Table 2.

Concentrations of heavy metals in soil from other studies compared to current work

Study area	Average concentrations of heavy metals (mg/kg)								Ref
	Cr	Ni	Cu	Zn	Cd	Pb	As	Hg
Yellow River basin, China	79.42	36.05	32.01	117.76	0.46	32.1	11.15	0.14	[35]
Qinghai-Tibet Plateau	93.29	54.73	40.74	145.74	0.68	72.49	–	0.28	[36]
Yerevan, Armenia	66.4	31.4	57.90	195	0.56	2.4	0.69	0.09	[37]
Changsha, Chaina	85.74	–	29.75	139.21	3.10	26.67	–	–	[18]
Krakow, Poland	9.9	6.50	13.40	56.80	0.80	33.9	–	–	[38]
Shushtar, Iran	39.58	58.66	18.39	43.09	0.30	6.12	2.77	0.01	Current work