Soil Heavy Metal Distribution with Depth around a Closed Landfill and Their Uptake by Datura stramonium

Table 1

Mean concentrations of heavy metals in soils around the landfill at a depth of 0–90 cm.

Location	Site	Concentrations (mg/kg)
		Cd	Cr	Cu	Fe	Ni	Zn
Eastern boundary	Site 1	0.40 ± 0.03	29.6 ± 3.38	127 ± 10.60	44716 ± 889	28.0 ± 1.97	288 ± 8.60
	Site 2	0.40 ± 0.00	25.6 ± 3.19	81.0 ± 12.60	41294 ± 744	35.0 ± 3.25	371 ± 8.30
	Site 3	0.37 ± 0.06	24.0 ± 2.70	78.2 ± 13.80	42309 ± 612	34.3 ± 3.34	342 ± 9.10
Northern boundary	Site 4	0.27 ± 0.07	23.8 ± 2.75	81.8 ± 14.40	39392 ± 857	31.8 ± 6.78	360 ± 5.20
	Site 5	0.11 ± 0.00	40.6 ± 4.40	93.6 ± 15.40	32622 ± 428	25.6 ± 3.37	267 ± 3.40
	Site 6	0.37 ± 0.09	41.9 ± 1.79	130 ± 9.70	45691 ± 802	28.9 ± 1.64	304 ± 7.50
Southern boundary	Site 7	0.51 ± 0.16	41.5 ± 3.53	129 ± 10.10	44694 ± 906	28.5 ± 1.80	297 ± 7.80
	Site 8	0.11 ± 0.00	39.6 ± 2.39	86.4 ± 8.80	33645 ± 855	22.0 ± 2.57	253 ± 4.70
	Site 9	0.11 ± 0.00	37.2 ± 1.16	79.0 ± 6.30	39796 ± 784	30.9 ± 2.68	349 ± 8.30
Western boundary	Site 10	0.11 ± 0.00	35.5 ± 1.55	63.9 ± 7.27	34849 ± 820	29.6 ± 3.48	333 ± 8.80
	Site 11	0.11 ± 0.00	35.3 ± 1.69	57.7 ± 8.08	34924 ± 924	29.4 ± 3.40	228 ± 8.10
	Site 12	0.11 ± 0.00	34.9 ± 1.52	69.9 ± 5.92	33238 ± 870	21.1 ± 2.88	273 ± 5.40
Control site		0.11 ± 0.00	11.7 ± 0.33	22.4 ± 1.81	12080 ± 439	19.7 ± 0.33	329 ± 8.14
NEMA (1988)		7.5	6.5	16	NA	91	240
WHO		0.01	0.05	1.50	20.0	6.5	15.0
SABS, 1999		2	80	6.6	N/A	50	46.5

NEMA, National Environmental Management act (1998). SABS, South African Bureau of Standards 1999.