Total Pollen Count Research Articles

Immunogenic yeast-based fermentation product reduces allergic rhinitis-induced nasal congestion: a randomized, double-blind, placebo-controlled trial

Allergic rhinitis (AR) impacts around 25% of the worldwide population. However, cost, safety, and a high dissatisfaction rate with numerous conventional medications continues to be an issue in the largest patient surveys, due primarily to a lack of efficacy on nasal congestion. Our previously published randomized trial demonstrated a significant reduction in cold and flu-like symptoms, and a secondary potential observation of a decrease in nasal congestion with an oral yeast-derived compound; therefore, the objective of this study was to test the effects of this same product on nasal congestion and other notable AR symptoms. A 12-week, randomized, double-blind, placebo-controlled clinical trial of 96 healthy subjects with a recent clinically documented history of seasonal allergies and AR was conducted. Participants received once-daily supplementation with 500 mg of a dried, modified Saccharomyces cerevisiae oral fermentation product (EpiCor, Embria Health Sciences, Ankeny, Iowa, USA) or placebo during the 12-week period of the highest recorded concentrations of total pollen counts for this Midwest geographic area. Clinical outcome measurements included in-clinic examinations, validated questionnaire and standard diary, and serologic analysis at baseline, 6 and 12 weeks. During the highest pollen count period (weeks 1-6), EpiCor significantly reduced the mean severity of specific AR symptoms, including a significant reduction in nasal congestion (P=0.04), rhinorrhea (P=0.005), and a nonsignificant reduction in ocular discharge symptoms. A significantly (P=0.04) reduced total number of days with nasal congestion (12.5 fewer days) favored EpiCor compared with placebo, as did the nasal congestion section of the quality of life questionnaire (P=0.04). Subjects receiving the intervention also experienced significantly (P=0.03) higher salivary IgA levels. Adverse events were similar to placebo. This yeast-derived product appeared to be safe and efficacious, and should receive more clinical research with and without standard medications to reduce the impact of seasonal allergies, especially AR-induced nasal congestion.

Poaceae pollen in Galicia (N.W. Spain): characterisation and recent trends in atmospheric pollen season

Airborne Poaceae pollen counts are greatly influenced by weather-related parameters, but may also be governed by other factors. Poaceae pollen is responsible for most allergic reactions in the pollen-sensitive population of Galicia (Spain), and it is therefore essential to determine the risk posed by airborne pollen counts. The global climate change recorded over recent years may prompt changes in the atmospheric pollen season (APS). This survey used airborne Poaceae pollen data recorded for four Galician cities since 1993, in order to characterise the APS and note any trends in its onset, length and severity. Pollen sampling was performed using Hirst-type volumetric traps; data were subjected to Spearman's correlation test and regression models, in order to detect possible correlations between different parameters and trends. The APS was calculated using ten different methods, in order to assess the influence of each on survey results. Finally, trends detected for the major weather-related parameters influencing pollen counts over the study period were compared with those recorded over the last 30 years. All four cities displayed a trend towards lower annual total Poaceae pollen counts, lower peak values and a smaller number of days on which counts exceeded 30, 50 and 100 pollen grains/m(3). Moreover, the survey noted a trend towards delayed onset and shorter duration of the APS, although differences were observed depending on the criteria used to define the first and the last day of the APS.

Prediction of birch airborne pollen counts by examining male catkin numbers in Hokkaido, northern Japan

Birch pollen is a very common cause of pollinosis in Hokkaido, northern Japan. Birch airborne pollen concentrations vary each year; hence, the development of a method for predicting annual airborne pollen concentration is very important in preventing widespread symptoms of pollinosis. In the current study, we investigated airborne pollen counts and male catkin numbers (male flower index) of birch in four cities of Hokkaido between 2002 and 2008. Airborne pollen surveys were conducted using Durham’s sampler, and male catkin numbers determined for three major birch species (Betula platyphylla var. japonica, B. emanii, and B. maximowicziana). We found an annual variation in male flower index for all the three birch species investigated. This variation worked in combination with the amount of precipitation during the pollen season to influence total birch pollen counts. In conclusion, the male catkin numbers of three major birch species reliably predict airborne pollen counts in Hokkaido, but only when the effect of precipitation during pollen season is considered.

Pollen Loads and Allergic Rhinitis in Darwin, Australia: A Potential Health Outcome of the Grass-Fire Cycle

Although the prevalence of asthma and allergic rhinitis has been increasing in tropical regions, little is known about the allergenicity of pollens from tropical plant families or the importance of ongoing environmental changes. We investigated associations between daily average pollen counts of several tropical plant families and sales of medications for the treatment of allergic rhinitis in Darwin, Australia-a tropical setting in which grass abundance has increased due to increased fire frequencies and the introduction of African pasture grasses. Daily pollen counts with detailed identification of plant species were undertaken in conjunction with a weekly survey of flowering plant species from April 2004 to November 2005. Five pharmacies provided daily sales data of selected medications commonly used to treat allergic rhinitis. We used generalized linear modeling to examine outcomes. All analyses accounted for the potential confounding effects of time trends, holidays, respiratory viral illnesses, meteorological conditions, and air pollution. The peak total pollen count was 94 grains/m(3). Despite the low levels of Poaceae (grass) pollen (maximum daily count, 24 grains/m(3)), there was a clear association with daily sales of anti-allergic medications greatest at a lag of 1 day. Sales increased by 5% with an interquartile range rise (3 grain/m(3)) in Poaceae pollen (5.07%, 95%CI 1.04%, 9.25%). No associations were observed with pollen from other plant families. Although further testing is required, we suggest that an overlooked aspect of the "grass-fire cycle" that is degrading many tropical landscapes, could be an increase in the prevalence of allergic rhinitis.

Forecasting Models for Sugi (Cryptomeria japonica D. Don) Pollen Count Showing an Alternate Dispersal Rhythm

Pollen information is indispensable for allergic individuals and clinicians. This study aimed to develop forecasting models for the total annual count of airborne pollen grains based on data monitored over the last 20 years at the Mie Chuo Medical Center, Tsu, Mie, Japan. Airborne pollen grains were collected using a Durham sampler. Total annual pollen count and pollen count from October to December (OD pollen count) of the previous year were transformed to logarithms. Regression analysis of the total pollen count was performed using variables such as the OD pollen count and the maximum temperature for mid-July of the previous year. Time series analysis revealed an alternate rhythm of the series of total pollen count. The alternate rhythm consisted of a cyclic alternation of an "on" year (high pollen count) and an "off" year (low pollen count). This rhythm was used as a dummy variable in regression equations. Of the three models involving the OD pollen count, a multiple regression equation that included the alternate rhythm variable and the interaction of this rhythm with OD pollen count showed a high coefficient of determination (0.844). Of the three models involving the maximum temperature for mid-July, those including the alternate rhythm variable and the interaction of this rhythm with maximum temperature had the highest coefficient of determination (0.925). An alternate pollen dispersal rhythm represented by a dummy variable in the multiple regression analysis plays a key role in improving forecasting models for the total annual sugi pollen count.

Prevalence of airborne allergenic Amaranthus viridis pollen in seven different regions of Saudi Arabia

BACKGROUNDAmaranthus pollen grains are known to be highly allergenic and a potential cause of respiratory allergic diseases. Nevertheless, data on the prevalence of Amaranthus pollen in the environment is limited and almost non-existent for Saudi Arabia.METHODSWe conducted an investigation to record the airborne incidence of A. viridis and other allergenic pollen in Al-Khobar, Dammam, Hail, Jeddah, Jizan, Qassim and Taif, using Burkard Volumetric Samplers. The samplers were operated continuously for one year at each location.RESULTSThe data revealed A. viridis as one of the major components of outdoor airspora, constituting a maximum of 96% of total pollen counts in Hail, followed by Al-Khobar (89%), Jeddah (87%), Qassim (85%), Taif (84%), Dammam (83%) and Jizan (61%). These higher percentages contributed largely to the total weed pollen catch during August to November in all seven regions. In addition, the data also showed that A. viridis pollen were present throughout the year with distinct seasonal variations. The diel periodicities for at least five sites averaged over a year showed mid-day to early evening maxima. The maximum concentration approached 3000/m3 of air in October and 1827/m3 of air in September. The data also exhibited a seasonal pattern in their maximum appearance.CONCLUSIONFurther studies related to biochemical and allergological aspects are needed to confirm the allergenic impact of Amaranthus pollen and sensitization in allergic individuals in the Kingdom of Saudi Arabia.

Association between CD4 +CD25 high T cells and atopy in children

There is evidence that CD4(+)CD25(high) T-regulatory cells are important for establishing tolerance to allergens, but information in children is limited. To test the hypothesis that greater numbers and function of CD4(+)CD25(high) T cells are associated with a reduced risk of childhood allergies and wheezing. A cohort of 151 six-year-old children from atopic families was analyzed for peripheral blood CD4(+)CD25(high) and CD4(+)CD25(int) T cells by flow cytometry and for clinical and immunologic correlates of atopy. The associations between these variables were assessed by regression analysis. Factors positively associated with % CD4(+)CD25(high)/CD4 T cells were male sex, number of positive allergen-specific IgE tests, total IgE, season, and 1-month average total pollen count preceding blood draw. The percentage of CD4(+)CD25(high)/total CD4 T cells did not correlate with induced cytokine production, and correlated negatively with suppressive capacity of CD4(+)CD25(+) T cells (r = -0.45; P = .034). The percentage of CD4(+)CD25(int)/CD4 T cells was 54% higher in pollen-sensitized children compared with nonsensitized children in spring (P = .023 for interaction), and correlated positively with IL-5, IL-10, and IL-13 (P < or = .001 for all). Our findings suggest that blood CD4(+)CD25(high) cells are a mixture of activated and regulatory T cells, and that these cells could be seasonally regulated by environmental factors such as pollen exposure. Seasonal increases in CD4CD25(high) expression in children with allergy may represent systemic immune activation caused by pollen exposures.

Increase in prevalence of childhood asthma in Budapest between 1995 and 2003: is there a connection with the air pollution data or the total pollen count?

Introduction: According to the data of the Hungarian pulmonological network, the prevalence of asthma in the last 15 years has increased (almost linearly) in Hungary. In 2004 it was 1.8%. There are only a few data about the prevalence of childhood asthma. Aims: The aim of the authors was to measure the prevalence of bronchial asthma in childhood in Budapest in 1995, 1999 and 2003, using questionnaires directed to district pediatricians. Methods: There were only two questions in these questionnaires: how many children are in their districts, and how many are suffering from asthma? Besides of this survey the dust, CO, NO 2 and SO 2 concentrations in the air were measured on-line at 8 points in Budapest, while ozone level measurements were also made at 2 stations. The counts of pollen and of fungal elements in the air were calculated separately for Buda and for Pest. Results: In 1995, replies were received from 118 pediatricians in 11 districts, who were responsible for the supervision of 104 060 children, out of these 1.88±0.87% had been diagnosed as having asthma. In 1999 replies were sent by 153 physicians in 22 of the 23 districts, who had a total of 142 679 children under their care. These included 3228 asthmatics, i.e. a prevalence of 2.26±0.95%. In 2003 the authors received answers from all of the 23 districts of Budapest. The 204 pediatricians were responsible for the supervision of 176 049 children. The number of patients with the diagnosis of asthma was 4712 (corresponding for a prevalence of 2.68±1.3%). The increase between 1995 and 1999, and between 1999 and 2003 was highly significant (p &lt; 0.0001). This significant increase was valid even when the authors analysed only those 11 districts, which answered already in 1995. The level of air pollution in Budapest did not deteriorate in the period in question, and the concentration of pollen grains of plants causing allergy did not increase compared to previous years. Conclusions: On the basis of the results of more than 100 thousand children, the authors conclude that between 1995 and 2003 the proportion of asthmatic children increased by 50% in Budapest, while the air pollution did not deteriorate and the pollen concentration from sensitizing plants did not increase.

Changes in the Abundance and Diversity of Proteaceae in South‐western Australia: a Review of an Integrated Palaeoenvironmental Study

AbstractSouth‐western Australia is a globally significant hotspot of Proteaceae diversity. This review reports on changes in the abundance and diversity of Proteaceae in south‐western Australia. Using palynology, the data were obtained from three sediment sequences from the Eocene, Pliocene and Holocene, as well as a modern pollen rain study, in the context of a vegetation history framework. The total percentages of Proteaceae pollen in pollen counts indicate that the number of Proteaceae in the vegetation are highest at present, slightly lower, yet still high in the Eocene, reduced by the Pliocene and lowest in the Holocene. It was found that Proteaceous genera can contribute up to 50% of the total modern pollen rain. Sediment from Lake Lefroy showed Nothofagus‐dominated rainforest occurred in the Middle to Late Eocene. Proteaceae species were at least as diverse as today, contributing up to a maximum of 42% of the total pollen rain, and varying across small lateral distances. A laminated Pliocene age sequence from Yallalie confirmed other studies that south‐western Australia was covered by a rich vegetation mosaic consisting of heath and wet rainforest elements. Proteaceae species were a consistent component of the counts, although diversity and abundance (maximum 5%) were low. A Holocene record from Two Mile Lake, near the Stirling Range, recorded little environmental change. Proteaceae species were noted in low abundance, at a maximum of 3.5% of the total pollen count. It is likely that both changing pollination mechanisms and changes in associated vegetation are important in determining the dispersal of Proteaceous pollen.

An Eight Year Survey (1998-2005) of the Major Tree Pollens in the Washington, DC Area

RATIONALE: The last significant sampling for the Washington, DC area was over a decade ago (1989-1994); detailing concentrations and peak pollination periods for 16 major area tree species. The current investigation provides an update to the previous study and allows for comparison with respect to the predominant species and their peak pollinating periods.METHODS: Aeroallergan sampling was conducted using a volumetric rotating arm impaction Rotorod Sampler (Multidata/Sampling Technologies, St. Louis Park, Minnesota). Pollen counts were collected as recommended by the National Allergy Bureau and recorded in grains/cubic meter.RESULTS: The Fagaceae family (oaks and beech) are the predominant pollinating trees; accounting for 47% of the pollen collected. Other identified pollens included 10% Cupressaceae (cypress, juniper, cedar), 9% Pinaceae (pine), 8% Moraceae (mulberry), 5% Betulaceae (birch, alder), and 21% other (each <5%). The peak total pollen count (avg 1275 g/m3) and timing varied between the 2nd week of April to the 1st week of May each year. The most prevalent tree pollens peaked in April or May, except for Cupresseaceae and the alders of Betulaceae peaking in February or March.CONCLUSIONS: As part of a continual aeroallergen survey conducted at Walter Reed Army Medical Center, our data was consistent with previous surveys showing a “tree season” of February to June for this geographic area. Peak total pollen counts appear late in the season with oak as the primary pollinating trees. Further study is needed to establish an area specific severity scale and to correlate these observations with allergic disease outcomes. RATIONALE: The last significant sampling for the Washington, DC area was over a decade ago (1989-1994); detailing concentrations and peak pollination periods for 16 major area tree species. The current investigation provides an update to the previous study and allows for comparison with respect to the predominant species and their peak pollinating periods. METHODS: Aeroallergan sampling was conducted using a volumetric rotating arm impaction Rotorod Sampler (Multidata/Sampling Technologies, St. Louis Park, Minnesota). Pollen counts were collected as recommended by the National Allergy Bureau and recorded in grains/cubic meter. RESULTS: The Fagaceae family (oaks and beech) are the predominant pollinating trees; accounting for 47% of the pollen collected. Other identified pollens included 10% Cupressaceae (cypress, juniper, cedar), 9% Pinaceae (pine), 8% Moraceae (mulberry), 5% Betulaceae (birch, alder), and 21% other (each <5%). The peak total pollen count (avg 1275 g/m3) and timing varied between the 2nd week of April to the 1st week of May each year. The most prevalent tree pollens peaked in April or May, except for Cupresseaceae and the alders of Betulaceae peaking in February or March. CONCLUSIONS: As part of a continual aeroallergen survey conducted at Walter Reed Army Medical Center, our data was consistent with previous surveys showing a “tree season” of February to June for this geographic area. Peak total pollen counts appear late in the season with oak as the primary pollinating trees. Further study is needed to establish an area specific severity scale and to correlate these observations with allergic disease outcomes.

Airborne Pollen Concentrations and the Incidence of Allergic Asthma and Rhinoconjunctivitis in Northern Italy from 1992 to 2003

Background: Aeroallergens and the environment play an important role in the pathogenesis of respiratory allergies. In a 12-year study carried out in Northern Italy (geographic area of Parma), the effects of airborne pollen and meteorological conditions on the incidence of allergic asthma and rhinoconjunctivitis were evaluated. Patients and Methods: Among 9,060 subjects examined for respiratory pathologies at our Allergy Unit, Parma Hospital, Italy, from 1992 to 2003, only 1,054 positive to only one type of inhalant allergen in the skin prick test were studied, to avoid bias of cross-reactivity. Allergy and clinical aspects were compared with the duration of the pollination period, and peaks and total concentrations of airborne pollen. Results: Our data showed a significantly growing trend of allergy to mites, pets and birch pollen and a significant increase in asthma, and a significantly decreasing trend of positive reactions to grasses and a decrease in rhinoconjunctivitis. At the same time, there was a significant decrease in total pollen counts, concentration peaks and pollination period of grasses. A significant increase was only observed in ragweed and ash-olive total and peak pollen concentrations. Conclusions: Significant correlations between the increasing incidence in asthma and allergy to mites, pets and birch pollen are shown. The decrease in the total pollen count and concentration peaks of grass pollen was correlated to the decreasing trend of rhinoconjunctivitis. The trend of increasing concentrations of ash-olive and ragweed pollen was not accompanied by an increase in the related allergy.

A 10-year aerobiological study (1994–2003) in the Mediterranean island of Crete, Greece: Grasses and other weeds, aerobiological data, and botanical and clinical correlations

Grasses and weeds contain species that produce abundant pollen grains and have been implicated as causative agents in both asthma and allergic rhinitis. In this study, we present the pollen counts of allergenic grasses and weeds on the island of Crete and show their impact on allergic individuals. Heraklion is located at the center of the north shore of Crete and has been monitored with a Burkard 7-day volumetric spore trap since 1994, to determine the identity, concentration, and seasonal variation of airborne pollen grains. Data from 10 consecutive years were recorded, analyzed, and correlated to the growth of respective plants on this island. The island's vegetation and blossoming periods have been investigated by conducting field trips. In parallel, an atopic population of 576 individuals with a convincing history of allergic respiratory disease-rhinitis and/or asthma-was subjected to skin-prick tests with 50 common allergens. Quantitatively, there was a fair agreement between total pollen counts and positive skin-prick test frequencies for Parietaria (Urticaceae family). For the majority of the grass and weed genera, strongly positive skin test responses were observed frequently, despite rather low pollen counts.

A 10-year aerobiological study (1994–2003) in the Mediterranean island of Crete, Greece: Trees, aerobiologic data, and botanical and clinical correlations

Pollen grains from the plant cover of a given area participate largely in the composition of aeroflora (pollen and molds) of this area. Association of allergic respiratory disorders with concentration of allergenic particles in the atmosphere is well documented, and aerobiologic studies are of great relevance. A 10-year volumetric aerobiologic study was conducted in the city of Heraklion, located in the center of the north-shore of the island of Crete, Greece. Main allergenic families and genera encountered were, in descending order of frequency Oleaceae, Quercus, Platanaceae, Cupressaceae, Pinaceae, Populus, Moraceae, and Corylaceae. Concentrations noted for most of these aeroallergens were much lower than those reported from other European regions. In parallel, an atopic population of 576 individuals, exhibiting allergic symptoms mainly of the respiratory tract were subjected to a battery of skin-prick tests. A fair degree of agreement between total pollen counts and positive skin-prick test frequencies for the families of Oleaceae, Platanaceae, and Cupressaceae was noted. On the contrary a poor degree of concordance was noted for the rest of the families and genera.

Ambrosia pollen in the air of Lublin, Poland

Studies on Ambrosia pollen concentrations were carried out in Lublin in the period 1995–2004. The effects of a number of meteorological factors were analysed. In the first period of the study, the gravimetric method was used (1995–1999), while in the second period, the volumetric method was applied. The results show an increasing trend in the amount of airborne pollen. The Ambrosia pollen season in Lublin lasts from August to October. Over a period of 5 years, the highest number of pollen grains was recorded in September (53%), followed by August (44%) and October (3%). There were wide variations in annual totals. The annual total pollen counts was 167–1180 grains, with the peak value in 2002. Maximum daily pollen concentrations (56–312 pollen grains m−3) were recorded in the first half of August and in the first half of September. On the days when high Ambrosia pollen concentrations occurred, the temperature was above 21°C and the winds were mainly from the southeast, south and east. Maximum intradiurnal concentrations of pollen grains occurred in the afternoon hours. These results indicate, to some degree, that Ambrosia pollen is transported for long distances before descent.

Climatic and aeroallergen risk factors for chronic obstructive pulmonary disease in horses

To estimate the association between climate and airborne pollen and fungal factors and chronic obstructive pulmonary disease (COPD) in horses. Data from 1,444 horses with a diagnosis of COPD. The Veterinary Medical Database was used to identify records of horses admitted to veterinary teaching hospitals in the United States and Canada between 1990 and 1999. Rainfall, mean minimum and maximum temperature, and maximum monthly pollen and fungal spore (mold) counts recorded at the city closest to where the hospital is located were identified for each month data were reported to the Veterinary Medical Database. Associations between climatic and aeroallergen data and monthly prevalence of COPD were estimated by use of cross-correlation and logistic regression models. Significant positive correlations were found between prevalence of COPD and rainfall 3 months previously, minimum temperature 1 and 2 months previously, total pollen counts measured 3 months previously, and total mold counts measured during the same month and 1 month previously. Outdoor aeroallergens and climatic factors may contribute to the occurrence of COPD in horses.

Total pollen counts do not influence active surface measurements

Abstract We investigated the temporal association of various aerosol parameters with pollen counts in the pollen season (April 2001) in Linz, Austria. We were especially interested in the relationship between active surface (or Fuchs’ surface) because we had shown previously (Atmos. Environ. 37 (2003) 1737–1744) that this parameter during the same observation period was a better predictor for acute respiratory symptoms in school children (like wheezing, shortness of breath, and cough) and reduced lung function on the same day than particle mass (PM 10 ). While active surface is most sensitive for fine particles with a diameter of less than 100 nm it has no strict upper cut-off regarding particle size and so could eventually be influenced also by larger particles if their numbers were high. All particle mass parameters tested (TSP, PM 10 , PM 1 ) were weakly ( r approximately 0.2) though significantly correlated with pollen counts but neither was active surface nor total particle counts (CPC). The weak association of particle mass and pollen counts was due mainly to similar diurnal variations and a linear trend over time. Only the mass of the coarse fraction (TSP minus PM 10 ) remained associated with pollen counts significantly after controlling for these general temporal patterns.

Airborne pollen spectra at three sites in inland Croatia, 2003

The aim of this study was to determine whether there were major differences in the seasonal incidence and abundance of pollen grains and pollen types in pollen fall between sites of different land use. The material was collected from 5 January until 20 December 2003 at three sites in central Croatia. The sampling sites were located in an average urban setting (Zagreb), a rural setting (Ivanic Grad), and a small town surrounded by a large woodland with partially thermophilic vegetation (Samobor). Using the volumetric method of pollen collection, pollen grains of 35-37 taxa were identified, depending on the sampling site, eight of them producing the greatest amount of pollen (Alnus sp., Ambrosia sp., Betula sp., Carpinus sp., Poaceae, Quercus sp., Taxus/Juniperus, and Urticaceae). Differences among the sampling sites were recorded according to seasonal pollen concentration, total monthly pollen count, and total annual pollen count. The proportion of particular plant classes (tree, grass and weed) was quite comparable among the three sampling sites because of their relative geographic proximity (i.e. within the same climatic region). A difference was observed in the air pollen concentration. All three monitoring sites revealed the total annual airborne pollen concentration in inland Croatia to be dominated by highly allergenic pollen (Zagreb 54%, Samobor 58% and Ivanic Grad 82%) of the following taxa: Alnus sp., Ambrosia sp., Betula sp., Carpinus sp., Corylus sp., Poaceae, Urticaceae and Artemisia sp. Accordingly, there were no distinct phenologically induced differences in pollen species recorded at the three monitoring sites. However, substantial differences were observed in seasonal pollen grain count and in the percentage proportion of some allergenic pollen grains (Ambrosia sp., Betula sp., Carpinus sp., Poaceae), providing valuable information to individuals suffering from pollen allergy.

Transport of airborne pollen into the city of Thessaloniki: the effects of wind direction, speed and persistence

We examined the effect of the wind vector analyzed into its three components (direction, speed and persistence), on the circulation of pollen from different plant taxa prominent in the Thessaloniki area for a 4-year period (1996-1999). These plant taxa were Ambrosia spp., Artemisia spp., Chenopodiaceae, Corylus spp., Cupressaceae, Olea europaea, Pinaceae, Platanus spp., Poaceae, Populus spp., Quercus spp., and Urticaceae. Airborne pollen of Cupressaceae, Urticaceae, Quercus spp. and O. europaea make up approximately 70% of the total average annual pollen counts. The set of data that we worked with represented days without precipitation and time intervals during which winds blew from the same direction for at least 4 consecutive hours. We did this in order to study the effect of the different wind components independently of precipitation, and to avoid secondary effects produced by pollen resuspension phenomena. Factorial regression analysis among the summed bi-hourly pollen counts for each taxon and the values of wind speed and persistence per wind direction gave significant results in 22 cases (combinations of plant taxa and wind directions). The pollen concentrations of all taxa correlated significantly with at least one of the three wind components. In seven out of the 22 taxon-wind direction combinations, the pollen counts correlated positively with wind persistence, whereas this was the case for only two of the taxon-wind speed combinations. In seven cases, pollen counts correlated with the interaction effect of wind speed and persistence. This shows the importance of wind persistence in pollen transport, particularly when weak winds prevail for a considerable part of the year, as is the case for Thessaloniki. Medium/long-distance pollen transport was evidenced for Olea (NW, SW directions), Corylus (NW, SW), Poaceae (SW) and Populus (NW).

Allergenic airborne pollen monitoring of Vigo (NW Spain) in 1995–2001

Pollen data from the atmosphere of Vigo, NW Spain was collected using a Hirst type pollen trap over a seven-year period (1995–2001). A total of 56 different pollen types were identified, among which Urticaceae, Poaceae, Betula and Quercus represent the greatest risk for people suffering from allergic rhinitis (hay fever) or other allergic diseases. Although in the atmosphere of Vigo the presence of allergenic pollen is constant throughout the year, the months of March and April account for 40% of the annual total pollen count. Two main risk periods have been identified for asthma and allergies: (1) March – April, and (2) June – July, the latter is of greater importance due to high concentrations of Poaceae pollen. Correlation analysis with meteorological parameters demonstrates that rainfall, relative humidity, maximum temperature, sun hours and north-easterly winds are the main factors influencing the average daily pollen concentrations in the atmosphere.

A spatial and temporal Eocene palaeoenvironmental study, focusing on the Proteaceae family, from Kambalda, Western Australia

The spatial and temporal vegetation and environmental dynamics of an Eocene sequence from south-western Australia, based on pollen and geochemical analyses, is presented here. The vegetation was dominated by Nothofagus species with other gymnosperms such as Araucaria and Podocarpus intermixed with Myrtaceae, Proteaceae and Casuarinaceae. Pollen of Proteaceae were an important and consistent component of the vegetation; as much, or more so than at present. Results from this study show that the Proteaceous component is up to 42% of the total pollen counts. Removing data for the dominant Nothofagus taxon did not alter the apparent dominance of Proteaceae species, though the abundance and types of species changed. The abundance and diversity of the flora here supports the view that there are differences between the flora in eastern and western parts of Australia at this time. In addition, a main finding of this research is that there can be considerable spatial and temporal variability in the abundance and diversity of taxa, and specifically Proteaceous taxa, in landscapes in the Eocene.