Airborne Pollen Levels Research Articles

Anaphylactic reaction to clarithromycin in a child

200 grains/m ofPoaceae, and between 10 and 15 grains/m of Urticaceae. The use of nonparametric methods provided more informative estimations than traditional linear approaches for continuous environmental factors. The advantage of this innovative approach is that we do not need to make any a priori assumption about the functional form of the relationship. In comparison with categorical analyses, this method can be more efficient (3), also removing the need to select cut-off points for categories in an opportunistic manner. We observed evident nonlinearities for the estimated relationships between airborne pollen levels with allergenic capacity and risk of asthma emergency room admissions, updating our previous results (5) and being similar to those described for grass pollen in England (6). Note that GAMs are very conservative at the extremes of the curve, having wide confidence intervals, as the Fig. 1 shows. This is because usually there are few observations at the extremes of the exposure factor, and because of a slight boundary effect inherent in all flexible methods. Furthermore, results can be presented only in relation to a reference category. Then a graphical distortion can lead to misinterpretations as well as the arbitrary selection of the reference point (3). However, the highest risk of asthma morbidity in Madrid was that related to the highest airborne pollen levels when abruptly released into Madrid s environment. This study was funded by the Advisory Committee to the Madrid Regional Asthma Prevention & Control Programme (Comision Asesora del Programa Regional de Prevencion y Control del Asma de la Comunidad de Madrid). Aurelio Tobias had a postgraduate fellowship of Universidad Autonoma de Madrid. Marc Saez was partially funded by Fondo de Investigacion Sanitaria, FIS 00/0010–02.

Point-wise estimation of non-linear effects of airborne pollen levels on asthma emergency room admissions

AllergyVolume 64, Issue 6 p. 961-962 Point-wise estimation of non-linear effects of airborne pollen levels on asthma emergency room admissions A. Tobías, Corresponding Author A. Tobías *National School of Public HealthInstituto de Salud Carlos IIIC/Sinesio Delgado 8E-28029 MadridSpainTel.: (+34) 918222459Fax: (+34) 913877862E-mail: [email protected]Search for more papers by this authorM. Sáez, M. SáezSearch for more papers by this authorI. Galán, I. GalánSearch for more papers by this authorJ. R. Banegas, J. R. BanegasSearch for more papers by this author A. Tobías, Corresponding Author A. Tobías *National School of Public HealthInstituto de Salud Carlos IIIC/Sinesio Delgado 8E-28029 MadridSpainTel.: (+34) 918222459Fax: (+34) 913877862E-mail: [email protected]Search for more papers by this authorM. Sáez, M. SáezSearch for more papers by this authorI. Galán, I. GalánSearch for more papers by this authorJ. R. Banegas, J. R. BanegasSearch for more papers by this author First published: 11 May 2009 https://doi.org/10.1111/j.1398-9995.2008.01935.xCitations: 2 Relationships between the risk of asthma emergency room admissions and pollen levels were clearly non-linear. Thus, the use of non-parametric methods provided more informative estimations than the traditional approaches. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume64, Issue6June 2009Pages 961-962 RelatedInformation

Pollen allergenic potential nature of some trees species: A multidisciplinary approach using aerobiological, immunochemical and hospital admissions data

Trees are considered producers of allergenic pollen. The aims of this work were to characterize the aerobiology of the Platanus, Acer, Salix, Quercus, Betula and Populus pollen, linking it with monthly emergency hospital admissions and to identify the different reactivity levels in sensitized patients. This information would be of great importance to evaluate the convenience of changing the inventory of pollen producer trees related to the risk of allergenic reactions. The study was conducted in Porto, Portugal, from 2005 to 2007. Airborne pollen was sampled using a Hirst-type volumetric trap. The antigenic and allergenic properties of Acer negundo, Betula pendula, Platanus occidentalis, Populus hybrida, Quercus robur and Salix babylonica pollen, collected in public gardens or sidewalks, were investigated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunological techniques using polysensitized-patient sera. Monthly hospital admissions of asthma or dyspnea related with respiratory diseases were obtained from the Emergency Room database of Hospital Geral de Santo António. Tree pollen and hospital admissions were positively correlated. Tree pollen peaked in March which coincides with the hospital admissions maximum. The highest binding affinity was observed with A. negundo, S. babylonica and P. occidentalis pollen extracts and the lowest with P. hybrida. Consistently, Acer and Platanus maximum airborne pollen concentrations were observed during March attaining levels considered moderate to high risk for allergenic reactions. Prominent bands with approximately 71, 35, 31, 22, 19, 16, 14, 13 and 11 kDa were revealed. A 52 kDa band was shared by all analyzed sera. High levels of airborne pollen and emergency hospital admissions were related. High binding affinity of specific IgE to pollen extracts of the most abundant tree pollen present in the atmosphere was observed. Patient sera revealed multiple similar allergenic bands shared by the different extracts. This multidisciplinary approach is useful in day-to-day medical practice to help in diagnostic, therapeutic and allergy alerting system adjusting.

Does climate change affect the incidence of skin and allergic diseases in Germany?

Skin diseases have great socio-economic importance in Germany due to their high and in some cases still-increasing prevalence. Little attention has yet been paid to the influence of the change in climate on these diseases. Clarify the evidence of the effects of climate change on the prevalence of skin diseases and allergies in Germany. First, a theoretical model of the possible mechanisms and influence factors of climate and weather was created for different disease groups (skin malignancies, allergies, skin infections). Then, a systematic online and manual literature search was made for model-derived key words.The relevant publications were selected and evaluated according to a priori criteria. From a total of n = 31,221 hits, n = 320 publications remained for evaluation.Changes in the following parameters can be regarded as essential climatologic factors influencing the prevalence of skin and allergic diseases: temperature, UV radiation, precipitation/humidity, cloudiness, and general weather conditions.There were only a few original articles addressed to this topic. Most of them address recurring phenomena (especially levels of airborne pollen), UV radiation or ozone (and the ozone hole). Quantitative statements, prognosis models and climate scenarios have not yet been published for Germany with respect to skin diseases. Only few scientific articles on the relationship between climate changes and the prevalence of skin diseases have been published. They do not allow a reliable statement on future developments. The outlook for changes in prevalence requires further clarification using published climate models.

Pollen production by Pinus taeda growing in elevated atmospheric CO2

Summary 1Rising concentrations of atmospheric CO2 may have important consequences for reproductive allocation in forest trees. Changes in pollen production could influence population dynamics and is likely to have important consequences for human health. This is the first study to evaluate pollen production by forest trees in response to rising atmospheric CO2. 2Our research objective was to quantify pollen production by Loblolly Pine (Pinus taeda L.) trees growing in elevated CO2 (ambient + 200 µl l−1) since 1996. 3Trees grown in high-CO2 plots first began producing pollen while younger and at smaller sizes relative to ambient-grown trees. Pollen cone and airborne pollen grain abundances were significantly greater in the fumigated stands. We conclude that the greater number of mature trees in high-CO2 plots resulted in greater pollen production at the stand level. 4Precocious pollen production has important implications for fertilization and pollen dispersal from young, dense stands. Increasing levels of airborne pollen raise concerns for escalating rates of human respiratory disease.

Diurnal Variation of Airborne Ragweed Pollen in A Metropolitan Area - An 8 Year Perspective

RATIONALE: We conducted the following study to corroborate previous Ragweed pollen data. Ragweed is one of the major causes of seasonal allergic rhinitis in the Midwest. Previous data showed a diurnal pattern with peak airborne pollen levels occurring around noon.

Non-linear short-term effects of airborne pollen levels with allergenic capacity on asthma emergency room admissions in Madrid, Spain.

Several time-series studies have shown positive associations between pollen levels and asthma morbidity. However, few studies have included air pollution as a potential confounder when examining this relationship, and they have only done so on a linear basis. To investigate the potential non-linear short-term effects of the types of pollen with allergenic capacity across the whole range of exposure on the daily number of asthma-related hospital emergencies in Madrid for the period 1995-1998. Data were collected on the daily number of asthma emergency room admissions and daily average levels of major types of pollen with allergenic capacity: Olea, Plantago, Poaceae and Urticaceae. We used Poisson regression with generalized additive models, controlling for trend and seasonality, meteorological variables, acute respiratory infections and air pollutants. To study the non-linear effect of pollen levels on asthma emergency room admissions, pollens were categorized into five groups defined on the basis of their respective distributions. The strongest associations were registered in respect of a lag of 1 day for Urticaceae, a lag of 2 days for Plantago, and a day lag of 3 days for Poaceae. Adjustment for the different types of pollen failed to result in major changes. Non-linearities were evident for pollen levels. The greatest increase in risk vs. the reference category (minimum value - 50th percentile) was observed for the categories between the 95th and 99th percentiles, with increases of 32.0% for Plantago, 32.2% for Poaceae and 24.6% for Urticaceae, and between the 99th percentile and the maximum value, with increases of 31.3%, 78.7% and 49.8%, respectively. Olea was not related with asthma emergency room admissions. Pollens with allergenic capacity in Madrid are positively associated with asthma-related hospital emergencies. These associations remain stable when simultaneous adjustment is made for the four types of pollen and for air pollutants and meteorological variables. In terms of non-linear effects, Poaceae register the strongest association with asthma emergency room admissions.

Ragweed pollen forecasting

Rationale Pollen from Ambrosia species are the most important pollen allergens in North America, and the ability to accurately predict day to day pollen levels could provide important benefit to sensitive individuals. Methods Daily ragweed pollen concentrations from 1987 to 2001 collected with a Burkard spore trap were analyzed to determine pollen season characteristics. Daily concentrations were also compared with data from the National Weather Service to determine the effects of meteorological conditions on airborne pollen levels and to develop an empirical forecasting model. The model was used to predict daily pollen levels during the 2002 ragweed season. Results Pollen data from 1987 to 2001 showed that the mean start date (5% of season total) was 27 Aug; the mean date of the season peak was 10 Sep; and the mean ending date (95% of season total) was 11 Oct. Meteorological parameters used in model development include temperature, relative humidity, wind speed, and rainfall. Forecasts were generated each morning from 1 Sep to 31 Oct and published on the internet at http://pollen.utulsa.edu. Pollen levels were predicted as Low, Moderate, High, and Very High as defined by the National Allergy Bureau. In addition, intermediate levels were also used. Following the ragweed season, forecasts were compared with the daily pollen concentration. Analysis showed that the model successfully predicted pollen severity on 84% of the days during the 2002 ragweed season. Conclusions Pollen forecasting can provide predictions of daily pollen levels and enable sensitive individuals to avoid exposure to high pollen levels or take prophylactic medication.

Airborne pollen records response to climatic conditions in arid areas of the Iberian Peninsula

This study analyses the responses of the different components of flora from a high-mountain area with a sub-desert climate to changeable meteorological conditions that may affect their normal development. Local airborne pollen levels are used as bio-indicators of the vegetation behavior. In order to determine the fluctuations in this status, a set of 6-year pollen data obtained using aerobiological methods was used. The results show that the tree species ( Cupressus sp., Olea europaea; Quercus sp. and Platanus hyspanica) react differently to situations of water stress and changeable temperatures than herbaceous species ( Urticaceae, Chenopodiaceae, Poaceae species and Artemisia sp.). The flowering of tree species seems to be affected more by conditions in the months prior to flowering, in particular for species flowering in winter-early spring. As important as the amount of rainfall is the distribution of rainfall throughout the year, since this ensures permanent water availability. Herbaceous species present the most immediate response to weather conditions and if rainfall occurs during their principal pollination period, this period lasts longer. Sometimes, under favorable conditions, non-seasonal flowering may occur.

Relationship between pollen counts and weather variables in east-Mediterranean coast of Turkey. Does it affect allergic symptoms in pollen allergic children?

Background: Aeroallergen sampling provides information regarding the onset, duration and severity of the pollen season that clinicians use to guide allergen selection for skin testing and treatment. Objectives: This atmospheric survey reports (1) airborne pollen contributions in Adana in one-year period (2) pollen onset, duration and peak level (3) the relationship between airborne pollen and selected meteorological variables and; (4) effects on symptoms in pollen allergic children. Methods: Pollen sampling was performed with a volumetric Burkard Spore Trap. Meteorological data were measured daily from April 2001 to April 2002. Asthma symptom scores were investigated in 186 pollen allergic children that were on follow up in pediatric allergy outpatient clinics during same period. Results: Average measurements included 82.5% tree pollen, 7.7% grass pollen and 9.8% herb pollen 54 taxa were identified during one year. The most prominent tree pollens were Cupressaceae, Eucalyptus and Pinus. The most common herb was Chenopodiaceae pollen family. When airborne pollen levels were examined in relation to single meteorological conditions; daily variations in total pollen counts were not significantly correlated with any variable studied (humidity, rainfall, temperature and wind) (p>0.05). On the other hand, statistically significant relationship between pollen concentration and symptom scores were found (p>0.05). Positive correlations were seen between both Gramineae and Herb pollen, and humidity and rainfall from March to July. However, positive correlations were detected between tree pollen counts and temperature and humidity in May and June. Conclusion: This survey is the first volumetric airborne pollen analysis conducted in the survey area in Adana. This study suggested that the effects of weather on pollen count and symptom scores in this population could not be clearly identified with the evaluation of one-year data. However, pollen counts had effect on allergic symptoms in pollen allergic children. Examination of the complex interaction of multiple whether parameters would perhaps more fully elucidate the relationship between meteorology and aerobiology and provide the clinician with information necessary to forecast pollen prevalence. An awareness of the ever chancing, local aeroallergen patterns requires regular monitoring. Such awareness serves as a useful guide in the effective testing and treatment of atopic patients.

Hourly variation of airborne ragweed pollen in Kansas City.

Ragweed pollen is one of the major causes of allergic rhinitis in the midwest United States. Previous studies have demonstrated that ragweed pollen production begins after sunrise and airborne pollen levels peak several hours later. Variations in this pattern that may be of clinical importance within a small region and the effect of weather on these variations have not been investigated. Volumetric pollen collectors were stationed at four sites around the metropolitan area. Ten-minute grab samples were taken at each location every 2 hours for continuous 24-hour periods during the 1997 ragweed season. The downtown location had a weather station that logged meteorological conditions at hourly intervals during this time. Ragweed pollen grains were counted microscopically at 400 x. Uninterrupted data covering at least 20 days during the season were evaluated for each collection site. The lowest ragweed pollen counts occur at 6:00 AM and the highest occur at noon for both suburban and urban sites. Rainfall was seen to be the most influential weather-related factor. Significant rainfall events effectively removed pollen grains from the air. Though ragweed pollen emission begins at 6:00 AM, peak pollen exposure occurs at midday. This observation is in agreement with many other studies. The myth that highest ragweed exposure occurs in the early morning hours is not supported by this or previous studies.

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Volumetric Assessment of Airborne Pollen and Spore Levels in Rochester, Minnesota, 1992 Through 1995

To reassess airborne pollen counts and to study spore counts by volumetric collection in Rochester, Minnesota. Samples of pollen and spores were collected from the top of a six-story building in downtown Rochester by use of a rotational rod sampler, which was activated for 30 seconds every 10 minutes for 24 hours a day, 5 days a week, from mid-April to mid-October 1992 through 1995. Particles were stained with Calberla's fluid and viewed microscopically by transmitted light. Identifications were substantiated by comparison with field-collected "known" materials and standard reference guides. Data were expressed as "particles retained/cubic meter of air sampled." Because the methods of collection varied, only qualitative comparisons could be made with a study done in Rochester more than 3 1/2 decades earlier. For tree pollens, a similar progression of appearance and seasonal duration were noted for most species. Alder (Alnus), willow (Salix), and hickory-pecan (Carya), however, were found to have distinctly longer seasons, and walnut (Julgans) was detected 2 weeks earlier in the season. The most frequently detected tree pollen had changed from oak (Quercus) to apple and crab apple (Malus), which was not reported at all previously. Ragweed (Ambrosia) was still found to peak at the end of August and had a similar duration. Study of grass and nettle pollen as well as the Amaranthaceae-Chenopodiaceae complex yielded findings similar to those in the prior investigation. Fungal spores were detected from April through October and represented a substantial percentage of the airborne allergens; Cladosporium, ascospores, and basidiospores were the most common. Volumetric assessment of airborne pollen and spore levels in Rochester, Minnesota, yielded useful information for clinicians in southern Minnesota that could help direct skin test selection.

A national survey of airborne pollen and grass flowering in New Zealand, with implications for respiratory disorder

Airborne pollen and spore levels were monitored at seven sites in New Zealand using the Intermittent Cycling Rotorod sampler during the summer of 1988/1989. Grasses formed the major component of atmospheric pollen levels during spring and summer at every locality. Peak levels of grass and total pollen occurred during December or late November, with a slight latitudinal lag apparent at the more southern sites. Highest levels were recorded at the smaller rural centres of Gore and Kaikohe and the lowest at the larger urban centres of Auckland, Christchurch and Wellington. We make a first approximation of the likely risk to hayfever and allergic asthma patients at each of the seven centres. For example, significantly higher grass pollen levels were experienced at Kaikohe on 44% and 65% of days during November and December, compared with just 15% and 8% at Auckland. By recording the flowering seasons of the principal allergenic grass species at each locality, we determined the potentially allergenic grasses contributing to peak pollen levels, the most ubiquitous being tall fescue (Festuca arundinacea Schreb.), ryegrass (Lolium perenne L.,L. multiflorum Lam.), cocksfoot (Dactylis glomerata L.), Yorkshire fog (Holcus lanatus L.) and sweet vernal (Anthoxanthum odoratum L.).

Association of severe asthma attacks with weather, pollen, and air pollutants.

The association between exacerbations of asthma and weather or air pollution is not well understood. The relationships between visits to the emergency room for asthma attacks and the meteorological, aerobiological, and chemical characteristics of the outdoor air have been evaluated. The number of daily attendances for asthma attacks at the emergency room of Oulu University Central Hospital was recorded over one year together with daily meteorological readings (temperature, humidity, barometric pressure, rainfall), levels of air pollutants (nitrogen dioxide (NO2), sulphur dioxide (SO2), hydrogen sulphide (H2S), total suspended particles (TSP)), and pollen counts (birch, alder, pine, willow, total pollen). The relationship between the number of attendances and the measured variables was then analysed by multiple regression and stepwise discriminant analysis. The total number of attendances during the year was 232, with lower figures in summer and higher in winter. No association was found between visits for asthma attacks and airborne pollen levels or meteorological factors except for temperature, which had a low inverse correlation with attendance. The most significant correlations were found between asthma visits and the levels of NO2; those for SO2, TSP, and H2S were also significant. Intercorrelations between SO2 and temperature or NO2 and between temperature and TSP or NO2 were also found, but only NO2 correlated significantly with attendances after standardisation for temperature. Increased levels of pollutants, especially NO2, were associated with attacks of asthma, but the explanation for this is unclear. Air pollen levels were not associated with asthma attacks and only temperature among the meteorological factors had a small association with asthma.

Examining the Relationship between Airborne Pollen Levels and 911 Calls for Assistance

An effort was made to investigate the effect of airborne pollen levels on the number of 911 calls logged by the police department of a medium-sized midwestern city. Daily recordings of temperature, pollen count level, and the total number of 911 calls were available for the years 1986, 1987, 1988, and 1989, March through October. Each year was partitioned into three relatively equal time periods—TPI (March 1-May 24), TP2 (May 25-August 14), and TP3 (August 15-October 31)—the hypothesis being that airborne pollen and 911 calls would be positively correlated during TPI and TP3 (periods of high pollen activity) but not during TP2 (period of low pollen activity). Results tended to support this hypothesis, although multivariate analyses revealed that these findings were largely a result of the moderately strong relationship between pollen and temperature, the latter of which was more strongly correlated with 911 calls for assistance.

Comparison of airborne pollen levels in Switzerland at four recording stations in Davos, Lucerne, Nyon and Basle during 1989

Pollen data collected in 1989 and recorded from four stations in Switzerland (Basle, Davos, Nyon on Lake Geneva and Lucerne in central Switzerland) are presented and compared as flowering calendars. The data highlight the importance, for production of a pollen calendar over the whole country, of the fact that the beginning and duration of flowering occur at different times at the four stations.

Chapter 27 Aerobiology of pollen and fungal allergens

Clinically important pollinosis is primarily due to flowering plants with wind-dispersed pollens. Although these anemophilous species form a minority of flowering plants, they produce prodigious amounts of pollen. Entemophilous (insect-pollinated) plants produce relatively few pollen grains. Plants having only a portion of their pollen grains airborne are termed amphiphilous. Their role in pollinosis is not clear. The pollen-producing organs, stamens, consist of an anther attached to a filament. Allergenic pollens develop in and are released from pollen sacs contained in the anthers. Pollen sacs are lined with a nutritive cell layer, the tapetum. During its formation, each immature pollen grain secretes about itself a clear layer, the intine. Around this the tapetum deposits a multilayer exine composed of a polymer, sporopollenin. Release of pollen from the anther is known as anthesis. Drying creates gaps in the anther wall through which pollen escapes. Airborne pollen levels tend to increase during warm, dry, clear conditions and fall during cool, moist periods. Although pollen grains can travel several hundred miles, concentrations of windbome pollens generally decrease sharply within a few hundred meters of their source. Intact pollen grains are presumed to be the primary carriers of allergen, but ragweed allergens have been associated with particles <5 km, and Amb a I (antigen E) activity has been found in submicronic particles. Pollen allergens can be extracted from the somatic portion of ragweed plants and may become airborne in vegetable debris. Furthermore, allergens might be eluted from pollen grains deposited on moist surfaces, with dispersion of the resultant extract in droplets. Air sampling relies on recovery of pollen grains for microscopic evaluation. The gravity (Durham) sampler uses greased microslides for pollen collection. This obsolete device is limited by uncertainty in the volume of air sampled and a tendency to