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CAN: Composting plants – measurements to support risk assessment demonstrate presence of Legionella and Mycobacterium

In recent years, sustainable development and the long-term preservation of the environment have gained interest and therefore recycling methods such as composting are now widespread. By its nature, composting requires the action of microorganisms. Each composting phase corresponds to characteristic microorganisms and, consequently, to  specific bioaerosol emissions. Several gases may also be present in ambient air during composting activities. Workers can therefore be exposed to chemical and biological agents.

The objective of this study was to compare the concentrations of contaminants in the ambient air of three composting sites that treat different organic materials, source-sorted organic residues from a three-way collection, manure from a dairy cattle farm, and animal carcasses and tissues from a pig farm, in order to estimate their health risks.

The project also provides a methodology for assessing worker exposure based on analysis of microbial molecular markers and endotoxins. Furthermore, Legionella and Mycobacterium were detected in several samples of air and compost. Due to the inhalable particle diameter and high concentrations of contaminants, it would therefore be recommended to consider the use of respiratory protection when handling compost.

Fore more information in French