Spatial variations in airborne microorganism and endotoxin concentrations at green waste composting facilities

Abstract: The emission and dispersal of bioaerosols from open-air commercial composting facilities continues to be contentious. A meta-dataset enumerating cultivable microorganism emission and downwind concentrations is not yet available. A dataset derived from repeated and replicated field studies over a period of two years at two commercial composting facilities is presented. The data characterises patterns in Aspergillus fumigatus, actinomycetes, Gram-negative bacteria and endotoxin emission and downwind concentrations. For all bioaerosols, compost agitation activities had a significant impact on concentrations; levels were variable up to 600m downwind from site. Bioaerosols declined rapidly from source and exhibited a secondary peak 100–150m from site boundary. All bioaerosols were found downwind from site in elevated concentrations. Compared to those found 100m upwind, levels were significantly higher at 180m downwind for A. fumigatus; at 300–400m for actinomycetes and Gram negative bacteria, and at 100m for endotoxins. Periodically, elevated concentrations could be found for all bioaerosols at distances further downwind. The evidence provided by this data set provides operators and regulators of facilities with reliable data to inform the location, risk assessment and bioaerosol sampling strategies of commercial composting facilities. [Copyright &y& Elsevier]