Around the e-waste recycling workshops, 1,3-phenylene bisdiphenyl phosphate PBDPP, bisphenol A bisdiphenyl phosphate BPA-BDPP, triphenyl phosphate TPHP, TBBPA, and PBDEs were dominant am
Trang 1Flame retardant emission from e-waste recycling operation in northern
Vietnam: Environmental occurrence of emerging organophosphorus
esters used as alternatives for PBDEs
Hidenori Matsukamia,b,⁎ , Nguyen Minh Tuec,d, Go Suzukia, Masayuki Someyae, Le Huu Tuyend,
Pham Hung Vietd, Shin Takahashic,f, Shinsuke Tanabec, Hidetaka Takigamia,b
a
Center for Material Cycles and Waste Management Research, National Institute for Environmental Studies (NIES), 16-2 Onogawa, Tsukuba 305-8506, Japan
b
Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8563, Japan
c
Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577, Japan
d Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, 334 Nguyen Trai, Hanoi, Viet Nam
e Tokyo Metropolitan Research Institute for Environmental Protection, 1-7-5 Shinsuna Koto, Tokyo 136-0075, Japan
f
Center of Advanced Technology for the Environment, Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama 790-8566, Japan
H I G H L I G H T S
• Open storage and burning of e-waste
contributed to emission of FRs
• Types of FRs currently in emission are
shifting in response to regulations
of PBDEs
• Emerging PFRs were detected in soils
and sediments around e-waste
recycling area
• Presence of alternatives for PBDEs
should be regarded as a risk factor
G R A P H I C A L A B S T R A C T
a b s t r a c t
a r t i c l e i n f o
Article history:
Received 17 December 2014
Received in revised form 3 February 2015
Accepted 3 February 2015
Available online xxxx
Editor: Adrian Covaci
Keywords:
Organophosphorus flame retardants
Tetrabromobisphenol A
Polybrominated diphenyl ethers
E-waste recycling
Open storage
Open burning
Three oligomeric organophosphorus flame retardants (o-PFRs), eight monomeric PFRs (m-PFRs), tetrabromobisphenol A (TBBPA), and polybrominated diphenyl ethers (PBDEs) were identified and quantified
in surface soils and river sediments around the e-waste recycling area in Bui Dau, northern Vietnam Around the e-waste recycling workshops, 1,3-phenylene bis(diphenyl phosphate) (PBDPP), bisphenol A bis(diphenyl phosphate) (BPA-BDPP), triphenyl phosphate (TPHP), TBBPA, and PBDEs were dominant among the investigated flame retardants (FRs) The respective concentrations of PBDPP, BPA-BDPP, TPHP, TBBPA and the total PBDEs were 6.6–14000 ng/g-dry, b2–1500 ng/g-dry, 11–3300 ng/g-dry, b5–2900 ng/g-dry, and 67–9200 ng/g-dry in surface soils, and 4.4–78 ng/g-dry, b2–20 ng/g-dry, 7.3–38 ng/g-dry, 6.0–44 ng/g-dry and 100–350 ng/g-dry in river sediments Near the open burning site of e-waste, tris(methylphenyl) phosphate (TMPP), (2-ethylhexyl)diphenyl phosphate (EHDPP), TPHP, and the total PBDEs were abundantly with respective concentra-tions ofb2–190 ng/g-dry, b2–69 ng/g-dry, b3–51 ng/g-dry and 1.7–67 ng/g-dry in surface soils Open storage and burning of e-waste have been determined to be important factors contributing to the emissions of FRs The environmental occurrence of emerging FRs, especially o-PFRs, indicates that the alternation of FRs addition
Science of the Total Environment xxx (2015) xxx–xxx
⁎ Corresponding author at: Center for Material Cycles and Waste Management Research, National Institute for Environmental Studies (NIES), 16-2 Onogawa, Tsukuba 305-8506, Japan E-mail address: matsukami.hidenori@nies.go.jp (H Matsukami).
http://dx.doi.org/10.1016/j.scitotenv.2015.02.008
0048-9697/© 2015 Elsevier B.V All rights reserved.
Contents lists available atScienceDirect
Science of the Total Environment
j o u r n a l h o m e p a g e :w w w e l s e v i e r c o m / l o c a t e / s c i t o t e n v
Trang 2in electronic products is shifting in response to domestic and international regulations of PBDEs The emissions of alternatives from open storage and burning of e-waste might become greater than those of PBDEs in the follow-ing years The presence and environmental effects of alternatives should be regarded as a risk factor along with e-waste recycling
© 2015 Elsevier B.V All rights reserved
1 Introduction
Electronic waste, commonly known as e-waste, constitutes the most
rapidly growing waste problem worldwide E-waste amounts have
been increasing because of the increased ownership and shortened
lifespan of electronic products E-waste is generated globally at a rate
of approximately 40 million tons per year (Huisman et al., 2008)
E-waste originates from electronic products containing valuable and
re-usable materials such as noble metals and plastics Recycling of e-waste
has been recognized as the most appropriate strategy for e-waste
disposal (Scharnhorst et al., 2005; Rousis et al., 2008) E-waste is
gener-ated in economically developed regions and is exported to economically
developing regions as secondhand products (Widmer et al., 2005;
Terazono and Yoshida, 2008; Shinkuma and Nguyen, 2009) The hazard
of e-waste lies in the high content of toxic substances including heavy
metals andflame retardants (FRs) that pose both environmental and
human health risks (Robinson, 2009) Nevertheless, they are then
processed in uncontrolled and primitive recycling operations that
might include toner-sweeping, cracking and dumping of cathode
ray tubes, open burning of insulated copper wires, and
acid-stripping of circuit boards to extract gold (The Basel Action
Network and Silicon Valley Toxics Coalition, 2002) Recycling of
e-waste in economically developing regions has caused severe
envi-ronmental contamination by FRs, such as polybrominated diphenyl
ethers (PBDEs) and hexabromocyclododecanes (HBCDs) (Wong
et al., 2007; Leung et al., 2007; Bi et al., 2007; Luo et al., 2007,
2009; Tue et al., 2010, 2013; Labunska et al., 2013, 2014, 2015)
Ap-propriate strategies and policies for e-waste recycling in economically
developing countries or regions need to be improved to reduce and
con-trol the risk of FRs contamination to local environment and public
health The information of FRs emission caused by improper recycling
operation in developing countries and regions remains limited This
infor-mation is rather crucial for assessing the contamination status of local
ecosystem and for the green development of e-waste recycling area in
the future Therefore, we undertook environmental investigations of FRs
around the e-waste recycling area in Bui Dau, Hung Yen province,
north-ern Vietnam Due to the contamination of the indoor environment in
e-waste recycling workshops, dust ingestion has been estimated to be an
important exposure pathway of PBDEs (Tue et al., 2013) The levels of
PBDEs in human tissues from e-waste recycling residents in Bui Dau
have been found to be among the highest ever reported (Tue et al.,
2010) However, the current status of environmental emissions of FRs
from e-waste recycling operations has not been elucidated
Environmental occurrence of FRs was regarded as indicators of
contaminations derived from e-waste recycling because FRs are
incorporated into polymeric materials for electronic products to meet
fire safety standard requirements by passing standardized fire tests
(European Flame Retardants Association, 2008) The various types of
FRs have been used depending on the application andfire safety
requirements Among polymeric materials, brominatedflame retardants
(BFRs) and organophosphorusflame retardants (PFRs) are present in
great abundance According toThe Chemical Daily of Japan (2005),
the total consumption of FRs in 2004 in Japan was approximately
190,000 tons, of which BFRs accounted for 39%, whereas PFRs accounted
for 15% (The Chemical Daily of Japan, 2005) In Europe, the total
consumption of FRs in 2006 was approximately 465,000 tons, of which
BFRs accounted for 10%, whereas PFRs accounted for 20% (Van der Veen
and de Boer, 2012) PBDEs were extremely common FR mixtures before
2004 Each commercial formulation of PBDE technical mixtures,
Penta-BDE, Octa-Penta-BDE, and Deca-BDE was incorporated into different polymeric materials such as high-impact polystyrene (HIPS), acrylonitrile –butadi-ene–styrene (ABS), wire and cable insulation, and electrical and electronic connectors (WHO, 1994) In the last decade, Penta-BDE and Octa-BDE have been gradually banned world widely (UNEP, 2009) and Deca-BDE has been gradually phased out in many countries (Dodson, et al., 2012), because of their persistence, bioaccumulation, and potentially toxic ef-fects (Eriksson et al., 2002; Darnerud, 2003; Branchi et al., 2003; Viberg
et al., 2004) Tetrabromobisphenol A (TBBPA) is a current-use high production volume BFR, with similar applications to PBDEs which is not regulated It is mainly used in printed circuit boards as a reactive agent and in ABS as an additive (WHO, 1995; de Wit et al., 2010) PFRs are chemical additives that have been used in widely diverse combustible products Halogen-free PFRs such as triphenyl phosphate (TPHP), (methylphenyl)diphenyl phosphate (MPDPP), (2-ethylhexyl)diphenyl phosphate (EHDPP), tris(methylphenyl) phosphate (TMPP), and tris(dimethylphenyl) phosphate (TDMPP) are also used as lubricants and plasticizers Chlorinated PFRs such as tris(2-chloroethyl) phosphate (TCEP), tris(2-chloroisopropyl) phosphate (TCIPP) and tris(1,3-dichloroisopropyl) phosphate (TDCIPP) are used as FRs in polyurethane form Restrictions and bans on the production and new usage of PBDEs have engendered an increase of those monomeric PFR (m-PFR) applica-tions (Pakalin et al., 2007; Van der Veen and de Boer, 2012) Because of the semi-volatility of m-PFRs, emerging oligomeric PFRs (o-PFRs) such
as 1,3-phenylene bis(diphenyl phosphate) (PBDPP), bisphenol A bis(diphenyl phosphate) (BPA-BDPP), and 1,3-phenylene bis[di(2,6-dimethylphenyl) phosphate)] (PBDMPP) are widely used today in plas-tics of poly(phenylene oxide)/HIPS and polycarbonate/ABS blends (Syracuse Research Corporation, 2006; Pakalin et al., 2007; Rossi and Heine, 2007) Higher thermal stability and lower volatility of those o-PFRs compared to m-o-PFRs make the former ideal for use in applications that demand high processing temperatures (Pawlowski and Schartel,
2007) Particularly in electronic housings, PBDPP, BPA-BDPP, and PBDMPP are used as alternatives to Deca-BDE Although several studies have elucidated the emissions of FRs to the outdoor environment in the e-waste recycling area in China (Wong et al., 2007; Leung et al., 2007; Luo et al., 2007, 2009), the current status of the emissions of FRs, espe-cially o-PFRs, via e-waste recycling operations has not been considered The present study investigated the emissions of three o-PFRs (PBDPP, BPA-BDPP, and PBDMPP), eight m-PFRs (TPHP, MPDPP, EHDPP, TMPP, TDMPP, TCEP, TCIPP, and TDCIPP), TBBPA, and PBDEs to surface soils and river sediments around e-waste recycling area in Vietnam The cur-rent status of their emissions around the e-waste recycling workshops and the sites for open burning of insulated copper wires was elucidated
2 Materials and methods 2.1 Sample collection The study area was an informal e-waste recycling area in Bui Dau, Hung Yen province, northern Vietnam This area had small rural communes with 283 households and approximately 1000 people as of January 2012 (Suzuki et al., 2013) Recycling operations were family based and took place on a small scale in the backyards of homes, often within 20 m distance from living area The main recycling process included recovery of metals and plastics not only by collection, storage, and manual dismantling in workshops as well as shredding electronic housings into chips from e-waste such as disposed computers, TVs, video players, phones, and printers, but also from open burning to
Trang 3recover copper wires at footpaths in rice paddies as well as washing
wire residues along the river since the early 2000s Other details related
to the area have been presented elsewhere (Tue et al., 2010, 2013;
Suzuki et al., 2013) A map of Bui Dau and sampling sites of surface
soils and river sediments are shown inFig 1 In January 2012, surface
soil samples (0–5 cm) were collected from the footpaths around the
ricefields (n = 19, SS-1 to SS-19), the open burning sites (n = 3,
SS-20 to SS-22), and the workshops (n = 10, SS-23 to SS-32) River
sediment samples were collected from the upstream area (RS-1), the
e-waste recycling area (n = 3, RS-2 to RS-4), and the downstream
area (n = 4, RS-5 to RS-8) Each sample comprisedfive subsamples
and was collected with a stainless-steel shovel into a zip-locked
polyethylene bag from an area of approximately 10 m2 All samples
were air-dried and manually homogenized with a wooden hammer
after removal of pebbles, weeds, and twigs Air-dried samples were
transferred to a stainless-steel sieve (b2.0 mm) covered with a steel
lid and were shaken manually Sieved samples were collected and
stored in amber glass bottles at−20 °C until chemical analysis
2.2 Materials
Native TPHP, MPDPP, and TCEP were purchased from Tokyo Chemical
Industry Co., Ltd (Tokyo, Japan) Native EHDPP was purchased from Fluka
Chemie AG (Buchs, Switzerland) Native TMPP, TCIPP, and TDCIPP were
purchased from Wako Pure Chemical Industries Ltd (Osaka, Japan)
Deuterium-labeled TPHP (TPHP-d15) was purchased from Cambridge
Isotope Laboratories Inc (Tewksbury, MA, USA) Native TDMPP,
deuterium-labeled TMPP, TDMPP, and TCEP (TMPP-d21, TDMPP-d9, and
TCEP-d12) were purchased from Hayashi Pure Chemical Ind., Ltd
(Osaka, Japan) Technical mixtures of PBDPP (product name of
CR-733S), BPA-BDPP (product name of CR-741), and PBDMPP (product
name of PX-200) were used for quantification in the present study
Four-teen native PBDE congeners (BDE-3, 15, 28, 47, 99, 100, 153, 154, 183,
196, 197, 206, 207, and 209) and eleven13C-labeled PBDE congeners
(13C12-BDE-3, 15, 28, 47, 99, 153, 154, 183, 197, 207, and 209) were
ob-tained from Wellington Laboratories Inc (Guelph, Canada)
2.3 Chemical analysis Approximately 15 g of each sample was extractedfirstly using a rapid solvent extractor (SE-100; Mitsubishi Chemical Analytech Co., Ltd.) at 35 °C for 40 min with acetone:n-hexane (1:1, v/v) mixture at flow rate of 2 mL/min, and secondary at 80 °C for 40 min with toluene
atflow rate of 2 mL/min The combined extract was evaporated to
10 mL and then stored as a crude extract at 4 °C until cleanup For the analysis of 11 PFRs and TBBPA, a portion of crude extract (equal to 1.0 g of sample) was spiked with four deuterium-labeled m-PFRs, was evaporated and passed through two cleanup columns composed of 1 g
offlorisil (Kanto Chemical Co Inc., Tokyo, Japan) and 0.1 g of monomeric octadecyl, end-capped silica gel (DSC-18Lt; Sigma-Aldrich Corp., St Louis, MO, USA) and then eluted with 5 mL of Acetonitrile Measure-ments of PFRs and TBBPA were done using an ultra high performance liquid chromatograph (1290 Infinity; Agilent Technologies Inc., Santa Clara, CA, USA) equipped with a tandem mass spectrometer (Quattro Ultima; Waters Corp., Milford, MA, USA) with a column (ZORBAX Eclipse Plus C18 RRHD, 100 mm × 2.1 mm i.d., 1.8μm; Agilent Technol-ogies Inc., Santa Clara, CA, USA) Nitrogen was used as desolvation and nebulizer gas and argon as collision gas The LC injection volume was
2μL The flow rate of the mobile phase was set at 0.3 mL/min A water solution containing 10 mM ammonium acetate was used as eluent A and 100% methanol containing 10 mM ammonium acetate was used
as eluent B The following gradient was used: 0 min (60% B), 15 min (99% B), 20 min (99% B), and 20.1 min (60% B) The tandem mass spectrometer was run in the electron spray ionization interface using the positive mode for PFRs and the negative mode for TBBPA The capillary voltage was set to 3000 V, with source temperature of
120 °C, and desolvation temperature of 400 °C The desolvation gas flow was 700 L/h, cone gas flow 50 L/h, with collision gas pressure 3.0 × 10−3 mbar Transitions measured using multiple-reaction-monitoring for quantification are given in Table S1 of Supplementary data The analytical procedure used for PBDEs is given elsewhere (Tue
et al., 2010, 2013), but a brief summary follows A portion of crude ex-tract (equal to 2.0 g of sample) was spiked with the13C-labeled PBDE congeners, treated with sulfuric acid (Wako Pure Chemical Industries
200 m
Surface soil E-waste recycling workshop Open burning site
Rice paddy
River sediment Upstream area E-waste recycling area Downstream area
Vietnam
Bui Dau
Bui Dau Map
RS-1
RS-2 RS-3 RS-4
RS-5
RS-6
RS-7
RS-8
SS-20
SS-22
SS-21
SS-24 SS-23
SS-25 SS-26
SS-27 SS-28 SS-29
SS-30 SS-31
SS-32
SS-1 SS-2
SS-3 SS-4
SS-5 SS-6
SS-7 SS-8
SS-9 SS-10
SS-11 SS-19
SS-18
SS-17
SS-16
SS-12 SS-13 SS-15
SS-14
Fig 1 Map of the surface soil and river sediment sampling sites in Bui Dau, northern Vietnam SS-1 to SS-32: surface soil samples RS-1 to RS-8: river sediment samples.
Trang 4Ltd., Osaka, Japan), and passed through a multilayer silica gel column
(Wako Pure Chemical Industries Ltd., Osaka, Japan) Measurements of
mono-PBDE to hepta-PBDE congeners were conducted on a gas
chromatograph (GC) (7890 series; Agilent Technologies Inc., Santa
Clara, CA, USA) equipped with a mass spectrometer (MS) (5975C
MSD; Agilent Technologies Inc., Santa Clara, CA, USA) using a DB-1
capillary column (30 m × 0.25 mm i.d., 0.25μm film thickness;
Agilent Technologies Inc., Santa Clara, CA, USA) Measurement of
Octa-BDE to Deca-BDE congeners was performed on another GC–
MS system of the same models with a DB-1 capillary column
(15 m × 0.25 mm i.d., 0.1μm film thickness; Agilent Technologies
Inc., Santa Clara, CA, USA)
2.4 QA/QC
Samples were analyzed using established laboratory QA/QC
procedures All analytical processes were conducted under UV-cutoff
conditions by taking the degradation of PBDEs and TBBPA into
consider-ation Results of triplicate spike experiments to verify the recovery of
PFRs in surface soil and river sediment samples are available in
Supple-mentary data: Table S2 The average recoveries of PFRs were 56–104%
from spiked surface soil samples and 59–103% from spiked river
sedi-ment samples For TPHP-d15, TMPP-d21, TDMPP-d9, and TCEP-d12, the
average recoveries for all samples were 64–74% For13
C-labeled PBDE congeners, the average recoveries for all samples were 65–130% The
limit of quantification (LOQ) values of PFRs, TBBPA, and PBDEs
were calculated using the signal-to-noise ratio and shown in
Tables 1 and 2 Procedural blanks were analyzed simultaneously
with samples to check for interferences and contamination The
con-centrations of all the target compounds in procedural blanks were
below the LOQ values
3 Results and discussion 3.1 FR concentrations in surface soils and river sediments Three o-PFRs and eight m-PFRs, TBBPA, and PBDE congeners were identified and quantified in surface soils and river sediments around the e-waste recycling area in Bui Dau This is thefirst reported occur-rence of o-PFRs in the outdoor environment, although o-PFRs have been identified and quantified in air and dust from indoor environment (Matsukami et al., 2010; Brandsma et al., 2013) The concentrations of FRs in surface soil samples from the footpaths around the rice paddies, the open burning sites, and the workshops are shown inFig 2 Detailed concentration data in surface soil samples are shown in
Table 1 The concentrations of FRs in river sediment samples are given inTable 2
The detected concentrations of FRs were highest in surface soils around the workshop (Table 1), where PBDPP, BPA-BDPP, TPHP, the total PBDEs, and TBBPA were detected in concentrations up to micro-grams per gram The respective concentrations of PBDPP, BPA-BDPP, TPHP, TBBPA and the total PBDEs in surface soils were 6.6–14,000 ng/ g-dry,b2–1500 ng/g-dry, 11–3300 ng/g-dry, b5–2900 ng/g-dry, and
67–9200 ng/g-dry The concentrations of FRs in soils from the sampling sites SS-26 and SS-29 were higher than in those from other workshop sites PBDPP was the most abundant FR at SS-26, whereas the total PBDEs were the most abundant at SS-29 In contrast, the concentrations
of FRs at SS-27 and SS-31 were lower than those from other workshop sites In soils around the open burning sites, TMPP, EHDPP, TPHP, and PBDEs were dominant among the investigated FRs The respective concentrations of TMPP, EHDPP, TPHP, and the total PBDEs in surface soils wereb2–190 ng/g-dry, b2–69 ng/g-dry, b3–51 ng/g-dry and 1.7–67 ng/g-dry In soils from the footpaths around rice paddies, all FRs were detected with concentrations of up to 10 ng/g-dry
Table 1
Concentrations (ng/g-dry) of flame retardants in surface soil samples in the present study a
BDE — brominated diphenyl ether; TBBPA — tetrabromobisphenol A; TPHP — triphenyl phosphate; MPDPP — methylphenyl diphenyl phosphate; EHDPP — 2-ethylhexyl diphenyl phos-phate; TMPP — tris(methylphenyl) phosphate; TDMPP — tris(dimethylphenyl) phosphate; TCEP — tris(2-chloroethyl) phosphate; TCIPP — tris(2-chloroisopropyl) phosphate; TDCIPP — tris(1,3-dichloroisopropyl) phosphate; PBDPP — 1,3-phenylene bis(diphenyl phosphate); BPA-BDPP — bisphenol A bis(diphenyl phosphate); PBDMPP — 1,3-phenylene bis[di(2,6-dimethylphenyl) phosphate].
a
Sampling points for surface soil samples are shown in Fig 1
Trang 5It is readily apparent that the concentrations of FRs in river
sediments were highest in the e-waste recycling area (Table 2), 1–2
or-ders of magnitude higher than those from the upstream area PBDPP,
BPA-BDPP, TPHP, TBBPA and the total PBDEs were abundant FRs at
sam-pling site RS-2 in the e-waste recycling area The respective
concentra-tions of PBDPP, BPA-BDPP, TPHP, TBBPA and the total PBDEs in river
sediments were 4.4–78 ng/g-dry, b2–20 ng/g-dry, 7.3–38 ng/g-dry,
6.0–44 ng/g-dry and 100–350 ng/g-dry The concentrations of FRs in
sediments from downstream areas decreased in theflow direction At
sampling site RS-8, approximately 1 km downstream of the e-waste
recycling area, the concentrations of FRs were within the same order
of magnitude of those from the upstream area
Results show that BDE-209 was the most abundant PBDE congener
in each type of sample The proportions of BDE-209 in surface soils
around the rice paddies, the open-burning sites, and the workshops
were 27–100%, 26–87%, and 69–95% of the total PBDEs, respectively,
whereas those in river sediments were 84–93% of the total PBDEs In
soil around the open-burning sites, the proportions of BDE-47 were
3.0–20% of the total PBDEs, which were higher than those in soils
around the workshops, which were 0.038–5.5% of the total PBDEs
3.2 Comparison of FR concentrations in surface Soil and river sediments
The respective concentrations of the total PBDEs and TBBPA detected
in soils were 1.7–9200 ng/g-dry and 19–2900 ng/g-dry In previous
studies, those concentrations in soils from e-waste recycling areas in
China were 2.9–9156 ng/g-dry for total PBDEs and 26–104 ng/g-dry
for TBBPA (Leung et al., 2007; Luo et al., 2009; Xu et al., 2012) Those
concentrations in sediments from Bui Dau were 0.43–350 ng/g-dry
for the total PBDEs and 1.2–44 ng/g-dry for TBBPA In comparison,
those concentrations in the bottom sediments from China were
52–445 ng/g-dry for the total PBDEs and 0.2–22 ng/g-dry for TBBPA
(Luo et al., 2007; Xu et al., 2012) Comparisons of the concentrations
of the total PBDEs and TBBPA detected in soils and sediments from the present and previous studies indicate that the concentrations of the total PBDEs in soils and sediments collected from Bui Dau were within the same order of magnitude of those reported from e-waste recycling areas in China
Data related to the concentrations of PBDEs, TBBPA, TPHP, TCEP, TCIPP, and TDCIPP in European rural and urban soils have been reported (Hassanin et al., 2004; Harrad and Hunter, 2006; Sánchez-Brunete et al., 2009; Mihajlovic et al., 2011) Previous studies found that the concen-trations of the total PBDEs and TBBPA in soils from UK, Norway, and Spain were, respectively, 0.015–5.6 ng/g-dry and 0.34–32.2 ng/g-dry (Hassanin et al., 2004; Harrad and Hunter, 2006; Sánchez-Brunete
et al., 2009) The average concentrations of TPHP, TCEP, and TCIPP in urban soil samples collected from a university campus in Germany were 1.23–4.96 ng/g-dry TDCIPP could not be detected (Mihajlovic
et al., 2011) Comparisons of the concentrations of FRs detected in soils indicate that the concentrations of FRs in soils around the workshops and the open burning sites in Bui Dau were 1–3 orders of magnitude higher than those in soils from general rural and urban areas in Europe However, the concentrations offlame retardants in soils from footpaths around the rice paddies in Bui Dau were within the same order of magnitude of those from general rural and urban areas in Europe Numerous comparable data related to the concentra-tions of PBDEs and TBBPA in sediments from urban areas around the world are available from earlier studies (Watanabe et al., 1983; Sellström et al., 1998; Allchin and de Boer, 2001; de Wit, 2002; de Boer et al., 2003; Quade et al., 2003; Eljarrat et al., 2004; Morris et al., 2004; Mai et al., 2005; Zhang et al., 2009; Guerra et al., 2010) For example, PBDEs and TBBPA in the sediments from urban areas in Europe, USA, China, and Japan have been detected with respective concentrations of 0.5–59 ng/g-dry, 0.6–11600 ng/g-dry, and 0.6–9750
Table 2
Concentrations (ng/g-dry) of flame retardants in river sediment samples in the present study a
BDE — brominated diphenyl ether; TBBPA — tetrabromobisphenol A; TPHP — triphenyl phosphate; MPDPP — methylphenyl diphenyl phosphate; EHDPP — 2-ethylhexyl diphenyl phos-phate; TMPP — tris(methylphenyl) phosphate; TDMPP — tris(dimethylphenyl) phosphate; TCEP — tris(2-chloroethyl) phosphate; TCIPP — tris(2-chloroisopropyl) phosphate; TDCIPP — tris(1,3-dichloroisopropyl) phosphate; PBDPP — 1,3-phenylene bis(diphenyl phosphate); BPA-BDPP — bisphenol A bis(diphenyl phosphate); PBDMPP — 1,3-phenylene bis[di(2,6-dimethylphenyl) phosphate].
a
Sampling points for surface soil samples are shown in Fig 1
Trang 6ng/g-dry Comparable data related to the concentrations of PFRs are
few The concentrations of TPHP, TMPP, TCEP, TCIPP, and TDCIPP in
sediments have been reported from Austria and The Netherlands
(Martínez-Carballo et al., 2007; Brandsma et al., 2015) Comparisons
of FR concentrations detected in sediments examined in present
and previous studies indicate that the concentrations of FRs in
sedi-ments from e-waste recycling area in Bui Dau were within the same
orders of magnitude of those from the contaminated sites in urban
areas in Europe, USA, China, and Japan The concentrations of FRs in
sediments from downstream area in Bui Dau were found to reduce
along the steam, while the FR contaminations were rarely detected
in the soil outside e-waste area and burning site These results
sug-gest that e-waste recycle operation might only contaminate the
environment within the range of a few hundred meters Additional
studies must be conducted to clarify details of spatial diffusions of FRs
around the workshops and the open burning sites
3.3 Current status of FR emissions from e-waste recycling operations
As described above, the occurrence of FRs was confirmed around the
workshops and open burning sites in Bui Dau The concentrations of FRs
in soils collected at the sampling sites of SS-26 and SS-29 were higher
than those at other sites The respective concentrations of PBDPP and
the total PBDEs were 14,000 ng/g-dry and 680 ng/g-dry at SS-26, and
2600 ng/g-dry and 9200 ng/g-dry at SS-29 Those sites at which higher
concentrations of FRs detected were found exhibited open storage of
large amounts of e-waste such as cathode ray tubes, electronic housings,
and printed circuit boards around the roadside (Fig S1) In contrast, the
concentrations of FRs in soils at sampling sites of SS-27 and SS-31 were
lower than those at other sites The respective concentrations of PBDPP
and the total PBDEs were in the range of 6.6–29 ng/g-dry and 68–110
ng/g-dry Those sites with lower detected concentrations of FRs were
not found to have open storage of e-waste (Fig S1) Thus, it could be
as-sumed that open storage of e-waste is an important source of
environ-mental contamination by FRs
The presence of FRs in soils and sediments apparently reflects their
use in the electronic products being recycled BDE-209 is the major
component of technical Deca-BDE The presence of BDE-209 as the
major PBDE congener in soils around the workshops and open burning
sites indicates that e-waste originating fromflame-retarded products
containing technical Deca-BDE have been processed within Bui Dau
The presence of PFRs and TBBPA in soils and sediments, which are
in-creasingly used as alternatives for PBDEs, indicates that the types of
FRs incorporated intoflame-retarded plastics for electronic products are shifting in response to domestic and international regulations of PBDEs In fact, a survey of FRs in TVs and laptop computers on the Japanese market in 2008 revealed the predominant use of m-PFRs and TBBPA other than PBDEs in electronic housings and printed circuit boards (Kajiwara et al., 2011) TPHP itself was used as a FR and
plasticiz-er, while it is also a probable impurity of PBDPP and BPA-BDPP commer-cial products (Syracuse Research Corporation, 2006; Rossi and Heine, 2007; Pawlowski and Schartel, 2007) TPHP impurity in those commer-cial products might contribute to TPHP contamination in e-waste area The volume of e-waste containing PFRs and TBBPA is estimated to have increased gradually worldwide The emissions of PFRs and TBBPA from open storage of e-waste might become greater than those of PBDEs in the future
For TBBPA, the apparent half-life under anaerobic conditions was b1 d; more than two orders of magnitude shorter than the persistence criteria of six months for PBTs for soil and sediment of the Stockholm Convention on Persistent Organic Pollutants (Gerecke et al., 2006) Recent studies of the respective patterns of biodegradation of TPHP, PBDPP, and BPA-BDPP in activated sludge showed complete degrada-tion of TPHP and PBDPP within a few days, but high persistence of the structurally similar BPA-BDPP within 56 d for mineralization tests (Jurgens et al., 2014) Based on results obtained from these previous studies, TBBPA, TPHP, and PBDPP released from e-waste recycling operations might decompose eventually, but BPA-BDPP might persist together with PBDEs around e-waste recycling area
For residents around e-waste recycling area, high concentrations of FRs in surface soils and river sediments are expected to be associated with exposure concerns during their daily life They could expose to contaminants via laundry or swimming in the river or unconscious in-take of soil Such contamination could also enter the domestic food chain Diet has been highlighted as an important pathway of human ex-posure to PBDEs released from e-waste recycling areas Consumption of locally produced foods such as chicken meat, chicken eggs,fish, and pork has been recognized as an important pathway to human exposure
to PBDEs around e-waste recycling areas in China (Zhao et al., 2009; Ni
et al., 2012; Chan et al., 2013; Su et al., 2012; Yu et al., 2011; Labunska
et al., 2013, 2014, 2015) However, information related to human exposure to PFRs and TBBPA is not obtained from e-waste recycling area The behavior of PFRs and TBBPA should be regarded as a risk factor along with e-waste recycling operations Additional studies must be conducted to clarify details of contaminations of PFRs and TBBPA in foods that locally produced around e-waste recycling area
0 5000 10000 15000 20000
o-PFRs m-PFRs TBBPA PBDEs
0
100
200
300
400
500
Open burning site
E-waste recycling workshop
Rice paddy
Fig 2 Concentrations (ng/g-dry) of flame retardants in surface soil samples around e-waste recycling areas in Bui Dau PBDEs – polybrominated diphenyl ethers; TBBPA – tetrabromobisphenol A; o-PFRs – oligomeric organophosphorus flame retardants; m-PFRs – monomeric organophosphorus flame retardants Sampling sites are displayed in Fig 1
Trang 74 Conclusions
Results of the present study provided information related to the
environmental emissions of FRs by uncontrolled and primitive recycling
operations Open storage of e-waste and open burning of insulated
cop-per wires have been determined to be important factors contributing to
the emissions of FRs to the surrounding environment Serious
contami-nations by FRs could be observed in surface soils and river sediments
near the e-waste recycling workshops or open burning sites, but low
concentrations of FRs were found in the soils from footpaths around
rice paddies and the contaminations by FRs reduced along with the
stream in the downstream sediments For the actual operations,
restric-tions of open storage and burning of e-waste might mitigate the
envi-ronmental and human health risks of FRs posed by e-waste recycling
operations This information obtained from the present study will be
useful for planning outdoor exposure avoidance and appropriate
mea-sures for emission control of FRs The environmental occurrence of
emerging PFRs used increasingly as alternatives for PBDEs indicates
that the types offlame retardants incorporated into flame-retarded
plastics are shifting in response to domestic and international
regula-tions of PBDEs Considering the increasing consumption of alternatives
for PBDEs in the future, the emissions of alternatives from open storage
and burning of e-waste might become greater than those of PBDEs in
the following years The presence and environmental effects of
alterna-tives should be regarded as a risk factor along with e-waste recycling
Acknowledgments
We gratefully acknowledge the analytical support of Ms Kyoko
Yoneoka, Mr Hiroo Takagi, and Mr Akinori Hashimoto of NIES (Japan)
and the sampling support of CETASD (Vietnam) members
Appendix A Supplementary data
Supplementary data to this article can be found online athttp://dx
doi.org/10.1016/j.scitotenv.2015.02.008
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