Unlike those in other cities in China, PM_(10) and PM_(2.5) in Guangzhou had a diurnal pattern with lower concentrations in the morning, higher values in the afternoon and peak values at about 21:00 in the evening.

• 与国内很多城市不同；PM10、PM2.；5质量浓度日变化都呈上午低、下午高、夜间21点左右出现峰值的特征。