Passive fungal spore release from fruit and vegetable solid waste

Abstract

Food substrates in municipal solid wastes processing facilities and open dumpsites are a source for the release of fungal spores into air and can cause potential health and climate effects. Experiments were conducted in a laboratory scale flux chamber to measure the fungal growth and spore release from representative exposed cut fruit and vegetable substrates. The aerosolised spores were measured using an optical particle sizer. The results were compared to experiments conducted previously with a test species (Penicillium chrysogenum) on a synthetic media (czapek yeast extract agar). Significantly higher surface spore densities were observed for the fungi on the food substrates as compared to that on the synthetic media. The spore flux was high initially and then decreased on continued exposure to air. The spore emission flux normalised to the surface spore densities indicated that the emission from the food substrates was lower than the emissions from the synthetic media. A mathematical model was applied to the experimental data and the observed flux trends were explained in terms of the model parameters. A simple application of the data and the model to release from a municipal solid waste dumpsite was shown.