Ambient BTX measurements in Suzhou, China

Area of Science:

• Environmental Science
• Atmospheric Chemistry
• Urban Air Quality Monitoring

Background:

• Established Sino-Italian environmental protection cooperation in 2002.
• Developed a comprehensive air quality monitoring network in urban Suzhou adhering to European standards.
• Addresses a gap in systematic analysis of benzene, toluene, and xylenes (BTX) pollution in China.

Purpose of the Study:

• To systematically analyze BTX pollution in urban Suzhou, China.
• To investigate the spatial and temporal distribution of BTX concentrations.
• To compare manual and automatic measurement results for BTX.

Main Methods:

• Utilized passive samplers (Analyst®) for BTX investigation in 2003.
• Created isoconcentration maps to depict spatial distribution of BTX.
• Employed continuous BTX measurement via automatic gas chromatography at fixed stations (2005).

Main Results:

• Detailed city-scale BTX concentration maps were generated for the first time in China.
• Similar seasonal trends observed at urban residential and heavy traffic zones, with lowest similarity in August.
• Average daily BTX profiles showed morning and evening peaks, particularly in spring and winter.
• Daily average concentrations: Benzene (2.64 µg/m³), Toluene (11.52 µg/m³), m,p-Xylenes (3.52 µg/m³).
• Lower benzene/toluene ratio indicated significant toluene pollution from local stationary sources.

Conclusions:

• BTX pollution in Suzhou exhibits distinct spatial and temporal patterns.
• Toluene pollution levels are a concern, likely stemming from local stationary sources.
• The study provides foundational data for urban air quality management in China.
• Manual and automatic methods showed comparable trends despite concentration differences.