[Adaptation of the hypothalamo-hypophyseal-adrenal cortex system in children in various air pollution conditions].
Explore the source record for details and available documents.
Adaptation, Physiological↗
SEARCH · Search PubMed
Results for “AIR CONDITIONING”
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Weather effects in rheumatoid arthritis: from controversy to consensus. A review.
OBJECTIVE: To review and evaluate the evidence for the widespread view that signs and symptoms of rheumatoid arthritis (RA) are influenced, or even caused, by the weather. METHODS: A literature search from 1985 to April 2003 was performed using the PubMed database of the US National Library of Medicine. Additional relevant articles were identified from the bibliographies, and from our own archives. Methods and findings of the studies were critically reviewed. RESULTS: Only temperature and humidity appear to have clear influences on the symptoms of RA, although the reported findings do not agree. In many cases, the apparent controversies can be explained by the intimate relationship between temperature and humidity, and by taking local circumstances into account. The differences in the methods applied in studies on effects of weather on RA strongly hampered our evaluation. CONCLUSION: RA variables are positively correlated with the humidity of the microclimate at the patient's skin. High outdoor relative humidity is unfavorable, but has less influence when there are few barriers for water vapor, like clothes, and when air conditioning is used. High temperature is unfavorable since it increases absolute humidity, but beneficial as well, since it reduces the presence of barriers, and stimulates the use of air conditioning. The classic opinion, "Cold and wet is bad, warm and dry is good for RA patients," seems to be true only as far as humidity is concerned.
Arthritis, Rheumatoid↗
Type of ventilation system in office buildings and sick building syndrome.
To examine the role of types of building ventilation in office buildings as a determinant of ocular, nasopharyngeal, skin, and general symptoms often denoted as the sick building syndrome, a cross-sectional study was carried out in March 1991 on 2,678 workers from 41 office buildings selected randomly from the Helsinki metropolitan area. The ventilation type and other characteristics of these buildings were recorded on a site visit, and a questionnaire directed to workers inquired about the symptoms, perceived air quality, and possible personal and environmental determinants (response rate, 81%). The outcomes were weekly work-related symptoms experienced during the previous 12 months and symptom groups defined either by their anatomic location or hypothesized mechanism. In logistic regression analysis adjusting for potential confounders, simple mechanical ventilation (mechanical supply and exhaust ducts) was related to a higher risk of ocular symptoms (odds ratio (OR) = 1.31, 95% confidence interval (CI) 0.76-2.26), nasal congestion (OR = 1.78, 95% CI 0.92-3.42) and discharge (OR = 1.44, 95% CI 0.72-2.88), pharyngeal symptoms (OR = 2.32, 95% CI 1.01-5.33), and lethargy (OR = 1.71, 95% CI 0.99-2.95) compared with natural ventilation. Air conditioning was related to a slightly higher risk of symptoms compared with simple mechanical ventilation (for any symptom, OR = 1.30, 95% CI 1.00-1.68). Steam and evaporative humidification as well as air recirculation acted also as determinants of these symptoms. The risk of the studied symptoms is related to the type of ventilation in the existing office building stock. Future studies should explore the typical functional problems and specific causes connected with the high-risk ventilation systems.
Adult↗
Exercise intensity determines and climatic conditions modify the severity of exercise-induced asthma.
Recent studies have shown some evidence that exercise-induced asthma (EIA) may not be entirely explained by respiratory heat loss (RHL). We investigated the interrelationship between heat exchange, exercise intensity and EIA. In order to differentiate between the effects of RHL and exercise intensity, we arranged for tests to be performed with the same RHL, but with different intensities of exercise and inspired air conditions. Each of 8 asthmatic children exercised twice in random order for 6 min on a cycle ergometer. One test consisted of exercise performed at a greater level of effort while breathing room air, mean (+/- SE) air conditions being 25.0 +/- 0.4 degrees C and 15.7 +/- 0.2 mg H2O/L. The other test was performed at a lesser level of effort while breathing cold (0.0 +/- 0.5 degrees C) and dry air (O mg H2O/L). The mean ratio of minute ventilations in the 2 exercise tests was 1.78 +/- 0.03, but the RHL was similar in both tests. The EIA after the exercise at the greater level was more severe than after the lesser level, the percent fall in FEV2 from baseline being 36 +/- 7% and 21 +/- 5%, respectively (p less than 0.025). We conclude that the exercise level has a major role in determining the severity of EIA and that climatic conditions act as modifying factors.
Adolescent↗
A one-year survey of mold growth inside twelve homes.
A survey was performed of the mold flora in the air and on the surfaces inside twelve homes throughout four seasons. There were significant variations of the mold flora in homes associated with the outdoor spore count, various rooms, carpeting, central air-conditioning and pets. We conclude that homes may be a source of perennial mold exposure.
Air Conditioning↗
Analysis of refractory period after exercise and eucapnic voluntary hyperventilation challenge.
We compared specific airway conductance (SGaw) and the FEV1 after repetitive exercise or repetitive eucapnic voluntary hyperventilation (EVH) challenges. Replicate challenges were matched in terms of inspired air conditions and minute ventilations (VE) in order to determine the degree of refractoriness after each type of challenge in patients with exercise-induced asthma. Ten patients exercised or hyperventilated dry, room temperature air at matched VE on two study days. When the patients FEV1 had returned to 90% of baseline or better, or at 3.75 h if FEV, had not returned to 90% of baseline, patients repeated the identical exercise or the EVH challenge. Minimum FEV1 values expressed as a percent of predicted FEV1 after the first and second exercise challenges were 52 +/- 16 and 58 +/- 17, respectively, which were statistically different (p less than 0.001; paired t test). Minimum FEV1 values after the first and second EVH challenges were 52 +/- 13 and 59 +/- 9% of predicted, respectively, which were also statistically different (p less than 0.01; paired t test). Seven of 10 subjects demonstrated higher SGaw values after the second exercise challenge compared with the first challenge, whereas eight of 10 subjects showed higher SGaw values after the second EVH challenge compared with the first challenge. Paired t test analysis indicated that percent protection, measured by FEV1, was similar after either type of challenge. We conclude that replicate exercise or EVH challenges with similarly matched inspired air conditions and VE induce similar degrees of refractoriness.(ABSTRACT TRUNCATED AT 250 WORDS)
Airway Resistance↗
A combination of high oxygen atmosphere and equilibrium modified atmosphere packaging to improve the keeping quality of red fruits.
When high-barrier material is used to package fresh whole fruit in high oxygen atmospheres, shelf life is limited due to the accumulation of its produced CO2 and its creation of an anaerobic atmosphere. In this study, the effect of the combination of High Oxygen Atmosphere and Equilibrium Modified Atmosphere Packaging was tested on the shelf life of two non-climacteric red fruits, particularly strawberries and raspberries, at 7 degrees C. Herefor, the following packaging systems are compared: the conventional method of packaging in a macroperforated high-barrier film (air conditions) (1), Equilibrium Modified Atmosphere (EMA, i.e. 3-5% O2 and 5-10% CO2-balance N2) (2) and two novel modified atmospheres: High Oxygen Atmosphere (HOA, i.e. > 70% O2-balance N2) in a high-barrier film (3) and HOA in a EMA film with an adjusted film permeability (4). The shelf life of the fruits was determined by evaluating the evolution of the internal oxygen, carbon dioxide and ethylene concentrations in the packages, the microbial and sensorial quality during the storage, the loss of weight due to transpiration and respiration of the fruit and the loss of marketable fruit due to visual decay or to Botrytis growth. The High Oxygen Atmosphere in the EMA film re-established after five days to an equilibrium of 3% O2 and 5% CO2. The High Oxygen Atmosphere in the high-barrier film remained high during the first five days of storage, but decreased then rapidly to anaerobic conditions, resulting in off-flavours and odours. To avoid an accumulation of ethylene inside the high-barrier package, an ethylene adsorbing monolayer was added. Shelf life of strawberries and raspberries, packed in air conditions, was limited by growth of moulds and yeasts, rather than by sensorial unacceptance. On the other hand, sensorial properties limited the shelf life of the fruits packed under modified atmosphere. Especially High Oxygen Atmosphere improved the microbial quality, due to the inhibiting effect on yeasts and moulds. However, when oxygen was depleted and carbon dioxide had accumulated, sensorial quality (odour, taste andfirmness) was deteriorated. As this is not the case with high O2 in an EMA film, the latter can be assumed as a promising configuration for respiring fresh produce, combining the beneficial effect of high O2 and EMAP.
Bacteria↗
Effects of storage conditions on hatchability of chicken eggs in a warm climate.
1. A total of 3792 eggs from AF Bosbek layer parents were used to determine the effect of storage time on the hatchability of eggs kept either small end up (SEU) or small end down (SED). 2. These eggs were stored at room temperature (27 degrees C-31 degrees C) or in an air-conditioned room (20 degrees C-23 degrees C), for two, three, six or seven days and incubated in four replicate hatches. 3. Eggs kept SEU improved hatchability even for short-term storage when temperatures were high. 4. Simple air-conditioning can reduce the temperature sufficiently for the viability of the embryo to be preserved for up to a week.
Animals↗
[Allergic diseases in the indoor environment].
Allergic diseases have severely increased worldwide through the last 30 years. More than 50% of all allergic diseases are caused by allergens out of the indoor environment. The most important allergen-carriers are cats, mites and molds. Since the first energy-crisis in 1970 private houses and offices had to be saved from energy losts, which decreased the rate of air changing and increased the relative humidity in the indoor environment. The hygienic situation of air conditioning systems is often insufficient controlled and leads to microbiological contamination. In Germany the number of cats, kept in private homes has increased significantly. These are important facts which led to an increase of indoor air allergies. The greatest number of mites and mold allergens are to be found in mattresses and textile furnitures. For most of the allergens in indoor air the correlation between the sensitizing allergen concentration and onset of illness is unknown. Diagnostic and therapy of allergies in the indoor environment must be supported by prevention and eliminating the main sources of allergen exposure.
Air Conditioning↗
Measurement of acoustical characteristics of mosques in Saudi Arabia.
The study of mosque acoustics, with regard to acoustical characteristics, sound quality for speech intelligibility, and other applicable acoustic criteria, has been largely neglected. In this study a background as to why mosques are designed as they are and how mosque design is influenced by worship considerations is given. In the study the acoustical characteristics of typically constructed contemporary mosques in Saudi Arabia have been investigated, employing a well-known impulse response. Extensive field measurements were taken in 21 representative mosques of different sizes and architectural features in order to characterize their acoustical quality and to identify the impact of air conditioning, ceiling fans, and sound reinforcement systems on their acoustics. Objective room-acoustic indicators such as reverberation time (RT) and clarity (C50) were measured. Background noise (BN) was assessed with and without the operation of air conditioning and fans. The speech transmission index (STI) was also evaluated with and without the operation of existing sound reinforcement systems. The existence of acoustical deficiencies was confirmed and quantified. The study, in addition to describing mosque acoustics, compares design goals to results obtained in practice and suggests acoustical target values for mosque design. The results show that acoustical quality in the investigated mosques deviates from optimum conditions when unoccupied, but is much better in the occupied condition.
Acoustics↗
[Workplace contamination from sevoflurane. Concentration measurement during bronchosopy in children].
UNLABELLED: General anaesthetic agents are frequently used for paediatric bronchoscopy. A disadvantage of open-system anaesthesia is the contamination of the working environment. The aim of this study was to determine the exposure of the anaesthesiologist and endoscopist during paediatric bronchoscopy under general anaesthesia in different working environments and to compare these measurements to the currently valid international threshold limits. MATERIALS AND METHODS: Twenty-five children (ASA I-III) scheduled for diagnostic bronchoscopy were included in the study. After inhalational induction, all patients were intubated with a nonflexible bronchoscope and manually ventilated through a side-arm of the bronchoscope. Maintenance of anaesthesia was achieved with sevoflurane (2-3 vol.%) in pure oxygen. Trace concentrations were measured every 90 s in the breathing zones of the operating theatre (OT) personnel by means of a highly sensitive direct-reading instrument (Brüel & Kjaer 1302). The lower detection limit was 0.02 ppm. The investigation was done in an OT with and without air-conditioning and a scavenging system. RESULTS: The mean age of the children was 50.3 months (range: 3-109 months). Ventilation and oxygenation were stable throughout the bronchoscopic procedure. Mean exposure to sevoflurane in the OT without air-conditioning and a scavenging system was over 40 ppm for the anaesthetist and 50 ppm for the endoscopist. All international threshold limit values were exceeded. Peak concentrations higher than 100 ppm could be detected during 40% of the anaesthetics. CONCLUSION: The main finding of the present study is that under inhalation anaesthesia with sevoflurane for paediatric bronchoscopy, occupational exposure is higher than all known health regulation guidelines permit. Therefore, the use of total intravenous anaesthesia is advocated even in very small infants.
Anesthesia, Inhalation↗
Photosynthetic Characteristics of Rice Leaves Aged under Different Irradiances from Full Expansion through Senescence.
Effects of irradiance on photosynthetic characteristics were examined in senescent leaves of rice (Oryza sativa L.). Two irradiance treatments (100 and 20% natural sunlight) were imposed after the full expansion of the 13th leaf through senescence. The photosynthetic rate was measured as a function of intercellular CO(2) pressure with a gas-exchange system. The amounts of cytochrome f, coupling factor 1, ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), and chlorophyll were determined. The coupling factor 1 and cytochrome f contents decreased rapidly during senescence, and their rates of decrease were much faster from the 20% sunlight treatment than from the full sunlight treatment. These changes were well correlated with those in the photosynthetic rate at CO(2) pressure = 600 microbars, but not with those under the ambient air condition (350 microbars CO(2)) and 200 microbars CO(2). This suggested that the amounts of coupling factor 1 and cytochrome f from the full sunlight treatment cannot be limiting factors for the photosynthetic rate at ambient air conditions. The Rubisco content also decreased during senescence, but its decrease from the 20% sunlight treatment was appreciably retarded. However, this difference was not reflected in the photosynthetic rates at the ambient and 200 microbars CO(2). This implied that in vivo Rubisco activity may be regulated in the senescent leaves from the 20% sunlight treatment. The chlorophyll content decreased most slowly. In the 20% sunlight treatment, it remained apparently constant with a decline in chlorophyll a/b ratio. These photosynthetic characteristics of the senescent rice leaves under low irradiance were discussed in relation to acclimation of shade plants.
Journal Article↗
In-flight disinsection as an efficacious procedure for preventing international transport of insects of public health importance.
Aircraft disinsection with aerosol insecticides during flight has generally been held to be inadvisable because it was assumed that the insecticides would be rapidly removed by the cabin air-conditioning system. We have developed protocols to deliver 2% d-phenothrin at a dose of 35 g per 100 m3 in various aircraft, and trials undertaken on Boeing 747 and 767 aircraft showed that their air-conditioning systems do not preclude effective disinsection. Mortality levels of 100% for Culex quinquefasciatus and Musca domestica test insects were recorded under normal operating conditions during routine scheduled passenger flights with disinsection procedures undertaken at "blocks-away" or at "top-of-descent". As a result, "top-of-descent" disinsection has been introduced as the recommended procedure for aircraft landing in Australia.
Animals↗
Fungal colonization of fiberglass insulation in the air distribution system of a multi-story office building: VOC production and possible relationship to a sick building syndrome.
Complaints characteristic of those for sick building syndrome prompted mycological investigations of a modern multi-story office building on the Gulf coast in the Southeastern United States (Houston-Galveston area). The air handling units and fiberglass duct liner of the heating, ventilating and air conditioning system of the building, without a history of catastrophic or chronic water damage, demonstrated extensive colonization with Penicillium spp and Cladosporium herbarum. Although dense fungal growth was observed on surfaces within the heating-cooling system, most air samples yielded fewer than 200 CFU m-3. Several volatile compounds found in the building air were released also from colonized fiberglass. Removal of colonized insulation from the floor receiving the majority of complaints of mouldy air and continuous operation of the units supplying this floor resulted in a reduction in the number of complaints.
Air Conditioning↗
The effects of air pollution on acute respiratory conditions.
OBJECTIVE: Air pollution and its potential health effects are very important worldwide. It is particularly problematic in densely populated cities of developing countries that suffer from a lack of both short- and long-term programmes for air pollution control. We decided to study the short-term effects of air pollution on lung health by assessing the relationship between the levels of six air pollutants and emergency visits for asthma and COPD exacerbations in Tehran, Iran. METHODOLOGY: We monitored the daily attendances for acute respiratory conditions (asthma attacks and COPD exacerbations) to the emergency departments of five major hospitals together with the daily concentrations of six major pollutants during a 5-month period in Tehran. The association between these acute respiratory conditions and the levels of air pollutants was determined by multiple stepwise regression. RESULTS: A correlation was observed between the number of hospital admissions for asthma and the weekly mean concentration of nitrogen dioxide (P < 0.05). The 3-day and 10-day mean concentrations of sulphur dioxide were also found to be directly associated with the number of asthma admissions during this period (P < 0.05). No direct correlation was observed for other variables. CONCLUSION: This study further emphasizes the deleterious effects of air pollution on respiratory health in major populated cities such as Tehran and suggests that increased attention needs to be given to urgent control of air pollution problems.
Adult↗
Heat strain in Royal Navy helicopter aircrew.
A review of the literature on heat strain and aircrew and a questionnaire survey of Royal Navy aircrew have been completed. Aircrew appreciate, some 50% from first hand experience, that heat strain can reduce their operational endurance and performance. They are at greatest risk of developing it in the pre-flight period, especially when wearing Nuclear, Biological, or Chemical (NBC) protective equipment. Several techniques they use to reduce this risk are described. Some may be of particular assistance in the field should air conditioned facilities be unavailable. However, opportunities to improve the thermal environment within the aircraft on the ground and in flight are limited as the heat generated within it and high levels of solar radiation impinging on it severely challenge air conditioning units, themselves constrained by weight and size. Other demands placed on protective clothing offer little potential to increase the rate at which aircrew can lose accumulated heat. It is concluded that an appropriate micro-climate cooling system worn next to the skin may be required to achieve truly significant reductions in heat strain. Research at the Institute of Naval Medicine has identified liquid cooling techniques which may be suitable for aircrew in all but the smallest helicopters. Any views expressed are those of the author and do not necessarily represent those of the Department.
Aerospace Medicine↗
Mold colonization during use of preservative-treated and untreated air filters, including HEPA filters from hospitals and commercial locations over an 8-year period (1996-2003).
High efficiency particulate arrestance (HEPA; 99.97% efficient at 0.3 microm) filters, filters with ASHRAE particulate arrestance rating of 90-95% at 1 mum (90-95% filters), and lower efficiency cellulosic-polyester filters from air conditioning systems in hospitals and commercial buildings were removed from the systems and examined microscopically for mold colonization. Cellulosic-type filters from systems with water entrainment problems typically were colonized, or became colonized upon incubation in moisture chambers. Species of Acremonium, Aspergillus, and Cladosporium were most common. With air filters of all types, treatment of filter media with an antimicrobial preservative tended to reduce or delay colonization. Mold colonization of HEPA and 90-95% filters was observed most often on the load surfaces, but two untreated HEPA filters were permeated with fungi, one with Aspergillus flavus, the other with Cladosporium sp. Air filters in heating, ventilating, and air conditioning (HVAC) systems, particularly those with chronic or periodic exposure to moisture, may serve as point sources for indoor molds.
Air Microbiology↗
The Leiden scavenging system: a simple and effective anti-pollution device.
The Leiden scavenging system, a device to reduce air pollution by anesthetic gases and vapours in operating rooms, is described. The system can be used in combination with different suction sources (vacuum pipeline, injector, fan or pump, air conditioning system). A special disposal network, to be used in combination with the scavenging system, is also shown.
Air Conditioning↗