Investigation of fungal contamination in urban houses with children in six major Chinese cities: Genus and concentration characteristics

Abstract

Indoor fungi, as an important group of biological contaminants, are recognized as risk factors for human health. However, limited data are currently available on fungal pollution in houses of China. In this study, fungi in air, in settled dust and on surfaces in urban houses with children are determined in six major cities of China. Aspergillus spp., Penicillium spp. and Cladosporium spp. are the most frequent genera and are the dominant genera in air. The concentrations of these three fungi account for an average percentage of 87% and 83% of the total concentration of airborne fungi in winter and summer. Unlike airborne fungi, there is no particularly obvious dominant fungal genus in settled dusts and on interior surfaces. The average concentration of total airborne fungi in houses in summer is significantly higher (p < 0.001) than that in winter. In terms of total concentration of airborne fungi, indoor sources significantly contribute to indoor airborne fungi in winter, whereas the contribution of outdoor sources is relatively greater in summer. Average concentration of airborne fungi in northern houses is higher than that in southern houses in both summer and winter. Fungal concentrations in air, in settled dust and on interior surface do not show a strong relationship (r < 0.5), thus air, dust and surface sampling may be all essential to evaluate indoor fungal exposure. The findings of this study are favorable for understanding fungal exposure in houses and can provide bases for establishing control strategies for indoor fungi in China.