Short-Term Effect of Pollen and Spore Exposure on Allergy Morbidity in the Brussels-Capital Region

Belgium is among the European countries that are the most affected by allergic rhinitis. Pollen grains and fungal spores represent important triggers of symptoms. However, few studies have investigated their real link with disease morbidity over several years. Based on aeroallergen counts and health insurance datasets, the relationship between daily changes in pollen, fungal spore concentrations and daily changes in reimbursable systemic antihistamine sales has been investigated between 2005 and 2011 in the Brussels-Capital Region. A Generalized Linear Model was used and adjusted for air pollution, meteorological conditions, flu, seasonal component and day of the week. We observed an augmentation in drug sales despite no significant increase in allergen levels in the long term. The relative risk of buying allergy medications associated with an interquartile augmentation in pollen distributions increased significantly for Poaceae, Betula, Carpinus, Fraxinus and Quercus. Poaceae affected the widest age group and led to the highest increase of risk which reached 1.13 (95% CI [1.11–1.14]) among the 19- to 39-year-old men. Betula showed the second most consistent relationship across age groups. Clear identification of the provoking agents may improve disease management by customizing prevention programmes. This work also opens several research perspectives related to impact of climate modification or subpopulation sensitivity.     

The dispersion characteristics of airborne pollen in the Shijiazhuang (China) urban area and its relationship with meteorological factors

In this study, a Tauber pollen trap was used in the urban area of Shijiazhuang to monitor continuously the outdoor air pollen from 2007 to 2011. The trap was emptied at regular intervals (typically 15 days). The results show that airborne pollen assemblages are generally similar each year among 2007–2011 and are responsive to the flowering times of plants, being dominated by pollen from woody plants in the spring and by pollen from herbaceous plants in summer and autumn. Two peak pollen influx periods, especially for the main allergenic pollen taxa, are seen, one between early March to early June and a second between late August to early October. During the four seasons, the main pollen taxa are Juglans, Artemisia, Platanus, Populus, Chenopodiaceae, Urtica + Humulus, Rosaceae, Pinus, Poaceae, Cereals, Quercus, and Betula, and all taxa other than Rosaceae were confirmed by relevant studies to be allergenic pollen taxa. RDA analysis of pollen influx and meteorological factors shows that in spring, temperature and humidity have significant effects on the pollen influx of woody plants; in summer, humidity and precipitation have significant negative effects on pollen influx of herbaceous plants; in autumn, temperature, water vapor pressure, and precipitation have a significant positive influence on herbaceous pollen influx; in winter, there were no significant correlations between airborne pollen influx and meteorological factors. The results reveal the dispersion patterns of airborne pollen and provide an important reference to appropriate construction of urban green systems and the reliable reduction in regional pollinosis.     

Late Glacial and Holocene history of Plešné Lake and its surrounding landscape based on pollen and palaeoalgological analyses

Pollen analysis has been carried out on a 549 cm thick sediment profile from lake Ple?né jezero (Ple?né Lake) in the Bohemian Forest (?umava, Czech Republic; 1090 m a.s.l.; 48°47′ N; 13°52′ E). Analyses of 67 samples characterise the development of the lake biotope and the surrounding landscape during the last ca. 14,000 years. The pollen diagram shows a very distinct transition between the Late Glacial and the Holocene biostratigraphic units at a depth of ca. 312 cm. In the surroundings of Ple?né Lake the vegetation was treeless during the entire Late Glacial. The alpine tree limit, formed by Betula and Pinus with undergrowth of shrubs, might have been at ca. 500 m a.s.l. Pollen transported from long distances was significant due to the openness of the landscape, coming from southern Europe and even Africa, and including high numbers of Artemisia, Poaceae, Chenopodiaceae, and some other herbs and shrubs from steppe and forest-steppe areas in southern Europe or Africa (likely Ephedra, certainly Lygeum spartum). The expansion of shrubs, particularly Juniperus, preceded the expansion of trees near the end of the Late Glacial. Afforestation of the region by thin stands of Betula and Pinus occurred during the Preboreal. Significant warming in the Boreal resulted in the expansion of Corylus, Quercetum mixtum (QM) trees, and probably also Picea and Alnus. Picea as well as QM trees were further expanding during the Early Atlantic. Picea was the dominant tree during the Late Atlantic and Fagus started to spread towards its end. Abrupt expansion of Abies marks the Subboreal. A high degree of afforestation (Abies, Fagus, Picea) was characteristic for the Early Subatlantic. During Late Subatlantic, pollen of synanthropic plants appears. Phases of the lake biotope development were defined on the basis of coccal green algae and Isoëtes.     

Pollen diversity in the atmosphere of Havana,Cuba

With a view to obtaining fuller information on airborne pollen content in the city of Havana, pollen sampling was carried out using a volumetric capture method, for the first time in Cuba. The study was conducted during 2 years (2011 and 2015). An annual pollen integral of 3414 grains was registered during the first year of study, whereas 5120 grains were observed along the 2015. Monthly maximum concentrations were recorded during April, June and July with total values close to 800 pollen grains. Of the 45 pollen types identified, Cecropia (38% of the total pollen identified in both years), Poaceae (18%), Urera type (9%) and Casuarina (6%) were particularly abundant. Although the main pollen types differed in terms of intradiurnal distribution, the highest concentrations were in all cases recorded between 0900 and 1300 hours. Maximum temperature was the variable most influencing airborne pollen counts in the air, with the exception of Casuarina. This paper sought to establish a methodological basis for the further development of aerobiological research in Cuba, thus helping to enhance the prevention and diagnosis of pollen allergies in the affected island population.     

Modern pollen assemblages from human-influenced vegetation in northwestern China and their relationship with vegetation and climate

Modern pollen spectra can improve the interpretation of fossil pollen records used to reconstruct past vegetation, climate and human impacts. It is important, therefore, to carefully examine the relationships between modern pollen spectra, vegetation, climate and human activity. Here, we present the results of an analysis of the pollen spectra of 143 surface pollen samples from farmland, wasteland, desert, steppe/meadow, forest and river valley along a transect from Lanzhou to Urumqi, in northwestern China. The modern pollen assemblages are mainly composed of Amaranthaceae, Artemisia, Poaceae, Asteraceae, Ephedra and Nitraria. The results indicate that in general the surface pollen assemblages of different vegetation types reliably represent the modern vegetation in terms of the composition of the main taxa and the dominant types. Farmland is dominated by cereal-type (≥?15%) and Amaranthaceae (≥?20%), while the pollen assemblages of wasteland (i.e. the vegetation immediately surrounding farmland) are mainly composed of Amaranthaceae (≥?25%), Artemisia (≥?20%), Poaceae (≥?10%), Asteraceae (≥?5%) and Cyperaceae (≥?5%). Amaranthaceae (≥?45%) and Ephedra (≥?10%) are the most important taxa in desert, and Cyperaceae (≥?35%) and Thalictrum (≥?2%) are the dominant pollen types in steppe/meadow. Forest and river valley samples are characterized by high frequencies of Picea (≥?10%) and Cyperaceae (≥?20%). Both constrained and partial canonical ordination techniques (RDA and partial RDA) of the main pollen types and environmental variables show that the modern pollen spectra are primarily controlled by mean annual precipitation (MAP). Cyperaceae, Thalictrum and Brassicaceae are positively correlated with MAP and negatively correlated with mean July temperature (T_July), while the representation of certain other types, such as Amaranthaceae, Ephedra and Nitraria, is negatively correlated with MAP and positively correlated with T_July. The Human Influence Index (HII) is significantly correlated with cereal-type pollen, and it can also differentiate human-influenced and natural vegetation. Our results provide a basis for improving the interpretation of fossil pollen records from arid northwestern China and similar regions.     

Flowering phenology and potential pollen emission of three <Emphasis Type="Italic">Artemisia</Emphasis> species in relation to airborne pollen data in Poznań (Western Poland)

Artemisia pollen is an important allergen in Europe. In Poznań (Western Poland), three Artemisia species, A. vulgaris, A. campestris and A. absinthium, are widely distributed. However, the contributions of these species to the total airborne pollen are unknown. The aim of the study was to determine the flowering phenology and pollen production of the three abovementioned species and to construct a model of potential Artemisia pollen emission in the study area. Phenological observations were conducted in 2012 at six sites in Poznań using a BBCH phenological scale. Pollen production was estimated by counting the pollen grains per flower and recalculating the totals per inflorescence, plant and population in the study area. Airborne pollen concentrations were obtained using a Hirst-type volumetric trap located in the study area. Artemisia vulgaris began to flower the earliest, followed by A. absinthium and then A. campestris. The flowering of A. vulgaris corresponded to the first peak in the airborne pollen level, and the flowering of A. campestris coincided with the second pollen peak. The highest amounts of pollen per single plant were produced by A. vulgaris and A. absinthium. A. campestris produced considerably less pollen, however, due to its common occurrence, it contributed markedly (30 %) to the summation of total of recorded pollen. A. vulgaris is the most important pollen source in Poznań, but the roles of two other Artemisia species cannot be ignored. In particular, A. campestris should be considered as an important pollen contributor and likely might be one of the main causes of allergic reactions during late summer.     

Spatiotemporal models for predicting high pollen concentration level of Corylus,Alnus, and Betula

Corylus, Alnus, and Betula trees are among the most important sources of allergic pollen in the temperate zone of the Northern Hemisphere and have a large impact on the quality of life and productivity of allergy sufferers. Therefore, it is important to predict high pollen concentrations, both in time and space. The aim of this study was to create and evaluate spatiotemporal models for predicting high Corylus, Alnus, and Betula pollen concentration levels, based on gridded meteorological data. Aerobiological monitoring was carried out in 11 cities in Poland and gathered, depending on the site, between 2 and 16 years of measurements. According to the first allergy symptoms during exposure, a high pollen count level was established for each taxon. An optimizing probability threshold technique was used for mitigation of the problem of imbalance in the pollen concentration levels. For each taxon, the model was built using a random forest method. The study revealed the possibility of moderately reliable prediction of Corylus and highly reliable prediction of Alnus and Betula high pollen concentration levels, using preprocessed gridded meteorological data. Cumulative growing degree days and potential evaporation proved to be two of the most important predictor variables in the models. The final models predicted not only for single locations but also for continuous areas. Furthermore, the proposed modeling framework could be used to predict high pollen concentrations of Corylus, Alnus, Betula, and other taxa, and in other countries.     

<Emphasis Type="Italic">Cannabis</Emphasis> is indigenous to Europe and cultivation began during the Copper or Bronze age: a probabilistic synthesis of fossil pollen studies

Conventional wisdom states Cannabis sativa originated in Asia and its dispersal to Europe depended upon human transport. Various Neolithic or Bronze age groups have been named as pioneer cultivators. These theses were tested by examining fossil pollen studies (FPSs), obtained from the European Pollen Database. Many FPSs report Cannabis or Humulus (C/H) with collective names (e.g. Cannabis/Humulus or Cannabaceae). To dissect these aggregate data, we used ecological proxies to differentiate C/H pollen, as follows: unknown C/H pollen that appeared in a pollen assemblage suggestive of steppe (Poaceae, Artemisia, Chenopodiaceae) we interpreted as wild-type Cannabis. C/H pollen in a mesophytic forest assemblage (Alnus, Salix, Populus) we interpreted as Humulus. C/H pollen curves that upsurged and appeared de novo alongside crop pollen grains we interpreted as cultivated hemp. FPSs were mapped and compared to the territories of archaeological cultures. We analysed 479 FPSs from the Holocene/Late Glacial, plus 36 FPSs from older strata. The results showed C/H pollen consistent with wild-type C. sativa in steppe and dry tundra landscapes throughout Europe during the early Holocene, Late Glacial, and previous glaciations. During the warm and wet Holocene Climactic Optimum, forests replaced steppe, and Humulus dominated. Cannabis retreated to steppe refugia. C/H pollen consistent with cultivated hemp first appeared in the Pontic-Caspian steppe refugium. GIS mapping linked cultivation with the Copper age Varna/Gumelni?a culture, and the Bronze age Yamnaya and Terramara cultures. An Iron age steppe culture, the Scythians, likely introduced hemp cultivation to Celtic and Proto-Slavic cultures.     

First aerobiological study in Mediterranean part of Croatia (Dalmatia): pollen spectrum and seasonal dynamics in the air of Split

The aim of this study was to investigate aerobiological dynamics of pollen in the Mediterranean part of Croatia in the air of the city of Split. Pollen monitoring during the period from 2005 to 2013 was performed using a Hirst volumetric trap. Among the identified pollen of 50 taxa, 21 were allergenic. The average annual pollen index was 33,513. Three pollination seasons were established: early winter season dominated by tree pollen, spring–summer season dominated by herbaceous plants and summer–autumn season with lower amounts of Parietaria and Cupressaceae pollen. According to the abundance, the main taxa were: Cupressaceae, Parietaria/Urtica, Pinus, Quercus, Olea, Carpinus/Ostrya, Poaceae, Platanus and Ambrosia. The annual pollen index together with the daily maximum concentrations showed an upward trend for selected taxa during the study period. The highest monthly pollen index and the highest biodiversity were recorded in April and the lowest during the late autumn and winter months. The pollen calendar created for the city of Split confirmed Mediterranean features of the pollen spectrum. The longest pollen seasons were recorded for Cupressaceae, Parietaria/Urtica and Poaceae pollen types. The correlations between pollen concentrations and meteorological parameters were analyzed. The correlations between pollen concentrations and temperature were positive, while the humidity and the precipitation mostly showed negative influence.     

Source areas and long-range transport of pollen from continental land to Tenerife (Canary Islands)

The Canary Islands, due to their geographical position, constitute an adequate site for the study of long-range pollen transport from the surrounding land masses. In this study, we analyzed airborne pollen counts at two sites: Santa Cruz de Tenerife (SCO), at sea level corresponding to the marine boundary layer (MBL), and Izaña at 2,367 m.a.s.l. corresponding to the free troposphere (FT), for the years 2006 and 2007. We used three approaches to describe pollen transport: (1) a classification of provenances with an ANOVA test to describe pollen count differences between sectors; (2) a study of special events of high pollen concentrations, taking into consideration the corresponding meteorological synoptic pattern responsible for transport and back trajectories; and (3) a source–receptor model applied to a selection of the pollen taxa to show pollen source areas. Our results indicate several extra-regional pollen transport episodes to Tenerife. The main provenances were: (1) the Mediterranean region, especially the southern Iberian Peninsula and Morocco, through the trade winds in the MBL. These episodes were characterized by the presence of pollen from trees (Casuarina, Olea, Quercus perennial and deciduous types) mixed with pollen from herbs (Artemisia, Chenopodiaceae/Amaranthaceae and Poaceae wild type). (2) The Saharan sector, through transport at the MBL level carrying pollen principally from herbs (Chenopodiaceae-Amaranthaceae, Cyperaceae and Poaceae wild type) and, in one case, Casuarina pollen, uplifted to the free troposphere. And (3) the Sahel, characterized by low pollen concentrations of Arecaceae, Chenopodiaceae-Amaranthaceae, Cyperaceae and Poaceae wild type in sporadic episodes. This research shows that sporadic events of long-range pollen transport need to be taken into consideration in Tenerife as possible responsible agents in respiratory allergy episodes. In particular, it is estimated that 89–97% of annual counts of the highly allergenous Olea originates from extra-regional sources in southern Iberia and northern Africa.     

Airborne pollen in the El-Hadjar town (Algeria NE)

The diversity of airborne pollen grains in El-Hadjar town (northeast Algeria) was measured for 1 year, from July 1, 2012 to June 30, 2013, by means of the gravimetric method using Durham apparatus. The total number of pollen grains/cm² was calculated from slides that were changed daily. This aerobiological study documented the air concentration of pollen from 50 taxa, where 28 belonged to arboreal and 22 to non-arboreal taxa. The percentage of pollen from arboreal and non-arboreal taxa was 56 and 44 %, respectively. From the list, the major collected taxa causing allergy in humans dominant in the Mediterranean area were Cupressaceae (14.86 %), Olea sp. (7.18 %), Casuarina sp. (6.44 %), and Fraxinus sp. (3.83 %) among arboreal plants, whereas for the non-arboreal plants Poaceae (23.20 %), Mercurialis sp. (12.58 %), Plantago sp. (1.69 %), Urticaceae (0.95 %), and Chenopodiaceae (0.85 %). The highest pollen counts occurred in the period from February to April. The pollen calendar for the region presented in this paper may be a useful tool for allergologists and botanical awareness.     

Forecasting model of <Emphasis Type="Italic">Corylus</Emphasis>, <Emphasis Type="Italic">Alnus</Emphasis>, and <Emphasis Type="Italic">Betula</Emphasis> pollen concentration levels using spatiotemporal correlation properties of pollen count

The aim of the study was to create and evaluate models for predicting high levels of daily pollen concentration of Corylus, Alnus, and Betula using a spatiotemporal correlation of pollen count. For each taxon, a high pollen count level was established according to the first allergy symptoms during exposure. The dataset was divided into a training set and a test set, using a stratified random split. For each taxon and city, the model was built using a random forest method. Corylus models performed poorly. However, the study revealed the possibility of predicting with substantial accuracy the occurrence of days with high pollen concentrations of Alnus and Betula using past pollen count data from monitoring sites. These results can be used for building (1) simpler models, which require data only from aerobiological monitoring sites, and (2) combined meteorological and aerobiological models for predicting high levels of pollen concentration.     

Indoor and outdoor pollen concentrations in private and public spaces during the <Emphasis Type="Italic">Betula</Emphasis> pollen season

Although the number of studies of pollen concentrations inside and outside buildings is increasing, little is known about the efficiency of penetration of pollen from outdoor to indoor air, and further. We studied indoor and outdoor pollen concentrations in the town of Lappeenranta and in the municipality of Rautjärvi in SE Finland from May 3–23, 2004, i.e. throughout the Betula pollen season, and assessed the risk of exposure to pollen grains. Pollen concentrations were measured inside and outside a block of flats, a detached house, and the regional central hospital, using rotorod-type samplers; in the town of Joutseno data were compared with Burkard counts. Outdoor concentrations of Betula pollen grains ranged between low and abundant (0–855 grains m^?3). The corresponding indoor concentrations near the main front doors varied from low to moderate (0–17 grains m^?3) in the central hospital and were low (<10 grains m^?3) in both residential buildings. Indoor concentrations further from the main front door were low (<10 grains m^?3) at all study sites. The concentrations of Betula pollen decreased substantially from outdoors to indoors, and further toward the centre of the building, probably indicating relatively poor penetrating properties of the pollen grains and/or the short-lived presence of pollen grains in indoor air. The concentrations of Betula pollen inside the buildings during the peak flowering period were mostly at a level barely inducing reactions even in the most sensitive persons.     

Late-glacial vegetational history of Lake Kremensko-5 in the northern Pirin Mountains,southwestern Bulgaria

The core of Lake Kremensko-5, one of the cirque lakes in the northern Pirin Mountains of southwestern Bulgaria, contains sediments from more than 13,500 years b.p. and a pollen stratigraphy that can be correlated with the interstadial/stadial cycle of the Late-glacial period. Artemisia and Chenopodiaceae predominate in the basal part of the sequence, indicating the presence of mountain steppe type vegetation soon after the ice retreat. A sharp increase of Pinus diploxylon-type and Poaceae after 12,360 b.p. is followed by a return of Artemisia and Chenopodiaceae, marking the Younger Dryas. Its abrupt termination must result from an unconformity, for high values of Quercetum mixtum, dated at other sites in the Pirin Mountains as early Holocene, are missing here, perhaps because of erosion at a time of low lake level related to the high insolation maximum during the early Holocene.     

The impact of Sharav weather conditions on airborne pollen in Jerusalem and Tel Aviv (Israel)

Pollen grains have been a major focus of research mostly in temperate regions due to their effects on human health, especially allergies and asthma. The current study investigates a subtropical region characterized by a Mediterranean climate where Sharav conditions are experienced during the spring and autumn. The aim of the current study was to investigate whether Sharav conditions impacted airborne pollen concentrations of allergenic Amaranthaceae, Poaceae, Morus, Pinus, and Quercus more than standard Warm days during the main pollen seasons in the years 2010–2014 in Tel Aviv and Jerusalem (Israel). Slight variation was observed between the main pollen seasons in Tel Aviv compared to Jerusalem resulting from differences in temperature and relative humidity percentages. Additionally, more Sharav conditions occurred in Jerusalem than in Tel Aviv during the study period. The highest pollen concentrations occurred during Sharav days for Amaranthaceae, Poaceae, and Pinus but not for Morus and Quercus. Therefore, individuals who are allergic to Amaranthaceae, Poaceae, and Pinus pollen, and exposed to high pollen concentrations during Sharav days, might suffer more allergy symptoms than on Warm days.     

Pollen analysis of spider web samples from Korba District,Chhattisgarh (central India): an aerobiological aspect

Pollen analyses of spider web samples, collected from the recently planted Tectona grandis (T. grandis, teak)-dominated tropical deciduous forest of Bhulsidih Village, Korba District (Chhattisgarh, central India), shed light on the relationship between the extant vegetation and pollen rain. The study revealed the dominance of pollen of herbs and trees, whereas shrubs, fern spores and algal remains are meagre. Among the tree taxa, Sapotaceae, Syzygium, Holoptelea, Lannea coromandelica, Shorea robusta and Grewia are dominating with moderate to low and intermittent presence of Madhuca indica, Terminalia, Mitragyna, Schleichera, Anacardiaceae, Diospyros, Emblica officinalis and Flacourtia. However, the rest of the forest constituents are either not represented at all despite their presence in the floristics, which could be attributed to their low pollen productivity owing to entomophily as well as their poor pollen preservation pattern. On the other hand, the ground vegetation is represented by the very high frequency of grasses (Poaceae) along with Tubuliflorae, Chenopodiaceae/Amaranthaceae and Cerealia, however, Artemisia, Xanthium, Malvaceae, Caryophyllaceae and Justicia in moderate to lower values. Ferns, which occur abundantly along the adjoining stream banks, are marked by the sporadic retrieval of trilete spores that could be ascribed to the prevailing damp condition around the sampling provenance. The study, in addition to understanding the pollen–vegetation relationship, could also be helpful in aerobiological study, especially in assessing the allergenicity of various pollen grains/spores in the area of investigation, causing bronchial asthma, hay fever (allergic rhinitis/pollinosis), naso-bronchial allergy and other respiratory disorders along with conjunctivitis, contact dermatitis, eczema, food allergies and other health disorders.     

Pollen-monitoring: between analyst proficiency testing

This study presents the results of a Europe-wide training and Quality Control (QC) exercise carried out within the framework of the European Aerobiology Society’s QC Working Group and European COST Action FA1203 entitled “sustainable management of Ambrosia artemisiifolia in Europe (SMARTER)” with the aim of ensuring that pollen counters in Europe are confident in the identification of Ambrosia pollen grains. A total of 69 analysts from 20 countries examined a test slide by light microscopy, which contained Ambrosia pollen and pollen from other Asteraceae that could be recorded in the atmosphere at the same time of year (i.e. Artemisia, Iva, and Xanthium). Daily average pollen concentrations produced by individual participants were compared with the assigned value and the bias was measured by z-score. Both the assigned value and standard deviation for proficiency testing were calculated following the consensus value principle (ISO13528:2005) from the results reported by all the participants in the test. It took a total of 531 days from when the exercise commenced until all 69 analysts reported their results. The most outliers were reported for Artemisia pollen concentrations followed by Xanthium and Iva. The poor results for Artemisia and Xanthium were probably caused by low concentrations on the test slide leading to larger bias due to the unequal distribution of pollen over the microscope slide. Participants performed the best in identifying and quantifying Ambrosia pollen. Performing inter-laboratory ring tests with the same sample is very time consuming and might not be appropriate for large-scale proficiency testing in aerobiology. Pollen with similar morphology should be included in the education process of aerobiologists.     

An aeropalynological survey in the city of Van,a high altitudinal region,East Anatolia-Turkey

Pollen concentrations in the atmosphere of Van city has been monitored for two consecutive years (2010–2011). This was the first detailed aeropalynological study for the elevated East Anatolia Region of Turkey. The sampling was performed by Hirst-type volumetric sampler, and pollen grains of 35 taxa were identified. The main pollen producers of the pollen flora were recorded as: Poaceae (20.94 %), Cupressaceae (10.53 %), Fraxinus (8.56 %), Chenopodiaceae/Amaranthaceae (7.77 %), Populus (7.75 %), Quercus (6.70 %), Platanus (6.68 %), Morus (5.57 %), Plantago (3.03 %). The pollen spectrum reflected the floristic diversity of the region, and the highest pollen concentration was recorded in April. There were a great percentage of allergenic taxa found in the city atmosphere, otherwise many of them scored under threshold values for risk of pollinosis. Statistical analyses were performed for correlating daily pollen concentrations of dominated pollen types concurrent with the data of meteorological parameters in MPS periods and number of significant correlations found. In addition, comparing 2-year data in terms of pollen concentrations and meteorological factors in MPS durations, many variables were found explanatory and concordant with the data. MPS starting dates of many plant taxa were found nearly a month later compared with western sites and lower altitudes of the country as well as Mediterranean countries; this case is mostly thought the ecological factors of the study area which directly affects the plant growth about the timing.     

Aeropalynological study of two selected locations in North-Central Nigeria

Pollen and spores have been found as major biological sources of morbidity among individuals sensitive to respiratory disorders. The aim of the present study was to analyse the deposition rate of atmospheric pollen and fern spores at selected sites in Benue and Plateau states of the North-Central Nigeria between July 2015 and June 2016. This was accomplished by: (1) determining the pollen and fern spore content of each monitoring station; (2) establishing the relationship between total pollen count and meteorological parameters; and (3) comparing the recovered airborne pollen spectra with identified plants in the surrounding vegetation types of the sampling sites. The collection of atmospheric pollen was done using a modified Tauber sampler and plants in the surrounding environment of the sampling sites were enumerated. The residual solution was collected monthly and acetolysed, after which slide preparation and microscopy of the treated residue were done. Meteorological data were obtained from the Nigerian Meteorological Agency, Lagos. The results obtained reveal seasonal distribution patterns of various airborne pollen grains in the study locations. The most abundant pollen types recovered in Plateau State were produced by Syzygium guineense, Tridax procumbens, Alchornea sp., Terminalia sp., Poaceae and Amaranthaceae. Pollen types of Casuarina equisetifolia, Syzygium guineense, Tridax procumbens, Poaceae and Cyperaceae were preponderant in Benue State. Pteris sp., Nephrolepis sp. and a trilete fern spore were also represented in this study. The recovered airborne pollen spectra correspond favourably with some identified plants in the study locations. There was no significant correlation between monthly total pollen count and mean monthly values of meteorological parameters in Benue State. Air temperature and wind speed correlated significantly with monthly total pollen count in Plateau State. It is suggested that the allergenic effect of these abundant pollen types on humans should be further examined.     

Dead Sea medical tourism: an allergological point of view

A 1-year study was conducted, with the aim to investigate the airborne allergens around the Dead Sea (DS), identify and quantify airborne pollen and spores in the DS region, and determine the different sensitization prevalence among various population groups to these aeroallergens. According to results, we also aimed to define “safe seasons” when there are no or only few aeroallergens in the atmosphere that surrounds the Dead Sea. A Rotorod and a Hirst trap were used for continuous monitoring of pollen and spores which were then identified. Sensitization to aeroallergens was assessed by skin prick tests (SPT) in three groups of allergic residents: foreign tourists, Israeli tourists, and local workers from the hotel industry. Air around the DS is by no means free of aeroallergens, 50 pollen and 43 mold types were identified. Pollen was from native plants, imported ornamentals, and others transported by winds from long distances. Overall pollen concentrations were lower around the Dead Sea than in the Tel Aviv region, but in certain months, they were higher around the DS. Marked seasonal variations in pollen and spore dispersal were observed. By SPT, hypersensitivity to Chenopodiaceae, Amaranthaceae, Cupressus, Solidago, Poaceae, Olea, Artemisia as well as molds such as Alternaria and Aspergillus, was found. As assessed by SPT, some of tourists and permanent residents are allergic to pollen, molds, and house dust mites. The presented study enables one to denote “safe” seasons when the concentration of airborne allergens is below “allergenic risk”: June–August and November–February. These seasons are the most suitable for allergic medical tourists.