Visiting Hours Impact on Indoor to Outdoor Ratio of Fungi Concentration at Golestan University Hospital in Ahvaz, Iran

Prevalence of diseases originated from air pollution such as asthma and allergies, can be attributed to the bioaerosols. Bacteria and fungi are the main sources of hospital infections, which cause most of the diseases and mortality. The aim of this study was to determine the ratio of indoor to outdoor fungi concentration, the effect of population and people density on fungi concentration and the relationship between indoor and outdoor environment. In this study, three stations were used: outdoor of the hospital, general indoor and ICU wards of the Ahvaz hospital. These locations were chosen for sampling of the airborne fungi from October to December 2010. The samples were collected in 2 min, flow rate of 28.3 L/min using quick take (SKC Inc., PA, USA), based on the Andersen method. The three dominant culturable fungi genera in sampling stations were Aspergillus , Penicillium , and Cladosporium . The average of total culturable fungi concentration before visiting time was 365.8 CFU m -3 and increased to 578CFU m -3 after visiting time. The indoor to outdoor ratios (I/O) in ICU and internal for fungi before visit were 0.36 and 0.68, respectively. However, these ratios in ICU and internal station for fungi after visit were 0.78 and 0.99, respectively. Following the visit of the visitors, the concentration of fungi available indoor was conspicuously higher (even in the wards in which no visitors were allowed; e.g. ICU, etc). Hence the amount of indoor fungi was affected by the concentration of outdoor fungi and visitors crowd.