evaluation of bioaerosols in five educational hospitals wards air in hamedan, during 2011-2012

background some human diseases such as tuberculosis, legionnaires' disease and different forms of bacterial pneumonia, coccidioidomycosis, influenza, measles, and gastrointestinal illnesses are the result of exposure to bioaerosols. in addition, they are associated with some noninfectious airway diseases, such as allergies and asthma. objectives in the education hospitals of hamedan university of medical sciences, there were no previous qualitative and quantitative studies of bioaerosols in the air of wards, so in this study the quality and quantity of bioaerosols in hospital ward’s air was investigated to establish a reference for future studies or measures. materials and methods in this cross sectional research, 30 wards in five educational hospitals of hamadan city were studied. more than 180 air samples were collected from the hospitals. the samples were transferred to blood agar and sabouraud medium and cultivated immediately. type and number of colonies were determined in the laboratory. bioaerosol concentrations were calculated in terms of cfu/m3. after bioaerosols isolation, the isolates were identified by morphology of colony, gram staining and by standard biochemical tests as required for bacterial or fungal bioaerosols. the spss software was used for data management. anova and t-test statistical analyses were also used. results as the results demonstrated, highest and lowest averages of bioaerosol density were obtained from shahid beheshti and fatemieh hospitals (36.18 cfu/m3 vs. 24.03 cfu/m3), respectively. highest and lowest concentrations of bioaerosols were found inwomen1 and operating room wards of fatemiyeh hospital, respectively (54.4cfu/m3 vs. 13.3cfu/m3). it appears that there had been no significant correlation between concentration of bioaerosols in the hospitals and available guideline values (p = 0.3). the highest fungal populations were penicelium spp. (32.06%), cladosporium spp. (20.5%), aspergillus fumigatus (14.61%) and a. niger (7.43%), respectively. the highest bacterial population was coagulase-negative staphylococci (32.49%), bacillus spp. (14.74%), micrococcus spp. (13.68%) and staphylococcus aureus (11.34%), respectively. conclusions quantitative bioaerosols concentration in the air of some hospitals was more than the available guideline i.e., 30 cfu/m3. bioaerosol density of all surveyed hospitals can relate to patients presence in wards and their visitors, incorrect ventilation, and probably inefficient disinfection. most surveyed hospitals have no air treatment systems thus to reduce bioaerosol concentration, standard ventilation systems should designed and utilized.