Relationships between airborne pollen grains, wind direction and land cover using GIS and circular statistics

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.

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An assessment of the Ambrosia L. pollen threat at a regional scale using the example of the town of Sosnowiec (Silesian Uplands, Poland)

Acta Agrobotanica ◽

10.5586/aa.2011.017 ◽

2012 ◽

Vol 64 (2) ◽

pp. 51-62 ◽

Cited By ~ 3

Author(s):

Kazimiera Chłopek ◽

Katarzyna Dąbrowsa-Zapart ◽

Barbara Tokarska-Guzik

Keyword(s):

Wind Direction ◽

Regional Scale ◽

Pollen Grains ◽

Maximum Temperature ◽

Sampling Point ◽

Air Masses ◽

Daily Count ◽

Annual Total ◽

The Town ◽

Maximum Air Temperature

The investigation of Ambrosia pollen counts in the air of Sosnowiec was carried out from 1998 to 2010 by means of the volumetric method. The pollen season which was determined by means of the 98% method started at the end of July and the beginning of August and lasted until the end of October. The highest Ambrosia pollen count was recorded in 1999 (222 grains x m-3) and the lowest in 2001 (18 grains x m-3). It was stated that the daily count of pollen grains depended on the wind direction and maximum air temperature. The strongest correlations were found with maximum temperature and with a wind direction from the south east. A high negative correlation coefficient was found between the frequency of inflows of air masses from the west and the annual total of pollen grains and the value of the maximum daily count. The closest sites of Ambrosia L. are at a distance of 25-40 kilometres from the sampling point. Significant correlations with the frequency of inflow of air masses can support the conclusion that Ambrosia pollen grains recorded in Sosnowiec were most probably carried not only from local sources but also, at least in part, from distant places.

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

10.5194/acp-2020-794 ◽

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.

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On the Algorithms Used to Compute the Standard Deviation of Wind Direction

Journal of Applied Meteorology and Climatology ◽

10.1175/2009jamc2050.1 ◽

2009 ◽

Vol 48 (10) ◽

pp. 2144-2151 ◽

Cited By ~ 7

Author(s):

Pierre S. Farrugia ◽

James L. Borg ◽

Alfred Micallef

Keyword(s):

Standard Deviation ◽

Wind Direction ◽

Atmospheric Stability ◽

Angular Distance ◽

Circular Statistics ◽

Horizontal Wind ◽

Stability Class ◽

Mathematical Expressions ◽

Analytical Work

Abstract The standard deviation of wind direction is a very important quantity in meteorology because in addition to being used to determine the dry deposition rate and the atmospheric stability class, it is also employed in the determination of the rate of horizontal diffusion, which in turn determines transport and dispersion of air pollutants. However, the computation of this quantity is rendered difficult by the fact that the horizontal wind direction is a circular variable having a discontinuity at 2π radians, beyond which the wind direction starts again from zero, thus preventing angular subtraction from being a straightforward procedure. In view of such a limitation, this work is meant to provide new mathematical expressions that simplify both the computational and analytical work involved in handling the standard deviation of wind direction. This is achieved by deriving a number of Fourier series and Taylor expansions that can represent the minimum angular distance and its powers. Using these expressions, the relation between two algorithms commonly used to determine the standard deviation of wind direction is analyzed. Furthermore, given that these trigonometric expansions effectively reduce the mathematical complexity involved when dealing with circular statistics, their potential application to solve other problems is discussed.

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The late flowering of invasive species contributes to the increase of Artemisia allergenic pollen in autumn: an analysis of 25 years of aerobiological data (1995–2019) in Trentino-Alto Adige (Northern Italy)

Aerobiologia ◽

10.1007/s10453-020-09663-7 ◽

2020 ◽

Vol 36 (4) ◽

pp. 669-682 ◽

Cited By ~ 1

Author(s):

Antonella Cristofori ◽

Edith Bucher ◽

Michele Rossi ◽

Fabiana Cristofolini ◽

Veronika Kofler ◽

...

Keyword(s):

Invasive Species ◽

Pollen Season ◽

Airborne Pollen ◽

Pollen Grains ◽

Late Summer ◽

Natura 2000 ◽

Allergenic Pollen ◽

Pollen Concentration ◽

Pollen Concentrations ◽

Negative Impacts

AbstractArtemisia pollen is an important aeroallergen in late summer, especially in central and eastern Europe where distinct anemophilous Artemisia spp. produce high amounts of pollen grains. The study aims at: (i) analyzing the temporal pattern of and changes in the Artemisia spp. pollen season; (ii) identifying the Artemisia species responsible for the local airborne pollen load.Daily pollen concentration of Artemisia spp. was analyzed at two sites (BZ and SM) in Trentino-Alto Adige, North Italy, from 1995 to 2019.The analysis of airborne Artemisia pollen concentrations evidences the presence of a bimodal curve, with two peaks, in August and September, respectively. The magnitude of peak concentrations varies across the studied time span for both sites: the maximum concentration at the September peak increases significantly for both the BZ (p < 0.05) and SM (p < 0.001) site. The first peak in the pollen calendar is attributable to native Artemisia species, with A. vulgaris as the most abundant; the second peak is mostly represented by the invasive species A. annua and A. verlotiorum (in constant proportion along the years), which are causing a considerable increase in pollen concentration in the late pollen season in recent years.. The spread of these species can affect human health, increasing the length and severity of allergenic pollen exposure in autumn, as well as plant biodiversity in both natural and cultivated areas, with negative impacts on, e.g., Natura 2000 protected sites and crops.

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Do Conocarpus erectus airborne pollen grains exacerbate autumnal thunderstorm asthma attacks in Ahvaz, Iran?

Atmospheric Environment ◽

10.1016/j.atmosenv.2019.06.010 ◽

2019 ◽

Vol 213 ◽

pp. 311-325 ◽

Cited By ~ 5

Author(s):

Hassan Dehdari Rad ◽

Mohammad-Ali Assarehzadegan ◽

Gholamreza Goudarzi ◽

Armin Sorooshian ◽

Yaser Tahmasebi Birgani ◽

...

Keyword(s):

Airborne Pollen ◽

Pollen Grains ◽

Conocarpus Erectus ◽

Thunderstorm Asthma

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Airborne Pollen Records of Shomolu Local Government Area in Lagos State

Notulae Scientia Biologicae ◽

10.15835/nsb649355 ◽

2014 ◽

Vol 6 (4) ◽

pp. 428-432 ◽

Cited By ~ 1

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.

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Corrigendum to do Conocarpus erectus airborne pollen grains exacerbate autumnal thunderstorm asthma attacks in Ahvaz, Iran? [Atmos. Environ.] volume 213, 15 September 2019, pages 311-325

Atmospheric Environment ◽

10.1016/j.atmosenv.2019.116851 ◽

2019 ◽

Vol 214 ◽

pp. 116851

Author(s):

Hassan Dehdari Rad ◽

Mohammad-Ali Assarehzadegan ◽

Gholamreza Goudarzi ◽

Armin Sorooshian ◽

Yaser Tahmasebi Birgani ◽

...

Keyword(s):

Airborne Pollen ◽

Pollen Grains ◽

Atmos Environ ◽

Conocarpus Erectus ◽

Thunderstorm Asthma

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Volumetric analysis of airborne pollen grains in the city of Uşak, Turkey

TURKISH JOURNAL OF BOTANY ◽

10.3906/bot-1703-58 ◽

2018 ◽

Vol 42 ◽

pp. 57-72 ◽

Cited By ~ 5

Author(s):

Ulaş UĞUZ ◽

Aykut GÜVENSEN ◽

Nedret ŞENGONCA TORT ◽

Aylin EŞİZ DEREBOYLU ◽

Pelin BARAN

Keyword(s):

Airborne Pollen ◽

Pollen Grains ◽

Volumetric Analysis ◽

The City

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Tree Pollen Spectra and Pollen Allergy Risk in the Osijek-Baranja County

Archives of Industrial Hygiene and Toxicology ◽

10.2478/10004-1254-64-2013-2235 ◽

2013 ◽

Vol 64 (1) ◽

pp. 115-122 ◽

Cited By ~ 4

Author(s):

Magdalena Sikora ◽

Marina Valek ◽

Zdenka Šušić ◽

Vera Santo ◽

Dario Brdarić

Keyword(s):

Airborne Pollen ◽

Pollen Allergy ◽

Pollen Grains ◽

Weather Conditions ◽

Research Information ◽

Tree Pollen ◽

Pollen Concentrations ◽

North Eastern ◽

Measuring Site ◽

Monitoring Stations

The forests of north-eastern Croatia, as well as various plants and trees in the parks and streets of the Osijek-Baranja County, produce large amounts of pollen during the pollen season, which can cause allergy symptoms in pollen sensitive individuals. The aim of this study was to determine the most frequent types of pollen in this area and estimate possible health risks, especially the risk of allergy. In 2009 and 2010, the staff of the Health Ecology Department of the Osijek Public Health Institute monitored tree pollen concentrations in four cities from the Osijek - Baranja County (Osijek, Našice, Đakovo and Beli Manastir) using a Burkard volumetric instrument. The results were affected by weather conditions. Windy and sunny days facilitated the transfer of pollen, whereas during rainy days, the concentration of pollen grains decreased. High pollen concentrations of Cupressaceae/Taxaceae, Betulaceae, Salicaceae and Aceraceae could be the cause for symptoms of pollen allergy. In 2009, conifers, birch and poplar pollen were dominant at all monitoring stations with 5000 pollen grains (PG), 3188 PG and 3113 PG respectively. The highest number of pollen grains was recorded at measuring site Osijek. The variations in airborne pollen concentration between pollen seasons were recorded at all monitoring stations. The most obvious variations were recorded at measuring site Osijek. The usual pollination period lasts two to three months, which means that most pollen grains remain present from February to early June. However, the Cupressaceae / Taxaceae pollination periods last the longest and their pollen grains remain present until the end of summer. The risk of allergy was determined at four monitored measuring stations and the obtained data confirmed that the largest number of days with a high health risk was at the Đakovo measuring station for a species of birch. The research information aims to help allergologists and individuals allergic to plant pollen develop preventive measures and proper treatment therapies.

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