A new method for determining the sources of airborne particles.

Air quality is a major issue for humans owing to the fact that the content of particles in the atmosphere has multiple implications for life quality, ecosystem dynamics and environment. Scientists are therefore particularly interested in discovering the origin of airborne particles. A new method has been developed to model the relationship between the emission surface and the total amount of airborne particles at a given distance, employing olive pollen and olive groves as examples. A third-degree polynomial relationship between the air particles at a particular point and the distance from the source was observed, signifying that the nearest area to a point is not that which is most correlated with its air features. This work allows the origin of airborne particles to be discovered and could be implemented in different disciplines related to atmospheric aerosol, thus providing a new approach with which to discover the dynamics of airborne particles.

Airborne study of grass allergen (Lol p 1) in different-sized particles.

BACKGROUND: The Poaceae family is considered one of the main causes of pollen allergy in industrialized countries. The aim of this study is to establish the dynamics of the Poaceae allergens and determine their distribution in the different-sized particles in the atmosphere. METHODS: The air of Granada (southern Spain) was sampled during the pollination period of Poaceae using a cascade impactor and a Hirst-type volumetric collector simultaneously. The sampled airborne allergens were analyzed by indirect ELISA and field emission scanning electron microscopy. Airborne pollen was evaluated with the Spanish Aerobiological Network methodology. RESULTS: Poaceae pollen and allergenic activity have parallel dynamics during the period of maximum pollination, which is reflected in the positive correlations between the 2 variables. In addition, the highest Lol p 1 concentrations were recorded in particle sizes lower than 3.3 mum (stage 4-F). The Spearman correlation test showed that airborne allergens are not dependent on meteorological factors, such as humidity, wind direction or sunshine, however, Lol p 1 allergen correlated positively with Poaceae pollen. CONCLUSIONS: The results of the present study confirm that the Lol p 1 allergen is detected more frequently with pollutants than with coarse particles with similar dynamics and a positive correlation between airborne pollen and aeroallergens. Moreover, Lol p 1 is released in stable weather conditions without large changes in humidity or temperature.

Aerobiological and allergenic analysis of cupressaceae pollen in Granada (Southern Spain).

Cupressaceae pollen has been cited in recent years as one of the major airborne allergens of the Mediterranean region, prompting us to conduct an exhaustive analysis on the aerobiological behaviour of this pollen in the Iberian Peninsula and the repercussion that it has had on the atopic population. The aerobiological study, performed from 1996 to 2003 in the city of Granada (S. Spain), used a volumetric Hirst collector. The results indicate that this pollen is present in the air most of the year, registering a high incidence during the winter months. This type of pollen behaved irregularly in the air, fluctuating yearly, seasonally, and within the same day. Temperature and humidity were the parameters that most directly influence the variability of this allergen, while rainfall prior to flowering increased pollen production. The predictive models used estimated a high percentage of the levels reached over the short term by this pollen in the atmosphere of Granada. The clinical study performed with atopic patients showed that some 30% of the population with pollinosis are sensitive to Cupressaceae pollen, affecting people of both genders equally. On the other hand, the most sensitive age group was 21-40 years of age, while children and the elderly registered almost negligible values. Most of the sensitive subjects resided within the city or in the metropolitan area, where environmental pollution reached high levels, while the pathology was found to be less frequent in rural zones. The most frequent symptoms were upper-respiratory ailments and an asthmatic profile.

Modeling olive pollen intensity in the Mediterranean region through analysis of emission sources.

Aerobiological monitoring of Olea europaea L. is of great interest in the Mediterranean basin because olive pollen is one of the most represented pollen types of the airborne spectrum for the Mediterranean region, and olive pollen is considered one of the major cause of pollinosis in this region. The main aim of this study was to develop an airborne-pollen map based on the Pollen Index across a 4-year period (2008-2011), to provide a continuous geographic map for pollen intensity that will have practical applications from the agronomical and allergological points of view. For this purpose, the main predictor variable was an index based on the distribution and abundance of potential sources of pollen emission, including intrinsic information about the general atmospheric patterns of pollen dispersal. In addition, meteorological variables were included in the modeling, together with spatial interpolation, to allow the definition of a spatial model of the Pollen Index from the main olive cultivation areas in the Mediterranean region. The results show marked differences with respect to the dispersal patterns associated to the altitudinal gradient. The findings indicate that areas located at an altitude above 300ma.s.l. receive greater amounts of olive pollen from shorter-distance pollen sources (maximum influence, 27km) with respect to areas lower than 300ma.s.l. (maximum influence, 59km).

Airborne pollen trends in the Iberian Peninsula.

Airborne pollen monitoring is an effective tool for studying the reproductive phenology of anemophilous plants, an important bioindicator of plant behavior. Recent decades have revealed a trend towards rising airborne pollen concentrations in Europe, attributing these trends to an increase in anthropogenic CO2 emissions and temperature. However, the lack of water availability in southern Europe may prompt a trend towards lower flowering intensity, especially in herbaceous plants. Here we show variations in flowering intensity by analyzing the Annual Pollen Index (API) of 12 anemophilous taxa across 12 locations in the Iberian Peninsula, over the last two decades, and detecting the influence of the North Atlantic Oscillation (NAO). Results revealed differences in the distribution and flowering intensity of anemophilous species. A negative correlation was observed between airborne pollen concentrations and winter averages of the NAO index. This study confirms that changes in rainfall in the Mediterranean region, attributed to climate change, have an important impact on the phenology of plants.

Annual, daily and diurnal variations in pollen from Olea europaea L. in the atmosphere of Granada (Spain).

The allergenic capacity of Olea europaea L. pollen is very important in several cities of the southern Iberian Peninsula, producing most pollinoses diagnosed in these cities. We have carried out a study on the annual, daily and diurnal variations in pollen from O. europaea in the atmosphere of Granada (Spain) during 4 consecutive years. Samplings were carried out with the aid of a Burkard spore trap. Very low levels of Olea pollen grains were first detected in the atmosphere from the end of April. Pollen levels peaked in May and June, and started to decrease from the last days of June and in July. Pollen in the atmosphere is related to meteorological parameters: temperature has a positive influence on pollinization and rainfall produces a negative effect. The diurnal variation pattern of pollen grain concentrations was quite homogeneous throughout the study, featuring an important increase around midday and a moderate decrease in the first hours of the morning and in the late evening.

[Contribution to the aeromycological study in the atmosphere of the city of Granada (South of Spain): seasonal and daily variations.]. / Contribución al estudio aeromicológico de la atmósfera de la ciudad de Granada (S. España): variaciones estacionales e intradiarias.

The seasonal and daily variations in the concentrations of certain fungal spores in the atmosphere of the city of Granada (South of Spain) have been studied. Sampling was carried out in 1994 using a Hirst-type volumetric spore trap. The spores analysed correspond to the genera Alternaria, Cladosporium (Cladosporium cladosporioides and Cladosporium herbarum), Fusarium, Stemphylium and Ustilago. The seasonal-variation data obtained indicate that most of these spores are abundant throughout the year, with the exception of Fusarium, which was only present in trace amounts. The maximum concentrations of Alternaria, Cladosporium and Stemphylium are obtained during two sharp peaks in spring and autumn, with the minimum values being recorded during the summer and winter months; Fusarium and Ustilago spores are most abundant in autumn and winter. Although intradiurnal-variation models vary from one taxon to the next, the highest levels are generally recorded after 12:00 hours, with maximum levels being obtained in the afternoon.

Detection of airborne allergen (Ole e 1) in relation to Olea europaea pollen in S Spain.

BACKGROUND: In recent years, it has been demonstrated that the air carries not only airborne pollen but also plant particles of smaller size that have allergenic activity, and, being within the respirable range, these particles can trigger rapid attacks in the lower respiratory tract. The study of particles according to size (0.7-40 micro m) could provide valuable information on the real allergenic activity in the atmosphere. OBJECTIVE: The purpose of this study was to analyse the dynamics of airborne Olea europaea pollen in contrast to the allergenic activity of Ole e 1 in the atmosphere. METHODS: The analyses were carried out with a Hirst-type volumetric collector and a cascade impactor simultaneously during the MPS of the olive. The indirect ELISA was used to detect the allergenic activity. The sampling was performed in Granada city centre (S Spain), in the Science Faculty building on the University of Granada from 30 April to 26 June 2005. RESULTS AND CONCLUSIONS: This research demonstrates that both the allergenic activity as well as the pollen particles follow in a similar curve, except in periods before or succeeding the main Olea pollen season. The study of the distribution of the allergenic particles according to their sizes reveals that the highest concentrations are between 3.3 and <0.7 micro m, thus indicating that allergenic activity primarily involves paucimicronic particles.

The effect of meteorological factors on the daily variation of airborne fungal spores in Granada (southern Spain).

A study was made of the link between climatic factors and the daily content of certain fungal spores in the atmosphere of the city of Granada in 1994. Sampling was carried out with a Burkard 7-day-recording spore trap. The spores analysed corresponded to the taxa Alternaria, Ustilago and Cladosporium, with two morphologically different spore types in the latter genus, cladosporioides and herbarum. These spores were selected both for their allergenic capacity and for the high level of their presence in the atmosphere, particularly during the spring and autumn. The spores of Cladosporium were the most abundant (93.82% of the total spores identified). The Spearman correlation coefficients between the spore concentrations studied and the meteorological parameters show different indices depending on the taxon being analysed. Alternaria and Cladosporium are significantly correlated with temperature and hours of sunlight, while Ustilago shows positive correlation indices with relative humidity and negative indices with wind speed.