Characterisation and source identification of biofluorescent aerosol emissions over winter and summer periods in the United Kingdom

Abstract

Abstract. Primary biological aerosol particles (PBAPs) are an abundant subset of atmospheric aerosol particles which comprise viruses, bacteria, fungal spores, pollen, and fragments such as plant and animal debris. The abundance and diversity of these particles remain poorly constrained, causing significant uncertainties for modelling scenarios and for understanding the potential implications of these particles in different environments. PBAP concentrations were studied at four different sites in the United Kingdom (Weybourne, Davidstow, Capel Dewi, and Chilbolton) using an ultraviolet light-induced fluorescence (UV-LIF) instrument, the Wideband Integrated Bioaerosol Spectrometer (WIBS), versions 3 and 4. Using hierarchical agglomerative cluster (HAC) analysis, particles were statistically discriminated. Fluorescent particles and clusters were then analysed by comparing to laboratory data of known particle types, assessing their diurnal variation and examining their relationship to the meteorological variables temperature, relative humidity, wind speed, and wind direction. Using local land cover types, sources of the suspected fluorescent particles and clusters were then identified. Most sites exhibited a wet discharged fungal spore dominance, with the exception of one site, Davidstow, which had higher concentrations of bacteria, suggested to result from the presence of a local dairy factory and farm. Differences were identified as to the sources of wet discharged fungal spores, with particles originating from arable and horticultural land at Chilbolton, and improved grassland areas at Weybourne. Total fluorescent particles at Capel Dewi were inferred to comprise two sources, with bacteria originating from the broadleaf and coniferous woodland and wet discharged fungal spores from nearby improved grassland areas, similar to Weybourne. The use of the HAC method and a higher fluorescence threshold (9 standard deviations instead of 3) produced clusters which were considered to be biological following the complete analysis. More published data and information on the reaction of different speciated biological particle types to fluctuations in meteorological conditions, such as relative humidity and temperature, would aid particle type characterisation in studies such as this.

Real-time sensing of bioaerosols: Review and current perspectives

“…Many relevant PBAP cannot be appropriately aerosolized for laboratory study (e.g., wet-discharge fungal spores), and standard aerosolization methods can damage or kill bacterial cells (Heidelberg et al 1997). Forde et al (2019) recently highlighted remaining challenges in the use of laboratory data for training and validation of analysis methods. The co-benefits of unsupervised and supervised methods suggest that the choice of one or a combination depends on the required speed of classification and quality of training data used.…”

Intercomparison of Multiple UV-LIF Spectrometers Using the Aerosol Challenge Simulator

“…Ambient measurements have been conducted worldwide using UV-LIF spectrometers, and in comparison to the MBS, for which no published ambient data currently exist, multiple versions of the WIBS have been part of worldwide measurement campaigns [21][22][23][24][25][26][27][28]. Laboratory experiments conducted using UV-LIF spectrometers are limited in relation to the quantity of ambient measurements conducted worldwide.…”

Variability of the Atmospheric PM10 Microbiome in Three Climatic Regions of France

“…and other types of biological materials (e.g., plant and pollen debris, etc.) ( Forde et al, 2019 ; Huffman et al, 2020 ). They constitute a major fraction of the total concentration of organic matter (OM) in the atmosphere ( Coz et al, 2010 ; Bozzetti et al, 2016 ).…”

“…PBOAs are subject of increasing research interest, not least because of the growing evidence of their adverse effects on human health and agricultural issues (e.g., allergic asthma, aspergillosis, rhinitis, damage to food crops, etc.) and their influence on the hydrological cycle and climate by acting as condensation or ice nuclei in mixed-phase clouds ( Després et al, 2012 ; Forde et al, 2019 ). These various impacts are likely to be effective on a regional scale due to the transport of PBOA-containing air masses ( Després et al, 2012 ; Yu et al, 2016 ).…”