Occupational exposure to airborne fungi in two Croatian sawmills and atopy in exposed workers

Airborne fungi were collected over a one year period at 2-month intervals at 2 sawmills in Croatia (SM 1 and SM 2) processing mainly beech wood and oak wood. A questionnaire concerning respiratory symptoms and skin prick test (SPT) with common inhalatory allergens and moulds Cladosporium herbarum, Alternaria alternata, Aspergillus niger, Penicillium notatum, and Rhizopus nigricans were performed in 96 workers from the same sawmills. Average concentrations of airborne fungi were 1,696-7,316 cfu/m3 in SM 1 and 1,706-4,819 cfu/m3 in SM 2, respectively. Health hazardous levels of airborne fungi (above 104/m3) were present only in SM 1. These levels were related to saw working sites and were season-dependent, i.e. present only during the summer. Penicillium (50-100%), Paecilomyces (43-100%) and Chrysonilia (33-100%) dominated among 17 fungal genera identified in both sawmills. Symptoms of rhinitis, asthma, and dry cough were most frequently recorded among analysed workers. SPT to moulds was negative in all tested workers, except one positive to R. nigricans, indicating that moderate airborne fungi levels found in the analysed sawmills were not related to IgE-mediated sensitization to moulds in exposed workers, even in atopics. Atopy was present among woodworkers in similar proportions to the general population of Croatia, suggesting that the wood-processing industry is not selective for atopic workers.