Pollution Characteristics and Health Risk Assessment of Summertime Atmospheric Volatile Halogenated Hydrocarbons in a Typical Urban Area of Beijing, China

Twenty-three atmospheric volatile halogenated hydrocarbons (VHHs) were detected in a typical urban area of Beijing, China from 24 August to 4 September, 2012. The mean and range in daily mass concentrations of the 23 VHHs were 30.53 and 13.45–76.33 µg/m3, respectively. Seven of those VHHs were controlled ozone-depleting substances in China, with a mean of 12.95 µg/m3, accounting for 42.43% of the total. Compared with other national and international cities, the concentrations of the selected 11 VHHs in this study were relatively higher. Dichloroethane had the highest mass concentration, followed by difluorochloromethane. Maxima of total VHHs occurred within the period 8:30–9:00 a.m., while minima occurred during 1:30–2:00 p.m. Source apportionment suggested that the main sources of VHHs in the study area were solvents usage and industrial processes, leakage of chlorofluorocarbons banks, refrigerants, and fumigant usage. Among the selected 7 VHHs, trichloromethane, tetrachloromethane, 1,2-dichloroethane, and 1,4-dichlorobenzene posed potential carcinogenic risks to exposed populations, while none of the selected 11 VHHs posed appreciable non-carcinogenic risks to exposed populations. The carcinogenic risks from atmospheric VHHs in Beijing are higher than in other Chinese cities, indicating that it is necessary to implement immediate control measures for atmospheric VHHs in Beijing.

Portable mass spectrometry for the direct analysis and quantification of volatile halogenated hydrocarbons in the gas phase

Field chemical analysis (FCA) of volatile halogenated hydrocarbons is a highly debated topic of widespread interest due to the significant negative impact of these compounds on public health, on ecosystems and in the environment (e.g. destruction of the stratospheric ozone).

Determination of Volatile Halogenated Hydrocarbons in Wastewater by Single-Drop Microextraction Coupled to Capillary Gas Chromatography

Single-drop microextraction (SDME) coupled to capillary gas chromatography (GC) was established for the determination of seven volatile halogenated hydrocarbons in wastewater, including chloroform (CF), carbon tetrachloride (CT), trichloroethylene (TCE), bromodichloromethane (BDCM), perchlorethylene (PCE), dibromochloromethane (DBCM) and bromoform (BF). The SDME parameters such as extractants, extracting time，stirring rate and immerging depth of needle point were studyed and optimized. The abovementioned halogenated hydrocarbons were quantified by external standardization method using GC coupled with a flame ionization detector (FID). The linear regression calibration curves, detection limits (S/N=3) and the linear ranges of the method for determining each halogenated hydrocarbons were determined, respectively. The concentrations of componds abovementioned in a real wastewater sample, the average of the recoveries obtained in the spiked wastewater samples and the corresponding relative standard deviations were determined, respectively. The results showed the proposed method several attributes, friendly enviroment, economic and highly efficient pretreatment, less time, simplicity, sensitivity, accuracy and wide linear range and so on.