Levels of fungi aerosols in residential houses in Benin City, Southern Nigeria

Abstract

Lack of monitoring residential homes for fungi contamination, has reportedly resulted in various health outcomes in vulnerable occupants. This study assessed the level of indoor and outdoor airborne fungi contamination and reveal the identity of air borne fungi species in the study area. Forty-five households were randomly selected across the five local council areas in Benin city for airborne sampling. Airborne fungi were assessed bimonthly using the passive sampling technique. Discrete colonies of fungi were enumerated and mean values of triplicate concentrations were expressed in Colony forming unit / m³ (CFU/m³) Airborne fungi isolates were characterized and identified using standard procedures. The mean indoor and outdoor meteorological parameters ranged between 31.2 to 32.3°C and 31.1 to 32.5°C (Temperature); 71.6 to 74.1% and 63.0 to 74.1% (Relative humidity) respectively. The fungi concentrations varied from 301.0 to 747.1 CFU/m³ and 337.67 to 554.6 CFU/m³ (indoor); 223.8 to 450.4 CFU/m³ and 378.64 to 532.7 CFU/m³ (outdoor) in wet and dry seasons. The prevalent fungi genera isolated from the indoor and outdoor air across the sampling sites were Penicillium, Cladosporium, and Aspergillus. The outdoor fungi concentrations showed a significant association (R = 0.360 and 0.260; R² = 0.130 and 0.032; p< 0.01) with indoor fungi concentrations in both seasons. The study revealed high airborne fungi counts and fungi species of public health interest in the houses. Regular cleaning and maintenance practices to reduce the increasing effect of fungi spores is highly recommended.