Preliminary Study of the Airborne Particulate Matter 2.5 in Western Region of Zhuhai

Objectives To monitor and analyze the PM_2.5 level in Western Region of Zhuhai.

Methods Airborne PM_2.5 samples were collected with medium flow samplers at typical fields of both countryside and downtown areas, and determined by gravimetric method for more than 3 days of sampling in each field.

Results Firstly, the average concentration of PM_2.5 of western region of Zhuhai was 0.092 mg/m³, while that was 0.10 mg/m³ in city area and that was 0.078 mg/m³ in countryside (P > 0.05). Secondly, the average PM_2.5 level was 0.13 mg/m³ during heavy traffic time (more than 200 motor vehicles passing per 5 min) and 0.084 mg/m³ during the time not so much traffic (less than 200 motor vehicles passing per 5 min) (P < 0.01). Thirdly, the average concentration of PM_2.5 was 0.054 mg/m³ and 0.11 mg/m³ respectively when wind speed was beyond 0.5 m/s or not (P < 0.01).

Conclusions The average PM_2.5 level in Western Region of Zhuhai was lower than that in other big cities in China, but it was still higher than the standards of U. S. A and WHO. There was no significant difference (P > 0.05) between PM_2.5 levels of city and countryside in Western Region of Zhuhai. Moreover, PM_2.5 levels on roads with heavy traffic were significantly higher than those with light traffic. Finally, PM_2.5 levels reduced significantly when the wind speed was beyond 0.5 m/s (P < 0.01).