A year-round investigation of indoor airborne fungi in Croatia

Abstract

This study assessed the composition of aeromycota at a grain mill and four dwellings (two apartments and two basements) as well as in outdoor air during one year in Zagreb, Croatia. The incidence of Aspergilli from sections Flavi, Nigri, and Versicolores was also assessed. Airborne fungi were collected using an air-sampler and DG-18 agar plates. The average concentrations of airborne fungi in the grain mill ranged from 14,310 to 40,000 cfu m^-3, which was above the hazardous level (10⁴ cfu m^-3), whereas the values statistically estimated using Feller's correction were up to six times higher. Concentrations in the apartment (163-1244 cfu m^-3) were lower than in outdoor air (286-2090 cfu m^-3) and lower than in the basement (697-1203 cfu m^-3), except in the warmer period of the year when they were similar. The most abundant species throughout the year were Cladosporium spp. (90-100 %), Penicillium spp. (40-100 %), and Alternaria spp. (10-100 %), which are common for temperate climates. Aspergilli from the Flavi (50-100 %) and Nigri (15-40 %) sections as well as A. ochraceus (15-60 %) and Eurotium spp. (85-100 %) were the most abundant at the grain mill and were rarely found in outdoor air. In the basement, Aspergilli (Versicolores) were more abundant than in the apartment. The excess of aeromycoparticles in the grain mill throughout the year may have represented a serious health risk to mill workers. This is the first Croatian one-year study of indoor airborne fungi in a grain mill and dwellings; however monitoring should continue over a longer period.