Supplementary Information

Impact of Metals in Surface Matrices from Formal and Informal Electronic-Waste Recycling around Metro Manila, the Philippines, and intra-Asian Comparison Takashi Fujimori1,*, Hidetaka Takigami1, Tetsuro Agusa2, Akifumi Eguchi2, Kanae Bekki1,3, Aya Yoshida1, Atsushi Terazono1, Florencio C. Ballesteros Jr.4 1. Center for Material Cycles and Waste Management Research, National Institute for Environmental Studies (NIES), 16-2 Onogawa, Tsukuba, 305-8506, Ibaraki, Japan 2. Center for Marine Environmental Studies, Ehime University, 2-5 Bunkyo-cho, Matsuyama, 790-8577, Ehime, Japan 3. Division of Pharmaceutical Chemistry and Biology, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-cho, Kanazawa, 920-1192, Ishikawa, Japan 4. College of Engineering, University of the Philippines Diliman, Quezon City, 1101, Philippines *To whom correspondence should be addressed. E-mail: [email protected]

Contents: 18 Pages.

S1

Sampling at Formal/Informal Sectors and Preparation In 2010, we collected soil and dust samples from e-waste recycling sites in northern and southern Metro Manila (Fig. 1a), including Caloocan (North, Metro Manila), Province of Cavite, and Laguna, as shown in Fig. 1b. The terms “formal” and “informal” follow the definitions given in the Introduction. We visited two formal sites in Cavite and Laguna (Fig. 1b, c) and three informal sites in Caloocan (North) and Cavite (Fig. 1b, d). Table S1 describes the sampled e-waste recycling sites. It is note that “number of samples” in Table S1 indicates number of separately-located sampling points. Surface soil (a few cm in depth) was sampled using a shovel within 30 cm area in diameter and manually packed. We excluded foreign fragments such as stone, weed, and waste during sampling of surface soil. Before packing, surface soil was homogenized by a shovel as much as possible. According to FAO-UNESCO Soil Map of the World (ver. 3.6) [S1], soils at Cavite and Laguna are pellic vertisols. Soils at Caloocan are distric nitrosols. Surface soils at formal sites (“formal soil”, n = 6) were collected from segmented gardens at two factories. Surface soils at informal sites (“informal soil”, n = 7) were sampled below and near open-air dismantling work areas or at dumping sites. Surface dust was gently swept with a clean broom and sealed in the sample bag. Isolated sweeping areas of dust were selected at each buildings and open-air concrete floors. We collected surface dust at formal sites (“formal dust”, n = 11) from concrete work floors inside roofed buildings or outdoor concrete surfaces near a building. Surface dust from informal sites (“informal dust”, n = 6) was collected from concrete streets or dismantling floors in/out of houses. In addition, we sampled soil at the University of the Philippines Diliman (n = 1; “UP soil”). The UP soil was considered a control soil not exposed to e-waste recycling and its metal concentrations were merely used to check unpolluted level of soil by calculating enrichment factor (see Tables S5 and S6). After transporting samples to our laboratory, soil and dust samples were air-dried indoors for approximately one week. We then screened the dried soil and dust using 2 and 1 mm mesh screens, followed by powdering the soil and dust using a planetary ball mill (Pulverisette 6, FRITSCH) and freezer mill (6870, SPEX SamplePrep), respectively. Then, soil and dust were sieved to <150 μm for element measurement. S2

Measurement of 11 Metals and Quality Control We used powdered soil and dust samples to measure Ag, As, Cd, Co, Cu, Fe, In, Mn, Ni, Pb, and Zn. Samples (each 1.00 g) were placed in clean conical beakers and digested on a hotplate with HNO3 (60%, 3 mL) and HCl (35%, 3 mL), i.e., 1/1 HNO3-HCl (v/v) at 120°C for approximately 2 hr with a watch glass, and 120°C without a watch glass up to half in liquid (evaporating HCl). After cooling, we filtered the solution with 5B paper (ADVANTEC) and filtrate was used to measured eight metals (Ag, Co, Cu, Fe, Mn, Ni, Pb, and Zn) by inductively coupled plasma-atomic emission spectrometry (ICP-AES; VISTA-PRO, Seiko Instruments) and three metals (As, Cd, and In) by ICP-mass spectrometry (ICP-MS; 7500cx, Agilent Technologies) with a collision gas flow (He) to eliminate interference. We had previously bathed glass and plastic overnight in dilute HNO3 and rinsed them with Milli-Q water. In this study, we focused on precious or rare metals (Ag and In) in soil and dust samples from ewaste recycling sites. Silver is known to form precipitates (AgCl) in the presence of chloride ions (Cl －) in the liquid phase. To avoid precipitation of silver and to detect concentrations of multi elements, we reduced the hydrochloric acid digestion (1/1 HNO3-HCl, v/v) below the typical aqua regia levels (1/3 HNO3-HCl, v/v). Five certified reference materials were purchased including powdery solid samples such as soil, sediment, sludge, and dust (Table S2). Despite differences in the base matrices, average recovery ratios from the five matrices were satisfactory (including recovery of silver and indium): Ag (87±13%), As (84±11%), Cd (97±22%), Co (91±2.8%), Cu (75±9.3%), Fe (71±8.7%), In (84%), Mn (78±11%), Ni (69±7.4%), Pb (81±2.2%), and Zn (78±12%). Table S2 shows that the recovery ratios in this study are very similar to those obtained using aqua regia digestion [22,23]. Also, we had very similar recovery ratios compared to the 4/1 HNO3-HClO4 (v/v) acid digestion method [13]. According to the quality control, our 1/1 HNO3-HCl (v/v) method resulted in total acid digestion, which is indicative of a “pseudo” concentration in solid matrices since some elements trapped in silicate are difficult to digest. Therefore, we applied 1/1 HNO3-HCl (v/v) acid digestion to measure the 11 metals in the soil and dust samples.

S3

Enrichment Factor The enrichment factor (Ef) was defined by the following formula: Ef 

C / Mnsample C / Mncrust

(1)

where C is the measured concentration of an element in soil and dust (mg/kg). The subscript ‘sample’ represents the concentration measured in this study and the subscript ‘crust’ represents the average crustal value. The average crustal concentrations were obtained from the table of global upper continental crust by Wedepohl [24]. We used Mn as a base material [25,26] since Mn concentrations in the four types of surface matrices were similar to that of UP soil and had a relatively small concentration range, as shown in Table S5. In addition, Mn was thought to mainly be a crust-derived element (refer to Table 1 and Fig. 3b). The enrichment factor represents the level of enrichment compared with average crust (Ef ~ 1: same level as average crust). Fe as a representative soil-derived element showed no enrichment (Ef ~ 1) (refer to Fig. 2b), which supported correctness of equation (1).

S4

Hazard Assessment We assessed the health effects of oral exposure to multi-element contaminated soil and dust from ewaste recycling sites on adults and children to study the noncancer toxic/chronic risk. We calculated the average daily dose (ADD, mg-element/kg-weight/day, US EPA Exposure Factors Handbook [27]), hazard quotient (HQ), and hazard index (HI) as follows: ADD 

C  IngR  EF  ED (2) BW  AT HQ 

ADD (3) RfD

HI   HQi (i, element) (4) i

To compare potential hazardous risk with previous Asian case study by Leung et al. [13] under “same” exposure scenario between formal and informal sites (ref. Table S11), we chose parameters for the conservative ingestion rate (IngR) of 100 mg/day (adult [27]) or 200 mg/day (children [27]), body weight (BW) of 60 kg (adult [13]) or 15 kg (children [13] at 2.5 yrs [S2]), exposure frequency (EF) of 350 day/year [13], exposure duration (ED) of 6 years [13], and an average time (AT) of 2190 days [13]. Oral reference doses (RfD, mg-element/kg-weight/day) were selected as 0.005 (Ag [28]), 0.0003 (As [28]), 0.001 (Cd [28]), 0.02 (Co [28]), 0.04 (Cu [28]), 0.14 (Mn [28]), 0.02 (Ni [28]), 0.0035 (Pb [36]), and 0.3 (Zn [28]). Oral RfDs of Fe and In were not defined. Oral RfD represents the daily human exposure level that does not pose a risk [28]. When the HQ value is below 1, adverse health effects are unlikely. Here, the HQ value accounts for the toxic risk based on other benchmarks [13,28,29], i.e., ≤ 1 (minimal), > 1–5 (low), >5–10 (moderate), and >10 (high). In this study, we also applied these benchmarks of comprehensive risk assessment to the HI value because the HI value is a summation of the HQ values in equation (4).

S5

Statistical Analysis Statistical analysis was performed using SPSS software (version 19). Multiple comparisons were analyzed by the Tukey-Kramer method to work with unequal sample sizes when analysis of variance (ANOVA) was homoscedastic with p < 0.05. Otherwise, we performed nonparametric median tests. We divided similar groups by hierarchical cluster analysis (Ward method) and principal component analysis (clustered PCA), which are described below in detail.

S6

Table S1. Sampled soil and dust from formal/informal e-waste recycling sites around Metro Manila, the Philippines.

Soil/dust Formal/informal

Number of samples

Description

Soil

Formal

n =6

Two formal e-waste recycling factories (factories A and B). Segmented garden beside the gate and buildings used to dismantle, crush and store e-waste inside factories A and B.

Soil

Informal

n =7

Two informal e-waste recycling sites (junk shop and street). The junk shop is proximal to a dismantling work area. The dumping site is located beside the street near an informal e-waste recycling site.

Dust

Dust

Formal

Informal

n =11

Two formal e-waste sites; recycling factories A and B. The concrete work floor is roofed in three buildings in Factory A, where workers dismantle, sort, and store e-waste including CRT glass, wire cables, circuit boards, flat panel displays, refrigerators, solar panels, and plastics. One building includes a large-scale crushing machine. The concrete work floor is housed in one building and an open-air concrete work area is near Factory B.

n =6

There are two informal e-waste recycling sites. One is a narrow, openair concrete street near a dismantling site for e-waste including small chips and cables. The second is a concrete dismantling site for circuit boards (indoors) including a room to scrape the circuit boards.

S7

Table S2. Recovery ratio (%) of 11 elements in five certified reference materials using acid digestion (1/1 HNO3-HCl, v/v) with a hotplate (top). The typical aqua regia digestion (1/3 HNO3-HCl, v/v) with a hotplate or 4/1 HNO3-HClO4 digestion are also shown (bottom). Soil

Soil

Sediment

Sludge

Brown earth

Volcanic ash soil

JSAC 0403

JSAC 0411

Marine sediment NMIJ CRM 7302-a

Industrial sludge NIST SRM 2782

(n =6)

(n =2)

(n =2)

(n =2)

Indoor dust NIST SRM 2584 (n =2)

Average

SD

Ag

-

-

78

96

-

87

13

As

96

75

-

82

-

84

11

Cd

96

-

-

120

76

97

22

Co

-

91a

88

94

-

91

2.8

Cu

73

63

77

86

-

75

9.3

Fe

-

69a

65a

84a

68a

71

8.7

84

-

84

na

In

-

-

a

a

Mn

88

80

67

-

-

78

11

Ni

68

80

65

64

-

69

7.4

Pb

80

78

81

83

84

81

2.2

78

12

Zn a

a

Dust

77

59

83

a

88

85

Calculation by reference value

JSAC: The Japan Society for Analytical Chemistry NMIJ CRM: National Meteorology Institute of Japan, certified reference material NIST SRM: National Institute of Standards & Technology, standard reference material

Soilb

Soilb

Contaminated soil NIST SRM NIST SRM 2709 2711 Sandy soil

b c

Sedimentb

Soilc

River sediment NIST SRM 2704

Soild

Soild

Contaminated Contaminated Sandy soil soil soil NIST SRM NIST SRM NIST SRM 2711 2709 2711

(n =4)

(n =4)

(n =4)

Averageb

SDb

(n =3)

(n =?)

(n =?)

Ag

nm

nm

nm

-

-

>80

nm

nm

As

87

96

70

84

13

nm

nm

nm

Cd

87

84

75

82

6.2

>80

86-95

Co

nm

nm

nm

-

-

>80

98-132

Cu

94

91

82

89

6.2

>80

80-89

Fe

85

78

81

81

3.5

>60

nm

nm

In

nm

nm

nm

-

-

nm

nm

nm

Mn

86

76

87

83

6.1

>80

nm

nm

Ni

90

87

103

93

8.5

>80

90-100

Pb

64

83

79

75

10

>80

87-96

Zn

91

90

97

93

3.8

>80

91-108

Chen and Ma (2001): 1/3 HNO3-HCl (v/v) with hotplate

Turner and Ip (2007): 1/3 HNO3-HCl (v/v) with hotplate

d

Leung et al. (2008): 4/1 HNO3-HClO4 (v/v)

nm: not measured, -: no calculable data

S8

Table S3. Reference metal concentrations of soil from e-waste recycling sites and soil guideline values. mg/kg dry

City, country

Area

Abbr.

n

Guiyu, China

Reservoir area

RS

6

nd

Guiyu, China

Rice field

RF

30

Guiyu, China

Area near the open-buring site

NOBS

Guiyu, China

Open-burning site

OBS

Guiyu, China

Ag

As

Cd

Co

Cu

In

Mn

Ref.

Ni

Pb

Zn

29.5-42.7

5.47-20.3

79.4-93.1

44.2-106

4)

nd

29.9-240

3.37-434

56.9-155

7.9-114

4)

8

nd

59.4-114

4.04-68.7

97.8-123

6.01-42.4

4)

5

5.51-42.9

1374-14253

85.2-722

856-7038

546-5298

4)

Burnt plastic dump site

1?

1.7

496

155

104

258

5)

Guiyu, China

Printer roller dump site

1?

3.1

712

87.4

190

-

5)

Guiyu, China

Reservoir

1?

nd

9.2

8.4

55.4

78.0

5)

Guiyu, China Paddy field near e-waste recycling

S1

1

6.11

0.37

48

22

93

90

6)

Guiyu, China

Street in residential area

S2

1

7.21

0.11

54

6.5

62

67

6)

Guiyu, China

Adjacent street near dismantling circuit board

S3

1

17.01

0.16

8.4

9.2

18

69

6)

Guiyu, China

Abandoned workshop using acid extraction

S4

1

26.03

1.21

4800

480

150

330

6)

Guiyu, China

Open-burning site

S5

1

52.10

10.02

12700

1100

480

3500

6)

Guiyu, China

Area near the open-buring site

S6

1

23.09

1.60

140

30

62

130

6)

Guiyu, China

Area near the open-buring site

S7

1

5.02

0.16

27

25

54

96

6)

Guiyu, China

Field now closed to storage of ewaste

S8

1

60.03

6.01

82

21

56

770

6)

Banks of a river at closed e-waste Guiyu, China strage

S9

1

22.06

0.10

66

20

32

230

6)

A

1

2.6

296.3

48.0

501.9

432.7

8)

B

1

1.7

77.9

14.3

170.3

210.4

8)

C

1

1.9

155.7

11.7

173.7

177.7

8)

D

1

2.4

205.2

52.6

177.2

399.9

8)

E

1

7.4

140.8

66.3

81.3

660.8

8)

F

1

1.7

227.3

83.8

91.5

283.5

8)

G

1

3.3

161.4

66.1

115.2

237.2

8)

H

1

9.6

576.7

120.4

184.4

263.0

8)

Taizhou, China Taizhou, China Taizhou, China Taizhou, China Taizhou, China Taizhou, China Taizhou, China Taizhou, China Taizhou, China Taizhou, China Taizhou, China Taizhou, China Taizhou, China

Large-scale e-waste recycling plants Large-scale e-waste recycling plants Large-scale e-waste recycling plants Large-scale e-waste recycling plants Large-scale e-waste recycling plants Large-scale e-waste recycling plants Large-scale e-waste recycling plants Large-scale gold recovery plants Large-scale gold recovery plants

I

1

0.6

272.3

107.4

102.8

143.8

8)

Simple household e-waste recycling workshop Simple household e-waste recycling workshop Simple household e-waste recycling workshop

J

1

2.8

222.5

71.0

200.1

221.2

8)

K

1

7.9

361.7

53.3

295.2

437.3

8)

L

1

12.5

1641.3

68.6

2374.1

518.7

8)

Reference site

M

1

0.04

33.0

157.8

8)

449 (286849)

297 (90.42850)

326 (1262530)

7)

619 (483897)

126 (79.1262)

192 (119499)

7)

390 (262629)

22.8 (12.6- 41.0 (30.335.6) 59.8)

7)

756±611

1380±1174 1717±1050

9)

11.4±3.9

533±267

3254±1895

920±489

9)

1

0.08±0.2

11.5±2.2

232±32.5

115±3.6

9)

1

1.34±1

28.4±25.2

145±47

122±74.8

9)

35

85

140

30)

210

530

720

30)

2.33 (0.38538.9) 0.478 (0.3010.906) 0.165 (0.0820.296)

32.3

Bangalore, India

E-waste recycling site in slum

BES

7

14 (2.2320)

11 (5.2-42)

592 (61.74790)

Bangalore, India

E-waste recycling facility

BEF

3

2.5 (1.38.7)

14 (12-16)

429 (1542190)

Bangalore, India

Control site

BC

?

0.36 (0.240.53)

11 (4.9-17)

22.8 (10.040.4)

Hong Kong

E-waste dismantling workshop

EW (DW)

3

4.72±2.9

Hong Kong

E-waste open-burning site

EW (OBS)

1

Hong Kong

E-waste storage

EW (S)

Hong Kong

Agricultural control site

A

Netherlands

Optimum value

29

0.8

20

36

Netherlands

Action value

55

12

240

190

nd 0.722 (0.0924.62) 0.618 (0.4640.859) 0.105 (0.0590.208)

nd, not detected

S9

Table S4. Reference metal concentrations of dust from e-waste recycling sites. mg/kg dry

City, country

Area

Abbr.

n

Ag

As

Cd

Co

Cu

In

Mn

Ref.

Ni

Pb

Zn 4800a (98010000)

13)

Guiyu, China

Printed circuit board recycling workshop

PCBRW

12

27a

22a

9000a (110036000)

1500a±2460

110000 (22900206000)

Guiyu, China

Street lined with PCBRWs on both sides

Street B-1

16

14a

18a

6800a

300a

21000a

2400a

13)

Guiyu, China

A primary trunk road (2-lanes) approx. 10-12 m wide

Street B-2

16

5a

7a

740a

100a

1000a

580a

13)

Guiyu, China

Beilin primary/secondary school

School yard

4

5a

6a

500a

50a

690a

680a

13)

Guiyu, China

In front of entrance to school, small canteen

Near school

4

2a

8a

920a

770a±1420

2200a

480a

13)

Guiyu, China

An outdoor market selling fish, vegetables, meat

a

a

a

a

a

13)

a

Two roads around shedded plastic Guiyu, China fragments

Food market

14

4

a

6

a

330

a

1400

a

a

200

a

630

Street L-1, L-2

8

7

12

1700

100

220

500

13)

Guiyu, China

Street with hotels located 8km from Guiyu

Street G

16

4a

4a

60a

20a

80a

580a

13)

Guiyu, China

Control, Shantou University

SU

12

4a

9a

40a

10a

70a

200a

13)

Guiyu, China

Floor of plastic shredding & heatextruding workshop A

CH05001

1

5

<20

2.2

3

106

35

54

47

167

10)

Floor of plastic shredding & heatGuiyu, China extruding workshop A

CH05002

1

28

<20

30.7

28

3010

185

147

404

822

10)

Plastic shredding & heat-extruding Guiyu, China workshop B

CH05003

1

<2

<20

1.8

<2

188

50

71

89

199

10)

Guiyu, China

Street between shredding workshop A & B

CH05004

1

6

<20

1.6

5

777

321

118

163

443

10)

Guiyu, China

Floor of separation & solder recovery workshop A

CH05012

1

152

382

104

21

4100

491

292

51000

3770

10)

Guiyu, China

Floor sweepings, separation & solder recovery workshop A

CH05013

1

1170

1330

97

10

14000

261

507

66350

9345

10)

Guiyu, China

Floor of separation & solder recovery workshop B

CH05014

1

268

379

11.0

25

25400

1170

1020

31300

2340

10)

Guiyu, China

Floor of separation & solder recovery workshop C

CH05026a

1

527

514

50.8

18

10700

552

504

76000

9130

10)

Guiyu, China

Home of solder recovery worker

CH05018

1

9

50

4.0

8

585

610

64

719

772

10)

Guiyu, China

Home of solder recovery worker

CH05019

1

36

51

4.3

7

579

636

139

4110

1160

10)

Guiyu, China

Floor of printer-dismantling workshop

CH05020

1

12

<20

4.5

35

19200

1940

398

284

8950

10)

Home of neighbour NOT employed Guiyu, China in e-waste recycling

CH05035

1

4

<10

1.9

13

176

349

54

182

1580

10)

New Delhi, India

Floor of workshop where plastic mechanically ground

IT05015

1

<2

<20

11.4

<2

149

49

17

100

549

10)

New Delhi, India

Floor of circuit board & component separation workshop

IT04001

1

<2

<20

1.1

12

168

336

28

150

330

10)

New Delhi, India

Floor of circuit board & component separation workshop

IT05007

1

343

<20

97

21

6805

640

541

8815

4440

10)

New Delhi, India

Floor of open-air rooftop workshop heating circuit board

IT05008

1

97

<20

14.1

19

2800

834

239

2360

2200

10)

New Delhi, India

Floor of circuit board & component separation workshop

IT05011

1

134

<20

15.5

12

2140

446

163

10900

1410

10)

New Delhi, India

Floor of battery separation workshop, lead battery

IT05018

1

51

<20

42.6

20

1730

17700

154

88100

4920

10)

New Delhi, India

CRT storage shed

IT05019

1

10

47

310

12

439

298

3900

14600

21100

10)

New Delhi, India

Floor of battery separation workshop

IT05029

1

133

<20

200000

631

1610

362

47900

13300

1240

10)

New Delhi, India

Narrow street; area of recycling workshop

IT05022

1

4

<20

<0.5

11

152

604

38

1300

359

10)

New Delhi, India

Narrow street; area of recycling workshop

IT05023

1

9

<20

<0.5

5

187

250

25

37

263

10)

New Delhi, India

Narrow street; area of recycling workshop

IT05024

1

<2

<20

1.4

8

230

628

35

48

710

10)

New Delhi, India

Narrow street; area of recycling workshop

IT05025

1

2

<20

<0.5

9

60

367

27

31

297

10)

New Delhi, India

Narrow street; no known recycling activity area

IT05027

1

8

<20

<0.5

6

414

295

21

100

414

10)

New Delhi, India

Street in residential area

IT05028

1

<2

<20

<0.5

6

21

258

15

20

83

10)

a

mean from graph

S10

Table S5. Summarized concentration (mg/kg air-dry base) data of 11 elements in soil and dust from ewaste recycling sites. UP, University of the Philippines Diliman, was used as a control site not exposed to e-waste. Elements detected only once or under detection limits are described as the 50% value. mg/kg

Ag

-

-

<0.5

-

-

-

4/6

1.0

1.0

1.5

2.0

2.0

1.0

Dust

11

11/11

5.0

41

180

190

250

95

Soil

7

5/7

2.0

2.0

4.0

6.0

8.0

3.0 88

Dust

6

6/6

8.8

54

130

220

240

UP

Soil

1

1/1

-

-

3.6

-

-

-

Formal

Soil

6

6/6

2.3

2.4

2.6

3.1

3.2

2.6

Dust

11

11/11

2.5

3.7

5.1

15

35

7.7

Soil

7

7/7

2.0

2.6

3.2

7.3

8.9

3.7

Dust

6

6/6

1.9

4.3

7.6

16

24

7.4

UP

Soil

1

1/1

-

-

0.3

-

-

-

Formal

Soil

6

1/6

-

-

0.3

-

-

-

Dust

11

11/11

0.7

1.8

2.9

3.1

9.4

2.5

Soil

7

7/7

0.8

1.1

2.9

3.8

11

2.5

Dust

6

6/6

2.2

2.7

3.0

7.0

13

3.9

UP

Soil

1

1/1

-

-

22

-

-

-

Formal

Soil

6

6/6

14

16

21

130

440

32

Dust

11

11/11

19

21

53

130

240

55

Soil

7

7/7

18

20

26

49

74

30

Dust

6

6/6

13

14

17

170

540

33

UP

Soil

1

1/1

-

-

76

-

-

-

Formal

Soil

6

6/6

92

130

350

1000

1600

340

Dust

11

11/11

8700

17000

23000

32000

94000

26000

Soil

7

7/7

86

320

810

1500

2000

680

Dust

6

6/6

1900

2100

6600

18000

29000

6300

UP

Soil

1

1/1

-

-

36000

-

-

-

Formal

Soil

6

6/6

25000

27000

31000

32000

33000

30000

Dust

11

11/11

9500

26000

42000

78000

270000

49000

Soil

7

7/7

23000

26000

32000

74000

120000

40000

Dust

6

6/6

39000

40000

52000

76000

140000

57000

UP

Soil

1

0/1

-

-

<0.5

-

-

-

Formal

Soil

6

1/6

-

-

1.0

-

-

-

Dust

11

7/11

1.3

3.6

19

170

200

19

Soil

7

0/7

-

-

<0.5

-

-

-

Dust

6

0/6

-

-

<0.5

-

-

-

UP

Soil

1

1/1

-

-

800

-

-

-

Formal

Soil

6

6/6

600

680

800

950

1100

800

Dust

11

11/11

86

500

820

2900

4900

880

Soil

7

7/7

700

700

900

1000

1700

950

Dust

6

6/6

590

710

2100

3800

5700

1800

UP

Soil

1

1/1

-

-

23

-

-

-

Formal

Soil

6

6/6

7.0

9.3

16

110

320

24

Dust

11

11/11

760

970

2600

3100

8400

2100

Soil

7

7/7

14

19

64

100

120

47

Dust

6

6/6

70

110

200

3900

14000

380

UP

Soil

1

1/1

-

-

86

-

-

-

Formal

Soil

6

6/6

23

35

53

200

240

69

Dust

11

11/11

690

1300

9000

18000

130000

6200

Soil

7

7/7

130

270

650

4600

7800

800

Dust

6

6/6

150

420

1400

3300

4100

1100

UP

Soil

1

1/1

-

-

120

-

-

-

Formal

Soil

6

6/6

76

100

140

190

250

140

Dust

11

11/11

1300

1900

3000

5000

7700

3000

Soil

7

7/7

370

390

1000

1700

2000

900

Dust

6

6/6

460

1300

2800

9000

25000

2900

Informal

Ni

Informal

Pb

Informal

Zn

Geo. mean

0/1

Informal

Mn

Max

6

Informal

In

75%

1

Informal

Fe

50%

Soil

Informal

Cu

25%

Soil

Informal

Co

Min

UP

Informal

Cd

Detect/n

Formal Informal

As

n

Informal

S11

Table S6. Summarized enrichment factor data for ten elements in soil and dust from e-waste recycling sites. Enrichment factors were calculated using (X/Mn)sample/(X/Mn)crust, referring to the Wedepohl [24] for crust data. UP, University of the Philippines Diliman, was used as a control site not exposed to ewaste. Elements detected only once or under detection limits are described as the 50% value. Enrichment factor

Ag

-

-

na

-

-

-

4/6

14

14

19

26

27

19

Dust

11

11/11

17

370

1800

3400

28000

1000

Soil

7

5/7

19

21

27

66

77

35

Dust

6

6/6

29

180

600

2300

3500

480

UP

Soil

1

1/1

-

-

1.2

-

-

-

Formal

Soil

6

6/6

0.65

0.69

0.87

1.1

1.2

0.87

Dust

11

11/11

0.28

1.0

1.7

6.1

110

2.3

Soil

7

7/7

0.75

0.76

0.87

1.4

2.1

1.0

Dust

6

6/6

0.17

0.39

1.4

3.1

6.2

1.1

UP

Soil

1

1/1

-

-

1.9

-

-

-

Formal

Soil

6

1/6

-

-

2.2

-

-

-

Dust

11

11/11

1.8

3.3

19

31

170

15

Soil

7

7/7

3.6

8.1

11

15

35

14

Dust

6

6/6

4.6

5.0

12

27

83

11

UP

Soil

1

1/1

-

-

1.3

-

-

-

Formal

Soil

6

6/6

1.0

1.0

1.1

8.0

29

1.8

Dust

11

11/11

0.99

1.3

1.7

2.3

130

2.8

Soil

7

7/7

0.69

0.91

1.3

3.2

3.4

1.4

Dust

6

6/6

0.18

0.21

0.78

3.8

4.3

0.85

UP

Soil

1

1/1

-

-

3.5

-

-

-

Formal

Soil

6

6/6

3.1

6.2

16

48

65

16

Dust

11

11/11

140

700

1200

2100

8700

1100

Soil

7

7/7

3.5

17

33

57

78

27

Dust

6

6/6

22

44

100

660

1800

130

UP

Soil

1

1/1

-

-

0.77

-

-

-

Formal

Soil

6

6/6

0.50

0.56

0.64

0.73

0.79

0.64

Dust

11

11/11

0.23

0.88

1.0

1.3

1.9

0.95

Soil

7

7/7

0.51

0.54

0.58

1.2

1.4

0.71

Dust

6

6/6

0.24

0.26

0.57

1.1

1.6

0.55

UP

Soil

1

0/1

-

-

na

-

-

-

Formal

Soil

6

1/6

-

-

9.6

-

-

-

Dust

11

7/11

18

20

160

2200

2900

190 -

UP Formal Informal

Pb

Soil

7

0/7

-

-

na

-

-

Dust

6

0/6

-

-

na

-

-

-

Soil

1

1/1

-

-

0.82

-

-

0.86

Soil

6

6/6

0.44

0.35

0.58

4.2

4.8

Dust

11

11/11

28

31

55

89

880

69

Soil

7

7/7

0.18

0.88

1.7

2

13

1.4 6.2

Dust

6

6/6

1.1

2.8

5.8

22

67

UP

Soil

1

1/1

-

-

3.3

-

-

-

Formal

Soil

6

6/6

0.65

1.2

2.5

7.4

11

2.7

Dust

11

11/11

4.7

51

220

670

47000

220

Soil

7

7/7

5.8

9.4

20

140

160

26

Dust

6

6/6

6.1

10

25

32

40

19

UP

Soil

1

1/1

-

-

1.5

-

-

-

Formal

Soil

6

6/6

1.0

1.2

1.7

2.4

3.6

1.7

Dust

11

11/11

7.5

9.2

31

82

350

34

Soil

7

7/7

4.1

5.7

10

12

24

9.6

Dust

6

6/6

6.2

9.2

13

43

44

17

Informal

Zn

Geo. mean

0/1

Informal

Ni

Max

6

Informal

In

75%

1

Informal

Fe

50%

Soil

Informal

Cu

25%

Soil

Informal

Co

Min

UP

Informal

Cd

Detect/n

Formal Informal

As

n

Informal na, not analyzed

S12

Table S7. Metal concentrations of “informal soil” from e-waste recycling sites compared with concentrations reported for China, India, and Hong Kong. City, country

Area

n

Around Manila, Philippines

Informal sitea

7

Guiyu, China

Printer roller dump site

1

Guiyu, China

Abandoned workshop using acid extraction, S4

1

Taizhou, China

Simple household ewaste recycling workshop, J

Taizhou, China Taizhou, China

Ag

As

Cd

Co

Cu

Mn

Ni

Pb

Zn

3.0 (2.08.0)

3.7 (2.08.9)

2.5 (0.811)

30 (18-74)

680 (862000)

950 (7001700)

47 (14120)

800 (1307800)

900 (3702000)

Ref.

This study

3.1

712

87.4

190

1.21

4800

480

150

330

6)

1

2.8

222.5

71.0

200.1

221.2

8)

Simple household ewaste recycling workshop, K

1

7.9

361.7

53.3

295.2

437.3

8)

Simple household ewaste recycling workshop, L

1

12.5

1641.3

68.6

2374.1

518.7

8)

Bangalore, E-waste recycling site in slum, BES a India Hong Kong

mg/kg dry

E-waste dismantling workshop, EW (DW)b

7

3

26.03

14 (2.2320)

2.33 (0.39592 (61.7- 449 (28611 (5.2-42) 38.9) 4790) 849)

4.72±2.9

756±611

5)

297 (90.4- 326 (1262850) 2530)

7)

1380±1174 1717±1050

9)

a

Geometric mean (min-max)

b

Mean±standard deviation

S13

Table S8. Metal concentrations of “informal dust” from e-waste recycling sites compared concentrations reported from China and India (Table S4). mg/kg dry

City, country

Area

n

Around Manila, Philippines

Informal siteb

Around Manila, Philippines

Ag

As

Cd

Co

Cu

Mn

Ni

6

88 (8.8240)

7.4 (1.924)

3.9 (2.213)

33 (13-540)

6300 (190029000)

1800 (5905700)

380 (7014000)

Formal siteb

11

95 (5.0250)

7.7 (2.535)

2.5 (0.79.4)

55 (19-240)

26000 (870094000)

880 (864900)

Guiyu, China

Printed circuit board recycling workshop, PCBRW

12

27a

22a

9000a (110036000)

1500a± 2460

Guiyu, China

Street lined with PCBRWs on both sides, Street B-1

16

14a

18a

6800a

Floor of separation & solder recovery

Guiyu, China workshops A-C, CH05012-05014 and CH05026a, SSRW

Pb

Zn

Ref.

1100 (150- 2900 (460- This 4100) 25000) study

3000 (13007700)

This study

110000 (22900206000)

4800a (98010000)

13)

300a

21000a

2400a

13)

2100 (760- 6200 (6908400) 130000)

4

398 (2681170)

561 (3791330)

49 (11.0104)

18 (10-25)

11200 (410025400)

536 (2611170)

525 (2921020)

53300 (3130076000)

5240 (23409345)

Calc. of 10)

4.5

35

19200

1940

398

284

8950

10)

b

Guiyu, China

Floor of printers dismantling workshop, CH05020, PDW

1

12

<20

New Delhi, India

Floor of circuit board & component separation workshops, IT04001, 05007, and 05011, CCSW b

3

45 (<2343)

<20

12 (1.1-97) 14 (12-21)

New Delhi, India

Narrow street; area of recycling workshops, IT05022-05025, Street Nb

4

3.5 (<2-9)

<20

0.6 (<0.51.4)

7.9 (5-11)

1350 (168- 458 (3366805) 640)

141 (60230)

432 (250628)

135 (28541)

31 (25-38)

2430 (150- 1270 (330- Calc. 10900) 4440) of 10)

92 (311300)

376 (263- Calc.o 710) f 10)

a

mean value from graph Geometric mean (min-max)

b

S14

Table S9. Component matrix of metals in total dust (formal and informal). Bold, absolute value of principal component > 0.5. Group

Sub

Subsub Metal

I

II

IIb

IIba

IIbb

IIa

PC1

PC2

PC3

Mn

0.246

0.865

-0.129

Fe

0.330

0.822

-0.272

Zn

0.721

0.295

0.311

Cd

0.339

0.177

0.840

Ni

0.856

0.091

-0.226

Co

0.817

-0.038

-0.024

As

0.570

-0.126

0.324

Cu

0.594

-0.335

-0.452

Pb

0.564

-0.636

-0.245

Ag

0.237

-0.739

0.207

S15

Table S10. Hazard quotient (HQ) of nine elements in adults and children by oral ingestion of soil and dust from e-waste recycling sites. Oral reference doses (RfDs) of Fe and In are not defined. Cd was detected once in formal soil (described at 50% value). The hazard index (HI) was calculated by summation of HQs, HI = ∑i HQi (i, element). Bold value ≥ 1.0. Hazard quotient (HQ) in adults

n Ag

Formal Informal

As

Formal Informal

Cd

Formal Informal

Co

Formal Informal

Cu

Formal Informal

Mn

Formal Informal

Ni

Formal Informal

Pb

Formal Informal

Zn

Formal Informal

HI

Formal Informal

Detect/n

Soil

6

4/6

Dust

11

11/11

Min

25%

50%

75%

Hazard quotient (HQ) in children

Max

0.00032 0.00032 0.00048 0.00064 0.00064 0.0016

0.013

0.00064 0.00064

Min

25%

50%

75%

Max

0.0026

0.0026

0.0038

0.0051

0.0051

0.057

0.061

0.081

0.013

0.10

0.46

0.49

0.65

Soil

7

5/7

0.0013

0.0019

0.0026

0.0051

0.0051

0.010

0.015

0.021

Dust

6

6/6

0.0028

0.017

0.043

0.070

0.078

0.022

0.14

0.34

0.56

0.62

Soil

6

6/6

0.012

0.013

0.014

0.016

0.017

0.096

0.10

0.11

0.13

0.14

Dust

11

11/11

0.013

0.019

0.027

0.079

0.19

0.10

0.15

0.22

0.63

1.5

Soil

7

7/7

0.011

0.014

0.017

0.039

0.047

0.088

0.11

0.14

0.31

0.38

Dust

6

6/6

0.010

0.023

0.040

0.087

0.13

0.080

0.18

0.32

0.70

1.0

Soil

6

1/6

-

-

0.00048

-

-

-

-

0.0038

-

-

Dust

11

11/11

0.0011

0.0029

0.0046

0.0050

0.015

0.0088

0.023

0.034

0.040

0.12

Soil

7

7/7

0.0013

0.0018

0.0046

0.0060

0.018

0.010

0.014

0.037

0.048

0.14

Dust

6

6/6

0.0035

0.0042

0.0047

0.011

0.021

0.028

0.034

0.038

0.088

0.17

Soil

6

6/6

0.0011

0.0013

0.0017

0.010

0.035

0.0088

0.010

0.014

0.080

0.28

Dust

11

11/11

0.0015

0.0016

0.0042

0.010

0.019

0.012

0.013

0.034

0.080

0.15

Soil

7

7/7

0.0014

0.0016

0.0021

0.0039

0.0059

0.011

0.013

0.017

0.031

0.047

Dust

6

6/6

0.0010

0.0011

0.0013

0.014

0.043

0.0080

0.0088

0.010

0.11

0.34

Soil

6

6/6

0.0037

0.0051

0.014

0.040

0.063

0.030

0.041

0.11

0.32

0.50

Dust

11

11/11

0.35

0.68

0.92

1.3

3.7

2.8

5.4

7.4

10

30

Soil

7

7/7

0.0034

0.013

0.032

0.062

0.078

0.027

0.10

0.26

0.50

0.62

Dust

6

6/6

0.076

0.085

0.26

0.72

1.2

0.61

0.68

2.1

5.8

9.6

Soil

6

6/6

0.0069

0.0077

0.0091

0.011

0.013

0.055

0.062

0.073

0.088

0.10

Dust

11

11/11

0.00099

0.0057

0.0094

0.033

0.056

0.0079

0.046

0.075

0.26

0.45

Soil

7

7/7

0.0080

0.0080

0.010

0.011

0.019

0.064

0.064

0.080

0.088

0.15

Dust

6

6/6

0.0067

0.0081

0.024

0.044

0.065

0.054

0.065

0.19

0.35

0.52 0.21

Soil

6

6/6

0.0012

0.0088

0.026

0.0045

0.0060

0.0096

0.070

Dust

11

11/11

0.00056 0.00074 0.060

0.078

0.21

0.25

0.68

0.48

0.62

1.7

2.0

5.4

Soil

7

7/7

0.0011

0.0015

0.0051

0.0080

0.0095

0.0088

0.012

0.041

0.064

0.076

Dust

6

6/6

0.0056

0.0084

0.016

0.32

1.1

0.045

0.067

0.13

2.6

8.8

Soil

6

6/6

0.011

0.016

0.024

0.091

0.11

0.088

0.13

0.19

0.73

0.88

Dust

11

11/11

0.32

0.58

4.1

8.1

60

2.6

4.6

33

65

480

Soil

7

7/7

0.059

0.12

0.30

2.1

3.6

0.47

0.96

2.4

17

29

Dust

6

6/6

0.067

0.19

0.62

1.5

1.9

0.54

1.5

5.0

12

15

Soil

6

6/6

0.0010

0.0013

0.0033

0.0044

0.0058

0.0080

0.010

Dust

11

11/11

0.0066

0.010

0.016

0.027

0.041

0.053

0.080

0.13

0.22

0.33

Soil

7

7/7

0.0020

0.0021

0.0054

0.0090

0.011

0.016

0.017

0.043

0.072

0.088

Dust

6

6/6

0.0025

0.0070

0.015

0.048

0.13

0.020

0.056

0.12

0.38

1.0

Soil

6

6/6

0.044

0.049

0.10

0.16

0.18

0.35

0.39

0.80

1.3

1.4

Dust

11

11/11

1.2

1.8

4.6

12

61

9.6

14

37

94

490

Soil

7

7/7

0.10

0.16

0.41

1.0

3.7

0.80

1.3

3.3

8.0

30

Dust

6

6/6

0.24

0.62

1.4

2.2

4.0

1.9

5.0

11

18

32

0.00041 0.00055 0.00073

Oral RfD (mg/kg/day): Ag, 0.005; As, 0.0003; Cd, 0.001; Co, 0.02; Cu, 0.04; Mn, 0.14; Ni, 0.02; Pb, 0.0035; Zn, 0.3 Noncancer toxic health risk: HQ ≤ 1 (minimal), > 1-5 (low), > 5-10 (moderate), > 10 (high)

S16

Table S11. Adults’ hazard index (HI) and hazard quotients (HQs) of this study and another comparable study in China [13]; HIs are calculated by summation HQs of Cd, Co, Cu, Ni, Pb, and Zn under the same exposure scenarios and are thus comparable. Bold value ≥ 1.0.

City, country Around Manila, Philippines Around Manila, Philippines Around Manila, Philippines Around Manila, Philippines

Area, matrix

HI = ∑HQs (Cd, Co, Cu, Ni, Pb, Zn)

Average hazard quotient (HQ) in adults

n Cd

Co

Cu

Ni

Pb

Zn

Average

Max

Ref.

Formal sites, soil

6

0.00048

0.0016

0.020

0.0014

0.048

0.00067

0.072

0.15

This study

Formal sites, dust

11

0.0016

0.0063

1.33

0.22

9.29

0.018

10.9

60.9

This study

Informal sites, soil

7

0.0049

0.0027

0.039

0.0048

0.95

0.0057

1.00

3.67

This study

Informal sites, dust

6

0.0055

0.0087

0.40

0.20

0.81

0.032

1.45

3.73

This study

Guiyu, China

PCBRW, dust

12

0.043

0.0018

0.33

0.12

50.2

0.024

50.8

96.5

13)

Guiyu, China

Street B-1, dust

16

0.022

0.0015

0.25

0.024

10.3

0.013

10.6

62.7

13)

Guiyu, China

Street B-2, dust

16

0.009

0.00058

0.029

0.0071

0.45

0.0028

0.51

1.18

13)

Guiyu, China

School yard, dust

4

0.0067

0.00051

0.014

0.015

0.63

0.0033

0.68

1.73

13)

Guiyu, China

Street L, dust

8

0.012

0.00089

0.066

0.0082

0.1

0.0025

0.23

0.82

13)

Guiyu, China

Street G, dust

16

0.0068

0.00033

0.0023

0.0019

0.031

0.0029

0.052

0.223

13)

Guiyu, China

SU, dust

12

0.0076

0.00072

0.0016

0.0015

0.028

0.0010

0.049

0.070

13)

S17

Supplementary References [S1] FAO-UNESCO.

Digital

Soil

Map

of

the

World;

FAO-UN,

Rome,

Italy.

2007,

http://www.fao.org/geonetwork/srv/en/metadata.show?id=14116. Dec, 2011. [S2] T.-Y. So, E. Farrington, R. K. Absher, Evaluation of the accuracy of different methods used estimate weights in the pediatric population. Pediatrics 123 (2009) e1045-e1051.

S18