ABSTRACT

The air inhaled by people is contaminated by microorganisms which form so-called bioaerosols (Wojtatowicz et al., 2008). Bioaerosol is a colloidal suspension, formed by liquid droplets and particles of solid matter in the air, whose components contain or have attached to them viruses, fungal spores and conidia, bacterial endospores, plant pollen and fragments of plant tissues (Karbowska-Berent et al., 201 1).They account for 5-34% of indoor air pollution. Indoor air plays a special role as a health determinant and management of indoor air quality re approaches that differ from those used for outdoor air. For these reasons, the working group preparing the global update of the WHO air quality guidelines (WHO, 2008) recommended that WHO also prepare guidelines for indoor air quality. Microbial damage in indoor and outdoor areas is caused most frequently by molds and bacteria. This constitutes a common problem all over the world. The most significant environmental factors influencing the viability of microorganisms are temperature, relative humidity wind velocity (Jones, 2003). Also, the additional influences are exerted through oxygen, air ions, solar irradiance, and open monitoring of outdoor airborne microorganisms is necessary to evaluate the risk on human health and to study its evolution, and the interest in bioaerosol characterization has increased over the last few decades (Hurst, 2001). The air quality in indoor and outdoor environments has attracted research interest during the past decades or so (Jones, 2003). Most problems related to indoor and outdoor air quality result from complex interactions among building occupants, indoor environment (inadequate temperature, excessive humidity), insufficient outdoor air intake, building materials and furnishing, and air contaminants (chemicals, bacteria, molds, vapors) (Yu et al., 2009). Airborne bacteria are ubiquitous in the earth's atmosphere, and originate from numerous sources, such as lakes, 1 oceans, soils, humans, and animals (Bowers et al., 2012). A recent study revealed more than 1,800 types of bacteria in air samples taken from the Texas cities of San Antonio and Austin, with some of them posing a serious public health hazard (Brodie et al., 2007).