scholarly journals Phenological and seismological impacts on airborne pollen types: A case study of Olea pollen in the Region of Murcia, Mediterranean Spanish climate

2021 ◽  
pp. 152686
Author(s):  
L. Negral ◽  
F. Aznar ◽  
M.D. Galera ◽  
I. Costa-Gómez ◽  
S. Moreno-Grau ◽  
...  
Keyword(s):  
Airborne Pollen ◽  
Pollen Types

scholarly journals Neural networks for increased accuracy of allergenic pollen monitoring

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marcel Polling ◽  
Chen Li ◽  
Lu Cao ◽  
Fons Verbeek ◽  
Letty A. de Weger ◽  
...  
Keyword(s):  
Neural Networks ◽  
Airborne Pollen ◽  
Pollen Grains ◽  
Allergenic Pollen ◽  
Herbarium Specimens ◽  
Pollen Monitoring ◽  
Pollen Concentrations ◽  
Source Of Information ◽  
Urticaceae Pollen

AbstractMonitoring of airborne pollen concentrations provides an important source of information for the globally increasing number of hay fever patients. Airborne pollen is traditionally counted under the microscope, but with the latest developments in image recognition methods, automating this process has become feasible. A challenge that persists, however, is that many pollen grains cannot be distinguished beyond the genus or family level using a microscope. Here, we assess the use of Convolutional Neural Networks (CNNs) to increase taxonomic accuracy for airborne pollen. As a case study we use the nettle family (Urticaceae), which contains two main genera (Urtica and Parietaria) common in European landscapes which pollen cannot be separated by trained specialists. While pollen from Urtica species has very low allergenic relevance, pollen from several species of Parietaria is severely allergenic. We collect pollen from both fresh as well as from herbarium specimens and use these without the often used acetolysis step to train the CNN model. The models show that unacetolyzed Urticaceae pollen grains can be distinguished with > 98% accuracy. We then apply our model on before unseen Urticaceae pollen collected from aerobiological samples and show that the genera can be confidently distinguished, despite the more challenging input images that are often overlain by debris. Our method can also be applied to other pollen families in the future and will thus help to make allergenic pollen monitoring more specific.

scholarly journals Airborne pollen observations using a multi-wavelength Raman polarization lidar in Finland: characterization of pure pollen types

2020 ◽  
Author(s):  
Xiaoxia Shang ◽  
Elina Giannakaki ◽  
Stephanie Bohlmann ◽  
Maria Filioglou ◽  
Annika Saarto ◽  
...  
Keyword(s):  
Optical Properties ◽  
Airborne Pollen ◽  
Pollen Grains ◽  
Wavelength Dependence ◽  
Depolarization Ratio ◽  
Mean Values ◽  
Pollen Types ◽  
Pine Pollen ◽  
Significant Wavelength ◽  
532 Nm

Abstract. We present a novel algorithm for characterizing the optical properties of pure pollen particles, based on the depolarization values obtained in lidar measurements. The algorithm was first tested and validated through a simulator, and then applied to the lidar observations during a four-month pollen campaign from May to August 2016 at the European Aerosol Research Lidar Network (EARLINET) station in Kuopio (62°44′ N, 27°33′ E), in Eastern Finland. Twenty types of pollen were observed and identified from concurrent measurements with Burkard sampler; Birch (Betula), pine (Pinus), spruce (Picea) and nettle (Urtica) pollen were most abundant, contributing more than 90 % of total pollen load, regarding number concentrations. Mean values of lidar-derived optical properties in the pollen layer were retrieved for four intense pollination periods (IPPs). Lidar ratios at both 355 and 532 nm ranged from 55 to 70 sr for all pollen types, without significant wavelength-dependence. Enhanced depolarization ratio was found when there were pollen grains in the atmosphere, and even higher depolarization ratio (with mean values of 25 % or 14 %) was observed with presence of the more non-spherical spruce or pine pollen. The depolarization ratio at 532 nm of pure pollen particles was assessed, resulting to 24 ± 3 % and 36 ± 5 % for birch and pine pollen, respectively. Pollen optical properties at 1064 nm and 355 nm were also estimated. The backscatter-related Ångström exponent between 532 and 1064 nm was assessed as ~ 0.8 (~ 0.5) for pure birch (pine) pollen, thus the longer wavelength would be better choice to trace pollen in the air. The pollen depolarization ratio at 355 nm of 17 % and 30 % were found for birch and pine pollen, respectively. The depolarization values show a wavelength dependence for pollen. This can be the key parameter for pollen detection and characterization.

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.

Comparative Study of Airborne Pollen from the Northern to the Southern of Tunisia

2019 ◽  
pp. 1-8 ◽  
Author(s):  
S. Hadj Hamda ◽  
A. Ben Dhiab ◽  
M. Msallem ◽  
A. Larbi
Keyword(s):  
Crop Production ◽  
Airborne Pollen ◽  
Flowering Phenology ◽  
Plant Distribution ◽  
The South ◽  
Pollen Type ◽  
The North ◽  
Flowering Season ◽  
Pollen Types ◽  
Study Sites

Aerobiology is a multidisciplinary science dealing with biological particles in the atmosphere generated by natural activities during flowering season. Airborne pollen is now the main studied biological structure which is used as a reliable tool to study plant phenology, plant distribution changes and prediction of crop production. The main aims of this work is to determine the distribution of the different spring flowering species from the North to the South of Tunisia and to establish the pollen spectrum of three regions Mornag (North), Menzel M’hiri (Centre) and Chaal (South) in 2017. Airborne pollen data were collected using three volumetric Hirst-type spore traps placed in Mornag (36°39N; 10°16E), Menzel M’hiri (35°38N; 10°41E) and Chaal (34°34N; 10°19E) during olive flowering season. The highest pollen index was recorded in the north (Mornag, 6487.1) corresponding mainly to 18 different pollen types emitted by anemophilous species with an important presence of Cupressus pollen type having the highest contribution. Lower pollen amounts were recorded in Menzel M’hiri (5983.8) and Chaal (925.3). Olea eurpoeae was the most presented pollen type in these regions. However comparing the different study sites we can note a large distribution of some taxa from north to the south. The main common taxa were Olea europaea, Cupressaceae, Poaceae and Amaranhaceae. Their atmospheric concentrations varied also between the regions. Individual pollen index showed a sharp heterogeneity between the taxa in the same region in one hand and between the study sites in the other hand, thus a statistical analysis was performed to define the main group of taxa according to their individual pollen index. Flowering phenology of the main common taxa was also established.

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.

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

<p>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.</p><p>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.</p>

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.

Impact of land cover changes and climate on the main airborne pollen types in Southern Spain

2016 ◽  
Vol 548-549 ◽  
pp. 221-228 ◽  
Author(s):  
Herminia García-Mozo ◽  
Jose Antonio Oteros ◽  
Carmen Galán
Keyword(s):  
Land Cover ◽  
Airborne Pollen ◽  
Southern Spain ◽  
Land Cover Changes ◽  
Pollen Types

scholarly journals EVALUATION OF METEOROLOGICAL PARAMETERS INFLUENCE UPON POLLEN SPREAD IN THE ATMOSPHERE / METEOROLOGINIŲ PARAMETRŲ ĮTAKOS ŽIEDADULKIŲ SKLAIDAI ATMOSFEROJE ĮVERTINIMAS / ОЦЕНКА ВЛИЯНИЯ МЕТЕОРОЛОГИЧЕСКИХ ПАРАМЕТРО ВН АДИСПЕРСИЮ ПЫЛЬЦЫВ АТМОСФЕРЕ

2011 ◽  
Vol 19 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Laura Veriankaitė ◽  
Ingrida Šaulienė ◽  
Arūnas Bukantis
Keyword(s):  
Air Temperature ◽  
Meteorological Parameters ◽  
Airborne Pollen ◽  
Rank Correlation ◽  
Correlation Method ◽  
Pollen Concentration ◽  
Spearman’S Rank Correlation ◽  
Rank Correlation Method ◽  
Pollen Types ◽  
Complex Influence

The elements determining the meteorological conditions are the main parameters in processes of airborne pollen modeling. In modern research the influence of different meteorological element or their complex is analyzed basing upon the statistic methods or using dispersion models in which the possible influence of meteorological parameters upon airborne pollen is described in equations. The correlation of meteorological indicators and pollen concentration in the atmosphere fixed in Klaipėda Aerobiological Station is analyzed in this article. The coefficients of correlation of meteorological parameters and pollen concentration are calculated basing upon the Spearman's rank correlation method. The analysis of various factors was used for determining the complex influence of meteorological parameters upon the pollen concentration in the air. After evaluation of influence of meteorological parameters as separate factors one has determined that more than a half of analyzed pollen types showed statistically reliable (p < 0.05) correlation of pollen amount in the air and relative air humidity (89%), air temperature (74%) and amount of precipitation (52%). The investigation results showed that 37% of pollen amount of indicated plants genera and families in the atmosphere was determined by wind velocity. After evaluation of complex influence of meteorological factors on the concentration of pollen spread in the air one has determined that relative humidity and/or air temperature are one of the most significant environmental factors determining the amount of pollen in the atmosphere during the vegetation. Their influence was determined for all the three cases under study. Santrauka Meteorologines sąlygas nusakantys elementai yra pagrindiniai parametrai modeliuojant žiedadulkių sklaidą. Nūdienos moksliniuose tyrimuose tam tikro meteorologinio elemento ar jų komplekso poveikis analizuojamas statistiniais metodaisarba taikant sklaidos modelius, kuriuose pagrindinėmis lygtimis aprašoma galima meteorologinių parametrų įtaka žiedadulkių sklaidai. Straipsnyje analizuojama meteorologinių rodiklių sąsajos su Klaipėdos aerobiologinėje stotyje fiksuota žiedadulkių koncentracija ore. Meteorologinių parametrų ir žiedadulkių koncentracijų koreliacijos koeficientai apskaičiuoti Spearman ranginės koreliacijos metodu. Tiriant kompleksinę meteorologinių parametrų įtaką žiedadulkių koncentracijai ore, išanalizuota įvairūs veiksniai. Atskirai įvertinus įvairių meteorologinių parametrų įtaką, nustatyta statistiškai patikima (p < 0,05) daugiau nei pusės analizuotų žiedadulkių tipų žiedadulkių kiekio ore ir santykinės oro drėgmės (89 %), oro temperatūros (74 %) ir kritulių kiekio (52 %) sąsaja. Tyrimo rezultatai rodė, kad vėjo greitis turi įtakos 37 % identifikuotų augalų genčių ir šeimų žiedadulkių kiekiui ore. Įvertinus kompleksinę meteorologinių veiksnių įtaką oru sklindančių žiedadulkių koncentracijai, nustatyta, kad santykinis drvgnumas ir/arba oro temperatūra yra vieni reikšmingiausių aplinkos veiksnių, lemiančių žiedadulkių kiekį atmosferoje vegetacijos metu. Резюме Элементы, описывающие метеорологические условия, являются основными параметрами в процессах моделирования дисперсии пыльцы. В современных исследованиях воздействие каждого метеорологического элемента илиих комплекса анализируется с помощью статистических методов и моделей распространения, в которых фундаментальными уравнениями описываются возможные эффекты воздействия метеорологических параметровна распространение пыльцы. Статья посвящена анализу соотношения метеорологических величин с концентрацией пыльцы, зафиксированной на аэробиологической станции Клайпеды. Коэффициенты корреляции междуметеорологическими параметрами и концентрацией пыльцы вычислены на основе метода ранговой корреляцииСпирмена. Анализ различных факторов был использован для определения комплексного влияния метеорологических параметров на концентрации пыльцы в воздухе. Оценка метеорологических параметров как отдельныхфакторов показала, что более половины анализируемых типов пыльцы свидетельствует о статистически значимой(р < 0,05) связи между пыльцой в воздухе и относительной влажностью (89%), температурой воздуха (74%) иосадками (52%). Результаты исследования показали, что скорость ветра оказывает влияние на количество ватмосфере 37% определенных семейств и родов пыльцы. Оценка комплексного влияния метеорологическихфакторов на концентрацию пыльцы в воздухе показала, что относительная влажность воздуха и(или) температуравоздуха являются одними из наиболее важных экологических факторов, определяющих количество пыльцы ватмосфере в течение вегетационного периода. Их влияние выявлено вo всех изученных случаях.

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