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PubMed2005

Recurrent exposure to Histoplasma capsulatum in modern air-conditioned buildings.

BACKGROUND: Between 1989 and 1996, an epidemic of histoplasmosis occurred on a medical school campus. There had been numerous construction projects on the campus that involved previously wooded land and were adjacent to a large bird sanctuary. METHODS: We investigated the epidemic with active surveillance to detect cases, a histoplasmin skin-test survey, inspection of the air-filtration systems of the involved buildings, and cultures of soil samples. The investigation also included a simulation of entry into air-intakes of the buildings from spore sources by means of a wind-tunnel analysis of a model of the campus that used inert gas. After control procedures were instituted, sentinel population groups had follow-up with yearly serological tests. RESULTS: From 1989 through 1996, there were 29 cases of histoplasmosis that occurred among school employees. All cases with a defined onset began during periods of ongoing campus construction. Positivity rates for histoplasmin skin testing were higher among on-campus personnel (47%) than among off-campus employee control subjects (28%) (P<.001); the rates were highest in employees who worked on the upper floors of 2 research buildings. The air-handling units on the roofs of these buildings were not designed to exclude Histoplasma spores. The wind-tunnel experiment indicated that spores aerosolized in the bird sanctuary were not taken into campus buildings. CONCLUSIONS: The major sources of employee exposure to H. capsulatum spores were the construction sites. Low-level, recurrent exposures occurred over several years inside modern research buildings. This phenomenon, which has not been previously described, may play a role in the epidemiology of spore-transmitted diseases in urban settings.

Air Conditioning↗
PubMed1980

Are air-conditioning maintenance personnel at increased risk of Legionellosis?

We surveyed by use of medical questionnaires and blood tests 21 maintenance workers involved with cleaning and servicing cooling towers and evaporative condensers at a large company to determine the frequency of pneumonia and antibody levels against Legionella pneumophila serogroup 1. The 21 high-risk workers were compared with 27 low-risk workers, persons who were not directly involved in service or maintenance for the company. The overall prevalence of titers greater than or equal to 128 for the 21 high-risk workers was 19.0% compared with 22.2% for the low-risk group. There were no significant differences in the history of pneumonia between these groups. Possible explanations for these findings are discussed.

Adult↗
PubMed1998

[Lack of air conditioning and mycotoxin poisoning are basic co-factors in tropical spastic paraparesis].

INTRODUCTION: Chronic idiopathic spastic paraparesis (CHISPA) have been associated to HTLV-I virus infection, and unknown environmental factors have been suggested to play a role in its pathogenesis. METHOD: Based in our previous studies we wanted to know if the lack of refrigerators and the mycotoxin contamination of food might have any relationship with the presence of CHISPA in patients living at southeastern Colombia. RESULTS: Interestingly only four out of 15 patients with CHISPA had some method of refrigeration, in, 14 out of these 15 patients at least a metabolite of Fusarium was detected. CONCLUSIONS: The fact that mycotoxins found in the urine samples of these patients are immunosuppressors and demyelinating allow us to suggest that these toxins could be the most important environmental cofactors leading to the susceptible people to the clinically established disease.

Adult↗
PubMed1988

A heat recovery system for air conditioning which allows disposal of wet cooling towers.

The combined run-around coil heat recovery and cooling plant has been in full operation for about four months at the time of writing and appears to be performing as predicted. The predicted energy saving was 19,000 GJ/year and the actual is around 18,000 GJ/year. It provides a general limited cooling facility of 6 degrees K where previously cooling existed for operating theatres only. The capital cost of the total project was 390,000 pounds and disregarding fuel price fluctuations the heat recovery scheme should pay for itself in about seven years. In addition to the heat recovery and cooling provisions offered the scheme also enabled correction of a frost protection problem plus disposal of an existing wet cooling tower and hence should reduce the risk of Legionnaires Disease. Had these two projects been implemented separately the cost would have been 80,000 pounds but without heat recovery. The advantages of the scheme may be summarised as follows. Energy Cost Savings Frost Protection Elimination of Wet Cooling Tower Cooling Facility It is believed that a scheme as described in this paper would be of benefit to other existing hospitals and should be considered at the design stage of future new hospitals. At IRH it was possible to dispense completely with a wet cooling tower; for other schemes this may also be possible or at least the size and capacity of cooling towers could be reduced.

Air Conditioning↗
PubMed2003

Non-photic, non-thermic circadecadal solar cycle interaction with cardiovascular circannual and circasemiannual variation in heated air-conditioned habitat.

In order to re-examine the extent to which secular circulatory variation can be resolved into possibly accountable, if not yet predictable behavior, the 15-year record of blood pressure and heart rate of an adult male cardiologist (Y.W.) is reanalyzed. Gliding spectral windows with an interval of 4 years progressively displaced throughout the data series examine monthly means from August 1987 to August 2002. A circannual variation is only intermittent and appears to drift for years. A circasemiannual variation is consistent and prominent, yet only for a fraction of the record examined. By contrast to the circadian rhythm in blood pressure and heart rate, which is reliably detectable in most subjects in clinical health, the circannual variation in the human circulation is inconsistent and hence should be monitored, as in this case for its assessment as one goes, a conclusion that also applies to the circasemiannual variation, prominent for years but not detected thereafter. The results prompt the search for interactions between the photic, thermic and societal effects of the seasons that, if solely pertinent, should yield a consistent 1-year spectral component. That non-photic effects may also play an important role may point to modulation by solar cycle stage and solar cycle number, perhaps mediated by the solar wind. This conclusion is extended in proof to the role played by the most recently discovered transannual component in human blood pressure and heart rate, which is a probable further signature of the solar wind. The beating of the transannual and circannual components documented on another data series may contribute to the lack of a consistent 1-year synchronized circannual variation in this case and many others.

Adult↗
PubMed1971

An indoor system for the study of biological aerosols in open air conditions.

An indoor system designed for the study of survival of airborne micro-organisms in closed conditions has been successfully modified to allow the effect of open air to be measured. It was found that the unidentified open-air factors which are toxic for many species of microbes and rapidly lost when enclosed in conventional laboratory apparatus could be retained in the system by continuous ventilation at an adequate rate. The rate required allowed examination of Escherichia coli in aerosols generated from small amounts of material because of the short periods of ventilation required for appreciable viable decay to occur.The validity of the system was tested by comparing the survival of E. coli in true aerosols with its survival when the droplets were held on microthread. An investigation of the role of relative humidity in open-air toxicity was included.

Aerosols↗
PubMed2002

Impact of unilateral sinus surgery with resection of the turbinates by means of midfacial degloving on nasal air conditioning.

OBJECTIVE/HYPOTHESIS: One of the most important functions of the nose is the climatization of inspired air. The aim of the investigation was to determine the influence of radical sinus surgery with complete resection of the turbinates and the lateral nasal wall by means of midfacial degloving as treatment for inverted papilloma on the nasal humidification and heating of inspired air. STUDY DESIGN: Retrospective study. METHODS: Humidity and temperature were measured in the nasopharynx during normal respiration by means of a miniaturized thermocouple device and a humidity sensor for continuous detection. Eight patients after prior unilateral sinus surgery by means of midfacial degloving for a one-sided inverted papilloma were enrolled into the study. The humidity and temperature data of the surgically treated side were compared to the values of the healthy side that was not surgically treated. Active anterior rhinomanometry and acoustic rhinometry were performed. RESULTS: At the end of inspiration, absolute humidity and temperature values in the nasopharynx were statistically significantly lower on the surgically treated side compared with the side that was not surgically treated. CONCLUSIONS: Radical sinus surgery with resection of the turbinates by means of midfacial degloving seems to disturb the climatization of the inspiratory air in the nasal cavity. Reduced absolute humidity and temperature may contribute to crusting, bleeding, and nasal dryness as frequent complaints of patients after aggressive sinus surgery with resection of the turbinates.

Adult↗
PubMed1993

Exercise, regardless of induced bronchoconstriction or inspired air conditions, does not alter airway reactivity.

The effects of exercise on asthmatic airway caliber are well recognized. Only a few studies, however, evaluated the effects of prior exercise on asthmatic airway reactivity. Eight asthmatic children (ages 10 to 16 years; mean, 12) performed histamine inhalation tests on three occasions assigned in random order: (1) control; (2) 40 to 60 min after exercise (6 min ergometer cycling) done while breathing cold dry (CD) air (temperature = -13 degrees C, relative humidity = 0 percent); and (3) 40 to 60 min after exercise done while breathing warm humid (WH) air (temperature = 33 degrees C, relative humidity = 100 percent). While there was a marked exercise-induced bronchoconstriction (EIB) in the CD test with a postexercise fall in FEV1 of 39.2 +/- 8 percent (mean +/- SEM), there was no EIB in the WH test (4.6 +/- 2 percent). There was no difference, however, in the geometric mean histamine concentration required to produce a 20 percent fall in FEV1 (PC20) among the CD, WH, and control tests (0.52 mg/ml, 0.60 mg/ml, and 0.55 mg/ml, respectively). Airway reactivity in asthmatic children is not influenced by a prior exercise challenge, independent of the conditions of the inspired air during the exercise. Moreover, exercise per se, regardless of development of EIB, does not change the reactivity.

Adolescent↗
PubMed1990

[Working ability between air and trimix breathing gas under 8 ATA air condition].

Pneumatic caisson work in Japan has come into operation since 1924. Afterward, this technique of compressed air work has been widely utilized in the construction of foundation basements, shafts of the bottom tunnel shields for subway and so forth. While using this technique of compressed air work means that workers have to be exposed to hyperbaric environment, this technique has risks of not only decompression sickness (DCS) but also toxicity of poisonous gas and/or oxygen deficiency. However, this technique is independent of city construction work and the operation of compressed air work higher than 5ATA (4.0 kg/cm2G) is actually been planning recently. Accordingly unmanned caisson work is considered as a better technique for such higher pressurized work, even though workers must enter into hyperbaric working fields for maintenance or repair of unmanned operated machinery and materials. This research is to establish the safe work under hyperbaric air environment at 8ATA.

Adult↗
PubMed1996

Association of invasive pneumococcal disease with season, atmospheric conditions, air pollution, and the isolation of respiratory viruses.

We examined the relation of invasive pneumococcal disease to season, atmospheric conditions, and the rate of respiratory virus isolation in a community-wide surveillance program in Houston. Among adults, the number of cases of pneumococcal bacteremia peaked in midwinter and declined strikingly in midsummer, indicating a high degree of inverse correlation with the ambient temperature. We detected significant correlations between the occurrence of pneumococcal disease and the isolation of respiratory syncytial virus (P < .001), influenza virus (P < .001), and all viruses except influenza virus (P < .001), as well as with air pollution, as measured by SO2 levels (P < .001). In contrast, the rate of invasive pneumococcal disease among infants and children was relatively more sustained from October through May, with a notable decrease in summer months; the incidence of pneumococcal disease was therefore less strongly correlated with cold weather and less closely associated with the isolation of respiratory syncitial virus or influenza virus. However, pneumococcal disease among infants and children was associated with isolation of these viruses after a 4-week lag period as well as with isolation of adenovirus and ragweed pollen counts. The finding, with regard to children, that correlations tended to be stronger for events that occurred 1 month previously than for those that occurred contemporaneously is consistent with the concept that viral or allergic events predispose to otitis media with effusion, which becomes suppurative and leads to pneumococcal bacteremia or meningitis. For adults, a more immediate predisposition to pneumococcal pneumonia and bacteremia because of viral infection or air pollution was suggested.

Adenoviruses, Human↗
PubMedDate not supplied

Organophosphate pesticide exposures of traditional and integrated pest management farmers from working air conditions: a case study in Thailand.

Concentrations of organophosphate pesticides, including chlorpyrifos and methyl parathion, were measured in ambient air breathed by farmers in Tambon Bang Rieng, Thailand. An exposure assessment and comparison was made between the levels of pesticide exposure of traditional and integrated pest management (IPM) farmers. Thirty-three air samples were collected during pesticide spraying. Traditional farmers were exposed to higher levels of the pesticide(s), with an average concentration of 0.19 mg/m3, compared with 0.037 mg/m3 for the IPM farmers. It was estimated that a farmer of Tambon Bang Rieng would be exposed to 81-12,261 mg of the organophosphate pesticide(s) via inhalation throughout his or her lifetime. Moreover, traditional farmers absorbed more of pesticide via inhalation than did IPM farmers.

Agriculture↗
PubMed2006

Long-term growth of soybean at elevated [CO2] does not cause acclimation of stomatal conductance under fully open-air conditions.

Accurately predicting plant function and global biogeochemical cycles later in this century will be complicated if stomatal conductance (g(s)) acclimates to growth at elevated [CO(2)], in the sense of a long-term alteration of the response of g(s) to [CO(2)], humidity (h) and/or photosynthetic rate (A). If so, photosynthetic and stomatal models will require parameterization at each growth [CO(2)] of interest. Photosynthetic acclimation to long-term growth at elevated [CO(2)] occurs frequently. Acclimation of g(s) has rarely been examined, even though stomatal density commonly changes with growth [CO(2)]. Soybean was grown under field conditions at ambient [CO(2)] (378 micromol mol(-1)) and elevated [CO(2)] (552 micromol mol(-1)) using free-air [CO(2)] enrichment (FACE). This study tested for stomatal acclimation by parameterizing and validating the widely used Ball et al. model (1987, Progress in Photosynthesis Research, vol IV, 221-224) with measurements of leaf gas exchange. The dependence of g(s) on A, h and [CO(2)] at the leaf surface was unaltered by long-term growth at elevated [CO(2)]. This suggests that the commonly observed decrease in g(s) under elevated [CO(2)] is due entirely to the direct instantaneous effect of [CO(2)] on g(s) and that there is no longer-term acclimation of g(s) independent of photosynthetic acclimation. The model accurately predicted g(s) for soybean growing under ambient and elevated [CO(2)] in the field. Model parameters under ambient and elevated [CO(2)] were indistinguishable, demonstrating that stomatal function under ambient and elevated [CO(2)] could be modelled without the need for parameterization at each growth [CO(2)].

Acclimatization↗
PubMed2002

Rainforest air-conditioning: the moderating influence of epiphytes on the microclimate in tropical tree crowns.

Epiphytes are often assumed to influence the microclimatic conditions of the tree crowns that they inhabit. In order to quantify this notion, we measured the parameters "temperature" (of the substrate surface and the boundary layer of air above it), "evaporative drying rate" and "evapotranspiration" at various locations within tree crowns with differing epiphyte assemblages. The host tree species was Annona glabra, which was either populated by one of three epiphyte species (Dimerandra emarginata, Tillandsia fasciculata, or Vriesea sanguinolenta) or was epiphyte-free. We found that during the hottest and driest time of day, microsites in the immediate proximity of epiphytes had significantly lower temperatures than epiphyte-bare locations within the same tree crown, even though the latter were also shaded by host tree foliage or branches. Moreover, water loss through evaporative drying at microsites adjacent to epiphytes was almost 20% lower than at exposed microsites. We also found that, over the course of several weeks, the evapotranspiration in tree crowns bearing epiphytes was significantly lower than in trees without epiphytes. Although the influence of epiphytes on temperature extremes and evaporation rates is relatively subtle, their mitigating effect could be of importance for small animals like arthropods inhabiting an environment as harsh and extreme as the tropical forest canopy.

Animals↗
PubMed2006

Nasal air conditioning in patients before and after septoplasty with bilateral turbinoplasty.

OBJECTIVE: Septoplasty is one of the most frequently performed surgical procedures by ear, nose, and throat surgeons. Yet the objective control of success concerning septal surgery still is very difficult and causes controversy. Data concerning one of the main functions of the nose, namely the heating and humidification of inspired air, before and after nasal surgery, are still missing. Therefore, the aim of this study was to compare intranasal air temperature and humidity values before and after septoplasty with bilateral turbinoplasty. METHODS: Sixteen patients were included in this prospective study. Intranasal temperature and humidity were measured in the anterior turbinate area close to the head of the middle turbinate. A miniaturized thermocouple and a humidity sensor were applied for continuous intranasal detection. RESULTS: Significant differences between temperature and humidity values before and after septoplasty could be observed, including absolute temperature, increase in temperature, absolute humidity, and increase in humidity. The postoperative values were significantly higher than the preoperative ones (P < .05). CONCLUSIONS: According to the results of our study, patients seem to profit from septoplasty as heating and humidification as one of the most important nasal functions are restored and even improved after surgery. We therefore conclude that properly performed septoplasty is able to main its importance within the variety of nasal surgical procedures ensuring improved nasal function as well as patient contentment.

Adolescent↗
PubMed1995

Comparative investigations among meteorological conditions, air chemical-physical pollutants and airborne particulate mutagenicity: a long-term study (1990-1994) from a northern Italian town.

The findings of a continuos monitoring (Apr90-Mar94) on urban air quality of a Po Valley town are reported. Chemical-physical and genotoxicity data were detected. The results show the presence of mutagenic agents during the whole investigated period. Short term mutagenesis tests together with chemical-physical parameters analysis are able to better assess air quality and genotoxic risk for the population.

Air Pollutants↗
PubMed2003

The association between ambient air conditions (temperature and absolute humidity), irritant sodium lauryl sulfate patch test reactions and patch test reactivity to standard allergens.

To support the decision as to whether erythematous patch test reactions to allergens are irritant or allergic, sodium lauryl sulfate (SLS, 0.5% in water) has been added to the standard patch tests since July 1996 in the Dortmund Department of Dermatology. Data on 1600 patients patch tested up until June 2001, as well as standardized data on ambient temperature and humidity obtained by the German Meteorological Service, were included in a logistic regression analysis taking age, sex and atopy as potential confounders into account. The pattern of association was heterogeneous: while doubtful reactions to nickel sulfate were significantly associated with dry/cold weather conditions, but not with SLS reactivity, the opposite was observed for lanolin alcohol, benzocaine and Myroxylon pereirae resin (balsam of Peru). Doubtful reactions to other allergens, namely formaldehyde, fragrance mix or p-phenylenediamine, were associated with both factors. For several other allergens of the standard series, no distinct, significant pattern could be discerned. In conclusion, meteorological conditions and SLS reactivity independently contribute information on individual irritability at the time of patch testing, and both should be considered.

Allergens↗