Airborne Cladosporium fungal spores and climate change in France

Abstract

Fungal spores are among the most commonly encountered airborne biological particles, and it is widely proved that they represent a potential source of allergens involved in rhinitis and asthma. A change in temperature may influence the colonisation and growth of fungi directly through the physiology of individual organisms, or indirectly through physiological effects on their host plants or substrates and any competitors or enemies. In order to detect and monitor the evolution of the spore counts, air sampling was carried out using standard equipment (Hirst-type volumetric traps) and an identical method in several stations across France. Cladosporium has been here emphasised because of its very large contribution to the total fungal spectrum. Moreover, this taxon is of particular clinical importance because it possesses a high allergenic potential. The data from the oldest traps (Aix-en-Provence, Bordeaux, Lyon, Paris and Toulouse) were analysed on an annual base. Located at different latitudes and in different climatic areas, these five cities showed fundamentally different trends for the concentrations of Cladosporium spores: downward trend at the southernmost locations and upward trend at the other locations, whereas temperature was everywhere continuously rising over the study period. However, longer data sets are needed to be able to draw more definitive conclusions about quantitative trends in airborne fungal spore concentrations.