Table 2.

Concentrations of heavy metals in bulk samples of motorway, urban, and mountain road dusts

Elements	Cr	Zn	Fe	Pb	Ni	Cu	Ti	Sr	Ba	Se	Cd	Pd
Mean concentration (mg/kg)
Motorway dust (n = 3)	232	1420	42,038	321	62.3	198	2067	119	114	0.078	0.45	0.033
Urban road dust (n = 3)	211	2030	50,298	430	43.7	239	778	99.8	192	0.059	0.352	0.031
Mountain road (n = 1)	34.2	211	13,467	24.2	29.6	78.4	309	99.5	87.7	0.02	0.12	0.015