compost pile

Question

Our village will hold a briefing to encourage us to make compost. We're pretty reluctant, because we believe that this process is a reservoir of Pseudomonas ... What do you think?
Thank you very much.

Answer

Hello,
I did not find data on "private" composting and cystic fibrosis. Information on composting and health, are more oriented on municipal waste and health effects for people employed in these activities or for people who live near the facilities.
Compost piles are not particularly reservoirs of Pseudomonas, on the other side studies on concentrations of fungal spores in the compost facility and surrounding areas indicate that these concentrations are higher during certain process steps, such as turning and sifting, but they return to a normal level very close to these operations. The microbes that contribute to composting can be found in all places where there is decomposition of organic matter. Composting promotes the growth of microorganisms including thermophilic or thermotolerant Aspergillus fumigatus. The spores of the fungus Aspergillus fumigatus are creating the most concern. Aspergillus fumigatus is one of the micro-organisms most commonly found on the planet and it exists in almost all indoor and outdoor environments at a concentration of 1 to 50 spores per cubic meter, very different from the million spores per cubic meter which can be reached during the handling of substrates such as compost, manure or moldy hay. Although concentrations of spores of fungi are higher than the standard in composting facilities, studies with long-tenured workers indicate that these organisms generally have no adverse effect on the health of workers. However, some workers exposed to repeated and massive inhalation of fungal spores and thermophilic actinomycetes in the handling of substrates such as compost, moldy hay and manure, develop clinical manifestations grouped on the term extrinsic allergic alveolitis (farmer's lung, Mushroom worker's lung, ...).
The few data available on composting of plant debris in waste and garden (leaves, weeds, grass cutting), and it is true that bacteria are not a problem under these conditions. Today, it's another thing to reduce the volume of household waste (vegetable peelings, citrus peel, ...), some municipalities encourage composting by providing equipment and increasing the cost of garbage collection. This practice is somewhat different than traditional composting (professional or otherwise) by the technique (in which room of the house will the composter be installed and who will put the waste in the compost), by the nature of plant residues used in the composting (richer in sugars), and it is possible that it enables the multiplication of other microorganisms.
In the case of cystic fibrosis, two situations are absolute contraindications to handle compost: the presence of allergic bronchopulmonary aspergillosis (ABPA) and transplanted patients taking immunosuppressive therapy. In other cases the risk of having in one's garden a compost pile seems low, provided the patient does not stay in the immediate area during the phases of turning, sifting or spreading, does not keep plant debris and food in the house more than 24 hours and does not handle himself the waste in the compost bin. In a preventive perspective, it is desirable to ensure that patients are not exposed to significant sources of spores prior to an ABPA develops. As always in the absence of scientific evidence the balance between risk and pleasure should be weighed.
I hope that answers your question.

Dr Sophie Ravilly with the advises of Dr Jean-Philippe Bouchara (Angers)

28.03.2011