Supplementary Information Occurrence and Source Apportionment of Halogenated Flame Retardants in the indoor air of Nepalese cities: Implication on human health Ishwar Chandra Yadav, Ningombam Linthoingmabi Devi, Jun Li, Gan Zhang State key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou-510640, P.R. China Centre for Environmental Sciences, Central University of South Bihar, BIT Campus Patna-800014, Bihar, India SI 2.1.Air Sampling Four major cities i.e. Kathmandu, Pokhara, Birgunj and Biratnagar of Nepal were selected for collection of atmospheric samples. The detail about sampling location and study areas is described elsewhere (Yadav et al., 2017). A total of 34 polyurethane foam 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
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ars.els-cdn.com · Web viewdistinctive PBDEs congener (BDE-28, BDE-35, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154, BDE-183 and BDE-209), two DPs (anti- and syn-isomer) and six NBFRs
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Supplementary Information
Occurrence and Source Apportionment of Halogenated Flame Retardants in the indoor air of Nepalese cities: Implication on human health
Ishwar Chandra Yadav, Ningombam Linthoingmabi Devi, Jun Li, Gan Zhang
State key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou-510640, P.R. China
Centre for Environmental Sciences, Central University of South Bihar, BIT Campus Patna-800014, Bihar, India
SI 2.1.Air Sampling
Four major cities i.e. Kathmandu, Pokhara, Birgunj and Biratnagar of Nepal were selected for
collection of atmospheric samples. The detail about sampling location and study areas is
described elsewhere (Yadav et al., 2017). A total of 34 polyurethane foam passive air sampling
(PUF-PAS) samplers (8 each in Pokhara, Birgunj, Biratnagar and 10 in Kathmandu) were
deployed in open area of each cities >3m above the ground at different location. After exposure
of 8 weeks, from August-October, 2014, all PUF disk were retrieved, resealed and transported to
the laboratory and stored at −20 °C until analysis. The details about design and deployment of
PUF-PAS sampler has been described elsewhere (Jaward et al., 2005).
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2.2. Extraction and GC-MS analysis
All the chemical reagents, for example, dichloromethane (DCM), n-hexane, and acetone were
bought from fisher Scientific, USA and Tedia Co. USA. The surrogate and internal standard
decachlorobiphenyl (PCB 209) and 13C-PCB141 were acquired from Ultra Scientific,
respectively. All the glassware was dipped in K2Cr2O7-H2SO4 solution for 24 h and cleaned
before experimentation. All the 34 PUFs were spiked with 20ng PCB209 as surrogate standard
and were soxhlet extracted for 24 h with DCM. The concentrate was concentrated to 2-3mL
(approx.) by a rotary evaporator after extraction. At that point the concentrate was cleaned by
multilayer silica gel/alumina column followed by anhydrous sodium sulfate. The column was
packed from the bottom to the top, with neutral alumina (3 cm, 3% deactivated), neutral silica
gel (3 cm, 3% deactivated), 50% acid silica (3 cm), and anhydrous sodium sulfate (1 cm).
Around 30-40ml mixture of DCM/hexane (1:1volume) was utilized to elute the column and
focused the last volume to 0.2mL under delicate nitrogen stream. Around 25μl of dodecane was
added to the GC vial as solvent keeper. A known measure of 13C-PCB141 (10ng) was included as
internal standard before GC-MS investigation.
The eluted samples were infused into an Agilent 7890 gas chromatograph coupled to an Agilent
5975C mass selective detector (Mississauga, ON) working in electrochemical negative ionization
(ECNI) mode. HP-5MS section (15m×0.25 mm i.d.×0.1µm film thickness) was utilized. The 1 μl
infusion of the consolidated sample and C13 calibration solution were made in the splitless mode.
GC oven temperature was set to an initial temperature of 110°C for 5 min and raised to 200°C at
a rate of 20 °C/min (held for 4.5 min); expanded at a rate of 10°C/min to the last temperature of
310 °C (held for 12 min). Helium was utilized as carrier gas with flow rate of 1.2 ml/min. The
temperatures of the transfer line and ion source were 280 °C and 230 °C, separately. Nine
Birgunj 8 1.3-33 0.9-20 0.4-2.3 0.1-1.5 0.2-2.2 0.3-1.2 Nd-1.7 0.5-4.4 12-238 16.4-271 This studyBiratnagar 8 1.7-7.4 0.6-4.4 0.4-1.2 0.1-0.8 0.2-0.5 0.1-0.3 0.1-0.5 0.1-0.8 1.8-8.2 8.6-18.8 This study
a:median value
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Table S3 Concentration of DPs in air from different region in the world
Country N syn-DP anti-DP ∑DPs ReferencesBloomington, US 20 Nd-4 nd-23 nd-27 Venier et al., 2016Toronto, Canada 23 nd-76 Nd-243 Nd-316 Venier et al., 2016Brno, Czech Republic 20 - Nd-65 Nd-65 Venier et al., 2016Qingyuan, China 82 3.6-491.5 9.4-1302 13-1794 Chen et al., 2011Beijing, China 7 0.41 0.83 1.98 Kakimoto et al., 2015Japanese cities 7 0.26-1.8 0.46-4.97 0.87-6.7 Kakimoto et al., 2015Dalian, China 49 Nd-1.7 Nd-4.3 3 Yang et al., 2012Birmingham, UK 35 Nd-4.6 1.2-20 1.2-25 Tao et al., 2016Chicago, US 180 - - 0.65-5.9 Peverly et al., 2015Chinese cities 149 Nd-14 Nd-12 Nd-26 Liu et al., 2016Harbin, China 3 - - 6.9 Ma et al., 2011Shanghai, China 25 0.65-1.6 1.6-3.9 2.32-5.48 Yu et al., 2011Punjab, Pakistan 10 1.2-450 0.3-76 1.5-530 Syed et al., 2013Spain 8 - - 11.3 de la Torre et al., 2010Stockholm , Sweden 12 - - 36-320 Newton et al., 2015Kathmandu 10 1-73 0.9-56 2-129 This studyPokhara 8 0.71-2.52 0.1-1.52 0.81-4 This studyBirgunj 8 1.1-29.3 0.86-31 2-60 This studyBiratnagar 8 0.57-6.3 0.33-4.6 0.9-11 This study
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Table S4 Level of NBFRs reported in air from different regions
Country N PBEB HBB TBB BTBPE TBPH DBDPE ∑NBFRs ReferencesBloomington, US 20 Nd-92 Nd-5
81.3-144 Nd-0.74 Nd-109 Nd-71 1.3-475 Venier et al.,
Chinese cities 149 0.02-2.3 0.04-52 0.01-27 0.03-4.4 0.05-42.5 0.24-1020 0.39-1148 Liu et al., 2016Harbin, China 444 Nd-3.4 - - Nd-250 - Nd-1600 3.5-3500 Li et al., 2016East Africa Nd-1.83 - - Nd-90.5 - - Nd-216 Arinaitwe et
al., 2014Birmingham, UK 35 0.4-5.4 0.2-91 Nd-44 1-50 0.1-130 10-97 - Tao et al., 2016Kathmandu 10 0.1-22.6 0.38-2.95 0.33-9.9 0.67-8.76 0.57-9.38 62.24-4052 66.6-4083 This studyPokhara 8 0.1-0.43 0.38-1.95 0.43-459 0.33-1.48 0.95-6.81 11.7-1822 14.3-2290 This studyBirgunj 8 0.24-0.7 0.33-1.76 0.76-14.8 0.33-29.5 1.14-10.7 302-5706 309-5763 This studyBiratnagar 8 0.14-0.9 0.2-1.33 1.1-5 0.33-2.19 1.81-47.4 14-1131 18-1138 This study
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Fig. S1 Relative abundance of HFRs in Nepalese air
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Figure S2 Relative abundance of individual PBDEs, DPs and NBFRs analyzed in air samples
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10Figure S3 Site wide % contribution of individuals HFR in air