Table 1.

Variations of average of heavy metals concentration in Tembi River water in different seasons (mg/L).

Heavy metals	Sampling point	Sampling time
		Summer 2011	Autumn 2011	Winter 2011	Spring 2012
Cd	1	0.07 ± 0.010	0.12 ± 0.700	0.24 ± 0.002	0.25 ± 0.030
	2	0.1 ± 0.006	0.26 ± 0.010	0.30 ± 0.010	0.35 ± 0.050
Cr	1	0.13 ± 0.010	0.29 ± 0.005	0.16 ± 0.010	0.17 ± 0.010
	2	0.25 ± 0.010	0.40 ± 0.05	0.31 ± 0.060	0.58 ± 0.005
Cu	1	0.26 ± 0.020	0.45 ± 0.080	0.56 ± 0.010	0.62 ± 0.010
	2	0.40 ± 0.01	0.54 ± 0.050	0.63 ± 0.010	0.71 ± 0.010
Fe	1	0.24 ± 0.010	0.18 ± 0.010	0.82 ± 0.040	1.1 ± 0.005
	2	0.26 ± 0.020	0.28 ± 0.030	1.1 ± 0.050	1.87 ± 0.030
Mn	1	0.07 ± 0.003	0.09 ± 0.001	0.81 ± 0.01	0.82 ± 0.010
	2	1.00 ± 0.007	1.25 ± 0.030	1.40 ± 0.020	0.91 ± 0.020
Ni	1	0.16 ± 0.01	0.40 ± 0.050	0.52 ± 0.010	0.83 ± 0.02
	2	0.50 ± 0.050	0.75 ± 0.010	0.65 ± 0.070	0.80 ± 0.020
Pb	1	0.59 ± 0.06	1.45 ± 0.030	0.81 ± 0.080	1.64 ± 0.020
	2	1.80 ± 0.070	0.85 ± 0.070	1.02 ± 0.010	1.91 ± 0.030
Zn	1	0.12 ± 0.000	0.23 ± 0.005	0.34 ± 0.000	0.11 ± 0.000
	2	0.20 ± 0.010	0.29 ± 0.005	0.51 ± 0.020	0.40 ± 0.000

1: upstream; 2: downstream.