Table 4.

Concentration of chemical elements (Mean ± S.E) in the tissue of Gomphidae (Odonata) larvae at different sites of the Blyde River (S.E: standard deviation).

Element	S1	S2	S4	S5	S6
As	32.26 ± 0.0	19.81 ± 2.4	12.32 ± 0.0	16.59 ± 3.5	7.3 ± 3.3
Cd	0.56 ± 0.0	0.28 ± 0.03	0.17 ± 0.0	0.09 ± 0.03	0.25 ± 0.25
Cr	13.81 ± 0.0	4.59 ± 1.78	2.05 ± 0.0	5.55 ± 2.2	1.82 ± 0.53
Cu	187.13 ± 0.0	101.07 ± 28.1	78.18 ± 0.0	61.1 ± 29.2	52.9 ± 26.6
Mn	3173 ± 0.0	2106 ± 395	3068 ±0.0	3637 ± 1038	563.2 ± 33.6
Ni	11.13 ± 0.0	8.17 ± 2.79	9.99 ± 0.0	29.47 ± 10.3	6.23 ± 5.7
Pb	1.9 ± 0.0	0.55 ± 0.1	0.33 ± 0.0	1.11 ± 0.6	0.38 ± 0.05
Sb	3.54 ± 0.0	0.97 ± 0.05	1.46 ± 0.07	2.18 ± 0.95	1.03 ± 0.17
Zn	362.2 ± 0.0	168.2 ± 3.9	183.8 ± 0.0	108.7 ± 57.6	102.3 ± 41.2