment and immunocompromised characteristics of many hospitalized patients.
Topics: Acanthamoeba; Air; Air Conditioning; Air Pollution; Brazil; Genotype; Hospitals
PubMed: 32183918
DOI: 10.1017/S0031182020000487 -
Dermatologic Surgery : Official... Aug 2020Bleomycin foam is an effective sclerotherapy method for venous malformations. The preparation method is rather complicated, and the volume and stability of the foam are...
BACKGROUND
Bleomycin foam is an effective sclerotherapy method for venous malformations. The preparation method is rather complicated, and the volume and stability of the foam are limited.
OBJECTIVE
To modify the currently used method for preparing bleomycin foam, to simplify the preparation procedure, and to produce foam with greater volume and increased stability.
MATERIALS AND METHODS
Experiment 1: 6.0 IU of bleomycin powder was dissolved in different human serum albumin (HSA):saline solution (SS) ratios of 0.5:1.5, 0.75:1.25, 1:1, 1.25:0.75, 1.5:0.5, 1.75:0.25, and 2:0 in volume; then, an air:liquid ratio of 2:1 was used to create foam using the Tessari method. Experiment 2: 6.0 IU of bleomycin was dissolved directly in 2.0 mL of HSA; then, air:liquid ratios of 1:1, 2:1, 3:1, and 4:1 were used to create foam using the Tessari method. The optimum proportions of HSA:SS and air:liquid were screened by comparing the foam half-life (FHL).
RESULTS
Experiment 1: the optimum proportion of HSA:SS was 2:0, and the FHL was 7.5 minutes. Experiment 2: the optimum proportion of air:liquid was 3:1, and the FHL was 9.0 minutes.
CONCLUSION
The modified method is simpler and could produce more stable bleomycin foam with greater volume.
Topics: Air; Bleomycin; Drug Compounding; Drug Stability; Half-Life; Sclerosing Solutions; Sclerotherapy; Serum Albumin; Time Factors
PubMed: 31625953
DOI: 10.1097/DSS.0000000000002221 -
Environmental Science and Pollution... Nov 2022An indoor environment in a hospital building requires a high indoor air quality (IAQ) to overcome patients' risks of getting wound infections without interrupting the... (Review)
Review
An indoor environment in a hospital building requires a high indoor air quality (IAQ) to overcome patients' risks of getting wound infections without interrupting the recovery process. However, several problems arose in obtaining a satisfactory IAQ, such as poor ventilation design strategies, insufficient air exchange, improper medical equipment placement and high door opening frequency. This paper presents an overview of various methods used for assessing the IAQ in hospital facilities, especially in an operating room, isolation room, anteroom, postoperative room, inpatient room and dentistry room. This review shows that both experimental and numerical methods demonstrated their advantages in the IAQ assessment. It was revealed that both airflow and particle tracking models could result in different particle dispersion predictions. The model selection should depend on the compatibility of the simulated result with the experimental measurement data. The primary and secondary forces affecting the characteristics of particle dispersion were also discussed in detail. The main contributing forces to the trajectory characteristics of a particle could be attributed to the gravitational force and drag force regardless of particle size. Meanwhile, the additional forces could be considered when there involves temperature gradient, intense light source, submicron particle, etc. The particle size concerned in a healthcare facility should be less than 20 μm as this particle size range showed a closer relationship with the virus load and a higher tendency to remain airborne. Also, further research opportunities that reflect a more realistic approach and improvement in the current assessment approach were proposed.
Topics: Humans; Air Movements; Ventilation; Air Pollution, Indoor; Particle Size; Delivery of Health Care
PubMed: 36194323
DOI: 10.1007/s11356-022-23407-9 -
Journal of Veterinary Internal Medicine May 2018Organic dust is associated with Equine asthma. Ionization should reduce airborne dust levels. (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Organic dust is associated with Equine asthma. Ionization should reduce airborne dust levels.
OBJECTIVES
To determine the effect of ionization of air, type of bedding, and feed on the levels of airborne dust, endotoxin, and fungal colonies in horse stables.
ANIMALS
24 healthy University-owned horses occupied the stables.
METHODS
A randomized controlled cross-over study. Four units with 6 stables were equipped with an ionization installation (25 VA, 5000 Volt Direct Current). Horses were kept either on wood shavings and fed haylage (2 units), or on straw and fed dry hay (2 units). Measurements were performed with and without activated ionization, during daytime and nighttime, repeatedly over the course of a week and repeatedly during 4-6 weeks. Statistical analysis was performed using a mixed effect model with Akaike's Information Criterion for model reduction and 95% profile (log) likelihood confidence intervals (CI).
RESULTS
Ionization did not alter concentrations of dust, endotoxin, or fungi, fewer. In the units with straw and hay, the concentration of dust, endotoxin, and fungi (difference in logarithmic mean 1.92 (95%CI 1.71-2.12); 2.86 (95%CI 2.59-3.14); 1.75 (95%CI 1.13-2.36)) were significantly higher compared to wood shavings and haylage.
CONCLUSIONS AND CLINICAL IMPORTANCE
The installation of a negative air-ionizer in the horse stable did not reduce concentrations of dust, endotoxin, and viable fungal spores. The substantial effect of low dust bedding and feed is confirmed.
Topics: Air Ionization; Air Pollution, Indoor; Animal Feed; Animal Husbandry; Animals; Bedding and Linens; Cross-Over Studies; Horses; Housing, Animal
PubMed: 29485234
DOI: 10.1111/jvim.15069 -
Sensors (Basel, Switzerland) Jun 2022Air velocity of coal mine ventilation is an important consideration that may cause serious damage. This paper proposes a simple, low cost and effective air velocity...
Air velocity of coal mine ventilation is an important consideration that may cause serious damage. This paper proposes a simple, low cost and effective air velocity monitor (AVM) for coal mine ventilation. The AVM uses the lock-in characteristic of vortex-induced vibration (VIV) to sense the air velocity. Amplitude of the VIV is converted into frequency signal of a vortex-induced triboelectric nanogenerator (VI-TENG) to improve the durability. Structure of the AVM are designed, and parameters of the AVM are optimized with experiments. For the upper and lower air velocity thresholds of 3.1 and 3.6 m/s, the optimized flexible beam length, slider weight, electrode space and electrode width are 42.5 mm, 0.4 g, 0.2 mm and 0.5 mm, respectively. Experiments also show that the output frequency of the VI-TENG could represent the amplitude of VIV well with the correlation coefficient of 0.93. Durability test demonstrates that the AVM generates stable output frequency in 120,000 cycles. A prototype and its controller are fabricated. Wind tunnel tests of this prototype show that it can give alarm when the gas velocity goes above the upper threshold or below the lower threshold. The proposed AVM could be a good solution for simple and effective coal mine ventilation alarm.
Topics: Air Movements; Coal; Electrodes; Gases; Mining; Nanotechnology; Ventilation; Vibration
PubMed: 35808329
DOI: 10.3390/s22134832 -
Sensors (Basel, Switzerland) Jun 2022Various mechanical, hydraulic, pneumatic, electrical, and hybrid actuators can alter motion per the requirements of particular applications. However, except for... (Review)
Review
Various mechanical, hydraulic, pneumatic, electrical, and hybrid actuators can alter motion per the requirements of particular applications. However, except for electrical ones, all actuators are restricted due to their size, complex auxiliary equipment, frequent need for maintenance, and sluggish environment in renewable applications. This brief review paper highlights some unique and significant research works on applying electrical actuators to renewable applications. Four renewable energy resources, i.e., solar, wind, bio-energy, and geothermal energy, are considered to review electric actuators applicable to renewable energy systems. This review analyses the types of actuators associated with the mentioned renewable application, their functioning, their motion type, present use, advantages, disadvantages, and operational problems. The information gathered in this paper may open up new ways of optimization opportunities and control challenges in electrical actuators, thereby making more efficient systems. Furthermore, some energy-efficient and cost-effective replacements of convectional actuators with new innovative ones are suggested. This work aims to benefit scientists and new entrants working on actuators in renewable energy systems.
Topics: Electricity; Renewable Energy; Wind
PubMed: 35684894
DOI: 10.3390/s22114273