| Popis: |
High-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS) was used to measure contents of 2, 3, 7, 8-polychlorinated dibenzo-p-dioxin and furan (PCDD/F) in ambient air in Guangzhou city, and its sources were traced and tracked preliminarily. Spatial and seasonal distributions, the correlation between PCDD/F concentrations and various kinds of meteorological factors were studied with emphasis, as well as the trajectory of air mass simulated by hybrid single-particle lagrangian integrated trajectory (HYSPLIT) model of the U. S. A Air Resources Laboratory, which will provide important basic data for understanding PCDD/F pollution levels in urban regions. The results show, PCDD/F concentrations in the industrial area are higher than others, and in spring, PCDD/F TEQs are the highest. Meteorological factors, like wind direction and speed, temperature, air pressure, relative humidity, precipitation all have influence on pollution levels of atmospheric PCDD/Fs. Temperature and wind speed has a negative correlation with the concentration, but it is not obvious. By the analysis of the backward trajectory of air mass, something are obtained that the trajectory extends mainly to northwest areas in autumn, and air masses from inland migrate slowly in winter, while they arrive at Guangzhou after passing southeast coast or sea. |
