Aerobiologia

Little research has been carried out in London concerning fungal spore prevalence yet this information may help to elucidate geographical patterns of asthma and hay fever. Although many types of spore reach peak concentrations outdoors in late-summer, the incidences in the indoor environment may be more important through the winter because of heating and poor ventilation. Daily average concentrations of fungal spores in the ambient atmosphere were monitored with a Burkard volumetric spore trap on an exposed roof in North London from autumn 1991 until the summer of 1992. Indoor spore measurements were taken in 19 homes in the vicinity through the winter months, both by direct air sampling using a portable Burkard sampler and by dust culture. Trends in the occurrence and concentrations of fungal spores indoors and outdoors were examined. Relationships between the abundance of selected allergenic fungi and features of the houses were analysed including age of dwelling, dampness, cleanliness and presence of pets.Aspergillus andPenicillium were the most frequently occurring spore types in the homes. Overall, high spore incidence was associated with dampness and dust accumulation. The outdoor spore samples revealed generally low concentrations through the winter until March when concentrations of many types includingCladosporium, Epicoccum andAlternaria increased in abundance in response to the warmer weather. Even during the late-spring and early-summer, concentrations of most fungal spores were notably below those reported for rural sites.

While pollen sampling has been standardised in the last decades, allergen extraction from aerobiological samples still needs standardisation. With the aim to identify the most practical, efficient and reproducible method, in this study, protein extraction protocols from Poaceae pollen, i.e. Lolium perenne, Phleum pratense and Dactylis glomerata, were evaluated. Three extraction protocols were selected and compared in terms of protein yield and allergen extraction. The methods were based on the use of: (1) lysis buffer; (2) pollen hydration in PBS buffer followed by sonication; and (3) pollen hydration in PBS buffer. After extraction, protein concentration was measured. Results indicated that the different extraction protocols could extract significantly different protein amounts, being the lysis buffer-based protocol the most efficient in terms of total protein extraction. However, when allergen extraction was compared, no significant differences were detectable among the different protocols. Results afforded the selection of a suitable extraction protocol for Poaceae pollen allergens. In particular, results suggested a PBS extraction followed by sonication; as it allowed the highest allergen extraction, it might be the most reproducible protocol minimising any possible interference with proteomics and immunological studies when compared to lysis buffer method.

The goal of this study was to compare hazel pollen seasons in Sosnowiec in 1997–2019 and to analyse the impact of weather conditions on these seasons. The measurements were conducted using a volumetric method with a Burkard spore trap. The duration of pollen seasons was determined using the 98% method. SPI (Seasonal Pollen Index) was calculated as the sum of daily pollen concentrations in a given season. The measurements showed that high temperatures in January and February had an impact on the beginning of the hazel pollen season. They revealed that there are positive correlations with temperatures and sunshine hours long before the season, i.e. 210–180 days before. The daily hazel pollen concentration in Sosnowiec showed a positive and statistically significant correlation with air temperature, sunshine hours, and average and maximum wind speed. Negative correlation was demonstrated for snow cover depth and relative humidity of the air. Daily concentration levels depend also on the type of weather front as well as direction of air mass flow and its type. Variance analysis showed that the highest concentrations of hazel pollen grains were recorded when warm air moves from the south and south–western direction, whereas the lowest ones were noted for air moving from the east, south–east, north and north–east directions. Atmospheric precipitation, snow cover depth, and average, maximum, minimum and near-the-ground temperatures in the season also had an impact on the SPI of hazel pollen grains. High positive correlation coefficients were also observed in the case of thermal conditions, sunshine hours, relative humidity and precipitation from July to September in the year preceding a given pollen season. The duration of the hazel pollen season depends on precipitation, snow cover depth and temperature during a given season.

Zygophyllum fabago is a herbaceous plant withairborne pollen found widely in the MurciaRegion, in the Southeast of Spain. Although itsallergenicity has been recently reported,little is known of its involvement inpollinosis. Aerobiological study andsensitization in pollinotics weremeasured using a Hirst volumetric trap. Wehave measured the atmospheric concentrationsof this pollen and other allergenicpollen types in our region, between March 1993 andMarch 1997. Z. fabago pollen wascollected for a morphometric study of thepollen grain, and a lyophilized extract wasprepared for skin prick tests. We haveconducted skin tests with different pollen typesfrom our region and with Z. fabago in1736 patients with symptomssuggesting pollinosis. The size of the pollengrain averages 15.17 × 17.35 µm. Thepollination period extends from May to August,with a mean accumulated concentration of 448grains/m3. Out of 1736 pollinotics,263 (15.15%) showed a positive skin test forZ. fabago, 6 were monosensitized and 257were sensitized to other common pollen types fromour Region. Specific IgE to Z. fabago wasequal or higher than 0.35 ku/l in 86.56% ofsensitized patients. Chenopodiaceae pollinateduring spring and autumn and sensitize a largernumber of patients; Urticaceae reach thehighest pollen concentrations for a longerperiod but are not the primary cause ofpollinosis. This study shows that Z. fabagopollen becomes airborne, elicits an IgEresponse and, like other pollens, contributestowards triggering allergic symptoms.It should therefore be considered arelevant allergen and accordingly beincluded in skin test procedures.

In the last few years Ostrya carpinifolia pollen is consideredas an important cause of respiratoryallergy in Mediterranean areas. The concentration ofthe pollen was measured over a period of fifteen yearsfrom 1981 to 1996 in an area around Genoa; the resultsof this study have clearly indicated an increasingtrend that correlate with persons sensitization. In this study we sought to define the immunochemical andbiochemical properties of hop-hornbean pollen. Soluble proteins extracted from Ostryacarpinifolia pollen and from the taxonomicallyrelated species Corylus Avellana, were analyzedby polyacrylamide gel electrophoresis (SDS-PAGE), byhorizontal isoelectrofocusing (IEF) and by twodimensions electrophoresis (2D-PAGE). Allergenicproteins were identified with sera of sensibilizedpatients and cross-reactivity was evaluated byimmunoblotting techniques. The electrophoreticanalysis showed a partial identity between theproteins from Ostrya and Corylus extracts. The immunoblotting assay, developed withhuman IgE from subjects allergic to hop-hornbeampollen, displayed the major IgE reactivity for acomponent with a molecular weight of 17 kDa expressedin both Ostrya and Corylus extracts. This reactivity is consistent with the presence ofBet v 1 that is described as the major pollen allergenin the Betulaceae and Corylaceae families. Sera fromsubjects allergic to Ostrya were then preadsorbed with recombinant Bet v 1 immobilized in the Pharmacia CAP System; a significant reduction ofthe IgE binding activity was observed after thetreatment. We therefore suggest that Bet v 1 couldbe one of the allergenic proteins present in theOstrya pollen possibly being responsible forcross-reactivity with other members of taxonomicallyrelated families.

Exposure to airborne microorganisms in indoor environments may result in infectious disease or elicit an allergic or irritant response. Air handling system components contaminated by fungi have been implicated in the dispersal of spores into the indoor environment, thereby serving as a route of exposure to occupants. This study was conducted to provide quantitative data on the dispersal of spores from fungal colonies growing on three types of duct material. Galvanized metal, rigid fibrous glass ductboard, and fiberglass duct liner were soiled and contaminated with a known concentration of Penicillium chrysogenum spores. The duct materials were incubated in humidity chambers to provide a matrix of growing, sporulating fungal colonies at a contamination level of 109 colony forming units (CFU) per duct section, consistent for all materials. For each experiment a contaminated duct section was inserted into the air handling system of an experimental room, and the air handling system was operated for three 5-minute cycles with an air flow of 4.2 m3 min−1. The duct air velocity was approximately 2.8 m sec−1. The airborne concentration of culturable P. chrysogenum spores (CFU m−3), total P. chrysogenum spores (spores m−3), and total P. chrysogenum-sized particles (particles m−3) were measured in the room using Andersen single-stage impactor samplers, Burkard slide impactor samplers, and an aerodynamic particle sizer, respectively. The highest airborne concentrations (104 CFU m−3; 105 spores m−3; 104 particles m−3) were measured during the first operating cycle of the air handling system for all duct materials with decreasing airborne concentrations measured during the second and third cycles. There was no significant difference in spore dispersal from the three contaminated duct materials. These data demonstrate the potential exposure for building occupants to high concentrations of spores dispersed from fungal colonies on air handling system duct materials during normal operation of the system.