Table 2.

Comparison of Pb concentrations of raw milk samples to other studies

Location (province)		Year study	Sample	Method of detection*	Metal concentration (Mean±SD, ppm)	Reference
Present study		2020	cow’s milk	GFAAS	0.012 ± 0.005	-
Iran	Isfahan	2018	bovine, ovine, caprine, buffalo and camel milks	GFAAS	0.0117 ± 0.001	[29]
	East Azerbaijan	2018	cow’s milk	ICP-OES	0.010 ± 0.001	[30]
	Khuzestan	2016	bovine milk	GFAAS	0.047 ± 0.003	[14]
	Shahroud	2015	cow’s milk	GFAAS	0.038 ± 0.001	[27]
	Hamadan	2014	cow’s milk	ICP-OES	0.032 ± 0.020	[11]
	Lorestan	2014	cow’s milk	GFAAS	0.003 ± 0.001	[15]
	Khorram-abad	2014	cow’s milk	GFAAS	0.002 ± 0.002	[31]
	Zabol	2014	cow’s milk	GFAAS	0.009 ± 0.002	[32]
	Iran	2013	cow’s milk	Volta metric	0.014 ± 0.002	[33]
	West Azerbaijan	2012	cow’s milk	GFAAS	0.007 ± 0.001	[17]
	Fars	2012	cow’s milk	FAAS	0.010 ± 0.004	[34]
	Northeast Iran	2012	cow’s milk ewe milk	GFAAS	0.0129 ± 0.006 0.0149 ± 0.007	[18]
	Arak	2011	cow’s milk	GFAAS	0.016 ± 0.002	[12]
	Isfahan	2008	cow’s milk	FAAS	0.0102 ± 0.007	[13]
Romania		2019	cow’s milk	AAS	0.12 ± 0.044	[35]
Mexico		2019	cow’s milk	ICP-OES	0.024 ± 0.01	[36]
China		2017	cow’s milk	ICP-MS	0.0012 ± 0.001	[37]
Croatia		2014	cow’s milk goat milk	GFAAS	0.011± 0.008 0.015± 0.025	[21]
Korea		2012	cow’s milk	ICP-MS	0.003 ± 0.000	[38]

*GFAAS = Graphite furnace atomic absorption spectrometric, FAAS = Flame atomic adsorption spectroscopy, ICP-AES = Inductively coupled plasma atomic emission spectroscopy, ICP-OES = inductively coupled plasma optical emission spectrometry, ICP-MS = Inductively coupled plasma mass spectrometry