Microbial and endotoxin emission from composting facilities: characterisation of release and dispersal patterns

摘要

The potential risk to human health posed by exposure to bioaerosols released from composting is an important issue. Further growth in the number of composting facilities in the UK is anticipated as biodegradable waste is diverted from landfill. To date, studies of bioaerosol emission from composting have focussed on cultivable bioaerosols. This paper describes both culturable bioaerosol and endotoxin release and dispersal from two large green waste composting facilities in the UK. Aspergillus fumigatus, actinomycetes, Gram-negative bacteria, and endotoxins were simultaneously and repeatedly sampled to describe the release and dispersal from these sites. Meteorological and site operational observations were recorded, allowing analysis of factors influencing bioaerosol release and dispersal. The highest measured concentrations of bioaerosols were associated with composting activities such as shredding and turning. Between release and 50-80m downwind bioaerosol concentrations reduced by 80-90%. An unexpected second peak was detected 100-150m downwind from source at both sites. Endotoxin dispersal patterns were site specific and showed some differences to dispersal patterns of culturable microorganisms.