Table 2.

Limits of detection of the analytical method (LOD) and percentage number of samples below the LOD for each metal.

Heavy metals µg/L	Pb	Cd	Cr	Hg	Ni	As	V
MATRIX	Blood	Urine	Urine	Urine	Urine	Urine	Urine
LOD	5	0.1	0.2	1	0.1	2	0.1
%<LOD exposed adolescents	65%	2%	11%	89%	52%	43%	85%
%<LOD control adolescents	21%	0%	0%	96%	48%	69%	83%