Comparative study of Alternaria airborne spore concentrations among urban, rural and natural areas in southern Spain

Abstract

One of the most cosmopolitan fungal spore types present in the air is that belonging to Alternaria. This spore type has been proved to have a negative impact on sensible population. Furthermore, Alternaria species are phytopathogens that cause high economic losses in agriculture. The aim of this study was to establish relationships between the airborne concentrations of Alternaria spores and the meteorological and climatic variables of the studied areas, as well as land use. For that, an aerobiological study has been carried out during 2018 in three sampling sites: a coastal urban city (Malaga), an inland rural city with high influence of crops and natural areas (Ronda), and a third site located inside a Natural Park (Sierra de las Nieves). The samplings were carried out by means of three Hirst-type volumetric pollen traps, and the samples obtained were mounted and counted following the methodology proposed by the Spanish Aerobiology Network (REA). Statistical analysis was carried out by using R software and ”AeRobiology” package. Negative and significant Spearman correlations were found between daily values of Alternaria spore concentration and precipitation as well as relative humidity in all the sampling sites, while positive and significant correlations were found with temperatures (the highest with maximum temperature). Alternaria daily concentrations showed significant differences between stations. As the results obtained by other authors, regarding the climatic parameters, we find a direct relationship between the continentality index and the total amount of Alternaria spores detected during spring and summer in the different sampling stations. Similar results were obtained with average annual temperature and total annual rainfalls. Regarding land use, the highest concentrations were obtained in the rural locality of Ronda.