Seasonal patterns and current sources of DDTs, chlordanes, hexachlorobenzene and endosulfan in the atmosphere of 37 Chinese cities

Transcription

1 Supporting information (SI) Seasonal patterns and current sources of DDTs, chlordanes, hexachlorobenzene and endosulfan in the atmosphere of 37 Chinese cities XIANG LIU 1, 2, GAN ZHANG 1,*, JUN LI 1, LI-LI YU 1, YUE XU 1, XIANG-DONG LI 3, YUSO KOBARA 4, AND KEVIN C JONES 5 1 State Key Laboratory of Organic Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, , China. 2 Pearl River Delta Research Center for Environmental Pollution and Control, Chinese Academy of Sciences, , China. 3 Department of Civil and Structural Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong. 4 National Institute for Agro-Environmental Sciences, Tsukuba, Ibaraki , Japan. 5 Lancaster Environmental Centre, and Department of Environmental Science, Lancaster University, Lancaster, LA1 4YQ, UK. The following supporting information is provided in 1 Microsoft Excel file (Tables, separate file) and 1 Microsoft Word file (Figures, this file), respectively. I. Tables (please refer to the separate Microsoft Excel file) Table S1. Background information for sampling sites Table S2. Results of HCHs, DDTs, chlordanes, endosulfans and HCB (pg d -1 ) in the atmosphere of 37 Chinese cities and background sites in 2005 Table S3. Comparison of concentrations of selected OCPs using PAS in China and the world (pg m -3 ) II. Text body (this file) Text S1: Detailed analytical procedures and QA/QC III. Figures (this file) Figure S1. Map showing the locations of passive air sampling sites Figure S2. Seasonal average air mass and back-trajectories/wind direction in China in 2005 Figure S3. Spatial-temporal distribution of TC and CC in the atmosphere of 37 Chinese cities in the year of 2005 Figure S4. Spatial-temporal distributions of HCB in the atmosphere of 37 Chinese cities in 2005 Figure S5. Endosulfan distributions in the atmosphere of 37 Chinese cities with cotton production area information (shaded areas on the map) in China S1

2 Text S1: Detailed analytical procedure and QA/QC Analysis. OCPs and polycyclic aromatic hydrocarbons (PAHs) (18) were eluted with 8 ml mixture of hexane and DCM (V:V=1:1). Further clean-up for OCP analysis was conducted on a second column (7mm i. d.) packed with 1 g anhydrous sodium sulfate, 0.3 g neutral alumina, 0.3 g silica gel and 2 g sulfuric acidic silica (W:W=1:1). OCPs were eluted with 6 ml mixture of hexane and DCM (V:V=6:4). The elute was concentrated to 1 ml in hexane and a known quantity of pentachloronitrobenzene (PCNB) and PCB54 was added as internal standards prior to GC-MSD analysis. An Agilent-5975N GC-MSD system was used to measure the target compounds. The instrument conditions have been described elsewhere (19). The following OCs were quantified and reported: o,p'-ddt, p,p'-ddt, p,p'-dde, heptachlor (Hep), transchlordane (TC), cis-chlordane (CC), trans-nonachlor (TN), cis-nonachlor (CN), HCB, α-endosulfan (α-endo), and β-endosulfan (β-endo). Quality Assurance/Quality Control (QA/QC). The method blanks showed no detectable target compounds. Fifty four field blanks were analyzed and had concentrations generally <5% of the quantities detected. Duplicate samples obtained at for the 4 sampling seasons reported RSDs within 20% for all the target chemicals. Surrogates were added to all samples and the recoveries for TCmX, PCB30, PCB198 and PCB209 were: 90.2±8.9%, 92.7±10.3%, 95.4±9.2% and 98.9±7.5%, respectively. All reported values were corrected by the field blanks and surrogate recovery. S2

3 Figure S1. Map showing the locations of passive air sampling sites N E KAZAKSTAN Kelamayi KYRGYSTAN Urumchi Kuerle NEPAL INDIA CHINA BANGLADESH BURMA Russia Mongolia NORTH KOREA Ejinaqi Hohhot Beijing Xi ning Wanliguan Chengdu THAILAND Urban sites ( ) and background sites ( ) Shijiazhuang Xinxiang SOUTH KOREA Xiamen VIENAM LAOS Beihai South China Sea PHILIPPINES South China Sea S3

4 Figure S2. Seasonal average air mass and back-trajectories/wind Direction in China in the year of 2005 The wind direction during winter, spring, summer and autumn were determined by analyzing meteorological data from the National Centre for Environmental Prediction (NCEP), the National Centre for Atmospheric Research (NCAR), and the Centre for Global Environmental Research (CGER). This figure presents the average back-trajectories/wind direction and wind speed at 10 m height. Each trajectory length is 10 days. Each line indicates every 1 week, and each dot indicates every 1 hour. These line showed 10 days back-trajectories over 3 background sites- Waliguan (blue lines), (green lines) and Hok Tsui (red lines), every 1 week for the sampling campaigns. For background sites long range air transport (LRAT) may be an important source derived from more contaminated sites, however, the influence could be less significant for primary source sites. S4

5 Winter: 2005/02/ /03/28 S5

6 Spring: 2005/04/ /05/28 S6

7 Summer: 2005/07/ /08/30 S7

8 Autumn: 2005/09/ /11/11 S8

9 Figure S3. Spatial-temporal distribution of TC and CC in the atmosphere of 37 Chinese cities in the year of 2005 E E N N TC CC TC CC Urumchi average Winter Hohhot Beijing E Kuerle average Wanliguan Summer Ejinaqi Xi ning Chengdu Hohhot N N TC CC TC CC Kelamayi Urumchi Kuerle Ejinaqi Hohhot average Spring Xi ning Wanliguan Chengdu Xinxiang E Kelamayi average Autumn Wanliguan Xi ning Ejinaqi Chengdu Beijing Beihai Xiniang Xiamen S9

10 Figure S4. Spatial-temporal distributions of HCB in the atmosphere of 37 Chinese cities in the year of 2005 N E Winter Urumchi Hohhot Beijing Average Beihai N E Spring Kelamayi Urumchi Kuerle Ejinaqi Hohhot Beijing Wanliguan Xining Chengdu Average Beihai N E Summer Kuerle Ejinaqi Hohhot Wanliguan Xining Chengdu Average N E Autumn Ejinaqi Beijing Wanliguan Xining Chengdu Xiamen Average Beihai S10

11 Figure S5. Endosulfan distribution patterns in the atmosphere of 37 Chinese cities with cotton production area information (shaded areas on the map) in China Endosulfan 200pg/d Winter Spring Summer Autumn S11