Markers of upper airway inflammation associated with microbial exposure and symptoms in occupants of a water-damaged building

Occupational exposure and respiratory health problems among nutmeg production workers in Grenada, the Caribbean

BACKGROUND

The nutmeg industry is a major contributor to the Grenadian economy. However, workers in the industry face many environmental and occupational health risks.

OBJECTIVES

The goal of this study was to investigate respiratory health problems and possible related occupational exposures among nutmeg production workers.

METHODS

A questionnaire, spirometry and allergen skin-prick test was given to 92 nutmeg workers. Samples for measurement of airborne dust, mold, and phosphine were also collected from work environments.

RESULTS

Approximately half of the workers with lower respiratory symptoms such as dry cough (49.4%) and shortness of breath (42.9%) reported that their symptoms were work related. Spirometry results showed that 18.8% of workers had obstruction. Area geometric mean (GM) inhalable dust concentrations, GM personal concentrations, and total mold spores during work activities were found to be high.

CONCLUSIONS

High prevalence of respiratory symptoms among workers in this facility was consistent with measured levels of dust and mold, and was widespread over all work areas.

Extrolites of Wallemia sebi, a very common fungus in the built environment

Wallemia sebi has been primarily known as a spoilage fungus of dried, salted fish and other foods that are salty or sweet. However, this fungus is also very common in house dust. The health effects of chronic exposure to mold and dampness are known to be associated with both allergens and various inflammatory compounds, including the secondary metabolites of building associated fungi and their allergens. IgE sensitization to W. sebi has been long reported from housing and occupational exposures. However, its allergens have not been described previously. Strains from food have been reported to produce a number of compounds with modest toxicity. Strains from the built environment in Canada produced a number of metabolites including the known compound walleminone and a new compound 1-benzylhexahydroimidazo [1,5-α] pyridine-3,5-dione which we call wallimidione. Based on an in silico analysis, wallimidione is likely the most toxic of the metabolites reported to date from W. sebi. We found that the primary human antigen of W. sebi is a 47 kDa excreted cellulase present in high concentrations in W. sebi arthrospores. This species is a basidiomycete and, unsurprisingly, the antigen was not found in extracts of other fungi common in the built environment, all ascomycetes.

Secondary metabolites from Penicillium corylophilum isolated from damp buildings

Indoor exposure to the spores and mycelial fragments of fungi that grow on damp building materials can result in increased non-atopic asthma and upper respiratory disease. The mechanism appears to involve exposure to low doses of fungal metabolites. Penicillium corylophilum is surprisingly common in damp buildings in USA, Canada and western Europe. We examined isolates of P. corylophilum geographically distributed across Canada in the first comprehensive study of secondary metabolites of this fungus. The sesquiterpene phomenone, the meroterpenoids citreohybridonol and andrastin A, koninginin A, E and G, three new alpha pyrones and four new isochromans were identified from extracts of culture filtrates. This is the first report of koninginins, meroterpenoids and alpha pyrones from P. corylophilum. These secondary metabolite data support the removal of P. corylophilum from Penicillium section Citrina and suggest that further taxonomic studies are required on this species.