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

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distinctive 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 (bis(2-

ethylhexyl)- 3,4,5,6-tetrabromophthalate (TBPH), pentabromoethylbenzene (PBEB), 1,2-

bis(2,4,6-tribromophenoxy)ethane (BTBPE), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB),

hexabromobenzene (HBB), 1,2-bis(pentabromodiphenyl)ethane (DBDPE) were targeted. The

GC-MS parameters of HFRs analyzed in this study are displayed in Table S1.

2.3. QA/QC

Strict quality control and assurance were followed for calculating the concentration of target

HFRs. All the chemicals used in this experiment were of analytical grade. Ten procedural and

three field blank samples were analyzed in the same manner for original sample to check any

interference and cross contamination. The chromatogram and peak of the blank solution and

standard solution were not overlapped and appeared clearly. The compounds of HFRs were

either non detected or detected in negligible amount in blank samples. The method detection

limits (MDLs) is the mean plus 3 times standard deviation of all the blank samples. In absence of

HFR compound in blank, the MDL was calculated as 3 times signal to noise ratio obtained from

lowest spiked standard. The MDL ranged from 0.11-0.17pg/m3 for PBDEs and DPs and from

1.1-3.3pg/m3 for NBFRs. The average surrogate recoveries for PCB 209 in all samples ranged

between 87 to 123 %. The concentrations of PBDEs, DPs and NBFRs were neither blank nor

recoveries corrected.

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Table S1GC-MS parameters of PBDEs, DPs and NBFRs analyzed in air

Common name

Full name CAS number Mol Wt

Log KOA Log KOW m/z RT (min)

Li et al., 2015;Tao et al., 2016; Cequier et al., 2014

PBDEsBDE-28 2,4,4'-tribromodiphenylether 41318-75-6 406.8 9.51 5.94 79,81 10.580BDE-35 3,3',4-tribromodiphenyl ether 147217-80-9 406.8 - - 79,81 10.750BDE-47 2,2',4,4'-tetrabromodiphenylether 5436-43-1 485.7 10.53×1021 7.16 79,81 13.361BDE-100 2,2',4,4',6-pentabromodiphenylether 189084-66-0 564.6 11.14 - 79,81 16.216BDE-99 2,2',4,4',5-pentabromodiphenyl ether 60348-60-9 564.6 11.31×1021 7.94 79,81 16.881BDE-154 2,2',4,4',5,6'-hexabromodiphenylether 207122-15-4 643.5 11.93 8.75 79,81 18.455BDE-153 2,2',4,4',5,5'-hexabromodiphenyl ether 68631-49-2 643.5 12.1×1021 8.73 79,81 19.169BDE-183 2,2',3,4,4',5',6-heptabromodiphenylether 207122-16-5 722.5 11.97 9.44 79,81 20.985BDE-209 2,2',3,3',4,4',5,5',6,6'-

decabromodiphenylether1163-19-5 959 16.77×1022 12.11 486.7,

488.727.531

DPssyn-DP syn-Dechlorane 135821-74-8 653.8,

651.822.405

anti-DP anti-Dechlorane 135821-03-3 653.8,651.8

22.835

NBFRsPBEB 2,3,4,5,6-pentabromoethylbenzene 85-22-3 500.7 9.97 7.48 79,81 11.034HBB hexabromobenzene 87-82-1 551.4 10.26×1024 6.07 79,81 12.461TBB 2-ethyl-1-hexyl-2,3,4,5-

tetrabromobenzoat183658-27-7 549.9 12.34 8.75 357,

47117.137

BTBPE 1,2-bis(2,4,6-tribromophenoxy) ethane 37853-59-1 687.6 15.67 7.88×1025 79,81 21.537TBPH bis(2-ethyl-1-hexyl)-

tetrabromophthalate26040-51-7 706.2 16.86 11.95 462,464 22.469

DBDPE decabromodiphenylethane 84852-53-9 971.2 19.22 11.1×1025 79,81 29.558

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Table S2 The concentration of PBDEs reported in air around the world

Country N BDE-28

BDE-35

BDE-47 BDE-100

BDE-99 BDE-154

BDE-153

BDE-183

BDE-209

∑PBDEs References

Bloomington,US

20 Nd-145 - 4.5-818 Nd-272 Nd-1291

Nd-122 Nd-171 Nd-5 Nd-5461

4.9-5756 Venier et al., 2016

Toronto,Canada

23 1-166 - 5.4-759 0.4-22 1.3-73 Nd-4.4 nd-5.7 Nd-1.6 Nd-217 8.3-1149 Venier et al., 2016

Brno, Czech Republic

20 0.1-9.2 - 0.6-16 0.05-1 0.2-1.4 Nd-0.06

Nd-0.1 Nd-0.23 Nd-16 1-28 Venier et al., 2016

Greater Oslo, Norwaya

48 7.53 - 128 6.78 21 0.38 0.92 nd 3.76 170 Cequier et al 2014

Birmingham,UK

35 0.2-310 - 0.15-1700

0.1-600 Nd-1700

Nd-180 nd-180 Nd-12 23-3800 36-6400 Tao et al., 2016

E-waste sites, Thailand

5 0.7-9.5 - 2.9-84 0.17-30 1.4-169 Nd-18 0.32-20 - - 8-350 Muenhor, 2010

Stockholm, Sweden

10 nd-8 - 2.6-86 - 1.4-100 - 0.06-9 Nd-56 36-750 72-1400 Thuresson et al. 2012

Chinese cities 149 nd-23 nd-0.89 nd-6 nd-18 nd-7.5 nd-3.4 nd-3 nd-22 nd-1000 nd-1000 Liu et al., 2016

Munich,Germany

34 1-17.2 - 3.2-169 0.2-33 0.5-189 0.06-11 0.08-23 0.14-22 0.9-438 8.2-477 Fromme et al. 2009

Etang de Thau, France

13 0.8-1.3 - 71-104 16-23 62-90 4-5.5 4-5.7 0.09-0.2 0.8-1.4 158-230 Castro-Jiménez et al. 2011

Zurich, Switzerland

7 0.4-1.7 - 41-104 2.8-9.7 7.6-44 - 0.4-2.1 0.8-4.6 28-199 118-591 Bogdal et al. 2014

Kathmandu 10 0.05-59 0.1-37 0.05-1 0.05-0.6 0.1-1.9 0.05-0.5

0.05-0.6 0.24-2.6 2.2-85 5.7-103 This study

Pokhara 8 1-27.5 0.3-17 0.14-8.1 0.05-1 0.1-2.5 0.05-0.3

0.05-0.33

nd-0.52 2.2-11 6.6-57.8 This study

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.,

2016Toronto, Canada 23 0.95-7.4 0.85-60 3.1-291 Nd-2.4 Nd-43 Nd-74 4.9-478 Venier et al.,

2016Brno, Czech Republic

20 Nd-1.4 Nd-31 Nd-15 Nd-1.4 Nd-5.4 - Nd-54 Venier et al., 2016

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

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Figure S4 Relative abundance of PBDEs formulation

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