Assessing exposure to fungal bioaerosols in transport environments: Analysing fungal composition of passive dust samples collected in UK railway stations

Bioaerosols consist of a complex mixture of airborne microorganisms including fungi, bacteria, pollen, particulates and by-products of cells. While exposure to diverse microorganisms is essential for normal immune system development, bioaerosol inhalation has been associated with respiratory allergy and inflammation. Bioaerosol are ubiquitous, yet their composition within different environments is not well understood. Such information is essential for assessing exposure and associated health impacts. Here we focus on transport environments, namely railway stations (RSs), which pose a potential source of occupational and community exposure. 

Over 1200 passive dust samples were taken from 17 RSs across the UK from 03/2014-05/2015. GIS methods were used to provide information on population characteristics of the immediate surrounding area of the RSs. Together with information on RS layout and passenger numbers, this informed the selection of 250 samples, representing 9 RSs of varied geographical location, layout and footfall for further analysis. High throughput sequencing (HTS) with a metabarcoding approach targeting the ITS2 region was used to analyse the fungal composition of the sample subset. Such HTS techniques provide an opportunity to measure a wider range of microorganisms than traditional culture or microscopy techniques.

RS characteristics were varied and included indoor/enclosed and mostly outdoor layouts. Annual footfall varied from approximately 10-148 million.  The fungal composition of RS over time and relationships with different RS characteristics will be presented, identifying those driving any differences in composition.