Table 2.

Comparison of soil and road dust trace metal concentrations in current study with previous studies

Place	Pb	Cd	Cr	Mn	Times Samples collected	Unit	Reference
Soil
Guiyu Environ:
Mean	448.73*	0.71*	63.90	806.54	Repeated sampling (4 seasons)	mg/kg	This study
Geo mean	213.407	0.319	38.513	606.17			”
Haojiang Environ:
Mean	101.19	0.12	41.74	704.06	Repeated sampling (4 seasons)	mg/kg	This study
Geo Mean	91.734	0.074	31.730	613.03			”
Manila, Philippines Soil from e-waste (outside)	250	-	-	-	once	μg/g wet	Fujimori and Takigami (2013)
Manila, Philippines Soil e-waste	7.57	0.039	-	-		mg/kg	Fujimori et al. (2012)
Guiyu: Soil from e-waste area	1431	31.96	153.6	374.1	once	mg/kg dw	Alabi et al. (2012)
Burnt plastic dump area Guiyu	104	1.7	28.6	-	once	mg/kg dw	Leung et al. (2006)
Printer roller dump area Guiyu	190	3.1	74.9	-	once	mg/kg dw	Leung et al. (2006)
Taizhou: Soil from e-waste area	124.74	0.90	25.64	-	once	mg/kg dw	Zhou et al. (2012)
Guiyu soil (abandoned area)	150	1.21	2600	300	Once	mg/kg	Li et al. (2011)
Guiyu soil residue from open burning	480	10.02	320	500	Once	mg/kg	Li et al (2011)
* E-waste recycling area in slum in Bangal ore, India (BES)	297	2.33	73	449	Once	μg/g	Ha et al. (2009)
* E-waste recycling facility in Bangalore, India (BEF)	126	0.478	54	619	Once	μg/g	Ha et al. (2009)
Area near the open-burning area of e-waste in Guiyu, China	97.8–123	ND	7.02–155	-		μg/g	Wong et al. (2007)
Area at the open-burning area of e-waste in Guiyu, China	856–7038	5.51–42.9	137–477	-		μg/g	Wong et al.(2007)
Road dust
Guiyu
Mean	589.74*	1.94*	69.71	693.74	Repeated sampling (4 seasons)	mg/kg	This study
Geo Mean	391.955	1.134	55.410	528.64
Haojiang
Mean	115.61	1.23	85.38	552.48	Repeated sampling (4 seasons)	mg/kg	This study
Geo Mean	95.481	0.356	64.908	490.42
Around Manila, Philippines	6.44	0.044	-	-	Once		Fujimori et al.(2012)
E-waste - indoor dust	1467	59.0	-	-	Once	mg/kg	Zheng J et al. (2013)
E-waste - outdoor dust	4489	120.	-	-	Once	mg/kg	Zheng J et al.(2013)
E-waste PCB baking workshop dust; Guiyu	1910	2.4	67	761	Once	mg/kg	Zhu et al. (2012)
E-waste plastic processing workshop dust; Guiyu	323	1.7	56	800	once	mg/kg	Zhu et al. (2012)
Chinaa							SEPA (1995)
Grade I (natural background)	35	0.2	90	-		mg/kg
Grade II (agricultural and related use)	300	0.3	200	-
Grade III (industrial activity)	500	1	300	-
Dutch standard optimum	85	0.8	100	-		mg/kg	VROM (1994)
Action	530	12	380	-

Reported values for authors are mean except Ha et al. (2009) which is geometric mean

^*T-test analysis with log transformed values to compare exposed area and reference area (P<0.05; two tailed)

^aStandard Reference in China