Thermomonospora spp.

Occupational and environmental exposure to bioaerosols from composts and potential health effects -
A critical review of published data

Prepared by The Composting Association and
Health and Safety Laboratory
for the Health and Safety Executive 2003

First published 2003

In addition to the bacteria as described above, actinomycetes are also found in these
environments. Actinomycetes are filamentous Gram-positive bacteria that are commonly found
associated with soil and plant materials. Thermophilic actinomycetes, with a growth temperature
range of 30 to 60oC, thrive in wet compost that has begun the self heating process. Therefore
they can be used as indicator organisms for self heating of organic material, and as indicator
organisms for the presence of bioaerosols generated from compost (Dutkiewicz, 1997; Lacey,
1980; Lacey and Crook, 1988). The most common species present are Saccharopolyspora
(Faenia) rectivirgula, Saccharomonospora spp including S. viridis, Thermoactinomyces
thalpophilus, Thermoactinomyces vulgaris and
Thermomonospora spp. Mesophilic species such
as Streptomyces are also commonly present in high numbers.

Thermophilic actinomycete species are recognised respiratory allergens. Actinomycetes produce
thousands of very small spores (1-3m diameter) which easily become airborne in large numbers
when heavily colonised material is disturbed. Their small size means that they are potentially
capable of penetrating deep into the human lung. They are primarily responsible for occupational
allergic lung diseases such as Farmers Lung Disease and Mushroom Workers Lung Disease,
which are forms of
extrinsic allergic alveolitis (Hodgson and Flannigan, 2001).  

In Canada it is also  
sewage sludge disease