Monitoring and analysis of indoor environment quality in autumn and winter in rural Lanzhou, China

Objective To investigate the current situation of rural indoor environmental pollution in different seasons in Yuzhong County, Lanzhou, China, and analyze its influencing factors.

Methods A random sampling method was adopted to select 30 family houses in Xuejiaying Village, Lianda Town, Yuzhong County, Lanzhou. Data of noise, illumination, temperature, humidity, PM_2.5, PM₁₀, CO, CO₂, NO₂, benzene, toluene, xylene, total number of colonies, and total number of fungi were collected in the indoor environment in September 2023 (autumn) and December 2023 (winter). Median (interquartile, P₂₅ and P₇₅) was used for the statistical description of data. The differences between seasons and room types were analyzed by the non-parametric test. The correlations between indoor environment factors were analyzed by Spearman correlation.

Results Sixty air samples were collected in autumn and winter, respectively. The qualified rate of PM_2.5 was the lowest (0.00%) and the qualified rate of xylene was the highest (100.00%). Noise, temperature, humidity, total number of colonies, and total number of fungi were significantly higher in autumn than in winter. PM_2.5, PM₁₀, CO, CO₂, formaldehyde, benzene, and toluene were significantly higher in winter than in autumn. Temperature was significantly different among room types.

Conclusion PM_2.5 is the primary pollutant in some rural indoor air in Lanzhou. Attention should be paid to the influence of solid fuel combustion and cooking on rural indoor air.