Browsing by Author "Parks, Simon"

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    A controlled study on the characterisation of bioaerosols emissions from compost
    (2018-09-28) Nasir, Zaheer A.; Rolph, Catherine A.; Collins, Samuel; Stevenson, David; Gladding, Toni L.; Hayes, Enda; Williams, Ben; Khera, Shagun; Jackson, Simon; Bennett, Allan; Parks, Simon; Kinnersley, Robert P.; Walsh, Kerry; Pollard, Simon J. T.; Drew, Gillian; Garcia Alcega, Sonia; Coulon, Frederic; Tyrrel, Sean
    Bioaerosol emissions arising from biowaste treatment are an issue of public concern. To better characterise the bioaerosols, and to assess a range of measurement methods, we aerosolised green waste compost under controlled conditions. Viable and non-viable Andersen samplers, cyclone samplers and a real time bioaerosol detection system (Spectral Intensity Bioaerosol Sensor (SIBS)) were deployed simultaneously. The number-weighted fraction of fluorescent particles was in the range 22–26% of all particles for low and high emission scenarios. Overall fluorescence spectral profiles seen by the SIBS exhibited several peaks across the 16 wavelength bands from 298 to 735 nm. The size-fractionated endotoxin profile showed most endotoxin resided in the 2.1–9 μm aerodynamic diameter fraction, though up to 27% was found in a finer size fraction. A range of microorganisms were detected through culture, Matrix Assisted Laser Desorption and Ionisation Time of Flight Mass Spectrometry (MALDI-TOF) and quantitative polymerase chain reaction (qPCR), including Legionella pneumophila serogroup 1. These findings contribute to our knowledge of the physico-chemical and biological characteristics of bioaerosols from composting sites, as well as informing future monitoring approaches and data interpretation for bioaerosol measurement.
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    Scoping studies to establish the capability and utility of a real-time bioaerosol sensor to characterise emissions from environmental sources
    (Elsevier, 2018-08-09) Nasir, Zaheer A.; Hayes, Enda; Williams, Ben; Gladding, Toni; Rolph, Catherine A.; Khera, Shagun; Jackson, Simon; Bennett, Allan; Collins, Samuel; Parks, Simon; Attwood, Alexis; Kinnersley, Robert P.; Walsh, Kerry; Garcia Alcega, Sonia; Pollard, Simon J. T.; Drew, Gill; Coulon, Frederic; Tyrrel, Sean
    A novel dual excitation wavelength based bioaerosol sensor with multiple fluorescence bands called Spectral Intensity Bioaerosol Sensor (SIBS) has been assessed across five contrasting outdoor environments. The mean concentrations of total and fluorescent particles across the sites were highly variable being the highest at the agricultural farm (2.6 cm−3 and 0.48 cm−3, respectively) and the composting site (2.32 cm−3 and 0.46 cm−3, respectively) and the lowest at the dairy farm (1.03 cm−3 and 0.24 cm−3, respectively) and the sewage treatment works (1.03 cm−3 and 0.25 cm−3, respectively). In contrast, the number-weighted fluorescent fraction was lowest at the agricultural site (0.18) in comparison to the other sites indicating high variability in nature and magnitude of emissions from environmental sources. The fluorescence emissions data demonstrated that the spectra at different sites were multimodal with intensity differences largely at wavelengths located in secondary emission peaks for λex 280 and λex 370. This finding suggests differences in the molecular composition of emissions at these sites which can help to identify distinct fluorescence signature of different environmental sources. Overall this study demonstrated that SIBS provides additional spectral information compared to existing instruments and capability to resolve spectrally integrated signals from relevant biological fluorophores could improve selectivity and thus enhance discrimination and classification strategies for real-time characterisation of bioaerosols from environmental sources. However, detailed lab-based measurements in conjunction with real-world studies and improved numerical methods are required to optimise and validate these highly resolved spectral signatures with respect to the diverse atmospherically relevant biological fluorophores.