- 1Center of Allergy and Environment, Technische Universität München-Helmholtz Center, Munich, Germany.
- 2Department of Botany, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovakia
Although bioaerosol particles are invisible to our eyes, they have a big impact in human life. Already at the beginning of the past century, the first attempts to detect the airborne pathogens causing damages in crops took place (Hirst, 1994), leading to the development of the Hirst trap (Hirst, 1952). From the agriculture field, the use of this trap jumped to the medical field, being used to monitor pollen and spores for the allergy patients. Since then, the use of manual pollen traps has spread around the world (Buters et al., 2018). However, the lack of experts and the laborious work of counting spores with a bright field microscope due to their small size and high numbers, has led to a scarcity of data on airborne fungal spores as compared to pollen.
Recently, automatic monitors have been developed and are able to identify pollen in the air (Buters et al., 2022). Some automatic monitors have proven to perform well in pollen identification (Maya-Manzano et al., 2023) and are being used in official monitoring networks (Oteros et al., 2020, Sauvageat et al., 2020, Tešendić et al., 2020). These devices have brought a new opportunity to the identification of other bioaerosols, i.e., fungal spores.
One of such instruments is the BAA500 (Hund GmbH). This instrument is designed as a cascade impactor. The air is sucked at high speed and particles between 4-80 µm arrive to a sticky plate at the end, where they are photographed with a camera attached to a microscope. Then, a software based in convolutional neural networks identifies the particles. The Validation tool (https://validation.pollenscience.eu/) is a quality control tool that allows to see the particles detected by the monitor. Within these images, we have confirmed that fungal spores are being captured by the device. However, a closer examination to evaluate their capture efficiency has not been done yet.
In order to test the efficiency of the BAA500 in the capture of fungal spores, we collocated a Hirst trap next to an automatic monitor for five months (from May to October 2024) and compared the concentration of 5 fungal spore types, comprising a wide size range challenging the detection lower and upper limits of the instrument: Ganoderma, Cladosporium, Polythrincium, Epicoccum and Alternaria.
First results show that small (R2= 0.02, 0,08) and big (R2= 0.39) spores are under captured by the automatic device as compared to the Hirst trap, probably due to their size being in the limits of the cascade impactor, whereas medium-size spores correlate nicely with Hirst concentrations, showing a correlation of R2= 0.69 and 0.76. These results confirm the potential of the BAA500 to be used as fungi monitor for medium-size spores. Spores with a size close to the detection limit will need a scaling factor.
How to cite: González-Alonso, M., Žilka, M., Schmidt-Weber, C., and Buters, J.: Evaluating the capture efficiency of fungal spores with automatic monitors: the case of BAA500 (Hund GmbH), EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-21470, https://doi.org/10.5194/egusphere-egu25-21470, 2025.