Bioaerosol releases from compost facilities: Evaluating passive and active source terms at a green waste facility for improved risk assessments

The passive and active release of bioaerosols during green waste composting, measured at source is reported for a commercial composting facility in South East (SE) England as part of a research programme focused on improving risk assessments at composting facilities. Aspergillus fumigatus and actinomycetes concentrations of 9.8–36.8×106 and 18.9–36.0×106 cfu m−3, respectively, measured during the active turning of green waste compost, were typically 3-log higher than previously reported concentrations from static compost windrows. Source depletion curves constructed for A. fumigatus during compost turning and modelled using SCREEN3 suggest that bioaerosol concentrations could reduce to background concentrations of 103 cfu m−3 within 100 m of this site. Authentic source term data produced from this study will help to refine the risk assessment methodologies that support improved permitting of compost facilities.