Study on the Effect of Cu (II) and Zn (II) on the Accumulation of Pb (II) from Soil to the Biomass of Vegetable

Table 4

Concentration of lead in this metal-contaminated soil and in the biomass of lettuce grown in this soil.

Entry	Lead content in soil^a	Lead content in the biomass of lettuce^b
		Stems and leaves			Roots
		Range	Average	SD	Range	Average	SD
11	Background	0.15 ÷ 0.17	0.16	0.01	0.39 ÷ 0.47	0.42	0.04
12	100	0.23 ÷ 0.27	0.25	0.02	0.66 ÷ 0.75	0.71	0.05
13	200	0.31 ÷ 0.37	0.34	0.03	1.05 ÷ 1.21	1.13	0.08
14	300	0.63 ÷ 0.75	0.68	0.06	1.18 ÷ 1.37	1.26	0.10
15	400	0.70 ÷ 0.79	0.73	0.05	1.75 ÷ 2.09	1.97	0.19
16	600	1.06 ÷ 1.27	1.17	0.11	1.86 ÷ 2.18	2.05	0.17
17	800	1.54 ÷ 1.75	1.62	0.11	2.23 ÷ 2.58	2.41	0.18
18	1000	1.65 ÷ 1.95	1.79	0.15	3.67 ÷ 4.19	3.89	0.27
19	1200	1.76 ÷ 2.03	1.93	0.15	4.41 ÷ 5.13	4.72	0.37
20	1500	1.92 ÷ 2.17	2.07	0.13	4.61 ÷ 5.48	4.99	0.45

a, mg/kg of dried soil; b, mg/kg of fresh vegetable.