Transport of Alternaria spores from both local agricultural and remote areas has been implicated as a source of these spores in urban areas. The purpose of this study was to understand the relative contribution of local sources versus long distance transport on Alternaria spore concentrations, with applicability to Alternaria and other spore sampling sites worldwide. This was achieved by comparing two spore sampling sites in the cities of Worcester and Leicester in the UK, ~90 km apart, over a three year period (2016-2018) and focusing on a period of time when both sites experienced high spore counts. The study found 61 and 151 days of clinical significance (>100 spores/m³ air) at Worcester and Leicester, respectively. The spore concentrations were considerably higher in Leicester than in Worcester. Analysis of the crop map showed higher amounts of winter barley and oilseed rape near to Leicester compared to Worcester. HYSPLIT modelling during the episode revealed that the air masses arrived at both Leicester and Worcester from Ireland and the Atlantic Ocean. Long distance transport probably had a small but equal contribution to the observations at both sites. HYSPLIT particle dispersion simulations showed that the spores were dispersed and deposited from local sources. The results indicate that substantially higher concentrations of Alternaria spores occur in areas with high amounts of cereals and oilseed rape compared to those with lower amounts, or with different crops.

来自当地农业和偏远地区的链格孢子孢子的运输被认为是城市地区这些孢子的来源。这项研究的目的是了解当地来源与长距离运输对链格孢菌孢子浓度的相对贡献，并适用于链格孢菌和全球其他孢子采样地点。通过比较三年（2016-2018）期间相距约90公里的英国伍斯特市和莱斯特市的两个孢子采样点并着重研究两个孢子计数高的时期来实现。研究发现61天和151天具有临床意义（> 100孢子/ m ³空气）分别在伍斯特和莱斯特。莱斯特的孢子浓度比伍斯特的高得多。作物图的分析表明，与伍斯特市相比，莱斯特附近的冬季大麦和油料油菜数量更高。剧集中的HYSPLIT建模显示，气团从爱尔兰和大西洋到达莱斯特和伍斯特。长途运输可能对这两个站点的观测贡献很小但均等。HYSPLIT颗粒分散模拟表明，孢子是从本地来源分散和沉积的。结果表明，与少量或不同作物相比，谷物和油菜含量高的地区发生的链格孢孢子浓度明显更高。