scholarly journals Análisis del contenido aeropolínico estival en la provincia de Málaga

2001 ◽  
Vol 26 ◽  
pp. 89-98
Author(s):  
Marta Recio ◽  
M. Mar Trigo ◽  
Silvia Docampo ◽  
Baltasar Cabezudo
Keyword(s):  
Airborne Pollen ◽  
Summer Season ◽  
Palabras Clave ◽  
Low Concentrations ◽  
Pollen Content ◽  
Pollen Types ◽  
Pollen Concentrations ◽  
Atmospheric Pollen ◽  
Annual Total ◽  
Total Pollen

RESUMEN. Análisis del contenido aeropolínico estival en la provincia de Málaga. En el presente trabajo se realiza un estudio del contenido polínico de la atmósfera de la provincia de Málaga durante cl periodo estival (Julio-Septiembre) tomando los registros obtenidos durante los últimos años en varias localidades de la provincia: Málaga (1992-1999), Estepona (1995-1997), Antequera (1998-1999) y Nerja (2000). En general, durante estos tres meses se recoge sólo entre el 3 y el 6% del polen anual, estando el espectro aeropolínico estival de Málaga representado básicamente por 14 tipos polínicos: Eucalyptus, Castanea, Parkinsotzia, Cannabis, Apiaceae, Ligustrum, Chenopodiaceae-Amaranthaceae, Palmae, Compositae, Artemisia, Typha, Cyperaceae, Poaceae y U rticaceae. Los tipos que alcanzan mayores concentraciones son Eucalyptus, Chenopodiaceae-Amaranthaceae y Poaceae. El resto de los taxa citados aparecen en concentraciones muy bajas. Determinados taxa presentan concentraciones más elevadas en determinadas estaciones de muestreo: Castanea y Compositae en Antequera, Palmae y Parkinsonia en Málaga, y Artemisia en Nerja. La evolución a lo largo de los tres meses muestra, en general, dos tipos de tendencia: una descendente de Julio a Agosto (presente en todos los tipos polínicos estudiados, excepto en Artemisia y Palinae, y en todas las zonas estudiadas) y otra ascendente, de Agosto a Septiembre, de pequeña intensidad, aunque muy acusada para los dos tipos anteriores y para Chenopodiaceae-Amaranthaceae y Cotnpositae. La mayoría de los tipos polínicos estudiados tienen sus máximos diarios en primavera, estación del año con mayor concentración polínica en el sur de Europa, excepto Eucalyptus, Castanea, Parkinsonia y Cannabis, que generalmente lo tienen en verano, y que alcanzaron máximos históricos relevantes: Eucalyptus en 1994 (112 granos/111 3), Castanea en 1997 (233 granos/m 3), Cannabis en 1998 (28 granos/m 3).Palabras clave. Acrobiología, polen, verano, turismo, alergia, Málaga, sur de España.ABSTRACT. Analysis of the summer airborne pollen contera in the province of Malaga. In this work, a study about the atmospheric pollen content during the period July-September has been carried out in the province of Malaga. The study was made taking the data obtained during the last years in several localities of the province: Malaga (1992-1999), Estepona (1995-1997), Antequera (1998-1999) and Nerja (2000). In general, just between 3 and 6% of the annual total pollen were collected during those three months, the airborne pollen spectrum being represented by 14 pollen types: Eucalyptus, Castanea, Parkinsonia, Cannabis, Apiaceae, Ligustrum,Chenopodiaceae-Amaranthaceae, Palmae, Compositae, Artemisia,Typha, Cyperaceae, Poaceae y Urticaceae. During the period studied, the pollen types that reached highest concentrations were Eucalyptus, Chenopodiaceae-Amaranthaceae and Poaceae while the rest of the cited taxa were detected at very low concentrations. Some taxa present higher concentrations at determined sampling stations: Costana(' and Compositae in Antequera, Palmae and Parkin.s. onia in Malaga, and Artemisia in Ncrja. The evolution along the summer season shows, in general, two trends. The first one, in which the pollen concentrations are decreasing from July to August, is present in all the taxa and localities studied, except in Artemisia and Palmae. The other one, in which the pollen concentrations lightly increase from August to September, is present in the former two pollen types but also in Chenopodiaceae- Amarantliaceae and Compositae. Most of the pollen types studied reach their maximum daily peaks in spring (season in which the pollen concentrations are highest in southern Europe) except Eucalyptus, Castanea, Parkinsonia and Cannabis, that generally presented them in summer. These taxa reached notable maximum daily concentrations values: Eucalyptus in 1994 (112 grains/m 3), Castanea in 1997 (233 grains/ in3), Cannabis in 1998 (28 grains/m 3).Key words. Aerobiology, pollen, summer, tourism, allergy, Malaga, southern Spain.

scholarly journals A Survey of Atmospheric Pollen and Spores in North-Western Nigeria

2018 ◽  
Vol 10 (2) ◽  
pp. 182-192
Author(s):  
Olugbenga Shadrak ALEBIOSU ◽  
Olusola H. ADEKANMBI
Keyword(s):  
Meteorological Parameters ◽  
Airborne Pollen ◽  
Health Concern ◽  
Pollen Types ◽  
Pollen Concentrations ◽  
Atmospheric Pollen ◽  
Local Plants ◽  
Study Sites ◽  
The Impact ◽  
North Western

The incidence of airborne pollen occurring as aeroallergens of varied levels at different periods of the year has generated some public health concern globally. The present study was conducted in order to examine the monthly depositional rate of airborne pollen and fern spores, as well as the impact of meteorological parameters and local plants on pollen distribution at two study sites in Kaduna and Sokoto States of North Western Nigeria. The study spanned a period of one year, during which a modified Tauber pollen sampler was employed in the collection of atmospheric pollen and fern spores; local plants were also enumerated. Residual solution was collected monthly, subjected to acetolysis and the treated residues were viewed for microscopic studies. The results reveal monthly distribution of airborne pollen and fern spore types at the study sites during the sampling period. Dominant pollen types in Kaduna State were those of Alchornea laxiflora, Pinus caribaea, Terminalia sp., Sapotaceae and Poaceae family. Pollen of Syzygium guineense, Alchornea sp., Sapotaceae and Poaceae dominated in Sokoto State. Spores of Pteris sp., Nephrolepis sp. and a trilete fern were also recovered at both locations. Some local plants in the immediate vegetation contributed to the aeroflora of these locations. No significant correlation was recorded between monthly total pollen concentrations and mean monthly meteorological parameters of the locations. It is imperative to investigate the allergenicity of these dominant pollen types, so as to aid pollen hypersensitive individuals in adopting appropriate prophylactic measures.

scholarly journals Airborne Pollen Records of Shomolu Local Government Area in Lagos State

2014 ◽  
Vol 6 (4) ◽  
pp. 428-432 ◽  
Author(s):  
Tiwalade A. ADENIYI ◽  
Peter A. ADEONIPEKUN ◽  
James D. OLOWOKUDEJO ◽  
Idowu S. AKANDE
Keyword(s):  
Local Government ◽  
Airborne Pollen ◽  
Pollen Grains ◽  
State University ◽  
Current Trends ◽  
Pollen Content ◽  
Lagos State ◽  
Total Pollen ◽  
Pollen Distribution ◽  
The Town

Data on the prevalence of pollen in the atmosphere is limited and almost non-existent for Lagos State and Nigeria. Pollen grains are known to be highly allergenic and thus they are potential causes of respiratory diseases. To investigate airborne incidence of pollen, so as to construct a pollen calendar and contribute to current trends in the development of aeropalynology/allergy study in Nigeria, three highly populated locations in Shomolu Local Government areas of Lagos State: University of Lagos, Bariga and Gbagada, were sampled. Aero-samplers were harvested monthly from January 2013 to December 2013. After acetolysis treatment and analysis, the total pollen count was 4393, belonging to 38 pollen taxa and 29 families. The main taxa include Poaceae, Cyperaceae, Amaranthaceae, Ludwigia and Alchornea. Monthly pollen counts were highest in October and lowest in June. Almost three-quarters of the total pollen content came from grasses and weeds. This composition reflects the ornamental and grassland flora of the town, as well as the natural vegetation surrounding the urban area. The total pollen concentration correlates positively with the temperature and negatively with the wind, rainfall and relative humidity, which was similar in the dominant taxa Amaranthaceae and Alchornea. Dominant taxa Cyperaceae and Ludwigia have significant positive correlation with wheezing cough. Results from this work will form the basis for a forecast service required to inform and educate the general public and allergy sufferers about pollen distribution in Lagos State.

Seasonal pollen distribution in the atmosphere of Hobart, Tasmania: preliminary observations and congruence with flowering phenology

2010 ◽  
Vol 58 (6) ◽  
pp. 440 ◽  
Author(s):  
D. Y. P. Tng ◽  
F. Hopf ◽  
S. G. Haberle ◽  
D. M. J. S. Bowman
Keyword(s):  
Native Plants ◽  
Airborne Pollen ◽  
Flowering Phenology ◽  
Sampling Location ◽  
Minor Role ◽  
Sampling Effort ◽  
Pollen Load ◽  
Flowering Duration ◽  
Pollen Types ◽  
Atmospheric Pollen

The atmospheric pollen loads of Hobart, Tasmania, Australia, were monitored between September 2007 and July 2009. To examine the match of the airborne pollen composition with the flowering duration of their contributing plants, the phenology of native and non-native plants in various habitats near the pollen-trapping site was undertaken between August 2008 and July 2009. The pollen load was found to have a strong seasonal component associated with the start of spring in September. This is incongruent with the peak flowering season of the total taxa in October. In most taxa, atmospheric pollen signatures appeared before flowering was observed in the field. The presence of most pollen types in the atmosphere also exceeded the observed flowering duration of potential pollen-source taxa. Reasons for this may be related to the sampling effort of phenological monitoring, pollen blown in from earlier flowering populations outside of the sampling area, the ability of pollen to be reworked, and the large pollen production of some wind-pollinated taxa. In 2007–2008, 15 pollen types dominated the atmosphere, accounting for 90% of the airborne pollen load. The top six pollen types belonged to Betula, Cupressaceae, Myrtaceae, Salix, Poaceae and Ulmus. Comparatively, the annual pollen load of Hobart is lower than in most other Australian cities; however, the pollen signal of Betula is inordinately high. Native plants play a minor role as pollen contributors, despite the proximity of native habitats to the pollen-sampling location. The implications of the aerobiological observations are discussed in relation to public health.

scholarly journals Near-surface and columnar measurements with a micro pulse lidar of atmospheric pollen in Barcelona, Spain

2016 ◽  
Vol 16 (11) ◽  
pp. 6805-6821 ◽  
Author(s):  
Michaël Sicard ◽  
Rebeca Izquierdo ◽  
Marta Alarcón ◽  
Jordina Belmonte ◽  
Adolfo Comerón ◽  
...  
Keyword(s):  
Airborne Pollen ◽  
Correlation Coefficients ◽  
Vertical Motion ◽  
Surface Concentration ◽  
Correlation Study ◽  
Near Surface ◽  
Pollen Types ◽  
Pollen Concentrations ◽  
Micro Pulse Lidar ◽  
Depolarization Ratios

Abstract. We present for the first time continuous hourly measurements of pollen near-surface concentration and lidar-derived profiles of particle backscatter coefficients and of volume and particle depolarization ratios during a 5-day pollination event observed in Barcelona, Spain, between 27 and 31 March 2015. Daily average concentrations ranged from 1082 to 2830 pollen m−3. Platanus and Pinus pollen types represented together more than 80 % of the total pollen. Maximum hourly pollen concentrations of 4700 and 1200 m−3 were found for Platanus and Pinus, respectively. Every day a clear diurnal cycle caused by the vertical transport of the airborne pollen was visible on the lidar-derived profiles with maxima usually reached between 12:00 and 15:00 UT. A method based on the lidar polarization capabilities was used to retrieve the contribution of the pollen to the total aerosol optical depth (AOD). On average the diurnal (09:00–17:00 UT) pollen AOD was 0.05, which represented 29 % of the total AOD. Maximum values of the pollen AOD and its contribution to the total AOD reached 0.12 and 78 %, respectively. The diurnal means of the volume and particle depolarization ratios in the pollen plume were 0.08 and 0.14, with hourly maxima of 0.18 and 0.33, respectively. The diurnal mean of the height of the pollen plume was found at 1.24 km with maxima varying in the range of 1.47–1.78 km. A correlation study is performed (1) between the depolarization ratios and the pollen near-surface concentration to evaluate the ability of the former parameter to monitor pollen release and (2) between the depolarization ratios as well as pollen AOD and surface downward solar fluxes, which cause the atmospheric turbulences responsible for the particle vertical motion, to examine the dependency of the depolarization ratios and the pollen AOD upon solar fluxes. For the volume depolarization ratio the first correlation study yields to correlation coefficients ranging 0.00–0.81 and the second to correlation coefficients ranging 0.49–0.86.

scholarly journals The threat of allergenic airborne trees pollen to pollinosis sufferers in a rural area (Western Pomerania, Poland)

2015 ◽  
Vol 68 (4) ◽  
pp. 325-331 ◽  
Author(s):  
Aleksandra Kruczek ◽  
Małgorzata Puc ◽  
Alina Stacewicz ◽  
Tomasz Wolski
Keyword(s):  
Pollen Season ◽  
Birch Pollen ◽  
Pollen Grains ◽  
Daily Maximum ◽  
Pollen Concentrations ◽  
Diurnal Distribution ◽  
Annual Total ◽  
Total Pollen ◽  
Pollen Seasons ◽  
The Village

The aim of the study was to investigate the concentration of <em>Alnus</em> L., <em>Corylus</em> L. and <em>Betula</em> L. pollen in the village of Gudowo (Western Pomerania, Poland) in the years 2012–2014 in order to estimate the threat of allergenic tree pollen in this rural region. Measurements were performed using the volumetric method (VPPS Lanzoni 2000 pollen sampler). The duration of the pollen season was determined by the 98% method, taking days on which, respectively, 1% and 99% of the annual total pollen grains appeared as the beginning and end of the season. Pollen grains from hazel occurred in the air as the first ones, before pollen grains from alder and birch. The earliest beginning of the hazel pollen season was recorded in 2012, whereas alder and birch pollen seasons started the earliest in 2014. Daily maximum pollen concentrations of the investigated taxa were recorded in 2014. Birch pollen allergens posed the largest threat to pollinosis sufferers. In the years 2012–2014, pollen concentrations equal or higher than threshold values, at which people with pollinosis show allergic symptoms, were recorded most frequently for birch, hazel, and alder (25, 19, and 14 days, respectively). The highest hourly alder pollen concentration was recorded at 16:00 and in the case of hazel at 15:00. The diurnal distribution of birch pollen concentrations does not show any distinct peaks.

Influence of Saharan-Sahel dust outbreaks on pollen exposure in the Iberian Mediterranean areas

2021 ◽  
Author(s):  
Jesús Rojo ◽  
José María Moreno ◽  
Jorge Romero-Morte ◽  
Beatriz Lara ◽  
Belén Elvira-Rendueles ◽  
...  
Keyword(s):  
Iberian Peninsula ◽  
Mineral Dust ◽  
Airborne Pollen ◽  
Potential Effect ◽  
Dust Particles ◽  
Simultaneous Occurrence ◽  
Air Mass ◽  
Pollen Types ◽  
Pollen Concentrations ◽  
Pollen Exposure

&lt;p&gt;Airborne particulate matter such as mineral dust comes mainly from natural sources, and the arid regions of Sahara and Sahel in Africa release large amounts of the aerosols dispersed worldwide. There is evidence of concomitant presence of desert dust particles and bioaerosols such as pollen grains in the atmosphere, which produce a significant decline in air quality during the dust intrusions events. However, there is little knowledge about the influence of dust episodes on pollen exposure in allergy sufferers as well as the causes that may produce a potential effect of the intrusions on airborne pollen levels. This potential effect on the airborne pollen concentrations is analysed in the Iberian Mediterranean region in this study. Mediterranean countries are strongly affected by Saharan-Sahel dust intrusions, and the Iberian territory, specially the central and southern areas, suffer frequently great incidence of dust episodes due to its geographic location. In this study firstly, the simultaneous occurrence between airborne pollen peaks and Saharan-Sahel dust intrusions were analysed and compared with the behaviour in the days before and after the dust intrusions in the central and south-eastern Iberian Peninsula. Secondly, the weather conditions favouring high pollen concentrations during dust episodes namely prevalent winds, air mass pathways and variations in other meteorological variables like air temperature, relative humidity or atmospheric pressure were studied.&lt;/p&gt;&lt;p&gt;Pollen peaks often coincided with dust episodes during the pollen season in the central Iberian Peninsula. The increase of the airborne pollen concentrations during the dust episodes is clear in inland Iberian areas, although this was not the case in coastal areas of the southeast where pollen concentrations could even be seen to decrease when easterly winds from the sea prevailed during dust intrusions. Total pollen concentrations and also pollen types such as Olea, Poaceae and Quercus showed an increase in the central Iberian Peninsula during the dust episodes when two meteorological phenomena occurred simultaneously: 1) prevailing winds came from large areas of the main wind-pollinated pollen sources at medium or short scale (mainly from western and southwestern areas); and 2) optimal meteorological conditions that favoured pollen release and dispersal into the atmosphere (mainly high temperatures and low humidity). Both these conditions often occur during Saharan-Sahel dust intrusions in the centre. The findings suggest that the proportion of long-range transport is lower than those produced in medium and short distance by dust intrusions of air masses. Therefore, maximum pollen peaks are most likely to occur during dust episodes in the central Iberian Peninsula dramatically increasing the risk of outbreaks of pollinosis and other respiratory diseases in the population. The negative effects of the mineral dust on public health are well known, even more so when allergenic biological agents are co-transported together by the air mass movements coming from desert areas. The findings of this study have very relevant implications for defining health-emergency alerts for severe Saharan-Sahel dust outbreaks.&lt;/p&gt;

scholarly journals Land-Use and Height of Pollen Sampling Affect Pollen Exposure in Munich, Germany

Atmosphere ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 145 ◽  
Author(s):  
Jesús Rojo ◽  
Jose Oteros ◽  
Antonio Picornell ◽  
Franziska Ruëff ◽  
Barbora Werchan ◽  
...  
Keyword(s):  
Airborne Pollen ◽  
Pollen Grains ◽  
Ground Level ◽  
Large Area ◽  
Dispersal Capacity ◽  
Pollen Types ◽  
Pollen Concentrations ◽  
Pollen Sources ◽  
Poaceae Pollen ◽  
The City

Airborne pollen concentrations vary depending on the location of the pollen trap with respect to the pollen sources. Two Hirst-type pollen traps were analyzed within the city of Munich (Germany): one trap was located 2 m above ground level (AGL) and the other one at rooftop (35 m AGL), 4.2 km apart. In general, 1.4 ± 0.5 times higher pollen amounts were measured by the trap located at ground level, but this effect was less than expected considering the height difference between the traps. Pollen from woody trees such as Alnus, Betula, Corylus, Fraxinus, Picea, Pinus and Quercus showed a good agreement between the traps in terms of timing and intensity. Similar amounts of pollen were recorded in the two traps when pollen sources were more abundant outside of the city. In contrast, pollen concentrations from Cupressaceae/Taxaceae, Carpinus and Tilia were influenced by nearby pollen sources. The representativeness of both traps for herbaceous pollen depended on the dispersal capacity of the pollen grains, and in the case of Poaceae pollen, nearby pollen sources may influence the pollen content in the air. The timing of the pollen season was similar for both sites; however, the season for some pollen types ended later at ground level probably due to resuspension processes that would favor recirculation of pollen closer to ground level. We believe measurements from the higher station provides a picture of background pollen levels representative of a large area, to which local sources add additional and more variable pollen amounts.

scholarly journals QUANTITATIVE AEROPALYNOLOGY IN THE ATMOSPHERE OF TIMISOARA CITY, ROMANIA

1970 ◽  
Vol 63 ◽  
Author(s):  
Nicoleta Ianovici
Keyword(s):  
Airborne Pollen ◽  
Fungal Spores ◽  
Pollen Grains ◽  
Respiratory Allergy ◽  
Volumetric Method ◽  
Allergenic Pollen ◽  
Deciduous Trees ◽  
Pollen Concentration ◽  
Annual Total ◽  
Total Pollen

Many airborne pollen grains and fungal spores are important biopollutants responsible for human respiratory allergy. In the conditions of România the most important cause of pollinosis is allergenic pollen of some deciduous trees as well as grasses and weeds. The measurements of pollen concentration in the aeroplankton of Timişoara were carried out in 2003 by the volumetric method. The highest concentrations are noted in April and August. A total of 23 types of pollen taxa were recorded in the air of the study area in the 2003-year: Acer, Alnus, Ambrosia, Artemisia, Betula, Carpinus, Chenopodiaceae/Amaranthaceae, Corylus, Fraxinus, Juglans, Morus, Pinaceae, Platanus, Plantago, Populus, Poaceae, Rumex, Salix, Quercus, Taxaceae/Cupressaceae, Tilia, Urtica, Ulmus. The highest values of annual total of pollen grains in a group of trees were reached by Populus and Betula, as well as in a group of grasses and weeds – Ambrosia, Urtica and Poaceae. Trees pollen predominantly contributed to the total pollen sum with a percentage of 53.56%, followed by herbs 37.54% and grasses 8.9%.

scholarly journals Lidar Depolarization Ratio of Atmospheric Pollen at Multiple Wavelengths

2020 ◽  
Author(s):  
Stephanie Bohlmann ◽  
Xiaoxia Shang ◽  
Ville Vakkari ◽  
Elina Giannakaki ◽  
Ari Leskinen ◽  
...  
Keyword(s):  
Wavelength Dependence ◽  
Depolarization Ratio ◽  
Ambient Conditions ◽  
Pollen Concentrations ◽  
Multiple Wavelengths ◽  
Pollen Mixture ◽  
Atmospheric Pollen ◽  
Total Pollen ◽  
Pollen Number ◽  
Depolarization Ratios

Abstract. Lidar observations during the pollen season 2019 at the European Aerosol Research Lidar Network (EARLINET) station in Kuopio, Finland were analyzed in order to optically characterize atmospheric pollen. Previous studies showed the detectability of non-spherical pollen using depolarization ratio measurements. We present lidar depolarization ratio measurements at three wavelengths of atmospheric pollen in ambient conditions. In addition to the depolarization ratio detected with the multiwavelength Raman polarization lidar PollyXT at 355 and 532 nm, depolarization measurements of a co-located HALO Photonics Streamline Doppler lidar at 1565 nm were utilized. During a four days period of high birch (Betula) and spruce (Picea abies) pollen concentrations, unusually high depolarization ratios were observed within the boundary layer. Detected layers were investigated regarding the share of spruce pollen to the total pollen number concentration. Daily mean particle depolarization ratios of the pollen layers on the day with the highest spruce pollen share are 0.10 ± 0.02, 0.38 ± 0.23 and 0.29 ± 0.10 at 355, 532 and 1565 nm, respectively. Whereas on days with lower spruce pollen share, depolarization ratios are lower with less wavelength dependence. This spectral dependence of the depolarization ratios could be indicative of big, non-spherical spruce pollen. The depolarization ratio of pollen particles was investigated by applying a newly developed method and assuming a backscatter-related Ångström exponent of zero. Depolarization ratios of 0.44 and 0.16 at 532 and 355 nm for the birch and spruce pollen mixture were determined.

scholarly journals Lidar depolarization ratio of atmospheric pollen at multiple wavelengths

2021 ◽  
Vol 21 (9) ◽  
pp. 7083-7097
Author(s):  
Stephanie Bohlmann ◽  
Xiaoxia Shang ◽  
Ville Vakkari ◽  
Elina Giannakaki ◽  
Ari Leskinen ◽  
...  
Keyword(s):  
Wavelength Dependence ◽  
Depolarization Ratio ◽  
Ambient Conditions ◽  
Air Sampler ◽  
Pollen Concentrations ◽  
Multiple Wavelengths ◽  
Pollen Mixture ◽  
Atmospheric Pollen ◽  
Total Pollen ◽  
Depolarization Ratios

Abstract. Lidar observations during the pollen season 2019 at the European Aerosol Research Lidar Network (EARLINET) station in Kuopio, Finland, were analyzed in order to optically characterize atmospheric pollen. Pollen concentration and type information were obtained by a Hirst-type volumetric air sampler. Previous studies showed the detectability of non-spherical pollen using depolarization ratio measurements. We present lidar depolarization ratio measurements at three wavelengths of atmospheric pollen in ambient conditions. In addition to the depolarization ratio detected with the multiwavelength Raman polarization lidar PollyXT at 355 and 532 nm, depolarization measurements of a co-located Halo Doppler lidar at 1565 nm were utilized. During a 4 d period of high birch (Betula) and spruce (Picea abies) pollen concentrations, unusually high depolarization ratios were observed within the boundary layer. Detected layers were investigated regarding the share of spruce pollen to the total pollen number concentration. Daily mean linear particle depolarization ratios of the pollen layers on the day with the highest spruce pollen share are 0.10 ± 0.02, 0.38 ± 0.23 and 0.29 ± 0.10 at 355, 532 and 1565 nm, respectively, whereas on days with lower spruce pollen share, depolarization ratios are lower with less wavelength dependence. This spectral dependence of the depolarization ratios could be indicative of big, non-spherical spruce pollen. The depolarization ratio of pollen particles was investigated by applying a newly developed method and assuming a backscatter-related Ångström exponent of zero. Depolarization ratios of 0.44 and 0.16 at 532 and 355 nm for the birch and spruce pollen mixture were determined.

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