Comparative Study of Heavy Metal Concentration in Eggs Originating from Industrial Poultry Farms and Free-Range Hens in Kosovo

Table 1

Average concentrations and standard deviation of metals in hen eggs from poultry farms and free-range hens in parts per billion (μg kg⁻¹).

Elements/Eggs	Range (μg kg^−^1)	Mean ± SD (μg kg^−1)	Element presented on samples (%)
Chromium (Cr)	0.48–8.45	3.58 ± 3.041	32
Poultry farms	0.85–8.45	5.03 ± 3.23	30
Free-range hens	0.48–3.33	1.65 ± 1.49	30
Manganese (Mn)	38.77–289.00	154.49 ± 74.26	100
Poultry farms	38.77–268.78	145.27 ± 73.00	100
Free-range hens	79.50–289.00	176.04 ± 69.00	100
Iron (Fe)	4286.59–15383.74	8220.55 ± 2708.03	100
Poultry farms	4286.59–11942.41	7894.50 ± 2105.63	100
Free-range hens	4749.38–15383.80	9179.85 ± 3411.90	100
Nickel (Ni)	0.45–144.74	18.28 ± 34.72	73
Poultry farms	2.83–144.74	25.63 ± 48.24	66
Free-range hens	0.45–144.80	26.65 ± 48.97	80
Copper (Cu)	61.68–550.59	243.39 ± 150.25	100
Poultry farms	61.68–517.52	251.30 ± 151.50	100
Free-range hens	64.08–550.59	265.92 ± 278.95	100
Zinc (Zn)	1078.04–11378.56	4222.32 ± 2697.22	100
Poultry farms	1078.04–7587.63	4043.50 ± 2622.76	100
Free-range hens	1452.31–11378.56	4923.24 ± 2952.40	100
Arsenic (As)	0.29–35.42	2.96 ± 7.34	100
Poultry farms	0.29–1.31	0.805 ± 0.33	100
Free-range hens	0.36–35.42	5.196 ± 10.70	100
Cadmium (Cd)	0.27–6.54	2.18 ± 2.57	32
Poultry farms	0.83–6.54	4.16 ± 2.97	25
Free-range hens	0.27–1.71	0.70 ± 0.68	40
Mercury (Hg)	0.04–1.41	0.34 ± 0.33	77
Poultry farms	0.07–1.41	0.39 ± 0.47	66
Free-range hens	0.04–0.52	0.28 ± 0.14	100
Lead (Pb)	12.85–71.80	32.92 ± 23.18	36
Poultry farms	35.51–71.80	57.40 ± 19.26	25
Free-range hens	12.84–26.43	18.22 ± 5.96	50

SD, standard deviation.