Abstract:The hyphenated method of gas chromatograph and mass spectrometer (GC-MS) was applied to characterize PCBs in summer precipitation and atmosphere in Shijingshan District in Beijing, respectively. It was shown that PCBs in the dissolved phase was predominant in precipitation, accounting for 65.23%. Moreover, PCBs in the gaseous phase contributed as high as 67.70% in atmosphere. The washout ratios in particulate and gaseous phases were found to be comparable, with values of 6.00×104 and 5.37×104, respectively.The sum of eight dioxin-like PCBs TEQ concentrations in gaseous phase, particulate phase of atmosphere and rain were 0.36pg/m3, 0.02pg/m3and 0.29 ng/L. Total intake of the eight dioxin-like PCBs TEQ for adult from the air was estimated to be 0.08 pg/(kg·d), which exhibited lower exposure risk for human health in Shijingshan District in Beijing.