want position announcement
Anton Sonnenberg (mushex!as@relay.NL.net)
Mon, 28 Mar 94 17:01:31 +0100
For those interested in possible health effects of mold spores
associated with composting operations and present in air: We have
done a study of the etiology of mushroom worker's lung with the
The spores of the thermophilic actinomycetes Excellospora flexuosa,
Thermomonospora alba, T. curvata and T. fusca were collected from
the air in compost-fermentation tunnels during the spawning of
mushroom compost. They were found present at over 10 power 9 CFU per
cubic meter of air. ( This is 10 times higher than needed for
Aspergillus, Aureobasidium, Cladosporium, Penicillium and Scytalidium
were found at only 10 power 3 spores per cubic meter of air. Sera of
10 mushroom growers with MWL were all found positive for one or more
of the 4 actinomycetes by dot ELISA against spore antigens. No
antibodies were found against Streptomyces vulgaris,
Thermoactinomyces vulgaris, T. sacchari and Trichoderma viride. Sera
of 11 of 14 workers engaged in handling Phase 2 compost reacted
positively with 1 or more of the actinomyces. Their serum titers
increased with the duration of employment. The sera of 19 non-exposed
workers were negative. Results of inhalation provocation studies
showed a causal relationship between spore exposition and disease.
The study was published in Mycopathologia 122: 21-28 (1993). Mushroom
compost is very much like any other compost and can therefore be
considered as a model.
Influence of spores coming from composting plants through the air to
bone marrow transplant patients seems unlikely. Compost contains
mostly thermophilic actinomycetes. After longer incubation at 45 C,
thermophilic fungi will be found. A. fumigatus was never observed by
us in mushroom compost.
Tunnels contain 100 tons of compost. Simple calculation shows the
unlikeliness of contamination by compost derived fungal spores
through air. Besides, bone marrow patients are usually isolated in an
environment, that is made free of the microorganisms that are
abundantly available in the air of hospitals.
Leo Van Griensven
Mushroom Experimental Station, Horst, The Netherlands.