Objective To investigate the current status of indoor air pollution in residential buildings in Ganzhou, China, to analyze the potential health impact factors in indoor air.

Methods A total of 120 monitoring sites (living rooms and bedrooms) were randomly selected from 60 households in Ganzhou, and indoor air samples were collected in summer and winter to test the physical, chemical, and biological indicators of indoor air, which were assessed according to the standard values in the Standards for Indoor Air Quality (GB/T 18883-2022).

Results All samples met the requirements for wind speed; 110 samples (45.83%) had a suitable temperature, and 148 samples (61.67%) had a suitable humidity. The rate of reaching the standard was 100% for benzene, toluene, xylene, NO₂, CO, O₃, and SO₂. The pollution of CO₂, PM₁₀, PM_2.5, NH3, formaldehyde, and TVOC was observed in indoor air, with a rate of reaching the standard of 98.33%, 59.17%, 3.75%, 99.17%, 95.01%, and 97.92%, respectively. A total of 213 samples reached the standard for the total number of bacteria, with a rate of reaching the standard of 88.75%. Compared with summer, the rate of reaching the standard of relative humidity in winter was lower, and the difference was statistically significant (χ²=29.43, P < 0.001), There was no significant difference in the rate of reaching the standard of other indicators between summer and winter. The correlation analysis showed that PM₁₀ and PM_2.5 in indoor air were positively correlated with relative humidity in summer and winter (r=0.679, 0.683, 0.365, and 0.392, respectively, P < 0.01).

Conclusion Indoor air pollution is observed in residential buildings in Ganzhou, with the main pollutants of particulate matter and total number of bacteria.