Table 10.

International comparison of selected element concentrations (in ppm)in PRD with those reported in previous studies.

City	Cr	Co	Cu	Zn	Cd	Sb	Hg	Pb	Reference	Method	Analytical Method	Digestive Fluid Composition*	Sieve Size (μm)
Philadelphia, USA	119	355	374	588	-	-	-	516	This paper	Mean	ICP	HNO3+HCl	<841
Philadelphia, USA	82	331	261	349	-	-	-	202	This paper	Median	ICP	HNO3+HCl	<841
Hamilton, USA	28	-	60	589	-	-	-	297	Legalley and Krekeler, 2013	Mean	ICP	HNO3+HCl	<2000
Middletown, USA	160	8.7	28	374	0.2	1.8	-	85	Dietrich et al., 2018	Mean	ICP	HNO3	None - ground
Luanda, Angola	26	2.9	42	317	1.1	3.4	0.13	351	Ferreira-Baptista and De Miguel, 2005	Mean	ICP	HNO3+HCl+H2O	<100
Ottawa, Canada	43	8.3	66	113	0.4	0.9	0.03	39	Rasmussen et al 2001	Mean	ICP	HNO3+HCl+HF+HClO4	75-250
Beijing, China	85.6	9.4	42	214	1.2	-	0.3	61	Tanner et al., 2008	Mean	ICP	HNO3+H2O2+HF+H3BO3	<63
Beijing, China	84.7	-	69.9	222	0.72	-	-	105	Wei et al., 2015	Mean	ICP	HNO3+H2O2+HF	<125
Guangzhou, China	50.3	5.7	79	492	1.3	-	-	185	Duzgoren-Aydin et al., 2006	Median	ICP	HNO3+HF	<2000
Hong Kong, China	324	10.2	534	4,024	1.8	-	0.6	240	Tanner et al., 2008	Mean	ICP	HNO3+H2O2+HF+H3BO3	<63
Huludao, China	-	-	162	1,374	19.7	-	0.61	235	Zheng et al., 2010	Median	ICP	HNO3+HF+HClO4	<100
Nanjing, China	126	10.7	123	394	1.1	-	0.12	103	Hu et al., 2011	Mean	ICP	HNO3+HCl+HF+HClO4	<63
Shanghai, China	264	-	258	753	1	-	0.14	237	Shi et al., 2010	Mean	AAS	HNO3+HF+HClO4	<125
Urumqi, China	54	11	95	294	1.17	-	-	54	Wei et al., 2009	Mean	ICP	HNO3+HF+H2SO4	<149
Xi’an, China	65	-	72	295	-	3.7	0.43	131	Yongming et al., 2006	Median	AAS	HNO+HCl+HF+HClO4+H2SO4	<1000
Zhuzhou, China	115	15	98	1,140	10.3	9.8	0.21	254	Li et al., 2013	Median	ICP	HNO3+HF	None - ground
Kavala, Greece	196	-	124	272	0.2	-	0.1	301	Christoforidis and Stamatis, 2009	Mean	AAS	HNO3	<63
Amman, Jordan	29	32	139	351	1.9	-	-	271	Al-Momani, 2009	Mean	ICP	HNO3+HF+HClO4	<2000
Oslo, Norway	-	19	123	412	1.4	6	-	180	De Miguel et al., 1997	Mean	ICP	HNO3+HClO4+HF	<100
Seoul, South Korea	-	-	101	296	3	-	-	245	Chon et al., 1995	Mean	ICP	HNO3+HCl+HClO4	<2000
Avilés, Spain	41.6	7	183	4,892	22.3	8	2.56	514	Ordonez et al., 2003	Mean	ICP	HNO3+HCl+H2O	<2000
Madrid, Spain	61	3	188	476	-	-	-	1,927	De Miguel et al., 1997	Mean	ICP	HNO3+HClO4+HF	<100
Bursa, Turkey	-	-	-	57	3.1	-	-	210	Arslan, 2001	Mean	AAS	HNO3+HCl	<88
Birmingham, UK	-	-	467	534	1.6	-	-	48	Charlesworth et al., 2003	Mean	AAS	HNO3+HClO4+H2SO4+LaCl3	<1000
London, UK	-	-	80	372	2.7	-	-	370	Schwar et al., 1988	Mean	AAS	HNO3+HCl	<500
Average Value	104	36	153	785	3.8	4.7	0.48	290		Mean
Average Value (excluding this study)	103	11	142	794	3.8	4.7	0.48	280		Mean

^*= Composition of primary digestion, see manuscripts for Hg digestive fluids and all details