University of Castilla-La Mancha. Institute of Environmental Sciences, E-45071 Toledo, Spain.
Sci Total Environ. 2015 Dec 15;538:672-82. doi: 10.1016/j.scitotenv.2015.08.074. Epub 2015 Aug 30.
The interpretation of airborne pollen levels in cities based on the contribution of the surrounding flora and vegetation is a useful tool to estimate airborne allergen concentrations and, consequently, to determine the allergy risk for local residents. This study examined the pollen spectrum in a city in central Spain (Guadalajara) and analysed the vegetation landscape and land uses within a radius of 20km in an attempt to identify and locate the origin of airborne pollen and to determine the effect of meteorological variables on pollen emission and dispersal. The results showed that local wind direction was largely responsible for changes in the concentrations of different airborne pollen types. The land uses contributing most to airborne pollen counts were urban green spaces, though only 0.1% of the total surface area studied, and broadleaved forest which covered 5% of the study area. These two types of land use together accounted for 70% of the airborne pollen. Crops, scrubland and pastureland, though covering 80% of the total surface area, contributed only 18.6% to the total pollen count, and this contribution mainly consisted of pollen from Olea and herbaceous plants, including Poaceae, Urticaceae and Chenopodiaceae-Amaranthaceae. Pollen from ornamental species were mainly associated with easterly (Platanus), southerly (Cupressaceae) and westerly (Cupressaceae and Platanus) winds from the areas where the city's largest parks and gardens are located. Quercus pollen was mostly transported by winds blowing in from holm-oak stands on the eastern edge of the city. The highest Populus pollen counts were associated with easterly and westerly winds blowing in from areas containing rivers and streams. The airborne pollen counts generally rose with increasing temperature, solar radiation and hours of sunlight, all of which favour pollen release. In contrast, pollen counts declined with increased relative humidity and rainfall, which hinder airborne pollen transport.
基于周围植物群和植被的贡献来解释城市中的空气花粉水平是一种估算空气过敏原浓度的有用工具，进而可以确定当地居民的过敏风险。本研究检查了西班牙中部一个城市（瓜达拉哈拉）的花粉谱，并分析了 20 公里范围内的植被景观和土地利用情况，试图识别和定位空气花粉的来源，并确定气象变量对花粉排放和扩散的影响。结果表明，当地风向在很大程度上导致了不同空气花粉类型浓度的变化。对空气花粉计数贡献最大的土地利用类型是城市绿地，尽管仅占研究总面积的 0.1%，其次是阔叶林，覆盖了研究区域的 5%。这两种土地利用类型共占空气花粉的 70%。尽管农作物、灌丛和牧场占总表面积的 80%，但仅占花粉总数的 18.6%，而且这种贡献主要来自橄榄和草本植物的花粉，包括禾本科、荨麻科和藜科-苋科。观赏植物的花粉主要与来自城市最大的公园和花园所在地区的偏东风（悬铃木）、南风（柏科）和西风（柏科和悬铃木）有关。栎属花粉主要由来自城市东部山毛榉林的风向输送。杨属花粉计数最高与来自含有河流和溪流的地区的东风和西风有关。空气花粉计数通常随着温度、太阳辐射和日照时间的增加而升高，所有这些因素都有利于花粉释放。相比之下，花粉计数随着相对湿度和降雨量的增加而下降，这阻碍了空气花粉的传输。
