Table 1.

Concentrations of heavy metals in bulk and size-segregated brake lining dust samples

Elements	Weight %	Cr	Zn	Fe	Pb	Ni	Cu	Ti	Sr	Ba	Se	Cd	Pd
Mean concentration in brake pads dust (mg/kg)
Bulk sample	100	789	8310	184,780	2897	369	14,002	25,400	156	20,900	7.88	2.34	0.082
Mean concentration in fraction size of brake pads dust (mg/kg)
<20 μm	87.38	920	8763	208,099	2656	433	17,404	–	189	–	11.3	2.39	0.108
20–56 μm	6.83	899	6728	199,009	2902	456	16,309	–	166	–	9.8	2.21	0.083
56–90 μm	3.92	310	1490	169,950	928	56.3	301	–	20.5	–	1.02	0.98	0.022
90–250 μm	1.87	87.9	1039	160,358	789	20	158	–	18.1	–	0.46	0.65	0.020