The Effect of Legionella Pneumophila Contamination in the Surface Dust of the Air Ducts of Central Air Conditioning Systems on Indoor Air Quality

The aim of this study was to determine the concentration of Legionella pneumophila in the surface dust of the air ducts of central air conditioning systems and evaluate its effects on indoor air quality. Thirty dust samples were collected from thirty air ducts and analyzed using real-time TaqMan PCR targeting the mipgene. The concentration of surface dust, PM10 mass concentration of air, total plate count of surface dust, and total plate count of supply air were also investigated. Legionella pneumophila microorganisms were detected in 20 of the 30 samples (66.7%) with a mean copy number of 6212 copies/g surface dust. The Spearman’s rank correlation coefficient between Legionella pneumophila concentration and total plate count in surface dust of the air duct was 0.834 (P=0.000). The pollutants in the air ducts in central air conditioning systems were found to affect indoor air quality.