Objective To evaluate the contamination with microbes and dust in internal surface of heating, ventilating, and air conditioning (HVAC) airducts in underground stations of Shanghai Rail Transit and the improvement after cleansing; and to provide scientific basis and suggestions for disease prevention and hygiene supervision.
Methods Representative underground rail stations were selected in Shanghai. The total counts of bacteria, fungi, and the total weight of dust were evaluated according to the Air conditioning and ventilation system operating health requirements in public places (DB 31/405-2012).
Results We chose a total of 30 representative stations. The total counts of bacteria and fungi in the internal surface of airducts decreased from 14.33 cfu/cm2 to 1.49 cfu/cm2 and 3.51 cfu/cm2 to 1.25 cfu/cm2 after cleaning respectively. The total weight of dust decreased from 10.08 g/m2 to 0.45 g/m2 after cleansing. The differences in the three indicators were all statistically significant before and after cleansing (P<0.01).
Conclusion Airduct cleansing could effectively reduce the HVAC inner surface contamination in underground rail stations.
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