Iran Occupational Health

  Background and aims

  Bioaerosol exposure is associated with a vast range of adverse health effects including infectious diseases, acute toxic effects, allergy and cancer. This study was conducted to determine type and concentration of bioaerosols in ambient air of educational hospitals.

  Methods

  In this cross-sectional study, different wards of 5 educational hospitals including nurse station, patient room, isolation room and operation room were investigated. Totally, 300 air samples were taken based on NIOSH standard method. Blood agar and malt extract agar were

  used as sampling media. Andersen single-stage sampler with flow of 28.3 lit/min was applied for  air sampling. The average sampling time was 10 minutes. Soon after air sampling, samples were shipped to lab and incubated for 48 hours. Then, incubated samples were counted for colonies. Concentration was determined in CFU/m 3 .

  Results

  the highest and the lowest concentrations were observed in patient room andoperation room, respectively. In spite of sterilization, different types of fungi (i.e. Aspergillus  niger) and gram-positive bacteria are seen in samples. The results showed that in all hospitals the

  concentration in all wards were higher than 30 CFU/m 3 as the suggested value.

  Conclusion

  Concentrations of bioaerosols in all hospitals studied were higher than the suggested value. For reducing bioaerosol exposure, standard ventilation system should be  designed and utilized.