title: Predicting Aspergillus fumigatus exposure from composting facilities using a dispersion model: A conditional calibration and validation.
abstract: Bioaerosols are released in elevated quantities from composting facilities and are associated with negative health effects, although dose-response relationships are unclear. Exposure levels are difficult to quantify as established sampling methods are costly, time-consuming and current data provide limited temporal and spatial information. Confidence in dispersion model outputs in this context would be advantageous to provide a more detailed exposure assessment. We present the calibration and validation of a recognised atmospheric dispersion model (ADMS) for bioaerosol exposure assessments. The model was calibrated by a trial and error optimisation of observed Aspergillus fumigatus concentrations at different locations around a composting site. Validation was performed using a second dataset of measured concentrations for a different site. The best fit between modelled and measured data was achieved when emissions were represented as a single area source, with a temperature of 29°C. Predicted bioaerosol concentrations were within an order of magnitude of measured values (1000-10,000CFU/m3) at the validation site, once minor adjustments were made to reflect local differences between the sites (r2>0.7 at 150, 300, 500 and 600m downwind of source). Results suggest that calibrated dispersion modelling can be applied to make reasonable predictions of bioaerosol exposures at multiple sites and may be used to inform site regulation and operational management.
authors.affiliation: Imperial College London, Small Area Health Statistics Unit, MRC-PHE Centre for Environment and Health and National Institute for Health Research Health Protection Research Unit in Health Impact of Environmental Hazards at King's College London, in Partnership with Public Health England and Collaboration with Imperial College London, United Kingdom; Cranfield University, School of Water, Energy, and Environment, Cranfield, Bedfordshire, United Kingdom. Electronic address: p.douglas@imperial.ac.uk.
authors.forename: Philippa
authors.initials: P
authors.lastname: Douglas
authors.affiliation: Cranfield University, School of Water, Energy, and Environment, Cranfield, Bedfordshire, United Kingdom. Electronic address: s.tyrrel@cranfield.ac.uk.
authors.forename: Sean F
authors.initials: SF
authors.lastname: Tyrrel
authors.affiliation: Environment Agency, Evidence Directorate, Deanery Road, Bristol, United Kingdom. Electronic address: rob.kinnersley@environment-agency.gov.uk.
authors.forename: Robert P
authors.initials: RP
authors.lastname: Kinnersley
authors.affiliation: Cranfield University, School of Water, Energy, and Environment, Cranfield, Bedfordshire, United Kingdom; Leicester University, Department of Geography, Leicestershire LE1 7RH, United Kingdom. Electronic address: mjw72@leicester.ac.uk.
authors.forename: Michael
authors.initials: M
authors.lastname: Whelan
authors.affiliation: Cranfield University, School of Water, Energy, and Environment, Cranfield, Bedfordshire, United Kingdom. Electronic address: p.j.longhurst@cranfield.ac.uk.
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Longhurst
authors.affiliation: Imperial College London, Small Area Health Statistics Unit, MRC-PHE Centre for Environment and Health and National Institute for Health Research Health Protection Research Unit in Health Impact of Environmental Hazards at King's College London, in Partnership with Public Health England and Collaboration with Imperial College London, United Kingdom; Imperial College Healthcare NHS Trust, Public Health and Primary Care, United Kingdom. Electronic address: a.hansell@imperial.ac.uk.
authors.forename: Anna L
authors.initials: AL
authors.lastname: Hansell
authors.affiliation: Environment Agency, Evidence Directorate, Deanery Road, Bristol, United Kingdom. Electronic address: kerry.walsh@environment-agency.gov.uk.
authors.forename: Kerry
authors.initials: K
authors.lastname: Walsh
authors.affiliation: Cranfield University, School of Water, Energy, and Environment, Cranfield, Bedfordshire, United Kingdom. Electronic address: s.pollard@cranfield.ac.uk.
authors.forename: Simon J T
authors.initials: SJ
authors.lastname: Pollard
authors.affiliation: Cranfield University, School of Water, Energy, and Environment, Cranfield, Bedfordshire, United Kingdom. Electronic address: g.h.drew@cranfield.ac.uk.
authors.forename: Gillian H
authors.initials: GH
authors.lastname: Drew
mesh_terms: D000336:Aerosols; D000391:Air Microbiology; D000392:Air Movements; D000393:Air Pollutants / Q000032:analysis*; D001232:Aspergillus fumigatus; D002138:Calibration; D004784:Environmental Monitoring; D006801:Humans; D008962:Models, Theoretical; D015203:Reproducibility of Results; D012987:Soil
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D012987:Soil
keywords: ADMS; Aspergillus fumigatus; Bioaerosol; Calibration; Compost; Validation