Seasonal distribution of airborne pollen in the coastal plain of Israel

Airborne pollen was monitored in three major urban centers of the coastal plain of Israel during the years 1993–1995. Results show spatial and temporal variations among the three sites. Altogether, the number of identified species was rather low. Ornamental trees (Cupressaceae,Pinus, Olea, Casuarina, Ceratonia) and grasses, have constituted the main source of the pollen rain. A substantial contribution of the wild plants of the region was restricted toParietaria, Urtica, Mercurialis, Artemisia, grasses and members of the Chenopodiaceae and Amaranthaceae.     

Seasonal distribution of pollen in the atmosphere of melbourne: an airborne pollen calendar

Environmental monitoring of pollen grains in the atmosphere of Melbourne has been achieved using Burkard volumetric traps. Twenty-two families of flowering plants and confiers were identified in the pollen counts. About 62% of these pollen grains belonged to trees, 20% to grasses and 9% to herbs and weedy plants. During spring and summer, the atmosphere contained about 70% of the total annual pollen count. Tree pollen, predominantly elm and cypress, occurred abundantly in late winter and spring, with grass pollen predominantly in spring and early summer. These three types of pollen grains occurred in significant amounts, together accounting for more than 60% of the total annual catch. A seasonal incidence chart (pollen calendar) for Melbourne based on 2 years observation has been constructed. This pollen calendar is useful in identifying sources of allergies against particular seasonal airborne pollen types. Comparison of the time of occurrence of a particular pollen type using the pollen calendar and the time of allergic symptoms, can lead to accurate diagnosis and preventive measures being taken. This study has confirmed that grass pollen is the major source of allergenic pollen in the external environment triggering hay fever and allergic asthma in spring and early summer in Melbourne, Australia.     

Pinus pollen in the atmosphere of Vigo and its relationship to meteorological factors

The Pinus genus has an elevated pollen production and an anemophilous nature. Although considered to be hypoallergenic, numerous cases of allergies caused by Pinus pollen have been cited and different authors believe that its allergenicity should be studied in more depth. In the city of Vigo several patients have tested positive for Pinus pollen extracts in skin tests, some of them being mono-sensitive to such pollens. In order to ascertain the behaviour of Pinus pollen and its correlation to the main meteorological factors, we carried out an aerobiological study in the city of Vigo from 1995 to 1998 by using a Hirst active-impact volumetric sporetrap, model Lanzoni VPPS 2000, placed on the left bank of the Vigo estuary (42°14’15’’N, 8°43’30’’W). Pinus has high quantitative importance in the airborne pollen spectrum of the city. It is one of the best represented taxa constituting 13%–20% of the total annual pollen levels. The quantity of Pinus pollen present in the atmosphere of the city of Vigo throughout a year is 5751 grains (as the average for the sampled years), with a very long pollination period, from the middle of January until May. The maximum concentration was recorded in 1998 with 1105 grains/m³ on 3 March, a much greater value than those for the previous years. At the end of its pollination period there is usually a final increase in Pinus pollen concentrations coinciding with the pollination of Pinus silvestris, which are more abundant in mountainous areas far from the city. Received: 17 March 1999 / Revised: 20 December 1999 / Accepted: 20 December 1999     

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

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

拉萨市不同季节空气微生物浓度及影响因素分析

【背景】空气微生物是城市生态系统的重要组成部分,其浓度对于监测城市空气质量、治理环境污染、预防疾病发生具有重要意义。【目的】研究拉萨市空气微生物分布特征,探讨气象因素和空气颗粒物对空气微生物分布特征的影响。【方法】基于荧光显微镜法分析了2019年10月–2020年10月不同季节空气微生物浓度及附着特征,结合气象因素和环境指标分析其影响因素。【结果】在荧光显微镜下,经过SYBR Green I染色的微生物呈亮绿色,规则椭圆状,大小在0.5-1.0μm之间,同时还观察到微生物附着在有机物和黑碳上的现象。拉萨市空气微生物浓度变化范围为3.10×10³-2.38×10⁴ cells/m³,冬季空气中2种存在形式的微生物(自由漂浮和附着颗粒物)浓度最高。自由漂浮微生物浓度在秋季最低,与冬季存在显著差异(P<0.05),不同季节颗粒附着微生物的浓度差异不显著。Spearman相关性分析表明,微生物浓度与气象因素无显著相关,但与空气中颗粒物浓度呈显著正相关(P<0.05)。【结论】拉萨市空气微生物浓度与全国其他城市相比处于...     

The effect of meteorological factors on the daily variation of airborne fungal spores in Granada (southern Spain)

A study was made of the link between climatic factors and the daily content of certain fungal spores in the atmosphere of the city of Granada in 1994. Sampling was carried out with a Burkard 7-day-recording spore trap. The spores analysed corresponded to the taxa Alternaria, Ustilago and Cladosporium, with two morphologically different spore types in the latter genus, cladosporioides and herbarum. These spores were selected both for their allergenic capacity and for the high level of their presence in the atmosphere, particularly during the spring and autumn. The spores of Cladosporium were the most abundant (93.82% of the total spores identified). The Spearman correlation coefficients between the spore concentrations studied and the meteorological parameters show different indices depending on the taxon being analysed. Alternaria and Cladosporium are significantly correlated with temperature and hours of sunlight, while Ustilago shows positive correlation indices with relative humidity and negative indices with wind speed. Received: 16 April 1998 / Revised: 27 September 1999 / Accepted: 27 October 1999     

Changes in airborne pollen concentrations in Delhi,India

In order to find the qualitative and quantitative changes in airborne pollen concentrations in Delhi metropolis area an aerobiological survey was undertaken from September 1990 to August 1997. Air samples were collected daily using a Rotorod Aeroallergen Sampler at 10?m above the ground level. Ninety-four pollen types were recorded and the major contributors include Morus, Cannabis, Chenopod/Amaranth, Prosopis, Artemisia, and Eucalyptus. Ten pollen types contributed 90% of the total pollen load. Two major pollen seasons were recorded each year (February–April and September–November), although pollen grains in low frequency were recorded throughout the whole year. A significant reduction in pollen concentration was observed in subsequent years. The number of Morus, Cannabis, Prosopis, and Artemisia pollen decreased considerably while the number of Ricinus communis pollen did not show any considerable change during the study period. It is suggested that the reduction in pollen numbers from 1990 to 1997 in Delhi is due to massive clearing of vegetation for developmental activities of the city.     

2012—2016年海淀区气传花粉物候特征及其与气象要素的关系

利用重力沉淀法对2012—2016年海淀区气传花粉种类及含量进行监测,分析海淀区的花粉种类、峰值分布特征和含量变化、以及花粉浓度的不连续变化特征,在此基础上采用集合经验模态分解法对花粉浓度进行多时间尺度分析,并分析了花粉浓度与气象要素之间的关系.结果表明: 研究期间,海淀区的主要气传花粉种类已经发生改变,柏科、杨柳科等木本植物代替草本植物成为含量最多的气传花粉类别;花粉浓度的年内峰值分布并无明显改变;近5年花粉浓度整体呈下降趋势,但橘科等草本植物花粉浓度呈上升趋势;统计时段内,花粉浓度在4月上旬、5月下旬及8月上旬共发生3次不连续变化;花粉浓度存在准2 d、准51 d、准128 d的变化周期;温度对于花粉浓度的影响在各气象要素中占有主导地位,16～18 ℃范围内花粉浓度明显升高;气温的变化对逐日花粉浓度的影响具有一定的滞后性和持续性,通常与滞后2～7 d的花粉浓度相关性较高,日照时数和风速对当天的花粉浓度影响最显著.     

The effect of temperature, relative humidity and rainfall on airborne ragweed pollen concentrations

Major weather parameters have long been known to alter airborne pollen and spore concentrations. The following study was conducted to study the effect of three of these parameters on airborne ragweed pollen concentrations.During the ragweed (RW) season for the years 1997 and 1998, 10 minute pollen collections were taken at least every 4 hours using an Allergenco MK-3 spore trap. Slides were fixed, and counted microscopically at 400X. During this same period, weather parameters were monitored by an Automated Weather Systems recording station located within a few meters of the collector.The ragweed season for this region begins in mid August and ends by mid October. Temperature patterns for the period demonstrated usual daily fluctuations with highs 13 to 35 °C and lows 8 to 24 °C. Relative humidity readings for the period varied between 25 and 100%. Highest RW values were seen after seasonal cooling in September. Daily rainfall for the period varied between 0 and 100 mm. Airborne RW always declined sharply after strong rainfall events (> 10 mm/day). Peak airborne RW concentrations were often associated with the passing of frontal boundaries and the change in wind direction and velocity that accompanies that passing.Factors influencing airborne RW concentrations are multiple and complex, but atmospheric forces have great influence. The passing of major weather fronts and the associated temperature drops, wind disturbances and rainfall are the major factors.     

The effect of meteorological parameters on diurnal patterns of airborne olive pollen concentration

Aerobiological studies carried out in the atmosphere of Granada using a Hirst-type volumetric spore trap during the period 1993-1996 show that there is not a single diurnal pattern for olive pollen (Olea europaea L.) over the course of the main pollen season. Examination of the behaviour of airborne olive pollen concentration allows the establishment of either regular (54.4% of the studied days) or irregular (45.6% of the time) patterns of diurnal variation. On a given day, the pattern found will depend on a combination of different factors: the origin of the captured pollen (either local or regional), source distribution in relation to the pollen sampler, topography, and different meteorological variables (mean air temperature, sunshine hours, total rainfall, relative humidity, wind speed and direction, and periods of calm). Regional sources were significant contributors to city centre pollen concentrations when moderate (< 10 km/h) winds from the 4th quadrant and warm temperatures (19-26 C) allow swift transport from the W-NW of the province.     

Threat of allergenic airborne grass pollen in Szczecin,NW Poland: the dynamics of pollen seasons,effect of meteorological variables and air pollution

The dynamics of Poaceae pollen season, in particularly that of the Secale genus, in Szczecin (western Poland) 2004–2008 was analysed to establish a relationship between the meteorological variables, air pollution and the pollen count of the taxa studied. Consecutive phases during the pollen season were defined for each taxon (1, 2.5, 5, 25, 50, 75, 95, 97.5, 99% of annual total), and duration of the season was determined using the 98% method. On the basis of this analysis, the temporary differences in the dynamics of the seasons were most evident for Secale in 2005 and 2006 with the longest main pollen season (90% total pollen). The pollen season of Poaceae started the earliest in 2007, when thermal conditions were the most favourable. Correlation analysis with meteorological factors demonstrated that the relative humidity, mean and maximum air temperature, and rainfall were the factors influencing the average daily pollen concentrations in the atmosphere; also, the presence of air pollutants such as ozone, PM₁₀ and SO₂ was statistically related to the pollen count in the air. However, multiple regression models explained little part of the total variance. Atmospheric pollution induces aggravation of symptoms of grass pollen allergy.     

Seasonal airborne pollen pattern in Mar del Plata City, Argentina

Continuous aerobiological survey of the atmosphere of Mar del Plata was carried out from December 1991 to November 1993 with a Burkard volumetric spore trap. Daily slides were prepared and studied every 2 h with standard techniques. Weekly records were kept for 27 relevant pollen types selected either by their prevalence or relative high atmospheric concentration. Quantitative multivariate analysis enabled to distinguish three major pollen seasons, related to atmospheric dominance either arboreal pollen (AP) or non-arboreal pollen (NAP). June to October is the richest period in number of pollen types, mainly dominated by AP; while from November to May, there is an overwhelming dominance of NAP types, represented by grass, herb and weed pollen. The study and prediction of this phenomenon is of great interest not only from the ecosystem point of view, but in relation to human disease as well.     

北京城区气传花粉季节分布特征

研究北京城区气传花粉种类、数量及季节消长规律,为防治花粉症及建设合理城市绿地提供有效资料.应用Burkard采样器于2010年12月31日至2011年12月31日对北京城区气传花粉浓度进行监测,并对花粉浓度进行统计学分析.研究结果显示,2011年北京城区的花粉季节从3月20日起始,至10月18日截止,持续213d,占全年天数的58％;全年花粉含量月分布呈现两个高峰,第1个高峰为3-4月,主要花粉为木犀科、杨属、柳属等树木花粉,占全年花粉总量的30％;第2个高峰为8-9月,主要花粉为菊科、藜科及苋科等莠草花粉,占全年花粉总量的50％;2011年度北京城区最具代表性的气传花粉来自于菊科,比重占了收集到气传花粉的35％.研究结果还表明,秋季的气传花粉致敏性强,所以北京花粉症的高发季节主要集中在秋季,以8-9月为最高,其中有95％的病人在此期间出现花粉症症状.花粉浓度及飘散规律受当地植被状况及气候等多种因素影响,因此,北京城区空气中气传花粉飘散种类、数量及季节分布规律的调查结果,可以为本地区花粉症防治及绿化品种的选择提供可靠依据.     

Fifteen years' record of airborne allergenic pollen and meteorological parameters in Thessaloniki,Greece

A pollen calendar has been constructed for the area of Thessaloniki and relationships between pollen transport and meteorological parameters have been assessed. Daily airborne pollen records were collected over a 15-year period (1987-2001), using a Burkard continuous volumetric pollen trap, located in the centre of the city. Sixteen allergenic pollen types were identified. Simultaneously, daily records of five main meteorological parameters (mean air temperature, relative humidity, rainfall, sunshine, wind speed) were made, and then correlated with fluctuations of the airborne pollen concentrations. For the first time in Greece, a pollen calendar has been constructed for 16 pollen types, from which it appears that 24.9% of the total pollen recorded belong to Cupressaceae, 20.8% to Quercus spp., 13.6% to Urticaceae, 9.1% to Oleaceae, 8.9% to Pinaceae, 6.3% to Poaceae, 5.4% to Platanaceae, 3.0% to Corylus spp., 2.5% to Chenopodiaceae and 1.4% to Populus spp. The percentages of Betula spp., Asteraceae (Artemisia spp. and Ambrosia spp.), Salix spp., Ulmaceae and Alnus spp. were each lower than 1%. A positive correlation between pollen transport and both mean temperature and sunshine was observed, whereas usually no correlation was found between pollen and relative humidity or rainfall. Finally, wind speed was generally found to have a significant positive correlation with the concentrations of 8 pollen types. For the first time in the area of Thessaloniki, and more generally in Greece, 15-year allergenic pollen records have been collected and meteorological parameters have been recorded. The airborne pollen concentration is strongly influenced by mean air temperature and sunshine duration. The highest concentrations of pollen grains are observed during spring (May).     

Size distribution of viable, cultivable, airborne microbes and their relationship to particulate matter concentrations and meteorological conditions in a Mediterranean site

The biological loading of viable, cultivable airborne microbes (heterotrophic bacteria, actinobacteria and fungi) in 6 size fractions as well as the three different fractions of respirable particulate matter (PM₁, PM_2.5 and PM₁₀) and their relationship to meteorological conditions were studied in the ambient air due to health-related interests. An Andersen six stage viable particle impactor and a MAS 100 sampler were used for microbial measurements. 82 measurements were performed at three different periods (41 days) at a suburban, residential site in the city of Chania (Crete, Greece) during the period from April 2008 to June 2009. The concentrations of the viable, cultivable airborne microbes (bioaerosols) as well as of the PM₁, PM_2.5 and PM₁₀ were highly variable during the whole measurement period. Among the airborne microbes, fungi presented the most abundant taxonomic group in the ambient air. A characteristic profile of the mean size distribution of biological loading in different PM fractions was obtained for every measured microbial taxonomic group. Although, the highest concentrations of the airborne fungi and actinobacteria were determined at aerodynamic diameters between 2.1 and 3.3 μm, a nearly equal distribution of the mean concentrations of the airborne heterotrophic bacteria was observed in the six different size fractions. However, two small maxima were observed at the airborne heterotrophic bacteria distribution, one at the fraction with aerodynamic diameters between 1.1 and 2.1 μm, and at other at the coarse fraction with aerodynamic diameter larger than 7 μm. A considerable part of the airborne microbes Cycloheximide per mL of growth medium of bacteriwere resistant to drugs. Between 10 and 40 % of the viable, cultivable airborne microbes were resistant to low concentrations of drugs (5–10 μg of Streptomycin or a or fungi, respectively). Furthermore, multiple linear regression of the data showed that the variation in fungi concentrations depends on the variation in PM₁₀ mass concentration, PM₁ number concentration, relative humidity and solar radiation. Likewise, the concentration of heterotrophic bacteria was found proportional to the values of relative humidity and fungal concentration, whereas was negatively correlated to the solar radiation.     

Poaceae pollen in the atmosphere of Tetouan (NW Morocco): effect of meteorological parameters and forecast of daily pollen concentration

The Poaceae pollen season has been characterized in Tetouan during a 7-year period, and the effect of weather conditions on daily concentrations was examined. The forecast models were produced using a stepwise multiple regression analyses. Firstly, three models were constructed to predict daily Poaceae pollen concentrations during the main pollen season, as well as the pre-peak and post-peak periods with data from 2008 to 2012 and tested on data from 2013 and 2014. Secondly, the regression models using leave-one-out cross-validation were produced with data obtained during 2008–2014 taking into account meteorological parameters and mean pollen concentrations of the same day in other years. The duration of the season ranged from 70 days in 2009 to 158 days in 2012. The highest amount of Poaceae pollen was detected in spring and the first fortnight of July. The annual sum of airborne Poaceae pollen concentrations varied between 2100 and 6251. The peak of anthesis was recorded in May in six of the other years studied. The regression models accounted for 36.3–85.7% of variance in daily Poaceae pollen concentrations. The models fitted best when the mean pollen concentration of the same day in other years was added to meteorological variables, and explained 78.4–85.7% of variance of the daily pollen changes. When the year 2014 was used for validating the models, the lowest root-mean-square errors values were found between the observed and estimated data (around 13). The reasonable predictor variables were the mean pollen concentration of the same day in other years, mean temperature, precipitations, and maximum relative humidity.     

Spatial and temporal modeling of daily pollen concentrations

Accurate assessments of pollen counts are valuable to allergy sufferers, the medical industry, and health researchers; however, monitoring stations do not exist in most areas. In addition, the degree of spatial reliability provided by the limited number of monitoring stations is poorly understood. We developed and compared spatial models to estimate pollen concentrations in locations without monitoring stations. Daily Acer, Quercus, and overall tree, grass, and weed pollen counts, in grains/m³, were obtained from 14 aeroallergen monitoring stations located in the northeastern and mid-Atlantic region of the United States from 2003 to 2006. Pollen counts were spatially interpolated using ordinary kriging. Mixed effects and generalized estimating equations incorporating daily and seasonal weather characteristics, pollen season characteristics and land-cover information were also developed to estimate daily pollen concentrations. We then compared observed values from a monitoring station to model estimates for that location. Observed counts and kriging estimates for tree pollen differed (p = 0.04), but not when peak periods were removed (p = 0.29). No differences between observed and kriging estimates of Acer (p = 0.46), Quercus (p = 0.24), grass (p = 0.31) or weed pollen (p = 0.29) were found. Estimates from longitudinal models also demonstrated good agreement with observed counts, except for the extremes of pollen distributions. Our results demonstrate that spatial interpolation techniques as well as regression methods incorporating both weather and land-cover characteristics can provide reliable estimates of daily pollen concentrations in areas where monitors do not exist for all but periods of extremely high pollen.     

Theoretical daily variation patterns of airborne pollen in the southwest of spain

In this work we establish theoretical daily pollen variation grains for the 24 taxa most frequently occurring in the atmosphere of Córdoba (Spain) during three consecutive years, namely Alnus glutinosa, Broussonetia papyrifera, Casuarina equisetifolia, Chenopodiaceae, Amaranthaceae, Cupressaceae, Cyperaceae, Ericaceae, Fraxinus, Gramineae, Mercurialis, Morus, Myrtaceae, Olea europaea, Palmae, Pinaceae, Pistacia, Plantago, Platanus hybrida, Populus, Quercus, Rumex, Typha domingensis, Ulmus minor and Urticaceae. Sampling was carried out using a Burkard spore-trap and the data collected were used to establish theoretical patterns of daily variation represented by an ideal day with accounts for the daily behaviour of each taxon.

The application of centred-data analysis (CDA) allowed two groups of taxa to be established, namely (a) those with a homogeneous variation pattern and small differences between the times of maximum and minimum occurrence, and (b) those with a heterogeneous variation pattern arising from large differences between maxima and minima or from a rather erratic variation.

As a rule, maximum pollen concentrations were found to coincide with the times of maximum sunlight and temperature.