Atmospheric pollen and spores in relation to allergy. I

Isolating the species element in grass pollen allergy: A review

Grass pollen is a leading cause of allergy in many countries, particularly Europe. Although many elements of grass pollen production and dispersal are quite well researched, gaps still remain around the grass species that are predominant in the air and which of those are most likely to trigger allergy. In this comprehensive review we isolate the species aspect in grass pollen allergy by exploring the interdisciplinary interdependencies between plant ecology, public health, aerobiology, reproductive phenology and molecular ecology. We further identify current research gaps and provide open ended questions and recommendations for future research in an effort to focus the research community to develop novel strategies to combat grass pollen allergy. We emphasise the role of separating temperate and subtropical grasses, identified through divergence in evolutionary history, climate adaptations and flowering times. However, allergen cross-reactivity and the degree of IgE connectivity in sufferers between the two groups remains an area of active research. The importance of future research to identify allergen homology through biomolecular similarity and the connection to species taxonomy and practical implications of this to allergenicity is further emphasised. We also discuss the relevance of eDNA and molecular ecological techniques (DNA metabarcoding, qPCR and ELISA) as important tools in quantifying the connection between the biosphere with the atmosphere. By gaining more understanding of the connection between species-specific atmospheric eDNA and flowering phenology we will further elucidate the importance of species in releasing grass pollen and allergens to the atmosphere and their individual role in grass pollen allergy.

Forecasting methodologies for Ganoderma spore concentration using combined statistical approaches and model evaluations

High concentration levels of Ganoderma spp. spores were observed in Worcester, UK, during 2006-2010. These basidiospores are known to cause sensitization due to the allergen content and their small dimensions. This enables them to penetrate the lower part of the respiratory tract in humans. Establishment of a link between occurring symptoms of sensitization to Ganoderma spp. and other basidiospores is challenging due to lack of information regarding spore concentration in the air. Hence, aerobiological monitoring should be conducted, and if possible extended with the construction of forecast models. Daily mean concentration of allergenic Ganoderma spp. spores in the atmosphere of Worcester was measured using 7-day volumetric spore sampler through five consecutive years. The relationships between the presence of spores in the air and the weather parameters were examined. Forecast models were constructed for Ganoderma spp. spores using advanced statistical techniques, i.e. multivariate regression trees and artificial neural networks. Dew point temperature along with maximum temperature was the most important factor influencing the presence of spores in the air of Worcester. Based on these two major factors and several others of lesser importance, thresholds for certain levels of fungal spore concentration, i.e. low (0-49 s m(-3)), moderate (50-99 s m(-3)), high (100-149 s m(-3)) and very high (150 < n s m(-3)), could be designated. Despite some deviation in results obtained by artificial neural networks, authors have achieved a forecasting model, which was accurate (correlation between observed and predicted values varied from r s = 0.57 to r s = 0.68).

Immunotherapy for mold allergy

The objective of this article is to review the available studies regarding mold immunotherapy. A literature search was conducted in MEDLINE to identify peer-reviewed articles related to mold immunotherapy using the following keywords: mold, allergy, asthma, and immunotherapy. In addition, references cited within these articles were also reviewed. Articles were selected based on their relevance to the topic. Allergic responses to inhaled mold antigens are a recognized factor in allergic rhinitis and asthma. There are significant problems with respect to the production of relevant allergen material for the diagnosis and treatment of mold allergy with immunotherapy. Mold allergens contain proteases and should not be mixed with other allergens for immunotherapy. Most of the immunotherapy studies focus on two molds, Alternaria and Cladosporium. There is a lack of randomized placebo-controlled trials when evaluating the efficacy of mold immunotherapy with trials only focusing on immunotherapy to Alternaria and Cladosporium. Additional studies are needed regarding mold allergy and immunotherapy focusing on which molds are important for causing allergic disease.

A new 'bio-comfort' perspective for Melbourne based on heat stress, air pollution and pollen

Humans are at risk from exposure to extremes in their environment, yet there is no consistent way to fully quantify and understand the risk when considering more than just meteorological variables. An outdoor 'bio-comfort' threshold is defined for Melbourne, Australia using a combination of heat stress, air particulate concentration and grass pollen count, where comfortable conditions imply an ideal range of temperature, humidity and wind speed, acceptable levels of air particulates and a low pollen count. This is a new approach to defining the comfort of human populations. While other works have looked into the separate impacts of different variables, this is the first time that a unified bio-comfort threshold is suggested. Composite maps of surface pressure are used to illustrate the genesis and evolution of the atmospheric structures conducive to an uncomfortable day. When there is an uncomfortable day due to heat stress conditions in Melbourne, there is a high pressure anomaly to the east bringing warm air from the northern interior of Australia. This anomaly is part of a slow moving blocking high originating over the Indian Ocean. Uncomfortable days due to high particulate levels have an approaching cold front. However, for air particulate cases during the cold season there are stable atmospheric conditions enhanced by a blocking high emanating from Australia and linking with the Antarctic continent. Finally, when grass pollen levels are high, there are northerly winds carrying the pollen from rural grass lands to Melbourne, due to a stationary trough of low pressure inland. Analysis into days with multiple types of stress revealed that the atmospheric signals associated with each type of discomfort are present regardless of whether the day is uncomfortable due to one or multiple variables. Therefore, these bio-comfort results are significant because they offer a degree of predictability for future uncomfortable days in Melbourne.

[Methods of studying airborne pollen and pollen calendars]

INTRODUCTION

Pollen is a major cause of allergy and monitoring pollen in the air is relevant for diagnosis, treatment and prevention, as well as for biomedical and biological research. Many aero-biological studies have been conducted all over the world to ascertain aerial concentrations and seasonality of pollen grains.

BACKGROUND

Monitoring of airborne biological particles is carried out by various gravimetric, impaction, and suction sampling devices. The Hirst trap, later modified to Burkard(®) or Lanzoni(®) traps, is the most widely used sampler. Counting and identifying pollen grains is then performed under optical microscopy. Based on differences in airborne pollen recorded over several years of observation, pollen calendars have been drawn up as aids to allergy diagnosis and management but they could be replaced advantageously by allergy-risk calendars. Pollen counts also provide valuable information about the geographical origin of pollen grains.

VIEWPOINTS

Since the identifying and counting of pollen grains in ambient air samples is still a demanding and time-consuming task, there is an increasing interest in the automation of pollen monitoring. Furthermore, the divergence sometimes observed between clinical observations and pollen counts provides an incentive to collect aero-allergens directly. Lastly, pollen monitoring could be improved through the use of personal bioaerosol samplers.

CONCLUSIONS

Great progress has been made in aerobiology for over a century, but much remains to be accomplished, particularly in relation with the standardization of methods.

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.

Effects of meteorological factors on airborne bracken (Pteridium aquilinum (L.) Kuhn.) spores in Salamanca (middle-west Spain)

Temporal variation of airborne bracken (Pteridium aquilinum) spores concentration in Salamanca during 10 years from January 1998 to December 2007 were studied by using a Burkard spore trap, and correlations with some meteorological parameters were analyzed. The number of spores that were counted was very low, due probably to the distance between the spore trap and the main bracken populations which were located 70 km away from the city. Long-range transport caused by winds coming from the Second Quadrant (IIQ) is supposed to be responsible for the appearance of bracken spores in Salamanca. The season period from August to late October shows the most intense spore dispersal process, with an early morning distribution along the day. Years 2002 and 2007 with a low quantity of airborne spores were also characterized by low mean temperatures, always under 18 degrees C from May to June. Daily spore concentration shows positive correlation with temperature and sun hours but negative with IVQ winds and with relative humidity. No correlation between daily spore concentration and rainfall was found. Also, a positive correlation between number of spores and IIQ winds was observed during the main spore season (MSS) and prepeak period (PRE).

Skin prick test reactivity in allergic rhinitis patients to airborne pollens

The aim was to investigate the impact of atmospheric pollen in determining allergic rhinitis. It was conducted with 130 patients with allergic rhinitis in three different sites in Eskisehir, Turkey, in 2000-2001, using a gravimetric method with a Durham sampler. Skin prick test results, the symptoms of patients and their findings all confirmed the presence of allergic reactions to pollen allergens in the patients observed. During the period, a total of 47,082 pollen grains/cm(2) belonging to 45 taxa were recorded. Of the total pollen grains, 81.0% were arboreal and 18% non-arboreal. The majority of the investigated pollen grains were from Pinaceae, Salix spp., Chenopodiaceae/Amaranthaceae, Cupressaceae and Poaceae. Pollen concentrations reached the highest level in May (54.36%). The pollen allergens provoking severe sensitization were grasscereal mixtures (58.5%), followed by arboreals (33.8%). All patients (100.0%) were sensitive to grass. This study emphasizes the significance of determining the types and concentrations of pollen with a view to comparing changes in highly concentrated allergens.

Fungi and indoor conditions in asthma patients

This study was carried out with 127 asthmatic patients and 127 controls, which aimed to compare and evaluate the environmental conditions in the homes of asthmatic patients and the control group. Air samples were obtained by using an air sampler and the mean mould colony counts were established. Aspergillus and Penicillium were the most common isolated species. No significant difference was observed with regard to various house conditions and the mean mould colony counts between the houses of patients and controls. The mould colony counts were found to be lower in houses with wooden parquet flooring. The odds ratio for stone floors vs. wood floors was 2.3 (95% CI 1.08-4.98) for mould growth.

Interpreting atmospheric pollen counts for use in clinical allergy: allergic symptomology

BACKGROUND

Allergists generally consider atmospheric pollen counts to be an estimate of the antigenic challenge confronting allergic individuals. The nature of this challenge depends on the particular pollen types found in the atmosphere and also the airborne concentration of these pollen types. Both clinical experience and clinical investigations support these assumptions; however, a coherent system for relating pollen counts and allergic symptomology does not exist.

OBJECTIVE

This review article will systematically review the medical and technical literature concerning the clinical significance of atmospheric pollen counts.

DATA SOURCES

This review article will consider three independent bodies of literature: 1) data contrasting human exposure patterns with rooftop pollen counts; 2) data concerning dose-response relationships between atmospheric pollen counts and allergic symptomology; and 3) data concerning methods for indexing atmospheric pollen counts based on a pollen type's in vivo allergenicity and terminal velocity.

RESULTS

Three principal results emerged. First, rooftop pollen counts imperfectly approximate human exposure to atmospheric pollen. Differences in both the concentration and type of pollen encountered by humans can be expected to differ from samples obtained on rooftops. Second, allergic symptomology is positively correlated with atmospheric pollen counts. Investigations involving Betula (birch) pollen offer quantitative dose-response models. Complex, nonlinear relationships that seem to reflect both the priming effect and late-phase reactions exist. Last, atmospheric pollen counts can be indexed based on a contemporary application of Thommen's postulates. This system provides allergists with a means to estimate the clinical significance of various pollen types by combining data concerning in vivo allergenicity and terminal velocity.

CONCLUSIONS

These conclusions should allow allergists to judge the clinical significance of atmospheric pollen counts with greater sophistication than was previously possible.

Quantification of group 5 grass pollen allergens in house dust

BACKGROUND

It is widely known and accepted that grass pollen is a major outdoor cause of hay fever. However, it is of virtual importance for grass pollen allergic patients with symptoms all the year round to know the concentration of grass pollen allergens in their homes.

OBJECTIVE

The main objective of this study was to quantify the amount of grass pollen allergen in mass units (microg Phl p 5) in dust settled indoors and to detect the distribution of allergenic activity in different sampling locations of homes. Furthermore, we studied the seasonal fluctuation of allergen content in dust samples.

METHODS

We adapted the two site binding assay for detection of group 5 grass pollen allergens in samples from randomly selected homes in Hamburg (n = 371), Erfurt (n = 396), Hettstedt (n = 353), Zerbst (n = 289) and Bitterfeld (n = 226), Germany. Dust samples were collected from floor of living room (LR), bedroom (BR) or children's room (CR) and mattress (MA) during period of June 1995 to August 1998. The amount of the major grass group 5 allergens was detected in microg/g dust.

RESULTS

Phl p 5 was detected in 67% of the samples analysed (n = 4760). The range was between undetectable (< 0.03 microg/g dust) and 81 microg/g dust. Phl p 5 levels were significantly higher in the dust from LR (geometric mean 0.117 microg/g dust) or BR/CR floors (geometric mean 0.098 microg/g dust) than in mattresses (geometric mean 0.043 microg/g dust). We observed seasonal fluctuation of indoor Phl p 5 levels with peak in June but also annual differences. Thus Phl p 5 content indoors reflects also the different quantities of pollen counts of annual courses. During pollination period we found two times higher Phl p 5 levels (0.172 microg/g dust, P < 0.001) than outside of grass pollination season (0.095 microg/g dust). The indoor Phl p 5 levels outside of season seem to be independent of pollination before. We suppose that settled pollen grains or allergenic material from outdoor particles carried indoors via footwear and clothes accumulates in house dust.

CONCLUSION

Although we not known how the allergens in settled dust are equilibrated with those in the air, the considerable high level of Phl p 5 in indoor dust even during periods when no grass pollen is present in the atmosphere may be an important cause of pollen-allergy symptoms outside of season.

Analysis of the relationships between environmental factors (aeroallergens, air pollution, and weather) and asthma emergency admissions to a hospital in Mexico City

There have been several studies of the relationships between environmental factors, particularly air pollution, and attacks of asthma. Most of these studies have ignored the potential confounding effects of aeroallergens such as pollens and fungal spores. We report a statistical analysis of the relationships between emergency admissions for asthma to a hospital in Mexico City and daily average airborne concentrations of pollen, fungal spores, air pollutants (O3, NO2, SO2, and particulates) and weather factors. Asthma admissions had a seasonal pattern with more during the wet season (May-October) than the dry season (November-April). There were few statistical associations between asthma admissions and air pollutants for the three age groups studied (children under 15 years, adults, and seniors [adults over 59 years]) in either season. Grass pollen was associated with child and adult admissions for both the wet and dry seasons, and fungal spores were associated with child admissions during both the wet and dry seasons. The analysis was done with environmental data averaged over the day of admission and the 2 previous days. Our results suggest that aeroallergens may be statistically associated more strongly with asthma hospital admissions than air pollutants and may act as confounding factors in epidemiologic studies.

Cladosporium as an airborne allergen in Saudi Arabia

Airborne mold monitoring in three cities in Saudi Arabia has documented the presence of Cladosporium in high concentrations. The spore counts reached threshold levels for sensitization at Jeddah and Al-Khobar with prominent seasonal variations. The concentration in Riyadh (central region) showed levels with minor fluctuationgs and a minor peak towards the month of Novermber. Indoor monitoring also revealed the presence of Cladosporium. Ten species of Cladosporium were idenified with C. sphaerospermum, C. herbarum, C. cladosporoides and C. macrocarpum being most prevalent. The species are relevant in relation to extracts for diagnosis. Skin testing of asthmatic children in Riyadh and Makkah revealed reactivities to Cladosporium extract of 5.8% and 31.3%, respectively. This indicates that Cladosporium may be an important allergen in the region that necessitates further biochemical and immunochemical studies to confirm the allergic impact of the species of Cladosporium prevalent in the region.

Respiratory symptoms, immunological responses, and aeroallergen concentrations at a sawmill

After identification of a case of extrinsic allergic alveolitis due to exposure to wood dust at a sawmill, all employees at the sawmill where he worked were studied with an occupational, environmental, and symptom questionnaire, spirometry, skin prick tests, and serum specific IgG measurements. Ninety five of current and 14 of 17 ex-sawmill workers were studied. As a basis for comparison, a group of 58 workers from a nearby light engineering factory were also studied. Few women (6) were employed and they were excluded from the analysis. Workers at the sawmill were stratified into high and low exposure groups depending on their place of work. This division was supported both by their subjective assessment of the dustiness of their environment and the results of personal dust samples. There were no significant differences between the three groups in age, height, smoking habits, exposure to other causes of extrinsic allergic alveolitis, forced expiratory volume in one second, forced vital capacity, atopic state, or cutaneous reactivity to moulds. In the high exposure group the prevalence of work related cough and nasal and eye symptoms was higher than in the low exposure and comparison groups. The prevalence of work related wheeze was similar in both the high exposure and comparison groups, but was lower in the low exposure group. The prevalences of chronic bronchitis and symptomatic bronchial hyper-reactivity were similar in the high and low exposure groups but were lower in the comparison group. Serum concentrations of specific IgG against extracts of sawdust and Trichoderma koningii were significantly higher in the high exposure group than in the other two groups. The prevalence of symptoms suggestive of extrinsic allergic alveolitis was 4.4% in the high exposure group, greater than in the low exposure group (0%), and the comparison group (1.9%). In conclusion extrinsic allergic alveolitis probably occurs in British sawmills, and among the exposed population its prevalence may be as high as that reported in Sweden. The allergen responsible is likely to be from mould growing on the wood and may be from Trichoderma koningii.

Catálogo de los hongos aislados en el polvo acumulado en colegios de Córdoba (España)

En este trabajo se ha analizado el polvo de 12 Colegios de E.G.B. de la ciudad de Córdoba, con objeto de identificar, cuantificar y catalogar la micoflora presente en él, así como conocer su frecuencia y estacionalidad. De esta manera hemos aislado 91 táxones, los cuales se relacionan en el presente catálogo, indicando para cada uno de ellos si son potencialmente patogénicos, época del año en la que se han detectado e incidencia en nuestros muestreos.

Respiratory function in greenhouse workers

Respiratory findings were studied in a group of 135 female and 32 male workers employed in greenhouses. In addition 51 women and 30 men were studied as a control group. Exposed women had significantly higher prevalences of chronic cough, dyspnea, chest tightness, and rhinitis (P < 0.01) than the controls. Among the men, only rhinitis was more prevalent in greenhouse workers (P < 0.01) than in controls. Smokers had higher prevalences of all chronic respiratory symptoms than nonsmokers, but the differences were statistically significant only for chronic cough and rhinitis in women and for chronic phlegm in men. There was a high prevalence of acute symptoms during work. A large number of greenhouse workers complained of skin reactions to plants and pesticides (women: 37.8%; men: 34.4%). Workers had significantly lower mean ventilatory capacity measurements (except in the case of forced vital capacity) when compared to standard predicted values. Smokers and nonsmokers had similar values of lung function expressed as percentages of the predicted values. Greenhouse workers exposed for more than 10 years had a significantly lower FEF25, measured as a percentage of the predicted value, than workers exposed for less than 10 years. Our data indicate that occupational exposure to greenhouses may be associated with the development of acute and chronic respiratory symptoms and impairment of ventilatory capacity.

Catálogo de los hongos presentes en silos de la provincia de Córdoba (España)

En este trabajo se realizó durante un año el estudio de la presencia de hongos en el ambiente de dos silos y dos almacenes de semillas de la provincia de Córdoba. Para el muestreo del aire se utilizaron simultáneamente un método volumétrico y otro gravimétrico, ambos sobre medio de cultivo. Paralelamente se tomaron muestras de grano almacenado, para conocer la micoflora que contenían. Con los resultados obtenidos se ha elaborado un catálogo que incluye los 70 táxones identificados. Para cada tazón se indican, ecología, patogenicidad potencial y anteriores citas en España.

Immunoblot analysis of components of Penicillium notatum recognized by human IgE antibodies

Components of the crude extract of Penicillium notatum recognized by human IgE antibodies (Abs) were investigated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. The allergenic components were identified with sera from 19 allergic patients and 20 blood donors. The allergen-Ab complexes were visualized by 125I-labeled monoclonal antihuman IgE and autoradiography. A total of 11 allergenic components, ranging in molecular weights (MWs) from 94,000 to 20,000 daltons, were identified. Heterogeneity in the IgE-binding patterns of the serum samples tested was also observed. However, the major allergen appears to be the component with an MW of about 68,000 daltons that was recognized by IgE Abs in 56% of the 39 sera analyzed. Furthermore, the component with an MW of about 64,000 daltons that was recognized by IgE Abs in 46% of the sera analyzed was also considered as an important allergen. Results obtained from this study will be useful in additional characterization of allergens of P. notatum and related fungal species.

Significance of sampling height of airborne particles for aerobiological information

Pollen and spore counts from Burkard traps for routine pollen and spore sampling placed at 15 m above ground and at ground level were compared. Daily counts of most pollen types were higher on the ground than at roof level, but the counts were significantly correlated. The ratios of pollen frequencies at high and low levels varied between 1.0 and 11.5. The most prominent differences were recorded for herbaceous pollen (e.g. Artemisia counts 11.5 and Poaccae counts 4.4 times higher at ground level) and in Botrytis and Ustilaginales spores. Tree pollen grains and basidiomycetous spores were more equally distributed. Wind speed did not affect the variation of pollen frequencies at either height. Large spores are not so unevenly distributed as previously supposed. Artemisia and grass pollen was detected 1 to 2 weeks earlier at ground level than on the roof. It is therefore concluded that especially the beginning of flowering should be monitored at a low level.

Indoor moulds and asthma

SEVENTY-TWO ASTHMATIC patients aged 15 to 60 years were identified in a general practice. Together with 72 controls, matched for age and sex, they were investigated for evidence of allergy to moulds. Positive skin tests (weal at least 3mm greater in diameter than for saline control) to any of five moulds occurred in nine asthmatics and one control. Using RAST assay, IgE antibodies to any of four moulds were found in 38 asthmatics and 7 controls. Visible moulds were reported in the homes of 19 asthmatics (26%) and controls (12.5%). Penicillium was the mould most commonly found in the home and to which antibodies most often occurred, especially in the houses with mould. Exposure to indoor mould, especially Penicil lium, may be a contributory factor to the disease in some asthmatic patients.

Hazardous agents in agricultural dusts and methods of evaluation

Organic dusts in agriculture vary with type of agriculture, weather conditions, geographical location, and agricultural practices. It is difficult to ascribe a specific biological effect to a specific agent in agricultural dusts, and we are only able to develop a list of candidates for disease-causing agents. Future studies should be designed to define more specifically the hazardous agents in agricultural dusts by using more precise analytical techniques and documenting the clinical effects to man, developing dose-response relationships.

Volumetric aerobiological survey of conidial fungi in the North-East Netherlands. II. Comparison of aerobiological data and skin tests with mould extracts in an asthmatic population

A study was undertaken to see whether the principal airborne fungi in the North-East Netherlands were also found to be the most reactive in skin testing. Atmospheric samples were taken weekly with the Andersen sampler, from April 1981, up to and including, June 1983. At the same time skin tests of 833 patients referred to the outpatient Departments of Pulmonology and Allergology, because of recurrent bronchial obstructive complaints and a suspected allergy, were studied for strongly positive skin reactivity to fungi. 4.6% of the patients reacted with a wheal of 10 mm diameter or more to one or more of the tested fungi. Almost three-quarters of the airborne fungal "flora" was composed of seven genera, namely (in order of occurrence): Cladosporium (42.6%), Botrytis (8.6%), Yeasts (7%), Penicillium (5.8%), Basidiomycetes (5.7%), Aspergillus (3.7%), and Alternaria (0.9%). In skin-testing, however, a different order of occurrence existed: namely: Beauveria (6.8%), Botrytis (6.1%), Aspergillus (4.7%), Mucor (3.8%), Epicoccum (3%), Cladosporium (2.3%), and Alternaria (1.1%). It is concluded that the most prevailing airborne moulds are not necessarily the most potent allergens, at least in skin testing. Aspergillus and Botrytis showed a high sensitization rate, while Cladosporium and Alternaria did not. Botrytis deserves further study because of its frequent airborne occurrence and marked allergenic properties.

Volumetric aerobiological survey of conidial fungi in the North-East Netherlands. I. Seasonal patterns and the influence of metereological variables

In order to obtain actual data about the qualitative and quantitative occurrence of airborne fungi in The Netherlands, a viable-volumetric sample survey with the Andersen sampler was undertaken. From April 1981 to the end of June 1983, one day a week samples were taken on the unobstructed rooftop of a hospital in the N-E Netherlands. An average of 268 Colony Forming Units (CFU), per sample, per cubic metre of air were found. Almost three-quarters of the total catch consisted of seven genera, Cladosporium predominating. Botrytis showed in surprisingly high numbers when compared with other surveys, while Alternaria occurred in very low concentrations. Most atmospheric airborne spora were found between May and September. Aspergillus and Penicillium prevailed in the autumn and winter months, although were present the year-round. Momentary weather conditions seemed less important for the overall spore picture than the average meteorological characteristics for a whole season. The obtained aero-mycological information may be useful in determining clinical strategies for skin testing and serological investigations in patients with suspected mould allergies.

Investigation of the involvement of Echium plantagineum (Paterson's curse) in seasonal allergy. IgE antibodies to Echium and other weed pollens

The possible allergenicity of an insect pollinated weed, Echium plantagineum, was investigated in a rural area of Australia. Sixty-one subjects with respiratory allergy were studies. Positive skin test reactions to defatted ammonium bicarbonate extract of pollen were found in over 60% of subjects, and positive RAST tests in a similar number. The question of crossreactivity between weed pollens is discussed. The pollen of E. plantagineum was shown to reach the atmosphere in significant amounts about 1 month before the peak grass pollinating period. Evidence that the pollen of E. plantagineum becomes airborne and elicits an IgE response suggests that further attention should be directed to weed pollens as potential allergens.

A three-year-survey of microfungi in the air of Copenhagen 1977-79

The presence and prevalence of common saprophytic airborne microfungi has been studied. Since August 1977 culturable microfungi in the outdoor air of Copenhagen have been monitored. The method used is a volumetric analysis by means of a Biap Slit-Sampler. The microfungal flora was dominated by very few genera, thus Cladosporium, Alternaria, Penicillium and Aspergillus make up 86.8% of the organisms collected. The mere number of microfungal spores might be misleading as a guide to the relative importance of atmospheric allergens. An alternative or a supplementary parameters could be the spore substance expressed as cubic spore substance/m3 of air, as suggested by Hyde (20). Most fungi show a seasonal dependence as well as fluctuations from year to year. The high season for living microfungi is found to be from June until October. The microfungi thus constitute a prolongation of the pollen season, a fact of importance in relation to patients suffering from inhalation-allergy.

Air-borne fungi in the air of Barcelona (Spain). IV. Various isolated genera

During a two-year survey on the air-borne fungi in the atmosphere of Barcelona (Spain), the following genera were isolated in decreasing order: Aureobasidium, Rhizopus, Mucor, Arthrinium, Phoma, Fusarium, Trichoderma, and Botrytis.

Air-borne fungi in the air of Barcelona (Spain). II. The genus alternaria

The genus Alternaria Nees formed one of the more important components of the fungus population of the air at Barcelone (Spain), during a two-year study, from February 1976 through January 1978. Results were based only on studied of colonies obtained by gravity-exposed plates. The occurrence of this genus was greatly affected by climatic conditions. In general. however, Alternaria appeared to prefer warmer weather. A total of six species of Alternaria was identified, of which, Alternaria alternata (Fries) Keissler was by far the commonest, representing 71.3% of all colonies.

Childhood asthma and grass pollen aerobiology in Melbourne

Children from the Melbourne metropolitan area with laboratory proven bronchial sensitivity to ryegrass pollen were selected for a clinical trial which was run concurrently with an aerobiological survey during the grass pollen season of 1975 to 1976. During periods of high pollen counts, significant deterioration in the children's asthma occurred. The grass pollen season was of 10 weeks' duration with the highest daily counts during November and December. Highest diurnal pollen concentrations occurred at night and were associated with winds from the north, north-west, and south-east and with other meteorological factors.

Aerobiological studies based in Derby. I. A simplified automatic volumetric spore trap

A simplified version of the Hirst automatic volumetric spore trap has been developed in Derby for aerobiological studies. In comparative trials, the number of spores retained by the Morrow Brown trap were similar in the case of larger spores such as Alternaria (102%), rather higher in the case of grass pollen (136%) and considerably higher (166--201%) for very small spores such as Sporobolomyces and Tilletiopsis. Impaction efficiency has been improved by using a narrower slit. The trap designed in Derby is simple to produce and presents advantages in design over the Hirst version.

Aerobiological studies based in Derby. III. A comparison of simultaneous pollen and spore counts from the east coast, Midlands and west coast of England and Wales

The air spora of two sites on the east coast of Britain and one on the west coast were compared with each other and with the regular sampling site in Derby by the simultaneous operation of volumetric spore traps. Concentrations of airborne spores and pollen were found to be usually less at the coastal sites than in Derby. The effect of wind direction was shown to be important at coastal sites because daily counts often showed rises and falls corresponding to off- and on-shore winds respectively. Counts at the west coast site were nearly always lower than those on the east. These findings, together with the prevalence of westerly winds over Britain and the different land use in the east and west, suggest that fewer airborne allergens may be encountered on the west coast.

The seasonal symptoms of hyposensitized and untreated hay fever patients in relation to birch pollen counts: correlations with nasal sensitivity, prick tests and RAST

A 2 year prospective study of thirty-eight birch pollen-sensitive hay fever patients under specific immunotherapy and of nineteen untreated control patients showed a significant correlation between the total seasonal symptom scores of the patients and their clinical sensitivities assessed by the RAST and a graded nasal test. The agreement between a positive nasal test and a positive RAST was 74%. In the early season with low pollen counts the onset of symptoms was significantly associated with high sensitivity of the patients, while many patients showed symptoms in the late season irrespective of their nasal and RAST sensitivity. About 90% of both the treated and the untreated patients reported mild symptoms when the pollen count exceeded 80/m(3) in the early season. 80% of them still had symptoms when the count was below 30/m(3) in the late pollen season. Although hyposensitization therapy had no effect on the occurrence of the mild symptoms, the treated patinets had severe symptoms significantly less often than the untreated ones on days with high pollen counts.

Respiratory disease of workers harvesting grain

The incidence of respiratory symptoms caused by grain dust during harvesting was surveyed in a group of Lincolnshire farmers. A quarter complained of respiratory distress after working on combine harvesters or near grain driers and elevators, with cough, wheezing, and breathlessness, sometimes so severe as to prevent work. The airborne dust around combine harvesters contained up to 200 million fungus spores/m3 air with Cladosporium predominant while drivers were exposed to up to 20 million spores/m3 air. Verticillium/Paecilomyces type spores, mostly from Verticillium lecanii, Aphanocladium album, and Paecilomyces bacillosporus, were abundant in the dust. Extracts of these species produced immediate weal reactions in skin tests, precipitin reactions with sera, and rapid decreases in FEV1 when inhaled by affected workers. There was no delayed reactions. Results suggest type I immediate hypersensitivity to the spores although the physical effect of a heavy dust deposit could be important. Drivers could be protected by cabs ventilated with filtered air.