Table 4. Weights for the 10 dissolved heavy metals in the water samples from the Zhujiang River.

PC	Eigenvalue	Relative eigenvalue	Variable	Loading value	Relative loading value on same PC	Weight (relative eigenvalue × relative loading value)
1	2.26	0.37	V	0.18	0.07	0.02
			Cr	0.85	0.32	0.12
			Co	0.84	0.32	0.12
			Ba	0.79	0.30	0.11
			Total	2.66	1.00
2	2.09	0.34	Mn	0.81	0.34	0.12
			Ni	0.67	0.28	0.10
			Cu	0.89	0.37	0.13
			Total	2.38	1.00
3	1.82	0.30	Mo	0.47	0.24	0.07
	6.17		Cd	0.71	0.37	0.11
			Pb	0.74	0.38	0.11
			Total	1.91	1.00	1.00