An Investigation for Heavy Metals’ Contamination in Farmers’ Fingernails: Case Study in Libya

Table 5

Concentration levels of heavy metals in fingernails samples of the participating farmers and the control group.

Heavy metal	Subjects	Number of participants (N)	Level of heavy metals (µgg^−1)		Significance tests at
			Mean ± SD	Range	F-test		t-test		-value
					Calculated value	Critical value^1	Calculated value	Critical value^2
As	Farmers	127	3.016 ± 1.857	0.083–8.223	35.752	0.038	15.983	2.609
	Control group	25	0.354 ± 0.116	ND–0.429
Cd	Farmers	127	9.059 ± 4.026	0.122–18.003	43.607	0.038	17.613	2.609
	Control group	25	1.912 ± 0.963	0.222–3.388
Pb	Farmers	127	11.322 ± 3.785	0.319–21.111	46.548	0.038	8.230	2.609
	Control group	25	4.747 ± 2.847	0.453–8.399

ND: not detected (lower than the LOD of 0.0077 µgg⁻¹ for As).