Airborne Pollen Concentrations Research Articles

Influence of precipitation and temperature on airborne pollen concentration in Santiago de Compostela (Spain)

This paper presents data of airborne pollen concentration of Pinus , Platanus , Quercus , Betula , Poaceae and Castanea , the most abundant pollen types, during the last eight years, in Santiago de Compostela (NW Iberian Peninsula). We determined their respective principal pollen release periods and analysed statistically the influence of the main meteorological parameters on their pollen concentration, obtaining a negative correlation with precipitation and a positive correlation with temperature, in the majority of the cases, during these years. A detailed study of accumulated pollen values, in relation to accumulated average temperatures and the precipitation distribution, enabled us to establish a relationship between these parameters and the principal pollination period of each of these taxa.

Incidence of allergenic pollen of Acer spp., Fraxinus spp. and Platanus spp. in the city of La Plata, Argentina: preliminary results

This work studies the airborne pollenconcentrations of Acer spp.,Fraxinus spp. and Platanus spp. sincethe pollen of these three taxa has beencharacterized as etiological agents ofpollinosis. These tree species are present inlarge amounts in the streets of La Plata city.The aeropalynological monitoring was performedwith a Hirst-type spore trap (Lanzoni VPPS,2000). The emission period of the three taxaextends from approximately late August to October.The maximum cumulative totalof arboreal pollen was found to be 30824.7from September 12 to 18. This period coincideswith the peak of total pollen concentration.Pollen grains trapped were analysed andexpressed as daily averages of 5-hour bandsper day during the whole year. Maximum pollenconcentration was registered between 10 a.m.and 2 p.m. During the studied period, 67 patients examinedat the Allergy Service of ``Hospital Interzonalde Agudos R. Rossi'' (La Plata) showed allergicdisease. These allergenic episodes may beproduced by the large amount of pollen trees inthe city area.

Model for forecasting Olea europaea L. airborne pollen in South-West Andalusia, Spain.

Data on predicted average and maximum airborne pollen concentrations and the dates on which these maximum values are expected are of undoubted value to allergists and allergy sufferers, as well as to agronomists. This paper reports on the development of predictive models for calculating total annual pollen output, on the basis of pollen and weather data compiled over the last 19 years (1982-2000) for Córdoba (Spain). Models were tested in order to predict the 2000 pollen season; in addition, and in view of the heavy rainfall recorded in spring 2000, the 1982-1998 data set was used to test the model for 1999. The results of the multiple regression analysis show that the variables exerting the greatest influence on the pollen index were rainfall in March and temperatures over the months prior to the flowering period. For prediction of maximum values and dates on which these values might be expected, the start of the pollen season was used as an additional independent variable. Temperature proved the best variable for this prediction. Results improved when the 5-day moving average was taken into account. Testing of the predictive model for 1999 and 2000 yielded fairly similar results. In both cases, the difference between expected and observed pollen data was no greater than 10%. However, significant differences were recorded between forecast and expected maximum and minimum values, owing to the influence of rainfall during the flowering period.

The effect of temperature, relative humidity and rainfall on airborne ragweed pollen concentrations

Major weather parameters have long been known to alter airborne pollen and spore concentrations. The following study was conducted to study the effect of three of these parameters on airborne ragweed pollen concentrations.During the ragweed (RW) season for the years 1997 and 1998, 10 minute pollen collections were taken at least every 4 hours using an Allergenco MK-3 spore trap. Slides were fixed, and counted microscopically at 400X. During this same period, weather parameters were monitored by an Automated Weather Systems recording station located within a few meters of the collector.The ragweed season for this region begins in mid August and ends by mid October. Temperature patterns for the period demonstrated usual daily fluctuations with highs 13 to 35 °C and lows 8 to 24 °C. Relative humidity readings for the period varied between 25 and 100%. Highest RW values were seen after seasonal cooling in September. Daily rainfall for the period varied between 0 and 100 mm. Airborne RW always declined sharply after strong rainfall events (> 10 mm/day). Peak airborne RW concentrations were often associated with the passing of frontal boundaries and the change in wind direction and velocity that accompanies that passing.Factors influencing airborne RW concentrations are multiple and complex, but atmospheric forces have great influence. The passing of major weather fronts and the associated temperature drops, wind disturbances and rainfall are the major factors.

Possibility of real-time measurement of an airborne Cryptomeria japonica pollen allergen based on the principle of surface plasmon resonance

In order to establish a real-timemeasurement system for the concentration ofairborne pollen allergens, we examined Cry j 1,one of the major allergens of Cryptomeriajaponica pollen, as an example to establishthe system. The feasible system consisted of:collection of airborne pollen allergens usingthe Virtual Impactor or Cyclone sampler,extraction of Cry j 1 using 10mM HEPES buffercontaining 0.125M NH4HCO3 andfinally, real-time measurement of Cry j 1 usingthe BIACORE 3000 system. The sensitivity of thesystem was 5 ng/ml, and 0.1 ml sample volumeand at least 500 pg of Cry j 1 were requiredfor each measurement. Quantification of Cry j 1in the air can be determined 30 min aftercollection, i.e. 15 min for extraction, 10 minfor separation from particulate matters and 5min for the measurement.

Contribution of upwind pollen sources to the characterization of Juniperus ashei phenology

Local and long-range components of Juniperus ashei pollen deposition were isolated to provide a more accurate record of local pollination activity in the Arbuckle Mountains of south central Oklahoma. An aerobiological sampler recorded airborne pollen concentrations and deposition at the sample site from mid-December 1998 to the end of January 1999. Grid-based weather data was used to model the movement, position, and elevation (air mass trajectories) across the region. While a normal concentration distribution is expected for a pollination event at a single site, "very high" concentrations (>1500 pollen grains per cubic meter) creating "peaks" in the deposition record were identified using bi-hourly sample analysis of the pollen registrations in the sampler. These occurrences happened over a 2 1/2 week period beginning January 11 and are coincident with the occurrence of southerly winds throughout the region. Modeled trajectories indicate that the air masses associated with those occurrences traveled at ground level through the J. ashei population on the Edwards Plateau, some 200 kilometers to the south in Texas, then gained altitude prior to crossing the sample site, thus introducing a long-range pollen component at the sample site. Peaks with "high" concentrations (90 to 1500 pollen grains per cubic meter) were evaluated using the same methodology. Those peaks associated with trajectories having the potential of introducing a long-range component to the pollen deposition record were removed from the aerobiological record. The resulting adjusted aerobiological record shows a more normal pollen concentration distribution, reduced hourly variability, and a marked shift in the pollination initiation date. Based on the comparison of non-adjusted and adjusted aerobiological records, contributions from upwind pollen sources account for 55% of the total pollen record.

Olive phenology as a sensitive indicator of future climatic warming in the Mediterranean

ABSTRACTExperimental and modelling work suggests a strong dependence of olive flowering date on spring temperatures. Since airborne pollen concentrations reflect the flowering phenology of olive populations within a radius of 50 km, they may be a sensitive regional indicator of climatic warming. We assessed this potential sensitivity with phenology models fitted to flowering dates inferred from maximum airborne pollen data. Of four models tested, a thermal time model gave the best fit for Montpellier, France, and was the most effective at the regional scale, providing reasonable predictions for 10 sites in the western Mediterranean. This model was forced with replicated future temperature simulations for the western Mediterranean from a coupled ocean‐atmosphere general circulation model (GCM). The GCM temperatures rose by 4·5 °C between 1990 and 2099 with a 1% per year increase in greenhouse gases, and modelled flowering date advanced at a rate of 6·2 d per °C. The results indicated that this long‐term regional trend in phenology might be statistically significant as early as 2030, but with marked spatial variation in magnitude, with the calculated flowering date between the 1990s and 2030s advancing by 3–23 d. Future monitoring of airborne olive pollen may therefore provide an early biological indicator of climatic warming in the Mediterranean.

Relation between airborne pollen concentrations and daily cardiovascular and respiratory-disease mortality

In a time-series study in The Netherlands, we found a strong association between the day-to-day variation in pollen concentrations and that of deaths due to cardiovascular disease, chronic obstructive pulmonary disease, and pneumonia.

Influence of nearby stands of Artemisia on street-levelversus roof-top-level ratio's of airborne pollen quantities

Among aerobiologists it is commonly accepted that forlong-term monitoring of atmospheric pollen quantities,observations at roof-top level (15–30 m) areappropriate. Yet, possible differences in airbornepollen concentrations at different heights are hardlyinvestigated, particularly in relation to nearbypollen sources. In a six-year survey with twovolumetric pollen traps, airborne concentrations ofpollen from eight selected taxa at roof-top level arecompared with those at street level. For pollen fromplants further away than 1000 m from the street-leveltrap, no difference between quantities of pollen atroof-top and street level is found. Concentrations ofairborne pollen from sources closer than 20 m to thestreet-level trap are 1.2 to 6.8 times higher atstreet level than those at roof-top level,particularly for mugwort (Artemisia). Aftercutting mugwort plants in an area of 100 m around thestreet-level trap, the ratio dropped from 4.8 to 2.7,averagely for the season. It seems that, also in theabsence of nearby sources, airborne mugwort pollenquantities of street level are higher than those atroof-top level but, at least in Leiden, not as much ashas been reported earlier by others.

Effects of meteorological parameters and plantdistribution on Chenopodiaceae-Amaranthaceae, Quercus and Olea airborne pollen concentrationsin the atmosphere of Cartagena (Spain)

We have studied the effects of various meteorologicalparameters and plant distribution on the airborneconcentrations of three different pollen types:Chenopodiaceae-Amaranthaceae, Quercus and Olea, in the city of Cartagena, situated in SouthwestEurope. The aerobiological study has been carried outfrom March 1993 to March 1997, using a Hirst-typeLanzoni 2000 trap, situated on the roof of the citytrain station. Meteorological data were supplied bythe Environmental Service of Cartagena's Town Hall.Daily pollen concentrations were standardised.Correlation analysis showed the importance ofmeteorological data on airborne pollen concentrations.On the other hand, ANOVA analyses depicted theinfluence of vegetation distribution in relation tosampler location and wind directions. Finally,multiple regression analyses allowed us to developcorrelation models for the three different pollentypes considered, accounting for 32%(Chenopodiaceae-Amaranthaceae), 19% (Quercus),and 26% (Olea) of the variation in the airbornepollen concentration.

Wind Tunnel Comparison of the Collection Efficiency of Three Hirst-Type Volumetric Sampler Drum Coatings

A large number of sites worldwide measure airborne pollen and fungal spore concentrations using a Hirst-type volumetric impaction sampler. In Europe anumber of adhesive drum coatings are routinely used. The drum coating routinely used in the UK, V/P,consisting of 90% petroleum Jelly (Vaseline)/10%paraffin wax, has not previously been compared with other coatings, for fungal spores or pollens. The collection efficiency of different coatings was compared in a wind tunnel, at IACR-Rothamsted. Spores of different species were released and trapped in identical miniature suction traps which reproduce the aerodynamic features of a full size Hirst-type spore trap. The trapping surfaces were coated in one of three commonly used drum coatings: (1) V/P; (2) SiliconeFluid; (3) Glycerol Jelly. These are all used in Europe and both V/P and Glycerol Jelly are used the UK. Four spore types, Lycopodium clavatum (moss);Alternaria alternata; Botrytis cinerea;and Calvatia excipuliformis, which represent the size range of spores most frequently found in the air, were used. With the exception of B cinerea, the numbers of spores collected on Glycerol Jelly were significantly smaller than on the other two coatings. For all spore types, the numbers caught on the V/P andSilicone Fluid were not significantly different.

Concentration of airborne pollen of Vitisvinifera L. and yield forecast: a case study at S.Michele all'Adige, Trento, Italy

The possibility of creating a forecast model for grapeproduction using airborne pollen concentrations ofVitis vinifera L. was investigated. The studyarea is located in the province of Trento (46°11′,11°08′), North Italy. Because of its prestigious wineproduction, the area is quite important on a nationalscale.

Variation in pollen concentration of the mostallergenic taxa in Poznań (Poland), 1995–1996

The airborne pollen concentration of the four mostfrequent and most allergenic taxa in Poland; Alnus, Betula, Poaceae, and Artemisia atPoznan in the years 1995–1996 has been analyzed,using a Hirst-type volumetric spore trap. Theappearance of the earliest pollen producing taxa wasobserved as early as January and February, which isrelevant information for people subject to allergiesin the Poznan region, where Spring usually beginsin March. The periods of high and very high pollenconcentration of individual taxa have been comparedfor the two years.

Comparison of pollen sampling with a Burkard Spore Trap and a Tauber Trap in a warm temperate climate

Aerobiological data have been widely used by many scientists, including those that study modern flora as well as those wishing to reconstruct past vegetational associations. Burkard (Hirst-type) volumetric spore traps are widely used instruments for studying airborne pollen, while Tauber traps are typically used to analyze pollen deposition. The present study compared the pollen collected by these two methods in Tulsa, Oklahoma a warm temperate area with year-round pollen. There was a strong correlation between the pollen influx from the Tauber traps and cumulative sum of average daily airborne pollen concentrations recorded with the Burkard spore trap over the course of 12 months from 1 Feb 1997 through 1 Feb 1998. The correlation coefficient between all taxa over the 12 months was 0.914; while the correlation coefficient for the monthly totals was 0.972. The data showed that both methods reflected local anemophilous vegetation although variations occurred in the prevalence recorded by both samplers.

The influence of sampler height and orientation on airborne Ambrosia pollen counts in Montreal

Airborne pollen concentrations are normally estimated by sampling 10 liters of air a minute at a height of 15-20 meters, e.g. on top of a university or hospital building. It is generally believed that at this height a homogeneous cloud of pollen is sampled, and that the results obtained will be representative of a large area. However, this protocol still leaves some doubts about the actual concentration found at breathing level (1.5 m). Since pollen counts are often used to forecast risk of allergies using threshold values, the height difference in concentrations can have important implications. Many previous studies have tackled this problem, but contradictory results were obtained. In our protocol, personal volumetric Burkard samplers were used at 0, 5, 10 and 15 m and at two different orientation (NW and NE) of a single building in Montreal, Canada. Results from 320 samples show that exposure and sampling hours were non-significant factors of Ambrosia pollen variation, but that height was a factor more significant than daily variations (the usual factor investigated in Aerobiology). An interaction was also found between the influences of height and orientation.

Aerobiology of Artemisia airborne pollen in Murcia (SE Spain) and its relationship with weather variables: annual and intradiurnal variations for three different species. Wind vectors as a tool in determining pollen origin.

Detailed results from a 2-year survey of airborne pollen concentrations of Artemisia in Murcia are presented. Three consecutive pollen seasons of Artemisia occurring each year, related to three different species (A. campestris, A. herba-alba and A. barrelieri), were observed. A winter blooming of Artemisia could explain the incidence of subsequent pollinosis in the Murcia area. With regard to meteorological parameters, mathematical analyses showed relationships between daily pollen concentrations of Artemisia in summer-autumn and precipitations that occurred 6-8 weeks before. The cumulative percentage of insolation from 1 March seemed to be related to blooming onsets. Once pollination has begun, meteorological factors do not seem to influence pollen concentrations significantly. Intradiurnal patterns of pollen concentrations were similar for late summer and winter species (A. campestris and A. barrelieri). During autumn blooming (A. herba-alba), the intradiurnal pattern was particularly erratic. Theoretical values of wind run were obtained for each pollen season by the graphical sum of hourly wind vectors. When theoretical wind run was mapped onto the vegetation pattern, supposed pollen source locations were obtained for each hour. By comparing supposed hourly pollen origins with the intradiurnal patterns of pollen concentrations, it can be seen that this simple model explains variations in mean pollen concentrations throughout the day.

Wavelet-based fractal analysis of airborne pollen.

The most abundant biological particles in the atmosphere are pollen grains and spores. Self-protection of a pollen allergy is possible through information about future pollen contents in the air. In spite of the importance of airborne pollen concentration forecasting, it has not been possible to predict the pollen concentrations with great accuracy, and about 25% of daily pollen forecasts result in failures. Previous analyses of the dynamic characteristics of atmospheric pollen time series indicate that the system can be described by a low dimensional chaotic map. We apply a wavelet transform to study the multifractal characteristics of an airborne pollen time series. The information and the correlation dimensions correspond to a chaotic system showing a loss of information with time evolution.

High Levels of Olea europaea Pollen and Relation with Clinical Findings

Background: Olea europaea pollen is an important cause of seasonal allergic rhinitis and bronchial asthma in southern Spain. For patients allergic to grass pol– len the critical concentration of airborn pollen is 50 grains/m³, but in the case of Olea pollinosis no data is available. Methods: Fifty–six seasonal allergic rhinitis patients (29 in 1994 and 27 in 1995) were included in this study, all of whom lived in Jaen. Daily symptom card were filled in and pollen counts during May and June were performed in both years. A linear regression model was used for analysis of the airborne pollen concentration and the symptom score. Results: Significant correlations among daily counts of Olea pollen and rhinitis symptoms were obtained. Most of our monosensitized patients needed a high Olea pollen concentration in the atmosphere (around 400 grains/m³) to suffer at least from mild allergic rhinitis symptoms. Conclusion: Local conditions with a wide area dedicated to olive tree cultivars result in a high concentration of this pollen in the atmosphere. Monosensitized Olea patients in our area seem to need exceptionally high levels to suffer from allergic symptoms.

Airborne pollen concentration in Seville (Spain), 1993–1996. First results obtained with Hirst’s method

The data presented constitute the longest historical series of results obtained in Seville with a Hirst-type sampler, and are a further contribution to earlier aerobiological studies carried out in the city with a Cour trap. This work supplies an updated pollen calendar of the city, together with pollen counts and other aerobiological parameters for the 14 most important types in the 4-year period of sampling. These werePlatanus hispanica, Olea europaea, Quercus, Cupressaceae, Poaceae, Urticaceae, Moraceae, Chenopodiaceae/ Amaranthaceae,Plantago, Pinaceae,Rumex, Myrtaceae, Compositae, andCasuarina.

Emergency room visits of asthmatic children, relation to air pollution, weather, and airborne allergens.

The worldwide increase in the incidence, prevalence, and severity of asthma may suggest that environmental factors play a role in these epidemiologic changes. To examine the correlations between air pollutants, weather conditions, airborne allergens, and the incidence of emergency room (ER) visits of children with acute asthma attacks. One-year prospective study. Data of daily concentration of air pollutants, weather conditions, and selective airborne allergens were collected and compared with the number of ER visits of asthmatic children. 1076 asthmatic children (aged 1 to 18 years) who presented at the Pediatric ER between January 1 and December 31, 1993. Correlations between fluctuations in ER visits of asthmatic children and various environmental parameters were more relevant for weekly than for daily values. Emergency room visits correlated positively with concentrations of NOx, SO2 and with high barometric pressure; and negatively with O3 concentration and minimal and maximal temperature. There were no significant correlations with concentrations of particulates, humidity, or airborne pollen and spores. An exceptionally high incidence of ER visits of asthmatic children was observed during September. This peak coincided with the beginning of the school year and the Jewish holidays. The correlations between ER visits and the environmental factors increased significantly when the September peak was excluded, revealing that 61% of the variance in ER visits was explained by NOx, SO2, and 03 concentrations, 46% by weather parameters, 66% by NOx, SO2 and barometric pressure, and 69% by the combination of air pollutants and weather parameters. The major factors found to be associated with ER visits of asthmatic children were high NOx, high SO2, and high barometric pressure. Negative correlation was found between ER visits of asthmatic children and ozone concentrations. The particularly high number of ER visits at the beginning of the school year and the Jewish holidays was probably associated with an increase in the number of viral infections and/or emotional stress.