Table 3.

Calculated weathering and pollution indices.

Sample	CIW	PIA	Igeo				CF				CD	PLI
			Cu	Pb	Zn	As	Cu	Pb	Zn	As
A-1	23	21	1	6	6	5	4	83	73	68	227	35
A-2	51	49	0.7	4	4	3	3	26	18	14	60	11
A-3	67	64	0.3	3	2	2	2	16	8	5	31	6
A-4	71	69	0.2	3	3	1	2	15	10	4	30	6
A-5	77	75	−0.7	−0.8	0.1	0.2	1	0.9	1.6	1.7	5.1	1.2
A-6	74	72	−0.6	−0.6	−0.3	0.2	1	1	1.2	1.7	4.9	1.2
A-7	77	76	−0.7	−0.6	−1.4	−2.1	0.9	1	0.6	0.3	2.8	0.6
A-8	81	80	−0.4	−0.4	−1.2	−2.7	1.2	1.1	0.6	0.2	3.2	0.7

∗Note: Operating ASGM site (A-1 and A-2), historic ASGM site (A-3 and A-4) and ‘control’ sites (A-5 to A-8).