Table 2.

Median concentration (μg/L or μg/dL whole blood or μg/g creatinine) of metals in e-waste recyclers.

Compound	Age	LOD	Non-recyclers (n=20)	E-waste recyclers (n=40)	Median testb	NHANESc
	Groupa		Median (95%CI)	Median (95%CI)	p-value	Median (95%CI)
Whole blood measurements
Cadmium (ug/L)	All	0.1	0.59 (0.41 – 0.78)	0.59 (0.53 – 0.68)	>0.5	0.30 (0.28 – 0.32)
	18–<38		0.54 (0.36 –0.83)	0.47 (0.40 –0.55)	>0.5	0.26 (0.24 – 0.29)
	≥38–52		0.64 (0.35 – 0.88)	0.72 (0.65 – 0.84)	>0.5	0.35 (0.32 – 0.39)
Lead (ug/dL)	All	0.07	2.93 (2.62 – 3.88)	4.82 (4.52 – 5.96)	<0.0001	0.69 (0.63 – 0.75)
	18–<38		2.70 (2.24 – 20.89)	4.64 (3.95 – 6.08)	0.23	0.54 (0.51 – 0.58)
	≥38–52		3.44 (2.45 – 3.97)	4.99 (4.52 – 7.00)	<0.001	0.91 (0.87 – 0.96)
Methyl mercury (ug/L)	All	0.12	4.16 (2.93 – 5.08)	2.76 (2.30 – 3.22)	<0.05	0.50 (0.41 – 0.64)
	18–<38		3.23 (2.58 – 5.35)	2.38 (2.01 – 4.10)	>0.5	0.44 (0.35 – 0.54)
	≥38–52		5.04 (4.13 – 10.88)	2.76 (2.47 – 3.81)	<0.001	0.61 (0.46 – 0.83)
Mercury, total (ug/L)	All	0.28	3.46 (2.50 – 3.88)	2.49 (2.08 – 2.90)	0.055	0.68 (0.59 – 0.81)
	18–<38		3.02 (2.37 – 3.88)	2.48 (2.00 – 3.08)	0.11	0.59 (0.50 – 0.68)
	≥38–52		3.84 (1.87 – 4.80)	2.60 (2.05 –3.07)	0.14	0.85 (0.64 – 1.05)
Urine measurements (μg /g Creatinine)
Arsenic, total	All	0.26	46.94 (38.56 – 65.70)	42.35 (37.54 – 49.55)	0.17	6.84 (5.95 – 8.04)
	18–<38		44.59 (23.07 – 69.51)	43.38 (35.64 – 58.83)	0.43	6.49 (5.30 – 8.52)
	≥38–52		48.94 (38.56 – 116.22)	41.47 (36.22 – 49.55)	0.15	6.88 (6.39 – 9.28)
Arsenobetaine	All	1.16	7.62 (2.32 – 24.90)	6.96 (5.37 – 10.29)	>0.5	2.15 (1.75 – 2.90)
	18–<38		3.19 (1.91 – 49.24)	7.22 (2.65 – 30.65)	>0.5	1.95 (1.47 – 2.69)
	≥38–52		9.32 (2.13 – 24.90)	6.86 (3.91 – 10.85)	0.42	2.80 (1.81 – 3.36)
Arsenous Acid	All	0.12	1.91 (1.63 – 3.26)	1.79 (1.52 – 2.64)	0.39	<LOD
	18–<38		1.82 (1.61 – 4.86)	2.52 (1.71 – 3.74)	0.18	<LOD
	≥38–52		2.32 (1.42 – 3.99)	1.64 (1.43 – 2.48)	0.26	<LOD
Monomethylarsonic Acid	All	0.2	3.63 (3.21 – 4.25)	3.78 (2.93 – 4.64)	>0.5	0.91 (0.75 – 1.15)
	18–<38		3.63 (2.47 – 4.80)	3.78 (2.74 – 5.73)	>0.5	0.84 (0.71 – 1.07)
	≥38–52		3.78 (2.67 – 5.55)	3.71 (2.67 – 5.07)	>0.5	1.03 (0.68 – 1.31)
Dimethylarsenic Acid	All	1.91	26.24 (19.51 – 30.06)	27.50 (22.69 – 33.05)	>0.5	4.23 (3.71 – 4.59)
	18–<38		23.36 (18.62 – 39.32)	31.57 (21.94 – 37.82)	>0.5	3.65 (3.39 – 4.28)
	≥38–52		29.14 (16.89 – 41.71)	24.45 (22.52 – 36.35)	>0.5	4.52 (4.23 – 4.82)
Cadmium	All	0.036	0.832 (0.484 – 1.070)	0.998 (0.816 – 1.249)	0.41	0.192 (0.172 – 0.219)
	18–<38		0.574 (0.325 – 0.981)	0.812 (0.603 – 1.098)	>0.5	0.148 (0.126 – 0.171)
	≥38–52		1.058 (0.472 – 2.238)	1.217 (0.891 – 1.418)	>0.5	0.307 (0.275 – 0.342)
Lead	All	0.03	2.31 (1.73 – 2.68)	3.22 (2.69 – 3.99)	<0.05	0.34 (0.31 – 0.40)
	18–<38		2.43 (0.98 – 28.54)	2.89 (2.36 – 3.68)	<0.05	0.29 (0.25 – 0.33)
	≥38–52		2.17 (1.21 – 3.53)	3.98 ( 2.34 – 4.94)	0.26	0.49 (0.35 – 0.58)
Mercury, total	All	0.13	0.34 (0.23 – 0.71)	0.52 (0.42 – 0.80)	0.21	0.41 (0.33 – 0.46)
	18–<38		0.32 (0.22 – 0.76)	0.58 (0.37 – 1.00)	0.062	0.33 (0.25 – 0.46)
	≥38–52		0.46 (0.17 – 1.13)	0.49 (0.36 – 0.83)	>0.5	0.45 (0.41 – 0.58)

Abbreviations: Limit of detection (LOD) and the p-value for the comparison of the two exposure groups are given. NHANES median estimates are given as a comparison. LOD: 95% CI, 95% confidence interval; PCT >LOD, percentage of results above the limit of detection.

^aStratification for age; the all category contains all ages while the 18–<38 and ≥38–52 years were defined as stratification by the median of the control group.

^bMedian test for the analysis of comparison group and E-waste recyclers;

^cThe US median population estimate for females from the National Health and Nutrition Examination Survey (NHANES) for the survey years 2011 and 2012 using the same age stratification as for the Vietnamese women (Sjödin et al 2008 & CDC 2011–2012).

^d84% detection rate.

^e75% detection rate.

^f90% detection rate.