Bioaerosol Generation at Large-Scale Green Waste Composting Plants

Abstract

Bioaerosol release from composting plants is a cause of concern because of the potential health impacts on site workers and local residents. A one-year monitoring was undertaken in a typical composting plant treating green wastes by windrowing in the open. Aspergillus fumigatus spores and mesophilic bacteria were used as monitoring parameters and were collected in a six-stage Andersen sampler impactor from the air at different locations and during different operational activities. Background concentrations of both microorganisms were generally below 1000 colony-forming units m Ϫ3 when no vigorous activity was taking place. Shredding of fresh green wastes, pile turning, and screening of mature compost were identified as the activities generating the highest amounts of both bioaerosols 40 m downwind of the composting pad. These air concentrations were ϳ2 log units higher than background levels. Screening of mature compost generated lower amounts of A. fumigatus than the other two activities (an average of 1 log unit higher than background levels). Workers were identified as the main potential receptors of high bioaerosol concentrations in areas close to the composting pad, whereas no major risk for local residents was expected because the concentrations recorded at distances of 200 and 300 m downwind of the operational area were not significantly different from background levels.

Concentrations and Diversity of Microbes from Four Local Bioaerosol Emission Sources in Finland

“…This is in line with most other studies concerning the distances of microbial dispersion from biological waste treatment applications. 17,18 In the farming environment we did not see any significant differences in microbial levels between different distances from the cowshed. The concentrations remained within the range of background rural areas.…”

“…However, most studies have reported much smaller distances where elevated microbial levels can be analyzed. Sanchez-Monedero et al 17 detected an approximately 100-fold increase in the concentrations of viable A. fumigatus and mesophilic bacteria 40 m downwind of a composting site during different activities in large-scale green waste composting plant in northern England. However, no significant differences to background levels were found any longer at distances of 200 and 300 m from the operational area.…”

The air spora close to a compost facility in Northeast Oklahoma: Part I—spore trap sampling

“…Mean daily Penicillium/Aspergillus type spores concentrations have also been shown to be higher on-site (3,207 spores m -3 ) than off-site (264 spores m -3 ) (Hryhorczuk et al 2001). At a full scale composting facility, samples collected 25-40 m downwind showed increases in concentration of A. fumigatus up to two orders of magnitude from 3 · 10 2 to 5 · 10 4 cfu m -3 when the compost was turned, or during some other compost disruption event (Sanchez-Monedero et al 2005). Another study found A. fumigatus spore concentrations close to compost piles sometimes exceeded 10 6 cfu m -3 (Clark et al 1983).…”

Bioaerosol emissions arising during application of municipal solid-waste compost

“…Previous investigations have largely studied bioaerosol from composting plants or facilities (Van der Werf 1996;Folmsbee and Strevett 1999;Hryhorczuk et al 2001;Sanchez-Monedero et al 2005;Taha et al 2006). A few studies have looked at bioaerosol release from land application of biosolids and potential hazards posed by this (Pillai et al 1996;Gerba et al 2002;Brooks et al 2004;Brooks et al 2005); however, it seem that data relating to bioaerosol emissions as a result of application of municipal solid waste (MSW) compost are lacking.…”