Factors Influencing Air Quality in Public Spaces of Guangzhou Metro Station

Objectives  To investigate the sanitary condition of central air conditioning system in the public space of subway stations and analyze its influencing factors, to provide suggestions for their design and management.

Methods Central air conditioning systems in three lines of Guangzhou metro station were monitored in 2011-2012, and their influencing factors were analyzed.

Results The weight and microbe in the dust collected from inner surface of ducts, fresh air, cooling water, and condensate of central air conditioning systems in these 3 lines were all qualified. The qualified rate for bacteria, fungi and PM₁₀ in air supplier was 87.3%, 78.0% and 49.4%, respectively. There were positive relations on the number of fungi between the outlet of air supplier and tunnels (r=0.707, P=0.033, P < 0.05); and positive relations on the concentration of PM₁₀ between air supplier outlet and new air shaft (r=0.872, P=0.002, P < 0.01), tunnel (r=0.856, P=0.003, P < 0.01), and breathing zone in platform (r=0.966, P < 0.001).

Conclusions The pollutant in air conditioning systems was probably from outdoor air and tunnel wind.High concentration of PM₁₀ might be the result from high background level of inhalable particulate matter.