Skip header and navigation

Refine By

44 records – page 1 of 5.

Synoptic weather types and long-range transport patterns for ozone precursors during high-ozone events in southern Sweden.

https://arctichealth.org/en/permalink/ahliterature97951
Source
Ambio. 2009 Dec;38(8):459-64
Publication Type
Article
Date
Dec-2009
Author
Lin Tang
Per Erik Karlsson
Yongfeng Gu
Deliang Chen
Peringe Grennfelt
Author Affiliation
University of Gothenburg, Department of Earth Sciences, Sweden. lin.tang.gu@gmail.com
Source
Ambio. 2009 Dec;38(8):459-64
Date
Dec-2009
Language
English
Publication Type
Article
Keywords
Air Movements
Ozone - analysis
Seasons
Sweden
Weather
Abstract
We studied long-range transport patterns and related weather types in relation to high-ozone events in southern Sweden. The aim was to deepen the understanding of the relationship between Lamb-Jenkinson weather types and surface ozone concentration variation, thus widening the application of the weather type analysis of air quality at 4 sites in this region. The long-range transport patterns associated with high-ozone events were classified into trajectories from Western Europe, Eastern Europe, and in the vicinity of southern Sweden (VIC). The VIC type, characterized by short and whirling curves, represented more than 40% of the high-ozone events at the studied rural sites. More than half of the high-ozone events occurred under high-pressure conditions, belonging to weather type A (anticyclones). The high correlation coefficient between annual counts of weather type A and those of long-range transport pattern VIC confirmed the strong link between stagnant weather conditions and high-ozone events, especially during the summer. Furthermore, a strong linear anticorrelation was detected between high-ozone events and annual counts of weather type C (cyclones) during the summer. This relationship implies that the frequency of weather type C is a useful indicator for low risk of summertime high-ozone events in southern Sweden. Moreover, the relationship between the weather type and high ozone risk may be useful in examining the potential effect of climate change on the regional air quality.
PubMed ID
20175447 View in PubMed
Less detail

[The microclimate of the subway and its effect on the body of workers].

https://arctichealth.org/en/permalink/ahliterature238484
Source
Gig Tr Prof Zabol. 1985 Aug;(8):34-7
Publication Type
Article
Date
Aug-1985
Author
Zh V Sbitneva
Source
Gig Tr Prof Zabol. 1985 Aug;(8):34-7
Date
Aug-1985
Language
Russian
Publication Type
Article
Keywords
Air Movements
Climate
Humans
Hygiene
Microclimate
Moscow
Railroads
Temperature
PubMed ID
4054653 View in PubMed
Less detail

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

https://arctichealth.org/en/permalink/ahliterature182781
Source
J Hazard Mater. 2003 Dec 12;105(1-3):1-25
Publication Type
Article
Date
Dec-12-2003
Author
A G Venetsanos
T. Huld
P. Adams
J G Bartzis
Author Affiliation
National Centre for Scientific Research Demokritos, Environmental Research Laboratory, Institute of Nuclear Technology and Radiation Protection, 15310, Aghia Paraskevi, Attiki, Greece. venets@itpa.demokritos.gr
Source
J Hazard Mater. 2003 Dec 12;105(1-3):1-25
Date
Dec-12-2003
Language
English
Publication Type
Article
Keywords
Accidents
Air Movements
Explosions
Gases
Humans
Hydrogen
Sweden
Urban health
Abstract
Hydrogen is likely to be the most important future energy carrier, for many stationary and mobile applications, with the potential to make significant reductions in greenhouse gas emissions especially if renewable primary energy sources are used to produce the hydrogen. A safe transition to the use of hydrogen by members of the general public requires that the safety issues associated with hydrogen applications have to be investigated and fully understood. In order to assess the risks associated with hydrogen applications, its behaviour in realistic accident scenarios has to be predicted, allowing mitigating measures to be developed where necessary. A key factor in this process is predicting the release, dispersion and combustion of hydrogen in appropriate scenarios. This paper illustrates an application of CFD methods to the simulation of an actual hydrogen explosion. The explosion occurred on 3 March 1983 in a built up area of central Stockholm, Sweden, after the accidental release of approximately 13.5 kg of hydrogen from a rack of 18 interconnected 50 l industrial pressure vessels (200 bar working pressure) being transported by a delivery truck. Modelling of the source term, dispersion and combustion were undertaken separately using three different numerical tools, due to the differences in physics and scales between the different phenomena. Results from the dispersion calculations together with the official accident report were used to identify a possible ignition source and estimate the time at which ignition could have occurred. Ignition was estimated to occur 10s after the start of the release, coinciding with the time at which the maximum flammable hydrogen mass and cloud volume were found to occur (4.5 kg and 600 m(3), respectively). The subsequent simulation of the combustion adopts initial conditions for mean flow and turbulence from the dispersion simulations, and calculates the development of a fireball. This provides physical values, e.g. maximum overpressure and far-field overpressure that may be used as a comparison with the known accident details to give an indication of the validity of the models. The simulation results are consistent with both the reported near-field damage to buildings and persons and with the far-field damage to windows. The work was undertaken as part of the European Integrated Hydrogen Project-Phase 2 (EIHP2) with partial funding from the European Commission via the Fifth Framework Programme.
PubMed ID
14623417 View in PubMed
Less detail

[Effect of different air exchange regimens on common cold morbidity in younger schoolchildren].

https://arctichealth.org/en/permalink/ahliterature244053
Source
Gig Sanit. 1981 Nov;(11):30-1
Publication Type
Article
Date
Nov-1981
Author
B Z Voronova
E A El'kovskaia
Source
Gig Sanit. 1981 Nov;(11):30-1
Date
Nov-1981
Language
Russian
Publication Type
Article
Keywords
Air Movements
Child
Common Cold - epidemiology
Humans
Moscow
Seasons
Ventilation
PubMed ID
7319233 View in PubMed
Less detail

Impact of the 2002 Canadian forest fires on particulate matter air quality in Baltimore city.

https://arctichealth.org/en/permalink/ahliterature176504
Source
Environ Sci Technol. 2005 Jan 1;39(1):24-32
Publication Type
Article
Date
Jan-1-2005
Author
Amir Sapkota
J Morel Symons
Jan Kleissl
Lu Wang
Marc B Parlange
John Ondov
Patrick N Breysse
Gregory B Diette
Peyton A Eggleston
Timothy J Buckley
Author Affiliation
Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland 21205, USA.
Source
Environ Sci Technol. 2005 Jan 1;39(1):24-32
Date
Jan-1-2005
Language
English
Publication Type
Article
Keywords
Air Movements
Air Pollutants - analysis
Baltimore
Canada
Fires
Humans
Particle Size
Public Health
Trees
Abstract
With increasing evidence of adverse health effects associated with particulate matter (PM), the exposure impact of natural sources, such as forest fires, has substantial public health relevance. In addition to the threat to nearby communities, pollutants released from forest fires can travel thousands of kilometers to heavily populated urban areas. There was a dramatic increase in forest fire activity in the province of Quebec, Canada, during July 2002. The transport of PM released from these forest fires was examined using a combination of a moderate-resolution imaging spectroradiometer satellite image, back-trajectories using a hybrid single-particle Lagrangian integrated trajectory, and local light detection and ranging measurements. Time- and size-resolved PM was evaluated at three ambient and four indoor measurement sites using a combination of direct reading instruments (laser, time-of-flight aerosol spectrometer, nephelometer, and an oscillating microbalance). The transport and monitoring results consistently identified a forest fire related PM episode in Baltimore that occurred the first weekend of July 2002 and resulted in as much as a 30-fold increase in ambientfine PM. On the basis of tapered element oscillating microbalance measurements, the 24 h PM25 concentration reached 86 microg/m3 on July 7, 2002, exceeding the 24 h national ambient air quality standard. The episode was primarily comprised of particles less than 2.5 microm in aerodynamic diameter, highlighting the preferential transport of the fraction of PM that is of greatest health concern. Penetration of the ambient episode indoors was efficient (median indoor-to-outdoor ratio 0.91) such that the high ambient levels were similarly experienced indoors. These results are significant in demonstrating the impact of a natural source thousands of kilometers away on ambient levels of and potential exposures to air pollution within an urban center. This research highlights the significance of transboundary air pollution and the need for studies that assess the public health impacts associated with such sources and transport processes.
PubMed ID
15667071 View in PubMed
Less detail

Short- and long-term releases of fluorocarbons from disposal of polyurethane foam waste.

https://arctichealth.org/en/permalink/ahliterature95880
Source
Environ Sci Technol. 2003 Nov 1;37(21):5071-9
Publication Type
Article
Date
Nov-1-2003
Author
Kjeldsen Peter
Scheutz Charlotte
Author Affiliation
Environment & Resources DTU, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark. pk@er.dtu.dk
Source
Environ Sci Technol. 2003 Nov 1;37(21):5071-9
Date
Nov-1-2003
Language
English
Publication Type
Article
Keywords
Air Movements
Construction Materials
Environmental monitoring
Fluorocarbons - analysis
Models, Theoretical
Particle Size
Polyurethanes - chemistry
Refuse Disposal
Abstract
Several halocarbons having very high global warming or ozone depletion potentials have been used as a blowing agent (BA) for insulation foam in home appliances, such as refrigerators and freezers. Many appliances are shredded after the end of their useful life. Release experiments carried out in the laboratory on insulation foam blown with the blowing agents CFC-11, HCFC-141b, HCF-134fa, and HFC-245fa revealed that not all blowing agents are released during a 6-week period following the shredding process. The experiments confirmed the hypothesis that the release could be divided into three segments: By shredding foam panels, a proportion of the closed cells is either split or damaged to a degree allowing for a sudden release of the contained atmosphere in the cell (the instantaneous release). Cells adjacent to the cut surface may be only slightly damaged by tiny cracks or holes allowing a relative slow release of the BA to the surroundings (the short-term release). A significant portion of the cells in the foam particle will be unaffected and only allows release governed by slow diffusion through the PUR cell wall (the long-term release). The magnitude of the releases is for all three types highly dependent on how fine the foam is shredded. The residual blowing agent remaining after the 6-week period may be very slowly released if the integrity of the foam particles with respect to diffusion properties is kept after disposal of the foam waste on landfills. It is shown by setting up a national model simulating the BA releases following decommissioning of used domestic refrigerators/freezers in the United States that the release patterns are highly dependent on how the appliances are shredded.
PubMed ID
14620840 View in PubMed
Less detail

Comparison of forced-air warming systems with lower body blankets using a copper manikin of the human body.

https://arctichealth.org/en/permalink/ahliterature57250
Source
Acta Anaesthesiol Scand. 2003 Jan;47(1):58-64
Publication Type
Article
Date
Jan-2003
Author
A. Bräuer
M J M English
N. Lorenz
N. Steinmetz
T. Perl
U. Braun
W. Weyland
Author Affiliation
Department of Anesthesiology, Emergency and Intensive Care Medicine, University of Göttingen, Germany. abraeue@gwdg.de
Source
Acta Anaesthesiol Scand. 2003 Jan;47(1):58-64
Date
Jan-2003
Language
English
Publication Type
Article
Keywords
Air Movements
Algorithms
Comparative Study
Convection
Copper
Data Interpretation, Statistical
Heat
Humans
Manikins
Rewarming - instrumentation
Temperature
Abstract
BACKGROUND: Forced-air warming has gained high acceptance as a measure for the prevention of intraoperative hypothermia. However, data on heat transfer with lower body blankets are not yet available. This study was conducted to determine the heat transfer efficacy of six complete lower body warming systems. METHODS: Heat transfer of forced-air warmers can be described as follows:[1]Qdot;=h.DeltaT.A where Qdot; = heat transfer [W], h = heat exchange coefficient [W m-2 degrees C-1], DeltaT = temperature gradient between blanket and surface [ degrees C], A = covered area [m2]. We tested the following forced-air warmers in a previously validated copper manikin of the human body: (1) Bair Hugger and lower body blanket (Augustine Medical Inc., Eden Prairie, MN); (2) Thermacare and lower body blanket (Gaymar Industries, Orchard Park, NY); (3) WarmAir and lower body blanket (Cincinnati Sub-Zero Products, Cincinnati, OH); (4) Warm-Gard(R) and lower body blanket (Luis Gibeck AB, Upplands Väsby, Sweden); (5) Warm-Gard and reusable lower body blanket (Luis Gibeck AB); and (6) WarmTouch and lower body blanket (Mallinckrodt Medical Inc., St. Luis, MO). Heat flux and surface temperature were measured with 16 calibrated heat flux transducers. Blanket temperature was measured using 16 thermocouples. DeltaT was varied between -10 and +10 degrees C and h was determined by a linear regression analysis as the slope of DeltaT vs. heat flux. Mean DeltaT was determined for surface temperatures between 36 and 38 degrees C, because similar mean skin temperatures have been found in volunteers. The area covered by the blankets was estimated to be 0.54 m2. RESULTS: Heat transfer from the blanket to the manikin was different for surface temperatures between 36 degrees C and 38 degrees C. At a surface temperature of 36 degrees C the heat transfer was higher (between 13.4 W to 18.3 W) than at surface temperatures of 38 degrees C (8-11.5 W). The highest heat transfer was delivered by the Thermacare system (8.3-18.3 W), the lowest heat transfer was delivered by the Warm-Gard system with the single use blanket (8-13.4 W). The heat exchange coefficient varied between 12.5 W m-2 degrees C-1 and 30.8 W m-2 degrees C-1, mean DeltaT varied between 1.04 degrees C and 2.48 degrees C for surface temperatures of 36 degrees C and between 0.50 degrees C and 1.63 degrees C for surface temperatures of 38 degrees C. CONCLUSION: No relevant differences in heat transfer of lower body blankets were found between the different forced-air warming systems tested. Heat transfer was lower than heat transfer by upper body blankets tested in a previous study. However, forced-air warming systems with lower body blankets are still more effective than forced-air warming systems with upper body blankets in the prevention of perioperative hypothermia, because they cover a larger area of the body surface.
PubMed ID
12492798 View in PubMed
Less detail

Effects of metabolic rate on thermal responses at different air velocities in -10 degrees C.

https://arctichealth.org/en/permalink/ahliterature49897
Source
Comp Biochem Physiol A Mol Integr Physiol. 2001 Apr;128(4):759-68
Publication Type
Article
Date
Apr-2001
Author
T T Mäkinen
D. Gavhed
I. Holmér
H. Rintamäki
Author Affiliation
Oulu Regional Institute of Occupational Health, Aapistie 1, FIN-90220, Oulu, Finland. tero.makinen@occuphealth.fi
Source
Comp Biochem Physiol A Mol Integr Physiol. 2001 Apr;128(4):759-68
Date
Apr-2001
Language
English
Publication Type
Article
Keywords
Adult
Air Movements
Basal Metabolism
Body Temperature Regulation
Cold
Exercise
Humans
Male
Oxygen - metabolism
Respiration
Skin
Abstract
The effects of exercise intensity on thermoregulatory responses in cold (-10 degrees C) in a 0.2 (still air, NoWi), 1.0 (Wi1), and 5.0 (Wi5) m x s(-1) wind were studied. Eight young and healthy men, preconditioned in thermoneutral (+20 degrees C) environment for 60 min, walked for 60 min on the treadmill at 2.8 km/h with different combinations of wind and exercise intensity. Exercise level was adjusted by changing the inclination of the treadmill between 0 degrees (lower exercise intensity, metabolic rate 124 W x m(-2), LE) and 6 degrees (higher exercise intensity, metabolic rate 195 W x m(-2), HE). Due to exercise increased heat production and circulatory adjustments, the rectal temperature (T(re)), mean skin temperature (Tsk) and mean body temperature (Tb) were significantly higher at the end of HE in comparison to LE in NoWi and Wi1, and T(re) and Tb also in Wi5. Tsk and Tb were significantly decreased by 5.0 m x s(-1) wind in comparison to NoWi and Wi1. The higher exercise intensity was intense enough to diminish peripheral vasoconstriction and consequently the finger skin temperature was significantly higher at the end of HE in comparison to LE in NoWi and Wi1. Mean heat flux from the skin was unaffected by the exercise intensity. At LE oxygen consumption (VO2) was significantly higher in Wi5 than NoWi and Wi1. Heart rate was unaffected by the wind speed. The results suggest that, with studied exercise intensities, produced without changes in walking speed, the metabolic rate is not so important that it should be taken into consideration in the calculation of wind chill index.
PubMed ID
11282319 View in PubMed
Less detail

[Heat exchange characteristics of miners during open-pit mining in the Far North].

https://arctichealth.org/en/permalink/ahliterature245628
Source
Gig Tr Prof Zabol. 1980 Jul;(7):18-21
Publication Type
Article
Date
Jul-1980

Housing characteristics and indoor concentrations of nitrogen dioxide and formaldehyde in Quebec City, Canada.

https://arctichealth.org/en/permalink/ahliterature169725
Source
Environ Res. 2006 Sep;102(1):1-8
Publication Type
Article
Date
Sep-2006
Author
Nicolas L Gilbert
Denis Gauvin
Mireille Guay
Marie-Eve Héroux
Geneviève Dupuis
Michel Legris
Cecilia C Chan
Russell N Dietz
Benoît Lévesque
Author Affiliation
Air Health Effects Division, Health Canada, 269 Laurier Avenue West, PL 4903B, Ottawa, Ontario, Canada K1A 0K9. nicolas_gilbert@hc-sc.gc.ca
Source
Environ Res. 2006 Sep;102(1):1-8
Date
Sep-2006
Language
English
Publication Type
Article
Keywords
Air Movements
Air Pollution, Indoor - analysis
Cooking
Formaldehyde - analysis
Heating
Housing
Humans
Nitrogen Dioxide - analysis
Quebec
Questionnaires
Abstract
Concentrations of nitrogen dioxide and formaldehyde were determined in a study of 96 homes in Quebec City, Canada, between January and April 2005. In addition, relative humidity, temperature, and air change rates were measured in homes, and housing characteristics were documented through a questionnaire to occupants. Half of the homes had ventilation rates below 7.5 L/s person. Nitrogen dioxide (NO2) and formaldehyde concentrations ranged from 3.3 to 29.1 microg/m3 (geometric mean 8.3 microg/m3) and from 9.6 to 90.0 microg/m3 (geometric mean of 29.5 microg/m3), respectively. The housing characteristics documented in the study explained approximately half of the variance of NO2 and formaldehyde. NO2 concentrations in homes were positively correlated with air change rates (indicating a significant contribution of outdoor sources to indoor levels) and were significantly elevated in homes equipped with gas stoves and, to a lesser extent, in homes with gas heating systems. Formaldehyde concentrations were negatively correlated with air change rates and were significantly elevated in homes heated by electrical systems, in those with new wooden or melamine furniture purchased in the previous 12 months, and in those where painting or varnishing had been done in the sampled room in the previous 12 months. Results did not indicate any significant contribution of indoor combustion sources, including wood-burning appliances, to indoor levels of formaldehyde. These results suggest that formaldehyde concentrations in Quebec City homes are caused primarily by off-gassing, and that increasing air change rates in homes could reduce exposure to this compound. More generally, our findings confirm the influence of housing characteristics on indoor concentrations of NO2 and formaldehyde.
PubMed ID
16620807 View in PubMed
Less detail

44 records – page 1 of 5.