Characterization of polychlorinated biphenyls and brominated flame retardants in surface soils from Surabaya, Indonesia

Chemosphere 83 (2011) 783–791

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Chemosphere

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Characterization of polychlorinated biphenyls and brominated flame retardantsin surface soils from Surabaya, Indonesia

Muhammad Ilyas a,c, Agus Sudaryanto a,b,c, Iwan Eka Setiawan c, Adi Slamet Riyadi c, Tomohiko Isobe a,b,Shohei Ogawa a, Shin Takahashi a, Shinsuke Tanabe a,⇑a Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577, Japanb Senior Research Fellow Center, Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577, Japanc Technology Center for Marine Survey, Agency for the Assessment and Application of Technology (BPPT), Jl. M.H. Thamrin 8, Jakarta, Indonesia

a r t i c l e i n f o

Article history:Received 14 September 2010Received in revised form 17 January 2011Accepted 27 February 2011Available online 22 March 2011

Keywords:SoilPCBBFRsContaminationSurabaya CityIndonesia

0045-6535/$ - see front matter � 2011 Elsevier Ltd. Adoi:10.1016/j.chemosphere.2011.02.067

⇑ Corresponding author. Tel./fax: +81 89 927 8171.E-mail address: [email protected] (S. Ta

a b s t r a c t

In this study, soil contamination by PCBs, PBDEs, HBCDs and two novel BFRs such as 1,2-bis-(2,4,6-trib-romopenoxy) ethane (BTBPE) and decabromodiphenyl ethane (DBDPE) in various locations such as indus-trial, urban, rural, dumping site and agricultural areas of Surabaya, Indonesia has been characterized inorder to evaluate their contamination status, profiles, potential sources, fate and behavior. Range andmedian concentrations of PCBs, PBDEs, HBCDs, BTBPE and DBDPE were ND – 9.6 (1.2), 0.069 – 24 (7.4),ND – 1.8 (0.48), ND – 1.7 (0.14) and ND – 7.6 (2.2) ng g�1 dw, respectively. Industrial, urban and dumpingareas were inventoried as the main sources of these pollutants. Decreasing gradient levels were observedfor these contaminants from industrial district, urban, dumping site, rural and agricultural areas, in thatorder. Furthermore, organic carbon contents and proximity to the point sources were found as the majorcontrolling factors. Contaminant profiles were characterized by the predominance of hexa-, hepta- andpenta-homologues for PCBs; deca-, nona- and octa- for PBDEs and a-isomer for HBCDs. Product mixturessuch as Ar1260/KC600 and Ar1254/KC500 for PCBs, deca- and octa-BDEs for PBDEs were the possiblecommon formulations used in study area. To our knowledge, this is a first comprehensive study on char-acterization of soil contamination by PCBs, PBDEs and HBCDs together with two novel BFRs in a highlyindustrialized city located in tropical region. This study provides baseline information for establishingnational monitoring programs in Indonesia.

� 2011 Elsevier Ltd. All rights reserved.

1. Introduction

Polychlorinated biphenyls (PCBs) and some brominated flameretardants (BFRs) have been well recognized as the persistent or-ganic pollutants (POPs) of industrial origin, and are of concerndue to their possible adverse effects on humans and ecosystems(Tanabe, 1988; Gerecke et al., 2008; UNEP, 2010). Although pro-duction and use of PCBs have been restricted in most industrializedcountries since the 1970s, they are still detected in environmentalmatrices such as biota due to their persistent and bioaccumulativeproperties. In addition, polybrominated diphenyl ethers (PBDEs)and hexabromocyclododecanes (HBCDs) which have been usedintensively for reducing flammability of various household andcommercial products such as furniture and electronic components,thermal insulation in buildings and upholstery textiles (La Guardiaet al., 2006; BSEF, 2010), are studied during recent decade. Due totheir similar fate and behavior as PCBs, some BFRs have been reg-ulated and other alternative BFRs (Kierkegaard et al., 2004; Staple-

ll rights reserved.

nabe).

ton et al., 2008; Shi et al., 2009) such as BTBPE and DBDPE are usedas replacement products. Since BTBPE and DBDPE have widelybeen detected in house dust, sediment, air, sewage sludge, farm-land soil and toys (Kierkegaard et al., 2004; Stapleton et al.,2008; Chen et al., 2009; Shi et al., 2009; Ricklund et al., 2010),the evaluation of these compounds in the environment are alsoessential for risk assessment study of BFRs.

In the global contamination study of POPs, soils have been wellidentified as a major reservoir and sink for many organic pollutantsdue to its high binding capacity and sorption quality (Meijer et al.,2003). Nevertheless, only few studies reported the occurrence anddistribution of PCBs and BFRs in soil samples (Ockenden et al.,2003; Davis et al., 2005; Leung et al., 2007; Zou et al., 2007; Namet al., 2008; Eguchi et al., 2009; Jiang et al., 2010). Moreover, thesestudies generally focused only on specific contaminants (PCBs orPBDEs) and locations (municipal dumping sites, e-waste, indus-trial, urban or rural areas).

The present study aimed to characterize soil contamination byPCBs, PBDEs, HBCDs, BTBPE and DBDPE in the highly industrializedcity, Surabaya through analysis of surface soils collected from var-ious locations representing different activities such urban, indus-

784 M. Ilyas et al. / Chemosphere 83 (2011) 783–791

trial, rural, dumping site and agricultural areas. In addition, it alsoaimed to identify their point sources and factors influencing thelevels and distribution.

2. Materials and methods

2.1. Study area and sampling location

Surabaya City is located between 7�120 and 7�210 south latitudeand between 112�360 and 112�540 east longitude and situated at 3–6 m above sea level. The daily average temperature is between 22.4and 34.4 �C with an average humidity of 71.5%. The total area isaround 326.36 km2 with a population of approximately 2.74 mil-lion in the year 2005 (Ferita, 2006). Surabaya is the second largestcity in Indonesia and well known as a center for industries such asshipping, electronics, textiles, home appliances, cosmetics, tradi-tional herbs, handicrafts, ceramics and flour mills. There are threeindustrial clustered areas, namely Ngagel, Rungkut and Tandesindustrial estates (Fig. 1). Twenty-three surface soils were col-lected during August and September 2008 from five locations rep-resenting different activities (Fig. 1), namely industrial (IR; n = 4),urban (UR; n = 6), and rural roads (RR; n = 4); Benowo municipaldumpsite (DS; n = 6), and Sukolilo agricultural area (AGS; n = 3).Samples were kept in ice boxes, transported to Japan and storedat �20 �C in the Environmental Specimen Bank (es-Bank) of EhimeUniversity prior to chemicals analyses (Tanabe, 2006).

2.2. Chemical analysis

PCBs and BFRs were analyzed by using the method described byIsobe et al. (2007), Eguchi et al. (2010), and Ramu et al. (2010) withslight modification. Briefly, around 5–7 g soil samples were spikedwith surrogates containing 5 ng of 13C12 labeled PBDEs (13C12 la-

Surarr baya River

KaKK limii as River

WoWW nokrorr mo River

3 0 3 6 Miles

MADURA

GRESIK

SIDOARJO

SURABAYA

MaMM durarr Strarr it

: Main river

: Tributary/canals

: Sampling point

UR : Urban road

IR : Industrial roadaa

RR : RuR ral road

DS : Dumping site

AGS : Agricultural

LEGEND

UR-1

DS-1

AGS-1

AGS-2

AGS-3

IR-1

UR-6

UR-2

RRRR -1

RRRR -2

UR-3

UR-4

IR-2

UR-5

RRRR -33

IR-3

IR-4

RRRR -4

DDSS-2

DS-6

DS-3

DS-7

DS-88

N

7.07 S7. 45 S

112. 50 E 112. 82

Fig. 1. Map showing sampling location

beled BDE-3, -15, -28, -47, -99, -100, -153, -154, -183,-197, -207,-209, BTBPE and DBDPE), 10 ng of 13C12 labeled HBCDs (13C12

labeled a-, b- and c-HBCD) and 5 ng of 13C12 labeled PCBs (13C12

labeled CBs-28, -52, -95, -101, -118, -105, -153, -138, -167, -156,-157, -178, -180, -170, -189, -202, -194, -208, -206, -209 and -139) as internal standards (Wellington Laboratories Inc., Guelph,Ontario, Canada) for measuring the extraction efficiency and lossesduring extraction and clean-up. Samples were extracted throughsolid–liquid extractions using a mixture of acetone/hexane (50–50 v/v), shaken vigorously for 60 min in an electric shaker (SR-2 W model, TAITEC, Japan) and ultra-sonified for 15 min. After cen-trifugation, (2500 rpm, 10 min), the supernatant was concentratedto about 1–2 mL in a rotary evaporator. For the first step of clean-up procedure, the extract was passed through a multi layer silicagel column (silica gel, 2% potassium hydroxide impregnated silicagel, 44% and 22% sulfuric acid impregnated silica gel, and sodiumsulphate) and eluted with 25% of dichloromethane in hexane (v/v) as eluant. Further clean-up, the extracted samples were treatedwith concentrated H2SO4 and washed three times using milli-Qwater prior to gel permeation chromatography (GPC; Bio-BeadsS-X3, Bio-Rad laboratories, CA, 2 cm i.d. and 50 cm length). Fractioncontaining target compounds was concentrated and passedthrough a silica gel column packed with 4 g of activated silica gel(Wako gel S-1, Wako Pure Chemicals, Japan) for final purificationand fractionation. Fraction containing PBDEs, DBDPE, BTBPE andPCBs was eluted by 80 mL of 5% dichloromethane in hexane (v/v), while the fraction containing HBCDs was eluted by 100 mL of25% dichloromethane in hexane (v/v). PBDE, DBDPE, BTBPE andPCB fractions were concentrated to 5 mL and treated with acti-vated copper strings. Then 5 ng of 13C12-labeled BDE-139 wasspiked for checking instrument performance prior to gas chroma-tography–mass spectrometry (GC–MS) analysis. Identificationand quantification of PBDEs, BTBPE, DBDPE and PCBs were

100 110 120 130 140

100 110 120 130 140

400 0 400 800 Miles

N

-10

0

10

-10

0

10

IIIIIIIINDNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOONNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN SSSESEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEESSSIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

E

s of surface soils in Surabaya City.

M. Ilyas et al. / Chemosphere 83 (2011) 783–791 785

performed by a GC (Agilent 7980A) coupled MS (Agilent 5975C)with a DB-1MS fused silica capillary column (Agilent, Tokyo, Japan)of 30 m length � 250 lm i.d. � 0.25 lm film thickness for mono-to hepta-BDEs, BTBPE and PCBs, while a VF-1MS capillary column(15 m � 250 lm i.d. � 0.1 lm film thickness) was used for octa-to deca-BDE and DBDPE. Details of GC–MS conditions were de-scribed elsewhere (Eguchi et al., 2010). The fractions containingHBCDs were evaporated and spiked with 10 ng of d18-labeled a-,b- and c-HBCDs prior to liquid chromatography-coupled with tan-dem mass spectrometry (LC-MS/MS) following the methods de-scribed by Isobe et al. (2007), Minh et al. (2007), and Ramu et al.(2010). Identification and quantification of HBCDs, an AcquityUPLC liquid chromatography equipped with a Quattro Micro API(Waters, Tokyo) triple quadrupole mass-spectrometer was used.Liquid chromatography separation of three stereoisomers (a-,b- and c-HBCD) was achieved with an Extend-C18 column(2.1 mm i.d. � 100 mm, 1.8 lm, Agilent, Tokyo). The MS–MSanalysis in negative mode of electro spray ionization (ESI) was per-formed in multiple reactions monitoring mode (MRM). Quantifica-tion of native HBCDs was achieved using Mass Lynx 4.1 (Waters,Tokyo) software from the mean values of response at two MRMtransitions (i.e., m/z 640.6 > 81, m/z 642.6 > 81) corrected with re-sponse of 13C12-HBCDs (i.e., m/z 652.6 > 81 MRM transition). Theperformance of instrument and effect of matrices in sampleextracts were evaluated by response of a-, b- and c-HBCD-d18

(i.e. m/z 658.6 > 81 MRM transition). Forty-two PBDE congenersfrom mono- to deca-BDE, BTBPE, DBDPE, 3 HBCD isomers and 62PCB congeners (Tables SI-2, SI-3 and 1) were analyzed in this study.Concentrations of PBDE and PCB congeners and HBCD isomerswere summed individually to obtain the total concentrations ofthe respective compounds and expressed as nano gram per gramdry weight (ng g�1 dw), unless otherwise specified.

2.3. Quality assurance/quality control

A procedural blank analysis was performed with every 7 sam-ples for evaluating interferences and contamination. Surrogaterecoveries for PCBs, PBDEs, HBCDs, BTBPE and DBDPE throughoutthe paper range between 41% and 79%, 53% and 119%, 84% and106%, 26% and 70%, and between 50% and 118%, respectively. Entireanalytical procedure used for PBDEs and HBCDs in soil and sedi-ment have been validated using the Certified Reference Materials(CRM#1 air dried sediment) provided by National Institute for Envi-ronmental Studies (NIES), Japan for inter-laboratory calibration.The average values we found were 0.025; 0.14; 0.15; 0.032; 0.45;0.074; 1.2; 146 and 831 ng g�1 wet weight (ww), and those valueswere within the ranges of certified values reported (0.030–0.044;0.13–0.23; 0.099–0.22; 0.017–0.041; 0.26–0.49; 0.057–0.083;0.99–2.4; 140–190; 800–850 ng g�1 ww) for BDE-28, -47, -99, -100, -153, -154, -183, -209 and total HBCDs, respectively.

2.4. Organic carbon content

Total organic carbon (TOC) was analyzed following the methoddescribed by Ramu et al. (2010). About 1–2 g of soil was treatedwith 5 N HCl for removing inorganic carbon, washed three timeswith milli-Q water, and dried at 40 �C. The samples were groundand subjected to TOC analysis using CHN- Corder (MT-5; Yanaco).Acetanilide, antipyrine and 4-nitroaniline were used as externalstandards.

2.5. Statistical analysis

Shapiro–Wilk’s W test was applied for evaluating the normalityof data (set at p < 0.05), while Spearman rank analysis was per-formed to evaluate correlations among contaminant levels, cong-

eners and TOC with significance set at p < 0.05. The level andrelative contribution of PCBs and PBDEs were calculated and de-scribed in box plot. Principle component analysis (PCA) was per-formed to explain similarity among sampling sites, and betweensites and commercial formulations using homologue profiles inboth product mixtures and soil samples. The Mann–Whitney U testwas also performed to test differences of contamination levels be-tween locations (set at p < 0.05).

3. Results and discussion

3.1. Levels

Concentrations of PCBs and BFRs in all the samples are pre-sented in Table 1. The range and median concentrations of PCBs(sum of 62 congeners), PBDEs (sum of 42 congeners), BDE-209,octa- to nona-BDEs (sum of 10 congeners), mono- to hepta-BDEs(sum of 31 congeners), HBCDs (sum of 3 isomers), BTBPE andDBDPE were from ND – 9.6 (1.2), 0.069–24 (7.4), 0.038–21 (5.2),0.02–5.76 (1.8), 0.01–1.25 (0.34), ND – 1.8 (0.48), ND – 1.7 (0.14)and ND – 7.6 (2.2) ng g�1 dw, respectively, indicated ubiquitousoccurrence of these contaminants in Surabaya. Since PCB levelswere lower than PBDEs, it may indicate that PBDEs have been re-cently introduced by industrial activities as flame retardant formany consumer products in Surabaya City, while PCBs might be re-leased from disposal of electrical waste containing PCBs such astransformers, and contaminated soils. On the other hand, low con-centrations of HBCDs in this study, may be due to their limited con-sumption. For instance, in Asia, the usage of HBCDs as flameretardants is less when compared to other BFRs formulations(Watanabe and Sakai, 2003). Low levels of HBCDs have also beenreported in municipal dumping site soils from several Asian devel-oping countries (Eguchi et al., 2009). Furthermore, low levels ofHBCDs could also be due to the high transformation processes ofthese compounds, either by biotic and/or abiotic mechanisms insoil medium. For example, significant decreasing levels of HBCDsin aerobic (75% over 119 d) and anaerobic (92% within 21 d) soilshave been reported in a microcosm study (Davis et al., 2005).

Interestingly, two novel BFRs (BTBPE and DBDPE) were alsowidely detected in soils in this study (Table 1), indicating the useof these new chemicals as replacement products replacing conven-tional BFRs such as Octa- and Deca-BDE mixtures in polymericmaterials (de Wit et al., 2010) in Surabaya. DBDPE was higher thanBTBPE, however the levels were still lower than BDE-209. Rangeand median values of DBDPE/BDE-209 were 0.1–1.8 (0.62), indicat-ing still continuing dominant use of Deca-BDE in the study area.This pattern (PBDEs > DBDPE > BTBPE) was similar to those foundin house dust from USA (Stapleton et al., 2008b), sediments andfarmland soil from the Pearl River Delta (Southern China) and inair samples from Guangzhou City (Shi et al., 2009). Similarly, thispattern was also detected in children’s toys from South China(Chen et al., 2009). Overall, the contamination patterns of BFRs insoils in this study were BDE-209 > octa-to nona-BDE > DBD-PE > HBCDs > BTBPE, indicating common use of Deca-BDEs formu-lation among BFRs, followed by Octa-BDEs and DBDPE (Fig. 2).

Furthermore, correlations were found between the levels ofBDE-209 and other BFRs (Table 2) such as DBDPE (R = 0.92;p < 0.001), BTBPE (R = 0.71; p < 0.001), and HBCDs (R = 0.43;p < 0.05), explaining the similarity of their sources and distributionpathways in soil. Several studies reported that Deca-BDE productmixture and DBDPE have similar chemical structures, and com-monly used in electronic components and housing materials (Shiet al., 2009), plastic and toys (Chen et al., 2009), and textile appli-cations (Ricklund et al., 2010). In addition, HBCDs have been usedalso as flame retardants in upholstery textiles and electronics

Table 1Concentrations of PCBs, BFRs and organic carbon in surface soils collected from locations representing different activities in Surabaya.

Samplingsite

Latitude(S)

Longitude(E)

Sitecharacteristic

TOC(%)

Concentration (ng g�1 dw) DBDPE/BDE-209

PCBs Mono-tohepta-BDEs

Octa-tonona-BDEs

BDE-209

PBDEs a-HBCD

b-HBCD

c-HBCD

HBCDs BTBPE DBDPE

UR-1 7�19.8840 112�42.4440 Urban road 0.44 0.96 0.16 0.42 0.96 1.5 0.035 0.004 ND 0.04 0.11 0.65 0.68UR-2 7�17.9640 112�43.9860 Urban road 1.9 4.7 0.98 5.0 8.2 14 1.4 0.18 0.22 1.8 0.38 7.6 0.93UR-3 7�18.0480 112�44.4780 Urban road 0.88 2.7 0.54 3.3 9.2 13 0.32 0.76 0.30 1.4 ND 4.9 0.53UR-4 7�18.4500 112�47.9640 Urban road 0.92 0.63 0.51 2.9 10 14 0.99 0.15 0.15 1.3 0.43 4.7 0.46UR-5 7�15.4860 112�47.7720 Urban road 1.7 2.3 0.73 5.6 15 22 0.33 0.034 0.021 0.39 0.16 4.3 0.28UR-6 7�18.8040 112�42.1620 Urban road 0.53 0.89 0.34 1.8 5.2 7.4 0.53 0.14 1.2 1.8 0.12 3.3 0.65IR-1 7�13.8000 112�37.8000 Industrial

road1.7 4.6 1.3 5.8 13 21 1.0 0.093 0.14 1.3 0.48 ND NA

IR-2 7�11.9760 112�43.9020 Industrialroad

1.1 4.6 0.24 1.8 6.2 8.2 0.28 0.056 0.42 0.76 0.16 2.5 0.41

IR-3 7�13.4100 112�44.3040 Industrialroad

2.9 9.6 1.0 4.8 13 19 0.40 0.026 0.24 0.66 0.70 4.3 0.33

IR-4 7�15.5040 112�40.6260 Industrialroad

1.5 3.5 0.57 2.5 9.9 13 0.57 0.057 0.059 0.69 1.7 3.9 0.40

RR-1 7�19.6680 112�47.9940 Rural road 0.33 1.0 0.13 0.53 1.0 1.7 0.10 0.012 0.028 0.14 ND 1.1 1.0RR-2 7�20.7300 112�48.1260 Rural road 0.68 1.7 0.085 0.73 2.6 3.4 0.11 0.009 0.035 0.15 ND ND NARR-3 7�13.0620 112�42.1600 Rural road 0.19 0.18 0.011 0.21 0.36 0.58 ND ND 0.004 0.004 ND 0.39 1.1RR-4 7�13.4640 112�39.8220 Rural road 2.0 2.8 0.82 1.9 3.7 6.4 0.37 0.042 0.066 0.48 0.13 3.4 0.93DS-1 7�12.6000 112�36.6000 Municipal

dumping siteNA 1.1 1.1 1.9 1.7 4.7 0.088 0.001 0.076 0.17 0.14 1.1 0.62

DS-2 7�12.6000 112�37.8000 Municipaldumping site

1.1 4.1 0.29 3.1 21 24 0.060 0.005 0.026 0.091 0.091 2.2 0.10

DS-3 7�13.8000 112�37.8000 Municipaldumping site

0.67 0.037 0.33 1.7 6.5 8.5 0.22 0.054 0.38 0.65 0.088 2.0 0.31

DS-4 7�13.8000 112�36.6000 Municipaldumping site

1.4 0.25 0.58 2.8 11 14 0.32 0.76 0.30 1.4 0.15 1.7 0.16

DS-5 7�14.4000 112�37.2000 Municipaldumping site

0.32 1.3 0.36 1.1 4.2 5.7 0.11 0.022 0.11 0.24 0.085 2.5 0.60

DS-6 7�13.2000 112�36.0000 Municipaldumping site

0.73 0.54 0.26 0.34 0.29 0.89 ND ND 0.016 0.016 0.027 0.52 1.8

AGS-1 7�16.9670 112�47.4660 Agriculturalarea

2.0 ND 0.071 0.086 0.24 0.40 0.030 ND 0.004 0.035 0.056 0.16 0.64

AGS-2 7�17.4680 112�47.6520 Agriculturalarea

1.4 0.085 0.064 0.046 0.16 0.27 ND ND ND ND ND 0.11 0.66

AGS-3 7�16.9680 112�48.7260 Agriculturalarea

1.0 0.026 0.006 0.025 0.038 0.069 ND ND ND ND ND 0.058 1.6

UR = urban road; IR = industrial road; RR = rural road; DS = dumping site soil; AGS = agricultural soil, PBDEs = sum of 42 BDE congeners; PCBs = sum of 62 CB congeners;HBCDs = sum of 3 HBCD isomers; TOC = total organic carbon, ND = not detected; NA = not available.

786 M. Ilyas et al. / Chemosphere 83 (2011) 783–791

(Covaci et al., 2006; BSEF, 2010), while BTBPE is mainly used asadditive flame retardant in plastics (Balabanovich et al., 2003).

To understand the magnitude of contamination, concentrationsof PCBs and BFRs in the present study were compared with otherlocations worldwide (Table 3). However, to our knowledge, onlylimited information on the contamination by these compounds insoil was available in the literature. Levels of PCBs in the presentstudy were generally lower than other studies including industrialand unpolluted soils from Shanghai (Ma et al., 2007), backgroundsoils from Norway and UK (Meijer et al., 2002), and urban and ruralsoils from South of Sweden (Backe et al., 2004), but higher thanthose in soils collected across China (Ren et al., 2007). Furthermore,levels of BDE-209 was lower when compared with various studiesin China such as those from Pearl River Delta and Qingyuan e-waste site (Shi et al., 2009) and Yangtze River Delta (Duan et al.,2010). However, the levels in urban soils were higher than thoseobserved in a similar location in Shanghai (Jiang et al., 2010). Lev-els of HBCDs in the present study corresponded with those ob-served in the dumpsite soils collected from several Asiandeveloping countries (Eguchi et al., 2009), while BTBPE and DBDPEwere generally similar or lower than those found in soils from twolocations of China (Shi et al., 2009). Overall, the magnitude con-tamination by PCBs and BFRs in soil of the present study was gen-erally lower than those found in China and European countries(Table 3).

3.2. Spatial distribution and potential sources

Spatial distribution of contaminants in surface soil is shown inFig. 2. The detected concentrations vary among the study locations.Levels of PCBs were found to be in decreasing order in areas ofindustrial, urban, municipal dumping site, rural and agricultural.Statistically significant differences were observed between PCBsin IR and some other locations (DS, RR, AGS) (p < 0.05), but the con-centrations were relatively similar with UR. Generally, as PCB lev-els vary depending on the distance from point sources (Meijeret al., 2002), it can be presumed that industrial and urban activitiescould be the main sources of soil contamination by PCBs in thisstudy. The fact that industrial districts and urban areas as PCBsources has also been observed in some other countries of theworld (Breivik et al., 2002; Meijer et al., 2003; Ma et al., 2007;Nam et al., 2008; Li et al., 2010). There was no significant differenceon the levels of PCBs between UR and RR (p > 0.05), possibly due tothe fact that contamination in RR soils might have been highlyinfluenced by UR as the point source. This could be due to the shortdistance between UR to RR (Fig. 2). Proximity to the point sourcesas a possible factor on PCB fractionation in soils along an urban–rural transect (±200 km) in the city of Shanghai has already beenreported (Ren et al., 2007). On the other hand, significant differencewas found between agricultural soils and other locations (p < 0.05),indicating that soil contamination by PCBs in agricultural areas

Fig. 2. Spatial distribution (ng g�1 dw) of PCBs, PBDEs, HBCDs, BTBPE and DBDPE in surface soils from Surabaya City.

Table 2Spearman rank correlations among contaminants and TOC contents in surface soils (n = 23) from Surabaya.

PCBs Mono- to hepta-BDEs Octa- to nona-BDEs BDE 209 PBDEs HBCDs BTBPE DBDPE

TOC **0.57 **0.58 *0.46 0.28 0.34 0.23 �0.05 0.22PCBS *0.44 **0.53 *0.43 *0.47 �0.12 �0.11 **0.53Mono- to hepta-BDEs ***0.87 ***0.70 ***0.75 0.24 �0.15 ***0.65Octa- to nona-BDEs ***0.92 ***0.95 0.27 0.02 ***0.80BDE 209 0.28 *0.43 ***0.71 ***0.92PBDEs 0.23 �0.07 ***0.74HBCDs 0.37 0.26BTBPE 0.18

PCBs (total concentration of 62 PCB congeners), PBDEs (total concentration of 42 PBDE congeners, including BDE-209), HBCDs (total concentration of 3 HBCD isomers).* p < 0.05.** p < 0.01.*** p < 0.00 l.

M. Ilyas et al. / Chemosphere 83 (2011) 783–791 787

was the result of deposition process. Further studies are needed tounderstand the main sources of PCBs contamination in agriculturalsoils.

As in the case of PCBs, spatial distribution of PBDEs and HBCDswere also found to be higher in surface soils from industrialareas > urban > dumping site (Fig. 2). Statistically significant differ-ences were observed between IR, UR and DS and RR and AGS(p < 0.05) for PBDEs, indicating their major sources in such loca-tions (IR, UR and DS). HBCD levels were found to be higher in

UR, IR and DS than RR and AGS (p < 0.05). These results suggestthat urban, industrial and dumping site areas were the emissionsources of HBCDs. Spatial distribution of BTBPE and DBDPE indi-cates decreasing levels of these compounds from urban > indus-trial > rural (Fig. 3). Among the locations, BTBPE in IR site wasthe highest (p < 0.05), indicating that industrial activities as themain source of this compound. Furthermore, DBDPE was also high-er in UR, IR, DS and RR as compared to AGS (Fig. 2). Concentrationsof DBDPE in IR and UR were significantly different compared with

Table 3Concentrations of PCBs, PBDEs, HBCDs, BTBPE and DBDPE in soils from Surabaya City and other locations worldwide.

Location Typical site Samplingyear

Range concentrations (ng g�1 dw)

n PCBs BDE-209 HBCDs BTBPE DBDPE References

Shanghai (China) Urban area soils 2006 55 NA 0.0013–2.9

NA NA NA Jiang et al.(2010)

Shanghai (China) Industrial to unpollutedsites

2005;2006 12 0.5–587 NA NA NA NA Ma et al. (2007)_

Pearl River Delta (China) Farmland Soil/PRD 2007 4 NA 40–95 NA 0.020–0.11

18–60 Shi et al. (2009)

E-waste Site Qingyuan (China) Soil/the e-waste areas 2006 4 NA 21–179 NA 0.070–6.2 <2.5–4.6 Shi et al. (2009)Norway and UK Grassland and woodland

soils1998 41 0.051–22 NA NA NA NA Meijer et al.

(2002)Zhangjiagang and Changshu

(China)Agricultural soils 2004 198 ND – 33 NA NA NA NA Ying et al. (2007)

Chinese surface soils (China) Background, rural, urbansoils

2005 52 0.138–1.8 NA NA NA NA Ren et al. (2007)

South of Sweden Urban and rural soils 1993 11 2.3–986 NA NA NA NA Backe et al.(2004)

Yangtze River Delta (China) Background soils 2009 22 NA 0.080–35 NA NA NA Duan et al.(2010)

Asian developing countries Dumping site soils 1999–2004 40 NA NA ND – 2.5 NA NA Eguchi et al.(2009)

Industrial, Surabaya Industrial road soils 2008 4 3.5–9.6 6.2–13 0.66–1.3 0.16–1.7 ND – 4.3 This studyUrban, Surabaya Urban road soils 2008 6 0.62–4.7 0.96–15 0.038–1.8 ND – 0.43 0.65–7.6 This studyDumpsite, Surabaya Municipal dump site soils 2008 6 0.037–4.1 0.29–21 0.016–1.4 0.027–

0.150.51–2.54

This study

Rural, Surabaya Rural road soils 2008 4 0.18–2.8 0.36–3.7 0.004–0.48

ND–0.13 ND – 3.4 This study

Agricultural, Surabaya Agricultural soils 2008 3 0.026–0.085

0.037–0.24

ND –0.035

ND –0.056

0.058–0.16

This study

n = number of samples; ND = not detected; NA = not available.

788 M. Ilyas et al. / Chemosphere 83 (2011) 783–791

other locations (p < 0.05), but no difference between IR and UR wasobserved (p > 0.05). These results reveal that industrial and urbanareas are the major sources of DBDPE.

3.3. Contaminant profiles and its implications

The homologue/congener/isomer profiles of PCBs, PBDEs andHBCDs in soil samples can be applied to identify the use of com-mercial formulations in that place, in addition to evaluation oftheir behavior and fate in the environment (Hassanin et al.,2004; Wang et al., 2005; Leung et al., 2007; Zou et al., 2007; Eguchiet al., 2009; Sun et al., 2009; Jiang et al., 2010). In the present study,we found that PCB profiles in almost all the samples were domi-nated by hexa-, followed by hepta- and penta-CBs (Fig. 3). Lowerchlorinated congeners such as tri- and tetra-CBs were also found,but their contribution was very low when compared to penta- tohepta-CBs (Fig. 3). Among the locations, PCB congener profileswere generally similar, indicating that distance from point sourcesand types of product mixtures used were the dominant factorsdeciding the PCB profiles in the surface soils, as noticed in the pres-ent study.

Fig. 4 described PCA on the similarity of PCB and PBDE homo-logue patterns among locations and available commercial formula-tions (Breivik et al., 2002; Ishikawa et al., 2007). In this study, 65%of the total variance for 10 variables of PCB homologues was ex-plained by two principle components (PC1 and PC2). Generally,higher chlorinated congeners such as penta- to octa-CBs character-ized almost all the locations, except one site from urban area (UR-3) which was dominated by nona- and deca-CB. Lower chlorinatedCBs (di- to tetra-CBs) were found to characterize less number oflocations. In general, PCA indicated similar clusters of PCB homo-logue profiles between sampling sites and PCB product mixtureswhich contains higher chlorinated congeners such as those fromAr1260, Ar1254, KC600 and KC500, suggesting that these formula-tions were probably the product mixtures commonly used in Sura-

baya. Presence of other PCB homologues, particularly lowerchlorinated CBs seen in some locations can be explained as dueto the use of other PCB product mixtures such as KC300, KC400,Ar1242 and Ar1248, and/or as the products of dechlorination ofhigher chlorinated PCBs mixtures.

With regard to PBDEs, deca-BDE was the predominant homo-logue followed by nona-, octa-, hepta-, penta- and tetra-BDEs(Fig. 3). Contributions of deca-, nona- and octa-BDEs in total PBDEsvaried from 32% to 86%, 11% to 26% and 2% to 25%, respectively. ThePCA analysis explained total variance between PC1 and PC2(59.63%), in which heavier homologues (octa- to deca-BDE) charac-terized almost all the locations. Two sites from dumping site areas(DS-1 and DS-2) were characterized by tetra-, penta- and hexa-BDEs, whereas, lower homologues (mono- to di-BDEs) were foundin agricultural soils. Higher contributions of deca-BDE in soil sam-ples compared to other homologues indicate that Deca-PBDE tech-nical mixture was intensively used than two other PBDEformulations (Penta- and Octa-BDEs). However, the highly hydro-phobic nature of BDE-209 (log Kow � 10), which has a strong ten-dency to bind to sediment and soil (Hale et al., 2002) could alsobe a plausible explanation. High contribution of BDE-209 in river-ine and coastal sediments from Surabaya has also been observed(Ilyas et al., 2011). Since the composition of PBDEs in the presentstudy did not exactly resemble Deca-PBDE technical product(Bromkal 82-0DE) which consists 92% of BDE-209, 9.3% of nona-BDEs and 0.56% of octa-BDEs (La Guardia et al., 2006), it suggestedthat debromination of BDE-209 might be taking place in the soilproducing nona-, octa-BDEs and other lower congeners. In particu-lar, dumpsite areas were characterized by some lower BDE congen-ers. Spearman rank correlations (Table 2) showed significantly highcorrelations between BDE-209 and octa- to nona-BDEs (R = 0.92;p < 0.001) and mono- to hepta-BDEs (R = 0.70; p < 0.001), indicat-ing potential debromination of BDE-209, forming lower congeners.Debromination of BDE-209 has also been reported in anaerobicsediments producing nona-, octa-, hepta- and hexa-PBDEs (Tokarz

Rel

ativ

e co

ntri

buti

on(%

)

PCBs

PBDEs

Fig. 3. PCB and PBDE homologues in surface soils of Surabaya City (bar indicates median; range indicates minimum and maximum values).

UR-1UR-2

IR-1

RR-1

RR-2

UR-3

UR-4

IR-2

IR-3

RR-3

UR-5UR-6

IR-4 RR-4

DS-1

DS-2

DS-3

DS-4DS-5

DS-6AGS-2

AGS-3

KC-400

KC-500

KC-600

Ar1016

Ar1242

Ar1254

Ar1260

Ar1262

2 CB

3 CB

4 CB

5 CB6 CB

7 CB

8 CB

9 CB

10 C

- 4-2

0 4

0

2

4

6

PC1 (41%)

PC

2 (2

4%)

PCBs

UR-1

UR-2

IR-1

RR-1

RR-2

UR-3UR-4

IR-2

IR-3

RR-3

UR-5UR-6

IR-4

RR-4

DS-1

DS-2

DS-3DS-4DS-5

DS-6

AGS-1

AGS-2

AGS-3

Penta-PBDEFormulation

Octa-PBDEFormulation

Deca-PBDE Formulation

MoB

DE

Di B

DE

s

Tri BDEs

Te BDEs

Pe BDEs

He BDEs

Hep BDEsOc BDEs

Nona BDEs

De BD

-2- 4

2 6

0

4

PC1 (37%)

PC

2 (2

2)

PBDEs

Fig. 4. Principal component analysis (PCA) of 10 different PCB and PBDE homologues in the soil samples from industrial, urban, dumping site, rural, and agricultural areas aswell as commercial formulations.

M. Ilyas et al. / Chemosphere 83 (2011) 783–791 789

iii et al., 2008). Another study indicated debromination of BDE-209by bacteria in soil to form lower congeners (Huang et al., 2010).Furthermore, photolytic debromination of BDE-209 by natural sun-light could also produce lower BDE congeners (Söderström et al.,2004; Stapleton and Dodder, 2008). For instance, in soil, this typeof photolytic debromination produced BDE-206, -207, -208, fourunknown congeners of octa-, one unknown hepta-, -183, -128,two unknown hexa-, -154, and -119 (Söderström et al., 2004). Pho-tolytic debromination of BDE-209 has also been observed in housedust with products of debromination including BDE-206, -207, -208, unknown octa-, -196, -200, -203, -197, -201, -202, unknownhepta- and -183. Among these BDE-201 and -202 were known as

indicators of debromination of BDE-209 (Stapleton and Dodder,2008). In the present study, we found significant correlations be-tween BDE-209 and lower PBDE congeners such as BDE-206, -207, -208, -197, -183, -154, and particularly BDE-201 (p < 0.01)(Table SI-1 Supporting information).

For HBCDs, the isomer patterns were generally characterized bythe predominance of a-HBCD (45–87%) followed by c-(12–46%)(Table 1, Fig. SI-1 Supporting information), except in municipaldumping sites where contribution by a- and c-HBCD were equal(45%). These profiles indicate that HBCDs composition changedfrom that of the original HBCD product mixture which contained75–89% of c-HBCD, 10–13% of a-HBCD and 1–12% of b-HBCD

790 M. Ilyas et al. / Chemosphere 83 (2011) 783–791

(Covaci et al., 2006). In sediment and leachate samples, c-HBCDwas found to be the dominant isomer (Morris et al., 2004; Minhet al., 2007; Haukås et al., 2009; Ramu et al., 2010), while in aquaticbiota a-HBCD was higher (Isobe et al., 2007; Haukås et al., 2009;Takahashi et al., 2010; Ueno et al., 2010). Slightly higher of c-HBCD(52%) compared to a-HBCD (39%) has been reported in the refer-ence and municipal dumping site soils from Asian developingcountries (Eguchi et al., 2009) and in soil collected from HBCD pro-cessing factories with 52% of c-HBCD and 18% of a-HBCD (Covaciet al., 2006). However, there is still unclear explanation for the fac-tors differentiating HBCD profiles between environmental samplesand product mixture; whether it is due to thermal isomerizationduring the processing of HBCDs and/or by stereoisomer-specificprocesses in the environment. However, higher proportion of a-HBCD in most textile products as a result of isomerization of c-HBCD has been reported (Kajiwara et al., 2009).

3.4. Correlation with organic carbon content

In general, concentrations of POPs in soil and sediment arestrongly influenced by organic carbon content (Meijer et al.,2003; Nam et al., 2008; Sun et al., 2009). In this study, organic car-bon content in surface soil varied from 0.19–2.9% (Table 1). Signif-icant correlations between TOC were found only for PCBs andPBDEs, particularly mono- to hepta-BDEs, octa- to nona-BDEs andBDE-209 (when data from dumping site were excluded), indicatingthe important roles of organic carbon in soil contamination bythese compounds. This result corresponded with the study of soilsfrom Shanghai urban areas (Jiang et al., 2010) and European back-ground soils (Hassanin et al., 2004), particularly for the lower cong-eners. However, when dumping site data were included, there wasno correlation between TOC and BDE-209, probably because thepoint source was the important factor controlling BDE-209 levelsin dumping site soil. Weak correlation between TOC and somePBDE congeners were also observed in soils from Chong Min Island(Duan et al., 2010). Furthermore, there was no correlation betweenTOC and other BFRs including HBCDs, BTBPE and DBDPE (Table 2).Variation of the strengths of association between TOC and thesehydrophobic compounds might act as other co-existing factorsresponsible for accumulation in soils. For instance, Lohmannet al. (2001) suggested that factors such as distance from sources,land use type, wet deposition, degradation in the environmentand atmospheric transport could also control the levels of contam-inants in the environment. The weak association between TOC andHBCDs, BTBPE and DBDPE could also be due to their less amount ofusage in the study areas and around. In fact, these compoundswere detected at very low concentrations and below detection lim-it at some locations (Table 2).

4. Conclusions

Soil contamination by PCBs, PBDEs, HBCDs and two novel BFRsfrom various locations in Surabaya, Indonesia representing differ-ent activities has been evaluated for the first time. All compoundswere detected at widely varying concentrations, PCBs, PBDEs andDBDPE being the abundant contaminants. Industrial, urban andmunicipal dumpsite areas were identified as emission sources ofthese compounds. Levels of PCBs and BFRs in this study were lowwhen compared to other locations worldwide. Organic carbon con-tents and/or proximity to the point sources were the major factorscontrolling the levels and distribution of these contaminants. Pro-files of PCBs and PBDEs indicate Ar1260, KC600, Ar1254 and KC500for PCBs; and Deca-BDE for PBDEs, as the possible major commer-cial formulations used in Surabaya City. Nevertheless, debromina-

tion and dechlorination of higher halogenated congeners may alsocontribute to the profiles observed.

Acknowledgements

This study was supported by Grants-in-Aid for Scientific Re-search(S) (No. 20221003) from Japan Society for the Promotion ofScience (JSPS) and Research Grants for Promoting and DevelopingSound Material-cycle Societies (Nos. K2121 and K2129) from theMinistry of the Environment, Japan, Global Center of Excellence(G-COE) Program by the Ministry of Education, Culture, Science &Technology, Japan (MEXT) and JSPS. The authors also thank Profes-sor Annamalai Subramanian, CMES, Ehime University for criticalreading of the manuscript.

Appendix A. Supplementary material

Supplementary data associated with this article can be found, inthe online version, at doi:10.1016/j.chemosphere.2011.02.067.

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