Diurnal patterns of airborne pollen concentration of the selected tree and herb taxa in Gdańsk (northern Poland)

The diurnal variation of airborne pollen concentrations of Alnus, Betula, Pinus, Poaceae, Urtica and Artemisia was examined at the sampling station in Gdańsk, northern Poland. Diurnal patterns of Alnus and Pinus pollen show distinctly lower values and low frequency of diurnal maxima between midnight and late morning and a clear rise of pollen counts at around noon. The rather high values remain during the afternoon and evening. The Betula pollen counts are almost evenly distributed along day and night and diurnal maxima appear in similar frequency at any time of day. Pollen concentrations of Poaceae increase at about 9.00 hours and remain high till late evening. Diurnal patterns of Urtica and Artemisia show very clear variation with high peaks at around 9.00 hours (Artemisia) and 13.00 hours (Urtica). The comparison of the data from Gdańsk with the data from other aerobiological stations shows very similar general features in the diurnal patterns irrespective the region or the local situation.     

Intradiurnal variation of allergenic pollen in the city of Porto (Portugal)

This study reports the hourly distribution of the allergenic airborne pollen types more abundant in the atmosphere of Porto (Portugal) during the studied period. This knowledge will allow an adequacy daily routine for allergic patients during the hours of higher airborne concentrations. The airborne pollen concentration was continuously performed from January 2003 to December 2007 in the city of Porto using a Hirst-type volumetric sampler. Urticaceae, Cupressaceae, Acer spp., and Plantago spp. airborne pollen presented higher concentrations in the morning, while Alnus spp. and Betula spp. pollen were mainly present during the afternoon. Olea europaea and Platanus spp. pollen were regularly distributed along the day, while Poaceae and Pinus spp. pollen presented two diurnal maxima.     

The pollen season dynamics and the relationship among some season parameters (start,end, annual total,season phases) in Kraków,Poland, 1991–2008

The dynamics of 15 taxa pollen seasons in Kraków, in 1991–2008 was monitored using a Burkard volumetric spore trap of the Hirst design. The highest daily pollen concentrations were achieved in the first half of May, and they were caused mainly by Betula and Pinus pollen. The second period of the high concentrations took place from the middle of July to the end of August (mainly Urtica pollen). Tree pollen seasons were shorter (18–24 days) in comparison with the most herbaceous pollen seasons (73–89 days), except at Artemisia and Ambrosia seasons (30 and 24 days, respectively). The season phases (percentyles) of the spring and late-summer taxa were the most variable in the consecutive years. The highest annual sums were noted for Urtica, Poaceae (herbaceous pollen seasons) and for Betula, Pinus, Alnus (tree pollen seasons), and the highest variability of annual totals was stated for Urtica, Populus, Fraxinus and the lowest for Ambrosia, Corylus, Poaceae. For the plants that pollinate in the middle of the pollen season (Quercus, Pinus and Rumex), the date of the season start seems not to be related to the season end, while for late pollen seasons, especially for Ambrosia and Artemisia, the statistically negative correlation between the start and the end season dates was found. Additionally, for the most studied taxa, the increase in annual pollen totals was observed. The presented results could be useful for the allergological practice and general botanical knowledge.     

Airborne pollen sampling in Toledo, Central Spain

Toledo is one of the main tourist spots of Spain, attracting around two million visitors per year. Its geographical situation in the vast and scarcely monitored Region of Castilla La Mancha and the high number of tourists (especially in the spring) has resulted in the Spanish Aerobiology Network (REA) making this city a major study objective. Air monitoring studies carried out using REA sampling procedures commenced in October 2002. Thirty-two pollen types were identified during the sampling period (October 2002 to October 2004). The annual Pollen Index (PI) was 44124 for the agricultural year October 2002–October 2003, and 29666 in the same period of 2003–2004. The most abundant taxa were, in decreasing order of dominance: Cupressaceae, Quercus, Poaceae, Populus, Olea, Urticaceae, Platanus, Pinus and Ulmus. Other, less well-represented pollen taxa included Salix, Alnus, Fraxinus and Tamarix, which were characteristic of riverside areas, and Morus, Artemisia and Chenopodiaceae. The presence of Castanea pollen grains originating from chestnut crops far away from the city was clearly an example of long-distance transport. The highest concentrations of airborne pollen were detected from March to May and also in January, due to the flowering of Cupressaceae species. In general, there was a correlation between pollen and meteorological parameters: a positive correlation with temperature and a negative correlation with rainfall and humidity during the pre-peak period. A negative correlation between temperature and some tree pollen taxa was detected in the principal pollen period correlation analysis due to their long pollination periods.     

Aerobiology of Vigo, North-Western Spain: atmospheric pollen spectrum and annual dynamics of the most important taxa, and their clinical importance for allergy

Vigo is a city located in the northwest of the Iberian Peninsula. Influenced by the Atlantic climate, it is surrounded by a Eurosiberian-type vegetation, modified by the introduction of forestry and ornamental species. Different ruderal vegetation types, resulting from human influence, grow in the area. The study of the pollen content of the air of Vigo started in 1989, with a Cour trap. Average results for the period 1989–1995 are presented in this paper, together with the lowest and highest values found. The representativeness of the mean values is analysed by calculating the coefficient of variation of the data series. Most pollen types in the atmosphere of Vigo are from tree species (54.2%); an important proportion comes from herb species (43.9%) and very few (1.8%) correspond to shrub species. A total of 73 different pollen types have been identified. The most abundant, listed in decreasing order of mean annual values for the period, are:Pinus (25.1%), Poaceae (21.1%), Urticaceae (14.6%),Quercus (8.5%),Castanea (3.7%),Betula (3.6%),Eucalyptus (3.4%),Plantago (3.2%),Alnus (2.1%), Cupressaceae (2.1%), Oleaceae (1.6%;Olea 1.3%),Platanus (1.3%),Rumex (1.3%), Chenopodiaceae/Amaranthaceae (1.0%), Ericaceae (0.8%), Asteraceae (0.6%;Artemisia 0.1% andTaraxacum type 0.2%) andMercurialis (0.5%). A pollen calendar showing the annual dynamics of all these pollen types is presented in this paper. A parallel study of the clinical importance of respiratory allergies in Vigo was also conducted. From a sample of 2750 patients, 87.2% suffered from rhinoconjunctivitis, 26.0% of these due to pollen, and 78.3% from asthma, 17.2% due to pollen. The pollen types responsible for these allergies, listed in decreasing order, are: Poaceae (78%),Parietaria (12%),Chenopodium (11%),Plantago (9%), Oak (4%),Artemisia (3%),Pinus (3%),Eucalyptus (3%),Olea (2%),Platanus (2%),Castanea (2%),Taraxacum (2%),Rumex (2%),Betula (1%),Cupressus (1%) andMercurialis (1%).     

Annual pollen spectrum variations in the air of Bratislava (Slovakia): years 2002–2009

Pollen grains in the atmosphere of Bratislava were quantitatively and qualitatively analysed during an 8-year period (2002–2009) using a Burkard volumetric pollen trap. The mean annual total pollen grain count recorded during this period was 36,608, belonging to 34 higher plant taxa (22 trees and/or shrubs and 12 herbaceous species). The maximum annual total pollen grain count (50,563) was recorded in 2003 and the minimum (14,172) in 2009. The taxa contributing the highest concentration of pollen grains were Betula, Urticaceae, Cupressaceae-Taxaceae, Populus, Pinus, Poaceae and Ambrosia. During the study period, there was a remarkable increase in the number of pollen grains from February to April, with the highest daily mean pollen counts recorded in April. Total pollen concentration began to decrease markedly in May, but there was a second increase between July and August, followed by a decrease in September. The timing and length of the pollen seasons varied. Betula and Poaceae showed a rather constant 2-year fluctuating rhythm. The relationships between airborne pollen concentration and meteorological variables were assessed. Based on these results, the first pollen calendar in Slovakia has been constructed for the area of Bratislava, which provides a great deal of useful and important information.     

Pollen calendar for Vigo, North-West Spain (1995)

This is the first data from a pollen survey in Vigo, an Atlantic city in northwest Spain. The pollen calendar for Vigo is presented, as well as the pollination period for the nine most important allergenic plants. Through 1995, 30 083 pollen grains belonging to 52 taxa, were recorded using the Lanzoni VPPS 2000 volumetric spore-trap. The most relevant taxa found were: Urticaceae,Pinus, Poaceae andQuercus (75% of the total pollen),Betula, Castanea, Cupressaceae, Chenopodiaceae, Ericaceae, Myrtaceae,Olea, Plantago, Platanus andRumex (21%), and the final 4% was distributed mainly among pollen types, such as:Corylus, Alnus, Fabaceae, Compositae,Artemisia andCedrus. Of the total annual pollen count, 56% was found in March and April. Another, secondary peak was recorded in June corresponding to the flowering period of herbaceous species. The high pollen total of Urticaceae (7625 grains, 25% of the total) should be highlighted. The percentages ofOlea europaea (565 grains) should be noted as well, taking into account its geographical distribution.     

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

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

Risk of pollen allergy in Nerja (southern Spain): a pollen calendar

An aeropalynological study was carried out in the atmosphere of the city of Nerja (southern Spain) during a period of 4 years (2000–2003), using a Hirst type volumetric pollen trap. An annual pollen index of 59,750 grains, on average, was obtained with 80–85% of the total pollen recorded from February to May, with Pinus, Olea, Urticaceae, Cupressaceae, Quercus and Poaceae being the principal pollen producers in abundance order. A total of 29 pollen types that reached a 10-day mean equal to or greater than 1 grain of pollen per m³ of air is reflected in a pollen calendar. The results were compared with those obtained for nearby localities and a correlation analysis was made between the daily fluctuations of the main pollen types and total pollen, and meteorological parameters (temperature, rainfall and hours of sun). The daily, monthly and annual values reached by the most important pollen types from an allergenic point of view (Olea, Urticaceae and Poaceae) confirms Nerja as a high-risk locality for the residents and the numerous tourists who visit the area.     

Airborne pollen in Bahía Blanca,Argentina: seasonal distribution of pollen types

The composition and seasonal distribution of airborne pollen grains in the atmosphere of Bahía Blanca, Argentina, has been studied between June 2001 and December 2003 using the Rotorod sampler (model 40). The results show that the main pollen types during this period were Cupressaceae, Fraxinus, Myrtaceae, Poaceae, Amaranthus/Chenopodiaceae, Pinus, Urticaceae, Ulmus, Olea and Styphnolobium. The highest concentrations occurred from August to December (end of winter and spring), accounting for 80% of the total annual pollen count. The greatest diversity was found in the spring, with the major of pollen coming from short-flowering plant types, such as Populus, Acer, Platanus, Juglans, Tamarix, Ailanthus and Typha. The potential sources of pollen from woody ornamental species are Cupressus sempervirens, Eucalyptus camaldulensis and Fraxinus pennsylvanica. whereas those from herbaceous species are the Chenopodiaceae and Poaceae, which are found within the city and also in the surrounding natural vegetation, and the Urticaceae, which are only present in the city. Marked annual differences were noted during the study period. The increase in 2002 may have been due to the abundant rainfall that occurred prior to the spring season, which would have favored the vegetative stage and flower development of plants. The decrease in pollen concentration in 2003 was mainly due to low rainfall throughout the year.     

Aeropalynological spectrum of Hatay,Turkey, the eastern coast of the Mediterranean Sea

An aeropalynological study during the years 2014–2015 was performed in Hatay, which is a unique sociocultural and phytogeographical area located on the border of Turkey and Syria on the eastern coast of the Mediterranean. The sampling was performed by a Hirst-type volumetric sampler (Lanzoni VPPS 2000), and pollen grains of 54 taxa were identified, of which 83.21% of the annual sum belonged to woody taxa. The highest pollen concentration was recorded in February, of which a large amount came from the Cupressaceae/Taxaceae families. The diversity of the pollen reflected the vegetation of the area and plantations of the city center, but pollen grains from Euro-Siberian elements specific to Mount Amanos could not be recorded. Pollen types found at more than 3% of the annual pollen index and considered dominant pollen types were as follows: Cupressaceae/Taxaceae (50.86%), Olea europaea (12.67%), Moraceae (7.20%), Poaceae (5.99%), Quercus (5.35%), Urticaceae (3.79%) and Pinus (3.70%); almost all dominant pollen types in the city atmosphere were previously stated to be allergic. The main pollen season starting dates of common pollen types found were one or two weeks earlier than those of the surroundings. Many statistically significant correlations were found between daily pollen concentrations and daily meteorological parameters, e.g., Cupressaceae/Taxaceae Poaceae and Urticaceae pollen correlated negatively with mean temperature in both years, and in the hindermost two families daily pollen amounts significantly correlated with wind speed in the second year. Daily Olea europaea pollen concentration showed a significant negative correlation with the amount of total daily rainfall in the second year.     

Aprpaoches to airborne pollen in SE spain. First survey in murcia: one year of pollen monitoring (1993–94)

First data from a pollen survey carried out in the city of Murcia (SE Spain) are given in this paper. Using a Burkard Volumetric Spore Trap, daily slides were prepared and 80 pollen types belonging to 51 families andAlternaria spores were identified and counted. Special attention was paid to 14 relevant taxa: Cupressaceae,Pinus, Genisteae,Olea, Morus, Acer, Platanus, Plantago, Quercus, Urticaceae, Poaceae, Chenopodiaceae,Artemisia andAlternaria. The main sources of airborne particles wereAlternaria (27.7%), Cupressaceae (13.5%),Olea (9.36%), Chenopodiaceae (8.31%) and Urticaceae (5.8%). Annual variations in pollen abundance and length of the flowering seasons are given for individual species and are related to environmental factors. Results indicate a main pollen season from March to June and a second minor season in September to October. The relatively high concentrations of Genisteae and the appearance of anArtemisia winter season were noted.     

First airborne pollen calendar for Mexico City and its relationship with bioclimatic factors

The worldwide human population suffering from allergies continues to increase. Pollen grains are a major source of airborne allergens and significant cause of these diseases. Therefore, continuous monitoring of pollen grains released and transported in the air locally or regionally is required to determine the prevalence of various pollen types and identify intra-day and intra-annual seasonal variations over time. In this study, we developed the first pollen calendar for Mexico City, which includes a large variety of taxa, many of which show a long Main Pollen Season which may last throughout the year. The analysis and comparison of daily, monthly and annual values showed that the occurrence and abundance of the main types of aero-allergenic pollen in the atmosphere were species of Fraxinus, Cupressaceae and Alnus, which occur during the periods from December through March, whereas airborne pollens of several species of Poaceae and Urticaceae occurred throughout the year. The variation in pollen concentration showed that the greatest intra-diurnal variations occurred during the second half of the day. Regarding the relationship of pollen with bioclimatic factors, the increase in temperature favoured the presence of pollen in the air, whereas the increase in pluvial precipitation and relative humidity was associated with a decrease in airborne pollen. Large tracts of the Valley of Mexico have atmospheric conditions that are conducive to the accumulation of airborne particles, including pollen. Anomalous winds from the southeast dominated the surface wind variability during the first months of 2010. These patterns induced extreme values in wind convergence at the lower levels of the atmosphere, which resulted in high concentrations of pollen at our sampling site. We suggest that these conditions are related to the warm phase of the El Niño Southern Oscillation phenomenon (2009–2010).     

A survey of modern pollen and vegetation along a south–north transect in Mongolia

Aim This modern pollen‐rain study documents the spatial and quantitative relationships between modern pollen and vegetation in Mongolia, and explores the potential for using this relationship in palaeoclimatic reconstructions. Location East‐central Mongolia. Methods We collected 104 pollen surface samples along a south–north transect across five vegetation zones in Mongolia. Discriminant analysis was used to classify the modern pollen spectra into five pollen assemblages corresponding to the five vegetation zones. Hierarchical cluster analysis was used to divide the main pollen taxa into two major groups and seven subgroups representing the dry and moist vegetation types and the main vegetation communities within them. Results Each vegetation zone along the transect can be characterized by a distinctive modern pollen assemblage as follows: (1) desert zone: Chenopodiaceae–Zygophyllaceae–Nitraria–Poaceae pollen assemblage; (2) desert‐steppe zone: Poaceae–Chenopodiaceae pollen assemblage; (3) steppe zone: Artemisia–Aster‐type–Poaceae–Pinus Haploxylon‐type pollen assemblage; (4) forest‐steppe zone: Pinus Haploxylon‐type–Picea–Artemisia–Betula, montane forb/shrub and pteridophyte pollen assemblage; and (5) mountain taiga zone: Pinus Haploxylon‐type–Picea–Poaceae–Cyperaceae, montane forb/shrub and Pteridophyte pollen assemblage. Main conclusions Based on the ratio between the major pollen taxon groups and subgroups, we propose two pollen–climate indices that represent the precipitation and temperature conditions in the study region. When plotted along our south–north transect, the moisture indices (M) and temperature indices (T) mimic the regional gradients of precipitation and temperature across Mongolia very closely. These pollen–climate indices can be used for palaeoclimatic reconstruction based on fossil pollen data.     

A 3-year airborne pollen and fungal spores record in San Carlos de Bariloche, Patagonia, Argentina

Airborne pollen in San Carlos de Bariloche was sampled from September to March 2001–2004 with a Hirst-type volumetric spore trap placed at a height of 15 m in a city extending from the humid forests, through the mesic forests, to the steppe. The total amount of pollen recorded varied widely from year to year. The pollen index was 4,395 in the sampling period 2001/2002; 9,055 in 2002/2003 and 2,756 in 2003/2004. The main pollen period extended from October to January. In October, pollen concentration was the highest. Sixty-six pollen types were identified. Cupressaceae and Nothofagus were the major contributors. Betula, Prunus, Pinus and Populus, the most abundant ornamental taxa in the city, also contributed to the pollen record. Pollen of Maytenus and Lomatia was representative of the mesic forest, while pollen in the lower layers of the humid forest was present in trace amounts. Cupressaceae, Nothofagus and Betula prevailed during spring (September–December), and Plantago, Rumex and Poaceae during summer (December–March). The association of daily pollen concentration and meteorological variables, temperature (mean, maximum, minimum), dew point, rainfall and wind speed, was significant. Correlations showed to be negative, with the exception of that to wind speed. The total sum of fungi spores increased from 1,771 in 2001/2002; through 8,441 in 2002/2003 to 13,782 in 2003/2004. Relative concentration rose to 29%, 48% and 84% of the total number of pollen and fungal spores recorded during each sampling period.     

Intradiurnal patterns of allergenic airborne pollen near a city motorway in Berlin,Germany

In this study, the seasonally averaged intradiurnal patterns of four different pollen types (Fraxinus, Betula, Poaceae and Artemisia) and the role of traffic volume, air pollution and selected weather parameters were investigated. Measurements were carried out with a 7-day recording volumetric spore trap (Hirst type) near a congested city motorway (the A 100) in Berlin, Germany, in 2012, 2013 and partly 2011. Both Poaceae and Artemisia pollen showed distinct patterns which were similar across the years. The main period of grass pollen concentrations in the air was from 8 a.m. to 10 p.m. with peaks about midday or in the afternoon. Mugwort pollen mainly occurred between 6 a.m. and 2 p.m. with a clear maximum from 8 to 10 a.m. With regard to Fraxinus and Betula pollen, the patterns were not as clear and showed differences throughout the years. The intradiurnal patterns of traffic volume and pollen load, mainly of Poaceae in the afternoon and Artemisia in the morning, were partly coincident. The combination of both a high pollen count and air pollution, due to exhaust emissions, represents a special health threat which could result in a double burden for allergy sufferers. In the case of the daily means of Betula and Poaceae, relative humidity had a significantly negative effect on pollen concentrations on the same and/or next day/s, sunshine duration (Poaceae) and air temperature (Artemisia) a positive one.     

Exploitation of Local,Drifted and Imported Wood by the Vikings on the Faroe Islands

Summary

Two hundred wood samples have been examined from the Viking settlement at Argisbrekka on Eysturoydated to AD 770–1015. They fall into three categories:-1. local wood: Juniperus. Betula pubescens Ehrh., Corylus, Salix and heathland dwarf shrubs; 2. driftwood: Picea, Larix and Pinus section strobus; and 3. imported wood: Quercus, Pinus section sylvestris, Alnus and Fraxinus. The local tree vegetation was over-exploited and Betula became extinct in the course of the Viking Age. Driftwood, mainly of Siberian origin, seems to be the most important tree resource and was used for houses and utensils. Imported wood probably mostly comprised ships and finished products made in Scandinavia. The detection of tree Betula growth between 2,460 BC and AD 770 is a new contribution to the vegetational history of the Faroe Islands.     

Analysis of airborne allergenic pollen spectrum for 2009 in Timişoara, Romania

The objective of this investigation was to identify the overall pollen types and, more particularly, the allergenic pollen content in the investigated area and then to explore their seasonal variations. The measurement point was located in the Timi?oara city, Romania. A Lanzoni volumetric trap was used for sample collection. Duration of the pollen season of allergenic plants and respective variation in airborne pollen concentration are presented in the pollen calendar for the year 2009. Among the identified pollen of 23 types, 20 were allergenic: Taxaceae/Cupressaceae, Alnus sp., Fraxinus sp., Betula sp., Corylus sp., Carpinus sp., Salix sp., Populus sp., Ulmus sp., Juglans sp., Quercus sp., Pinaceae, Tilia, Poaceae, Urticaceae, Chenopodiaceae/Amaranthaceae, Rumex sp., Plantago sp., Artemisia sp., Ambrosia sp. These species prevail throughout almost the entire pollen season, from February–October, accounting for 87.03 % of the total pollen count. The greatest diversity of pollen types is detected in the months of spring. The summer months were characterized mostly by non-arboreal pollen types. In late summer and early autumn, Ambrosia airpollen was the most abundant in the atmosphere. The relationships between pollen concentrations and nine meteorological parameters are presented too. To analyze the correlation between pollen data and variables, the Spearman rank correlation coefficient was used. The correlation analysis of daily pollen counts and meteorological parameters showed that arboreal pollen and non-arboreal pollen counts were significantly correlated with temperature. The prevalence of pollen sensitization resulted to be very high in our patients with respiratory symptoms.     

Substrate dependency of Lateglacial forests in north-east Germany: untangling vegetation patterns, ecological amplitudes and pollen dispersal in the past by downscaling regional pollen

Aim Palynology has revealed that during the Lateglacial Allerød period, Pinus and Betula dominated the forests of north‐east Germany. Because of implicit restrictions, however, palynology fails to reconstruct in detail the distributional patterns and whether monospecific or mixed forests prevailed. Here we test the hypothesis that the distributional patterns of Pinus and Betula were largely determined by substrate. Location Fifteen sites in north‐east Germany. Methods As pollen data reflect the abundance of taxa around a sample site, our hypothesis implies that the abundance of e.g. Pinus pollen should reflect the abundance of substrate types that are favoured by Pinus. (In order to differentiate clearly between taxa and pollen types, the latter are displayed in small capitals. ) We analysed the percentage of Pinus and Betula pollen from an interval in the Allerød, and their relationship to the present‐day proportion of the two dominant substrate types (sand and boulder clay). The substrate proportion was determined in rings from 1 to 50 km around all sites, using four distance‐weighting functions. Results Pollen percentages of Pinus are linearly related to the proportion of sand, and Betula percentages to the proportion of boulder clay. The highest coefficients of determination (r² = 0.89 and 0.91, respectively) were observed for radii of c. 30 km, with distance weighting by 1 and 1/d. Main conclusions The present‐day distributional pattern of substrate types strongly indicates the distributional pattern of Pinus and Betula in north‐east Germany in the Allerød. Assuming that the pattern of substrates remained broadly constant, Pinus dominated on sand and Betula on boulder clay. Our new method thus enables us to refine significantly the reconstruction of habitat characteristics and distributional patterns of taxa in the Lateglacial and Holocene, independent of their present‐day ecological amplitudes. The good performance of the distance‐weighting functions 1 and 1/d indicates that the pollen source area of a site has rather discrete boundaries determined by convective air movements during daytime. Within these boundaries, pollen is evenly distributed over various distances. This implies that light pollen types are transported further than predicted by Sutton’s equation on particle dispersal.     

Airborne pollen and spores’ deposition in alveolar tissues as a tool in drowning forensic diagnosis

We report the results of a histological study of lung samples where an unusual quantity of airborne pollen and fungal spores was found in drowned rats. Pollen and spores were found in lungs of drowned rats but not in the post-mortem submerged ones. Another control group consisting of rats that underwent 60 min exposure to a highly pollen-loaded atmosphere also recorded negative for the presence of pollen or fungal spores. Pollen types coincided with plants growing at the surrounding gardens flowering during the days of the experiment, performed during spring, that were detected by the aerobiological trap located at the city. The pollen observed at the lower airways’ tissues were Chenopodiaceae, Cupressus, Ericaceae, Jasminum, Olea europaea, Plantago, Pinus, Poaceae, Quercus and Urticaceae. Regarding fungal spores Alternaria, Aspergillus, Cladosporium cladosporoides, Cladosporium herbarum, Leptosphaeria, Polythrincium and Phitomyces. Pollen and spores’ penetration into deeper regions of the respiratory tract is an unusual phenomenon not happening in regular breathing conditions. Our results revealed that these particles appeared in a significant number in lung samples of drowned animals probably pushed down from upper airways by the force of water inhalation during drowning. Their presence into alveolar spaces offer a useful forensic evidence in doubtful drowning autopsies, favoured by the characteristic of the sporopollenin (pollen wall) and chitin (fungal spore wall) resistance. Moreover, the presence of these particles in alveoli areas of drowned bodies can help forensics to obtain information about pre-mortem dates and places.