Table 2.

Geochemical background and threshold of REEs in topsoils from Ditrău area and reference soil.

	Study area			Reference soila
Element	Geochemical background	Geochemical threshold	Mean content	Geochemical background	Geochemical threshold
	μg/g	μg/g	μg/g	μg/g	μg/g
La	53.45 ± 58.04	111.49	66.11	44.3 ± 18	62.4
Ce	86.06 ± 60.34	145.44	87.98	55 ± 45	100
Pr	11.85 ± 10.1	21.9	12.86	8.5 ± 5.2	13.7
Nd	36.15 ± 29.04	65.19	39.01	58 ± 24.8	82.6
Sm	7.50 ± 5.64	13.14	7.76	5.1 ± 2.6	7.8
Eu	1.50 ± 1.6	3.10	1.78	1.1 ± 0.4	1.5
Gd	5.65 ± 4.5	10.15	6.11	3.5 ± 1.8	5.3
Tb	1.00 ± 1.08	2.08	0.98	0.5 ± 0.4	0.97
Dy	5.35 ± 4.42	9.77	5.74	4.3 ± 2.6	6.8
Ho	0.90 ± 0.82	1.72	0.96	0.3 ± 0.2	0.5
Er	2.55 ± 2.18	4.73	2.77	1.4 ± 0.6	2.0
Tm	0.4 ± 0.34	0.74	0.46	0.2 ± 0	0.2
Yb	2.70 ± 1.96	4.66	2.86	1.5 ± 0.8	2.2
Lu	0.30 ± 1.38	1.68	0.35	0.24 ± 0	0.24
Y	19.25 ± 17.42	36.65	21.67	17 ± 16.4	33.4

^aSoil developed on alkaline rocks [73].