[Pollution Characteristics of Non-methane Hydrocarbons During Winter and Summer in Foshan City].

Thirty non-methane hydrocarbons(NMHCs) samples were collected and analyzed in Foshan City during winter 2014 and summer 2015. The concentrations of NMHCs during the sampling period were 122.30 μg·m and 56.22 μg·m in winter and summer, respectively. The five highest concentration species of NMHCs in winter and summer were in the following order: toluene (25.12 μg·m), -xylene (13.76 μg·m), propane (9.17 μg·m), ethylbenzene (7.25 μg·m), ethylene (6.77 μg·m) and toluene (6.18 μg·m), -xylene (5.21 μg·m), -xylene (4.15 μg·m), -pinene(3.75 μg·m), propane (3.29 μg·m). Compared to 2008, the concentrations of NMHCs have dropped significantly. The proportions of aromatics, alkanes, alkenes and alkynes in NMHCs were 51.20%, 34.70%, 10.04%, 4.05% and 43.93%, 33.99%, 19.20%, 2.88% during winter and summer, respectively. The ratios of NMHCs/NO were 0.90 and 1.88, indicating that the peak ozone concentrations in Foshan City were controlled by NMHCs during the sampling period, and the emissions of NMHCs should be further strengthened. The propylene equivalent concentration and ozone formation potential were 45.09 μg·m and 40.64 μg·m, 392.77 μg·m and 207.77 μg·m in winter and summer. The -xylene; toluene and -xylene; isoprene had a very important influence on ozone formation potential. The ratios of Benzene/Toluene were 0.15 and 0.20 indicated that industrial process was the main source of NMHCs in Foshan City. Relative to 2008, isopentane didn't belong to the highest concentration of five pollutants for Foshan's NMHCs in this research, indicating the measures to prevent volatile gasoline impact on the environmental quality have achieved remarkable results.