Investigation on Indoor Air Pollution of Residents Residentiol District in Shenzhen at Xixiang

Objectives To understand the indoor air pollution situation and influecing factors of residents in Xixiang residental district, Shenzhen.

Methods In October and December 2017, the concentrations of PM₁₀, CO₂, NO₂, formaldehyde, benzene, toluene, xylene and total count of colonies in 35 living rooms and bedrooms in Xixiang residental district were monitored. Factors such as the residential area per capita, the use of air purifiers, the decoration in the past two years, the type of fuel used in the kitchen, and other factors which might affect the concentration of indoor pollutants were investigated.

Results The Unqualified rates of indoor PM₁₀, CO₂ and benzene concentrations were 55.7%, 4.3% and 0.7%, respectively. PM₁₀ was the most important pollutant, and no unqualified phenomena were detected in other air pollutants. There were no significant difference in the concentration distribution of indoor air pollutants and the unqualified rates of bedrooms and living rooms (P>0.05). And there were no significant difference in the concentration distribution of indoor air pollutants in residential area per capita, decoration in recent two years and use of air purifiers (P>0.05). The use of natural gas as source of fuel in kitchens is a risk factor for causing indoor PM₁₀ to exceed the concentration limit, and OR(95% CI) is 10.282(1.187-89.089). The indoor temperature was positively correlated with the concentrations of CO₂, NO₂, formaldehyde, toluene and xylene, and negatively correlated with the concentration of PM₁₀. The humidity was positively correlated with the concentrations of CO₂ and formaldehyde (P < 0.05).

Conclusions The results indicate that the main air pollutant in residential buildings of Xixiang residental distrut in Shenzhen was PM₁₀, and the concentration of PM₁₀ might increase in winter. Nature gas used in kitchen is probably the cause of indoor PM₁₀ to exceed the concentration limit.