Abstract

Studies focused on the seasonal distribution of pollen and spores in semiarid cities are scarce. At these sites, climate change potentiates the emission and transport of fine (PM₁₀) to ultrafine particles (PM_2.5), easily attached to pollen surfaces, causing allergen’s release. This study examines the potential correlation of seasonal variations of pollen, fungal spores, PM₁₀, and meteorological parameters with allergic reactions of 150 people living in a Sonoran desert city. We collected PM₁₀, airborne pollen, and spores during a year. We also studied topsoil and road dust samples as potential PM-emission sources. We obtained dust-mineralogy, chemistry, and particle size attached to pollen by X-ray diffraction and scanning electron microscope. Results show that seasonal high PM-loading in the urban atmosphere coincides with aeroallergens promoting micro- to nanoparticles’ attachment to pollen’s surface. A collapsed membrane was observed in several samples after individual grains show the following maximum wall coverage: Poaceae 28%, Asteraceae 40%, Chenopodiaceae-Amaranthacea 29%, Fabaceae 18%. Most of the particles covering pollen’s surface have a geogenic origin mixed with metals linked to traffic (bromide, chlorine, and antimony). Mineralogical, granulometric analysis, and main wind-direction show that two local soil-types are the main contributors to PM. A high frequency of positive sensitization to pollen with high particle loading was detected. These results suggest that climate-driven dust emissions may alter pollen and spore surfaces’ physicochemical characteristics with the further consequences in their allergenic potential.

Graphic abstract

中文翻译：

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干旱城市地区空气中颗粒物与花粉，真菌孢子和过敏症状的关系

摘要

很少有关于半干旱城市花粉和孢子季节性分布的研究。在这些地点，气候变化增强了细颗粒物（PM ₁₀）向超细颗粒（PM _2.5）的排放和运输，这些颗粒很容易附​​着在花粉表面，导致过敏原的释放。这项研究调查了花粉，真菌孢子，PM ₁₀和气象参数的季节性变化与生活在索诺兰沙漠城市的150人的过敏反应之间的潜在相关性。我们收集了_10号纸，空气中的花粉和孢子。我们还研究了表土和道路扬尘样品作为潜在的PM排放源。通过X射线衍射和扫描电子显微镜，我们获得了粉尘的矿物学，化学性质和附着在花粉上的粒径。结果表明，城市大气中季节性的高PM负荷与气态变应原相吻合，这些变应原促进了微颗粒到纳米颗粒与花粉表面的附着。在单个颗粒显示出以下最大壁覆盖率之后，在几个样品中观察到了膜塌陷：禾本科28％，菊科40％，藜科-mar菜29％，豆科18％。覆盖花粉表面的大多数颗粒都具有与成因相关的金属（溴化物，氯和锑）混合的地质成因。矿物学，粒度分析，主要风向表明，两种局部土壤类型是造成PM的主要因素。检测到高频率的高花粉负载对花粉的正敏感性。这些结果表明，气候驱动的粉尘排放可能会改变花粉和孢子表面的理化特性，并进一步影响其潜在的致敏性。

图形摘要