[Role of the Air Force Medical Service in the activities of air rescue and emergency air transportation of the sick and severely injured].
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Aerospace Medicine↗
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Responses of spring wheat (Triticum aestivum L.) to ozone produced by either electric discharge and dry air or by UV-lamps and ambient air.
The aim of the present study was to examine if ozone produced similar effects on spring wheat growth with and without small amounts of nitrogen oxides. Two methods were used to produce ozone: the first method consisted of dry pressurized air fed to an electric discharge generator generating the byproducts, N2O5 and N2O, the second method consisted of ambient air fed to UV-lamps. Two spring wheat cultivars (Triticum aestivum L. cvs Minaret and Eridano) were exposed in small open-top chambers to charcoal-filtered air, non-filtered ambient air, and non-filtered ambient air with the addition of ozone for 8 h (0900 to 1700 h) daily, for five weeks. Plants were harvested every week. The growth of Minaret was shown to be more sensitive to O3 than that of Eridano. Leaf senescence increased with increasing ozone level in both cultivars. The total above-ground biomass dry weight decreased with increasing ozone concentration in Minaret, but not in Eridano. The Minaret plants reacted with more damaged leaf dry weight and inhibition of growth when O3 was produced by UV-lamps than when O3 was produced by air fed to an electric discharge generator. This could be explained by more nitrogen content per plant but not by increased nitrogen concentration in plant tissue in plants exposed to increased O3 and small amounts of incidental nitrogen oxides.
Journal Article↗
Head and neck cooling by air, water, or air plus water in hyperthermia.
The effects of air, water, and air plus water head cooling on thermoregulatory responses and human operator performance were studied in nonacclimatized, heat-exposed men. Forty chamber exposures (46 degrees C, 30 mm Hg water vapor pressure) were conducted under noncooled and the aforementioned subconditions of head cooling. Five subjects, exposed for 80 min, were monitored for mean skin and rectal temperatures, heart rate, sweat loss, and compensatory tracking performance. A modified Air Force helmet shell provided facial air ventilation (24 degrees C) at 8 cfm. Eight interconnected neoprene modules fastened beneath a helmet linear provided water cooling (20 degrees C at 0.9 l/min). Tracking performances was unchanged across conditions. Elevation of rectal temperature and heart rate, sweat loss, and Physiological Index of Strain were significantly reduced by each condition of head cooling. Air is as effective as water as a cooling agent. Air ventilation acts synergistically with water cooling in reducing physiological strain. Relative merits of each approach to head cooling, in an operational context, are discussed.
Adult↗
Air quality biomonitoring: assessment of air pollution genotoxicity in the Province of Novara (North Italy) by using Trifolium repens L. and molecular markers.
Mixed air pollutants are considered a major cause of DNA damage in living species. In this study Trifolium repens L. cv Regal was used as a bioindicator to assess the genotoxicity of air stressors in the Italian province of Novara. Two on-site biomonitoring experiments were performed during the spring and autumn of 2004. Test plants were exposed at 19 monitoring sites distributed homogeneously throughout the province, and each experiment lasted for a period of 6 weeks. Genotoxicity was evaluated with Amplified Fragment Length Polymorphism (AFLP) molecular markers. The results show the predominantly rural central-west region of the Novara Province to have the worst air quality with regard to genotoxicity. Analyses of geomorphology, land use and climatic factors suggest that the compromised air quality in the region could be attributed to wind strength and direction, transporting pollution from vehicular traffic on the A4 highway and from the urban/industrialized centres of Novara and Vercelli. Plant growth, changes in plant photochemical efficiency and the presence of ozone related leaf injuries were also measured to better interpret the results of genotoxicity. Statistical analyses show that although climatic factors such as light intensity and temperature influence plant growth, they do not contribute to atmospheric stressor-induced DNA damage. Further analyses indicated that, as expected, a mixture of genotoxic and non-genotoxic pollutants coexist in the Novara Province troposphere, and that the elevated ozone concentrations experienced during the study may have contributed to the DNA damage in the tested plants by enhancing genotoxicity via interaction with other air stressors.
Air Pollutants↗
The effect of air humidification on symptoms and perception of indoor air quality in office workers: a six-period cross-over trial.
The objective of this study was to evaluate the effect of air humidification on (a) the dryness of the skin and mucosa, (b) allergic and asthmatic reactions, and (c) the perception of indoor air quality. A total of 290 office workers at the Pasila Office Center were included in a six-period cross-over trial. One wing of the building was operated with 30-40% humidification, and the other wing operated under conditions of no air humidification (relative humidity from natural conditions was 20-30%). The length of each study period was 1 work wk. The workers were instructed to keep a structured daily diary of their symptoms, their perception of the indoor air, and potential determinants of the symptoms. A total of 211 (72.6%) workers who returned at least two weekly diaries, and who had experienced both humidified and nonhumidified conditions, were included in the analyses. The primary outcome--dryness symptom score--was characterized by dryness, irritation or itching of the skin and eyes, dryness or irritation of the throat, and nasal dryness. Means of the daily symptom scores and perception ratings during the humidified and nonhumidified periods were calculated for each participant, and intraindividual differences in the means were used to assess the effect of air humidification. The dryness symptom score was significantly smaller during the humidified phase than during the reference phase (paired t test; p less than .05). Allergic symptoms that were considered as a separate outcome, a sensation of dryness, and draft were also significantly less frequent during the humidification phase (p less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Air hygiene in a pullet house: effects of air filtration on aerial pollutants measured in vivo and in vitro.
1. The natural history of air hygiene in a pullet house was assessed at three-weekly intervals using a combination of in vitro and in vivo assays. The performance of an internal air filter was also examined as an experimental technique for providing clean air. 2. Overall, air hygiene was poor by comparison with occupational standards for human health. The mass concentrations of respirable and inspirable dust were 1.4 and 11.3 mg/m3 compared to human exposure limits of 5 and 10 mg/m3 respectively. The concentration of ammonia was typically about 20 ppm. 3. The majority (greater than 99%) of airborne particles were non-viable. Commensal bacteria from the skin were the most numerous airborne bacteria. Scopulariopsis and Aspergillus spp. were the most prevalent fungi recovered from the air and bird's lungs respectively. The concentrations of airborne and lung fungi were positively correlated with ammonia concentrations. 4. The differences between in vivo and in vitro assays of airborne microorganisms suggest that an aerosol sampler should be devised which better mimics the physical and biochemical environment of the respiratory tract.
Air Microbiology↗
An analysis of candidates for addition to the Clean Air Act list of hazardous air pollutants.
There are 188 air toxics listed as hazardous air pollutants (HAPs) in the Clean Air Act (CAA), based on their potential to adversely impact public health. This paper presents several analyses performed to screen potential candidates for addition to the HAPs list. We analyzed 1086 HAPs and potential HAPs, including chemicals regulated by the state of California or with emissions reported to the Toxics Release Inventory (TRI). HAPs and potential HAPs were ranked by their emissions to air, and by toxicity-weighted (tox-wtd) emissions for cancer and noncancer, using emissions information from the TRI and toxicity information from state and federal agencies. Separate consideration was given for persistent, bioaccumulative toxins (PBTs), reproductive or developmental toxins, and chemicals under evaluation for regulation as toxic air contaminants in California. Forty-four pollutants were identified as candidate HAPs based on three ranking analyses and whether they were a PBT or a reproductive or developmental toxin. Of these, nine qualified in two or three different rankings (ammonia [NH3], copper [Cu], Cu compounds, nitric acid [HNO3], N-methyl-2-pyrrolidone, sulfuric acid [H2SO4], vanadium [V] compounds, zinc [Zn], and Zn compounds). This analysis suggests further evaluation of several pollutants for possible addition to the CAA list of HAPs.
Air Pollutants↗
Effect of clean indoor air laws on smokers: the clean air module of the SimSmoke computer simulation model.
OBJECTIVES: To develop a simulation model to examine the effects of clean indoor air laws on prevalence rates and smoking attributable deaths. METHODS: Based on empirical and theoretical research, the effects of clean air laws are modelled by type of law. The model considers clean air laws at the state levels between 1993 and 2000, and projects the number of smokers and smoking attributable deaths in the USA under different scenarios from 2000 onward. RESULTS: The model predicts that comprehensive clean air laws have the potential to reduce substantially the number of smokers and smoking attributable deaths, and these effects are predicted to grow over time. The predicted impact of new worksite laws are reduced when previously implemented private and public worksite restrictions are taken into account. CONCLUSIONS: Clean indoor air laws have the ability to reduce smoking rates substantially and save lives, but their impact is likely to depend on their comprehensiveness and prior private worksite restrictions in place.
Adult↗
Some aspects on the use of the Biotest RCS Air Sampler in unidirectional air flow testing.
The Biotest Air Sampler RCS is often used for monitoring microbiological quality of air. Unidirectional air flow tests show that the dispersion region of contaminants around the RCS sampler is much larger than that of undisturbed parallel air flow. This must be taken into consideration when the RCS air sampler is used within pharmaceutical production, especially during aseptic operations.
Air Microbiology↗
[Influence of local air suction on the density of air-borne bacteria during cementation of alloplasties].
At joint replacement operations local air suction is used to reduce the air pollution from organic solvents in the operation theatre during insertion of cement and prosthesis. In order to find out whether the local suction in an ultraclean-air operation theatre with laminar airflow influenced the number of colony forming units (cfu) of bacterial in vicinity of the wound, one m3 of air was sampled 20 cm and one metre from the wound before, during and after use of local suction during insertion of cement and prosthesis using a Sartorius membrane filter sampler. There was no significant difference between the groups in the numbers of cfu of bacteria found. It is concluded that use of local air suction over the operative area while cementing hip prosthesis does not affect the number of bacteria in the vicinity of the operation.
Air Microbiology↗
Direct and rapid analysis of ambient air and exhaled air via electrostatic precipitation of aerosols in an atomizer furnace and Zeeman spectrometry.
Techniques that allow the elements present in the air to be determined in a simple and rapid manner are very attractive. Direct aerosol sampling techniques avoid the need to pretreat the filter via wet digestion in order to remove any sources of contamination, and they decrease the precipitation time significantly. Analyzers based on this technique can also determine the concentrations of elements in the air automatically in situ. This paper is concerned with the development of a novel analytical system that is based on electrostatically precipitating aerosols from the air into a graphite furnace. The equipment includes a Zeeman spectrometer with high frequency modulation polarization (MGA-915), and an electrostatic precipitation system incorporated into the analyzer. The high sensitivity of the system developed here means that it can be used to determine element concentrations in the air exhaled by humans, as well as those in ambient air.
Aerosols↗
[Variance of the air sample in air analysis demonstrated on a sample of atmospheric aerosol].
Particulate matter, sampled during 24-h periods from 200 m-3 urban air, was collected on cellulose filters. Each of the four quarters of the filters was analyzed separately by atomic absorption spectroscopy; the concentration of 11 metals was so determined. The residual standard deviation among the quarters of the filter was 10%. In view of this deviation among the results, attributed to the variance of the air sample, it seems rather doubtful that the intercomparison of air sampling instruments, using ambient air as common "standard", will ever give reliable results. It seems likely that air samples, smaller than the 200 m-3 used here, will show an even greater variance, at least with regard to some specific pollutants.
Air Pollution↗
Laminar air flow provides high air quality in the operating field even during real operating conditions, but personal protection seems to be necessary in operations with tissue combustion.
We measured bacterial and particle concentrations at the level of operative fields during 105 operation procedures under laminar air flow conditions. Measured concentrations were at least a factor of 20 lower than in comparable rooms without ultra-clean air and laminar air flow. Kind of operation (septic/aseptic), number of participating persons and quantity of talking seem to have less influence on air quality than presumed, single use cover improves the air quality. The number of ultra-fine and small particles was dramatically increased when tissue was coagulated during operation. This may pose health risks to surgeons and nurses, needs risk assessment and decisions about personal protection.
Air Movements↗
Scanning force microscopy at the air-water interface of an air bubble coated with pulmonary surfactant.
To study the structure-function relationship of pulmonary surfactant under conditions close to nature, molecular films of a model system consisting of dipalmitoylphosphatidylcholine, dipalmitoylphosphatidylglycerol, and surfactant-associated protein C were prepared at the air-water interface of air bubbles about the size of human alveoli (diameter of 100 microm). The high mechanical stability as well as the absence of substantial film flow, inherent to small air bubbles, allowed for scanning force microscopy (SFM) directly at the air-water interface. The SFM topographical structure was correlated to the local distribution of fluorescent-labeled dipalmitoylphosphatidylcholine, as revealed from fluorescence light microscopy of the same bubbles. Although SFM has proven before to be exceptionally well suited to probe the structure of molecular films of pulmonary surfactant, the films so far had to be transferred onto a solid support from the air-water interface of a film balance, where they had been formed. This made them prone to artifacts imposed by the transfer. Moreover, the supported monolayers disallowed the direct observation of the structural dynamics associated with expansion and compression of the films as upon breathing. The current findings are compared in this respect to our earlier findings from films, transferred onto a solid support.
1,2-Dipalmitoylphosphatidylcholine↗
Polycyclic aromatic hydrocarbons air levels in Florence, Italy, and their correlation with other air pollutants.
Benzo(a)pyrene [B(a)P] air levels were measured in Florence (Italy) in the period 1992-2001. For the period 1999-2000 seven polycyclic aromatic hydrocarbons (PAH) (benzo(a)anthracene, crysene, benzo(a)pyrene (B(a)P), benzo(b)fluoranthene (B(b)F), benzo(k)fluoranthene, dibenzo(a,h)anthracene (DBA) and benzo(g,h,i)perylene (BGP)), were measured in the air in four different sites (one with heavy traffic (A), one in a park (B), one in a residential area (C) and one in a hill area (D)). B(a)P levels were elevated in 1992-1998 (maximum average value of winter months: 5.8 ng/ m3) but a decreasing trend was observed in the following years, probably due to improvement in vehicle emissions. The sum of PAH in the air in the period 1999-2000 was about one order of magnitude lower in the hill site (D) relative to the urban sites, and residential areas (B and C) had values 2.5-3 times lower compared to site A with a heavy traffic. PAH concentrations decreased in the warmer seasons of 2000 in all sites. A negative correlation was found between PAH levels and ozone. A positive correlation with carbon monoxide (CO) (r = 0.862, P < 0.001) and low B(a)P/BGP ratios, ranging from 0.44 to 0.51, indicated that vehicular traffic was the major PAH source in all monitored sites. Using B(a)P(TEF) values (toxic equivalency factors) for evaluating the biological activity of PAH, we found that the highest PAH contributors in terms of potential air carcinogenic activity were B(a)P and DBA. Therefore, in addition to B(a)P, DBA concentration should be considered in the evaluation of air quality in terms of PAH contamination.
Air Pollutants↗
Pleural tenting following upper lobectomies or bilobectomies of the lung to prevent residual air space and prolonged air leak.
OBJECTIVE: Apical residual air space and prolonged air leak are not uncommon entities following resection of upper lobe of the lung. This study was carried out to observe the efficacy of pleural tenting in preventing these problems. METHODS: This is a prospective randomised study. Pleural tenting after upper or upper and middle lobectomies was performed in 20 patients. In another 20 patients who underwent upper lobectomy or bilobectomy, pleural tenting was not performed. Both groups were compared in respect to durations of postoperative chest tube drainage and hospital stay, amount of total pleural drainage, and the presence of need for any additional intervention for prolonged air leak. RESULTS: Age, sex, pathology and pulmonary function tests of two groups were similar. Duration of chest tube drainage was shorter in whom pleural tenting was performed when compared to whom pleural tenting was not performed (4.3+/-0.16 days versus 7.40+/-0.68 days, P<0.0001). Mean hospital stay was shorter in tented group (7.60+/-0.4 days versus 9.35+/-0.6 days, P=0.024). Although the mean amount of total pleural drainage was less in tented group (667.5+/-57.7 ml versus 802.5+/-83.3 ml, P=0.1911), the difference was not statistically significant. Three (15%) patients in non-tented group needed an apical chest tube insertion in postoperative period for prolonged air leak with an apical pleural space. Asymptomatic apical residual space was observed in 3 patients in tented group. There was no morbidity in patients in tented group. CONCLUSION: Pleural tenting following upper lobectomy or bilobectomy of the lung shortens the duration of chest tube drainage and hospital stay, and it prevents apical residual air spaces and related complications. Pleural tenting is safe and relatively simple procedure, which has no associated morbidity.
Air↗
Outcomes of the first round of local authority air quality Review and Assessments under the UK's air quality strategy.
In 1997, the UK government instigated the practice of Local Air Quality Management (LAQM) in the UK. This process is based on local authorities undertaking Review and Assessments of air quality within their areas. The first round of Review and Assessments have now been completed and represents the most extensive and coordinated analysis of air pollution ever undertaken in the UK, and probably in Europe. This paper takes a broad look at the outcomes of this process so far and identifies some of the key areas where lessons have/can be learnt both about patterns of air pollution in the UK and about the framework for investigating these that has been implemented under the LAQM regime. The process has led to a much higher number of local authorities finding problems with air pollution than initially expected. It has also challenged many assumptions about the significance of various pollutants and their sources.
Air Pollution↗
Air quality modeling in the South Coast Air Basin of California: what do the numbers really mean?
This study evaluates air quality model sensitivity to input and to model components. Simulations are performed using the California Institute of Technology (CIT) airshed model. Results show the impacts on ozone (O3) concentration in the South Coast Air Basin (SCAB) of California because of changes in: (1) input data, including meteorological conditions (temperature, UV radiation, mixing height, and wind speed), boundary conditions, and initial conditions (ICs); and (2) model components, including advection solver and chemical mechanism. O3 concentrations are strongly affected by meteorological conditions and, in particular, by temperature. ICs also affect O3 concentrations, especially in the first 2 days of simulation. On the other hand, boundary conditions do not significantly affect the absolute peak O3 concentration, although they do affect concentrations near the inflow boundaries. Moreover, predicted O3 concentrations are impacted considerably by the chemical mechanism. In addition, dispersion of pollutants is affected by the advection routine used to calculate its transport. Comparison among CIT, California Photochemical Grid Model (CALGRID), and Urban Airshed Model air quality models suggests that differences in O3 predictions are mainly caused by the different chemical mechanisms used. Additionally, advection solvers contribute to the differences observed among model predictions. Uncertainty in predicted peak O3 concentration suggests that air quality evaluation should not be based solely on this single value but also on trends predicted by air quality models using a number of chemical mechanisms and with an advection solver that is mass conservative.
Air Pollution↗