scholarly journals Particulate Matter Exposures under Five Different Transportation Modes during Spring Festival Travel Rush in China

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1133
Author(s):  
Yao Zhang ◽  
Nu Yu ◽  
Mengya Zhang ◽  
Quan Ye
Keyword(s):  
Particulate Matter ◽  
High Speed ◽  
Personal Exposure ◽  
Exposure Level ◽  
Yangtze Delta ◽  
Spring Festival ◽  
Transportation Modes ◽  
Quality Guideline ◽  
Traffic Related Pollution ◽  
Exposure Levels

Serious traffic-related pollution and high population density during the spring festival (Chinese new year) travel rush (SFTR) increases the travelers’ exposure risk to pollutants and biohazards. This study investigates personal exposure to particulate matter (PM) mass concentration when commuting in five transportation modes during and after the 2020 SFTR: China railway high-speed train (CRH train), subway, bus, car, and walking. The routes are selected between Nanjing and Xuzhou, two major transportation hubs in the Yangtze Delta. The results indicate that personal exposure levels to PM on the CRH train are the lowest and relatively stable, and so it is recommended to take the CRH train back home during the SFTR to reduce the personal PM exposure. The exposure level to PM2.5 during SFTR is twice as high as the average level of Asia, and it is higher than the WHO air quality guideline (AQG).

scholarly journals Personal Passive Air Samplers for Chlorinated Gases Generated from the Use of Consumer Products

2021 ◽  
Vol 18 (17) ◽  
pp. 8940
Author(s):  
Yeonjeong Ha ◽  
Yerim Koo ◽  
Jung-Hwan Kwon
Keyword(s):  
Personal Exposure ◽  
Consumer Products ◽  
Passive Sampler ◽  
Passive Samplers ◽  
Exposure Level ◽  
Closed Chamber ◽  
Gas Removal ◽  
Chlorine Gas ◽  
Exposure Levels ◽  
Gas Exposure

Various chlorine-based disinfectants are being used during the COVID-19 pandemic; however, only a few studies on exposure to harmful gases resulting from the use of these disinfectants exist. Previously, we developed a personal passive air sampler (PPAS) to estimate the exposure level to chlorine gas while using chlorinated disinfectants. Herein, we investigated the color development of the passive sampler corresponding to chlorine exposure concentration and time, which allows the general population to easily estimate their gas exposure levels. The uptake and reaction rate of PPAS are also explained, and the maximum capacity of the sampler was determined as 1.8 mol of chlorine per unit volume (m3) of the passive sampler. Additionally, the effects of disinfectant types on the gas exposure level were successfully assessed using passive samplers deployed in a closed chamber. It is noteworthy that the same level of chlorine gas is generated from liquid household bleach regardless of dilution ratios, and we confirmed that the chlorine gas can diffuse out from a gel-type disinfectant. Considering that this PPAS reflects reactive gas removal, individual working patterns, and environmental conditions, this sampler can be successfully used to estimate personal exposure levels of chlorinated gases generated from disinfectants.

scholarly journals Evaluation of Personal Exposure to Air Pollutants and Estimation of the Inhaled Dose for Commuters in the Urban Area of Milan, Italy

Proceedings ◽  
2019 ◽  
Vol 44 (1) ◽  
pp. 4 ◽  
Author(s):  
Francesca Borghi ◽  
Giacomo Fanti ◽  
Andrea Spinazzè ◽  
Davide Campagnolo ◽  
Sabrina Rovelli ◽  
...  
Keyword(s):  
Experimental Data ◽  
Particulate Matter ◽  
Nitrogen Dioxide ◽  
Air Pollutants ◽  
Ultrafine Particles ◽  
Personal Exposure ◽  
Traffic Condition ◽  
Different Seasons ◽  
Exposure Levels ◽  
Low Traffic

The aim of this study is to evaluate a commuter’s exposure to different pollutants (nitrogen dioxide (NO2) and fractionated particulate matter (PM), including ultrafine particles (UFP)), via miniaturized and portable real-time monitoring instruments in different and selected environments; the inhaled doses of these pollutants were also estimated in each of these environments. Experimental data were collected during four working weeks, in two different seasons (winter and summer). Principal results show how higher exposures were measured in Underground (for all PM fractions and NO2) and in Car (UFP), while lower exposure levels were measured in Car (PM and NO2) and in Train (UFP). On the contrary, instead, higher values of inhaled dose were found in environments defined as Other, followed by Walking (ht—High Traffic condition), while lower values were found in Walking (lt—Low Traffic condition) and in Car.

scholarly journals Exposure to Atmospheric Particulate Matter-Bound Polycyclic Aromatic Hydrocarbons and Their Health Effects: A Review

2021 ◽  
Vol 18 (4) ◽  
pp. 2177
Author(s):  
Lu Yang ◽  
Hao Zhang ◽  
Xuan Zhang ◽  
Wanli Xing ◽  
Yan Wang ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Particulate Matter ◽  
Real Time ◽  
Health Effects ◽  
Aromatic Hydrocarbons ◽  
Anthropogenic Activities ◽  
Personal Exposure ◽  
Epidemiological Studies ◽  
Atmospheric Particulate Matter ◽  
Polycyclic Aromatic

Particulate matter (PM) is a major factor contributing to air quality deterioration that enters the atmosphere as a consequence of various natural and anthropogenic activities. In PM, polycyclic aromatic hydrocarbons (PAHs) represent a class of organic chemicals with at least two aromatic rings that are mainly directly emitted via the incomplete combustion of various organic materials. Numerous toxicological and epidemiological studies have proven adverse links between exposure to particulate matter-bound (PM-bound) PAHs and human health due to their carcinogenicity and mutagenicity. Among human exposure routes, inhalation is the main pathway regarding PM-bound PAHs in the atmosphere. Moreover, the concentrations of PM-bound PAHs differ among people, microenvironments and areas. Hence, understanding the behaviour of PM-bound PAHs in the atmosphere is crucial. However, because current techniques hardly monitor PAHs in real-time, timely feedback on PAHs including the characteristics of their concentration and composition, is not obtained via real-time analysis methods. Therefore, in this review, we summarize personal exposure, and indoor and outdoor PM-bound PAH concentrations for different participants, spaces, and cities worldwide in recent years. The main aims are to clarify the characteristics of PM-bound PAHs under different exposure conditions, in addition to the health effects and assessment methods of PAHs.

Implementing variable valve actuation on a diesel engine at high-speed idle operation for improved aftertreatment warm-up

2019 ◽  
Vol 21 (7) ◽  
pp. 1134-1146
Author(s):  
Kalen R Vos ◽  
Gregory M Shaver ◽  
Mrunal C Joshi ◽  
James McCarthy
Keyword(s):  
Particulate Matter ◽  
High Speed ◽  
Exhaust Valve ◽  
Exhaust Gas ◽  
Warm Up ◽  
Aftertreatment System ◽  
Idle Speed ◽  
Variable Valve Actuation ◽  
Brake Mean Effective Pressure ◽  
Valve Opening

Aftertreatment thermal management is critical for regulating emissions in modern diesel engines. Elevated engine-out temperatures and mass flows are effective at increasing the temperature of an aftertreatment system to enable efficient emission reduction. In this effort, experiments and analysis demonstrated that increasing the idle speed, while maintaining the same idle load, enables improved aftertreatment “warm-up” performance with engine-out NOx and particulate matter levels no higher than a state-of-the-art thermal calibration at conventional idle operation (800 rpm and 1.3 bar brake mean effective pressure). Elevated idle speeds of 1000 and 1200 rpm, compared to conventional idle at 800 rpm, realized 31%–51% increase in exhaust flow and 25 °C–40 °C increase in engine-out temperature, respectively. This study also demonstrated additional engine-out temperature benefits at all three idle speeds considered (800, 1000, and 1200 rpm, without compromising the exhaust flow rates or emissions, by modulating the exhaust valve opening timing. Early exhaust valve opening realizes up to ~51% increase in exhaust flow and 50 °C increase in engine-out temperature relative to conventional idle operation by forcing the engine to work harder via an early blowdown of the exhaust gas. This early blowdown of exhaust gas also reduces the time available for particulate matter oxidization, effectively limiting the ability to elevate engine-out temperatures for the early exhaust valve opening strategy. Alternatively, late exhaust valve opening realizes up to ~51% increase in exhaust flow and 91 °C increase in engine-out temperature relative to conventional idle operation by forcing the engine to work harder to pump in-cylinder gases across a smaller exhaust valve opening. In short, this study demonstrates how increased idle speeds, and exhaust valve opening modulation, individually or combined, can be used to significantly increase the “warm-up” rate of an aftertreatment system.

FORMATION OF HEMOLYSIN BY STRAINS OF PSEUDOMONAS AERUGINOSA

1966 ◽  
Vol 12 (2) ◽  
pp. 231-241 ◽  
Author(s):  
Robert A. Altenbern
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Particulate Matter ◽  
High Speed ◽  
Heat Labile ◽  
Intracellular Release ◽  
No Release ◽  
Subsequent Exposure

Hemolysin is formed in sonic extracts of cells of Pseudomonas aeruginosa by the action of a heat-labile substance, probably an intracellular "release" enzyme, on a substrate from the disrupted cell. The substrate and most of the hemolysin released can be sedimented by high-speed centrifugation. Hemolysin-negative strains appear to possess no release enzyme but do contain the substrate since addition of particulate matter to extracts of hemolysin-positive cells increases the rate and extent of hemolysin formation. The rate of hemolysin release in sonic extracts is strongly influenced by the concentration of the two reactants, and minor dilution abolishes all activity. There is only a small amount of release enzyme and substrate present in 24-h cells but increasingly greater amounts appear in extracts of 48- and 72-h cells. The hemolysin-forming system is sensitive to heat and is inactivated in 2 min at 100°. Treatment of particulate matter with lysozyme plus EDTA does not reduce the amount of hemolysin released by subsequent exposure of the particles to the release enzyme present in fresh sonic extract.

CFD Simulation of Particle Transport and Dispersion in Indoor Environment by Human Walking

2012 ◽  
Author(s):  
Iman Goldasteh ◽  
Goodarz Ahmadi ◽  
Andrea Ferro
Keyword(s):  
Particulate Matter ◽  
High Speed ◽  
Cfd Simulation ◽  
Three Dimensional ◽  
Study Data ◽  
Turbulent Dispersion ◽  
Experimental Chamber ◽  
Indoor Environments ◽  
Three Dimensional Model ◽  
Particle Resuspension

Particle resuspension is an important source of particulate matter in indoor environments that significantly affects the indoor air quality and could potentially have adverse effect on human health. Earlier efforts to investigate indoor particle resuspension hypothesized that high speed airflow generated at the floor level during the gate cycle is the main cause of particle resuspension. The resuspended particles are then assumed to be dispersed by the airflow in the room, which is impacted by both the ventilation and the occupant movement, leading to increased PM concentration. In this study, a three dimensional model of a room was developed using FLUENT™ CFD package. A RANS approach with the RNG k-ε turbulence model was used for simulating the airflow field in the room for different ventilation conditions. The trajectories of resuspended particulate matter were computed with a Lagrangian method by solving the equations of particle motion. The effect of turbulent dispersion was included with the use of the eddy lifetime model. The resuspension of particles due to gait cycle was estimated and included in the computational model. The dispersion and transport of particles resuspended from flooring as well as particle re-deposition on flooring and walls were simulated. Particle concentrations in the room generated by the resuspension process were evaluated and the results were compared with experimental chamber study data as well as simplified model predictions, and good agreement was found.

scholarly journals Measuring personal exposure to fine particulate matter (PM2.5) among rural Honduran women: A field evaluation of the Ultrasonic Personal Aerosol Sampler (UPAS)

2019 ◽  
Vol 123 ◽  
pp. 50-53 ◽  
Author(s):  
Ajay Pillarisetti ◽  
Ellison Carter ◽  
Sarah Rajkumar ◽  
Bonnie N. Young ◽  
Megan L. Benka-Coker ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Fine Particulate Matter ◽  
Field Evaluation ◽  
Personal Exposure ◽  
Fine Particulate

scholarly journals Ambient Particulate Matter Air Pollution in Mpererwe District, Kampala, Uganda: A Pilot Study

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Stephan Schwander ◽  
Clement D. Okello ◽  
Juergen Freers ◽  
Judith C. Chow ◽  
John G. Watson ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Pilot Study ◽  
Fine Particles ◽  
Airborne Particulate Matter ◽  
Personal Exposure ◽  
Ambient Air ◽  
Combustion Products ◽  
Carbonaceous Aerosol ◽  
Coarse Particles

Air quality in Kampala, the capital of Uganda, has deteriorated significantly in the past two decades. We made spot measurements in Mpererwe district for airborne particulate matter PM2.5(fine particles) and coarse particles. PM was collected on Teflon-membrane filters and analyzed for mass, 51 elements, 3 anions, and 5 cations. Both fine and coarse particle concentrations were above 100 µg/m3in all the samples collected. Markers for crustal/soil (e.g., Si and Al) were the most abundant in the PM2.5fraction, followed by primary combustion products from biomass burning and incinerator emissions (e.g., K and Cl). Over 90% of the measured PM2.5mass can be explained by crustal species (41% and 59%) and carbonaceous aerosol (33%–55%). Crustal elements dominated the coarse particles collected from Kampala. The results of this pilot study are indicative of unhealthy air and suggest that exposure to ambient air in Kampala may increase the burden of environmentally induced cardiovascular, metabolic, and respiratory diseases including infections. Greater awareness and more extensive research are required to confirm our findings, to identify personal exposure and pollution sources, and to develop air quality management plans and policies to protect public health.

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