Heavy Metal Content and Health Risk Assessment of Some Selected Medicinal Plants from Obuasi, a Mining Town in Ghana

Table 3

Levels of heavy metals in medicinal plant samples (n = 20).

Code	Botanical name	Mean ± SD concentration (mg/kg)
		Arsenic (As)	Cadmium (Cd)	Chromium (Cr)	Mercury (Hg)	Manganese (Mn)	Nickel (Ni)	Lead (Pb)
DS	Dalbergia saxatilis	0.361 ± 0.003	0.553 ± 0.002	2.437 ± 0.003	0.012 ± 0.002	33.839 ± 0.002	4.183 ± 0.003	5.855 ± 0.006
AI	Azadirachta indica	0.321 ± 0.001	0.626 ± 0.005	2.936 ± 0.002	0.033 ± 0.002	51.244 ± 0.004	3.978 ± 0.002	3.587 ± 0.003
EA	Entandrophragma angolense	0.385 ± 0.001	0.492 ± 0.003	3.376 ± 0.002	0.001 ± 0.001	28.247 ± 0.003	3.740 ± 0.001	1.426 ± 0.002
AC	Alchornea cordifolia	0.306 ± 0.006	0.714 ± 0.003	3.414 ± 0.004	0.027 ± 0.003	282.798 ± 0.004	4.340 ± 0.005	26.410 ± 0.002
QA1	Quassia amara	1.092 ± 0.005	0.723 ± 0.002	4.139 ± 0.003	0.025 ± 0.003	142.658 ± 0.001	2.681 ± 0.002	2.655 ± 0.005
MI	Mangifera indica	0.339 ± 0.001	0.649 ± 0.006	2.933 ± 0.001	0.029 ± 0.002	39.133 ± 0.002	2.310 ± 0.002	3.330 ± 0.003
CN	Cola nitida	0.574 ± 0.004	0.542 ± 0.001	3.039 ± 0.003	0.013 ± 0.003	74.192 ± 0.003	4.666 ± 0.002	2.162 ± 0.004
QA2	Quassia amara	0.408 ± 0.002	0.596 ± 0.002	2.507 ± 0.001	0.004 ± 0.001	35.821 ± 0.003	1.875 ± 0.003	7.111 ± 0.003
KS	Khaya senegalensis	0.479 ± 0.003	0.674 ± 0.004	2.005 ± 0.005	0.005 ± 0.001	28.219 ± 0.001	4.552 ± 0.004	13.026 ± 0.003
SJP	Sphenocentrum jollyanum Pierre	0.463 ± 0.002	0.601 ± 0.002	4.602 ± 0.001	0.015 ± 0.003	43.594 ± 0.003	2.447 ± 0.005	4.128 ± 0.001
OV	Ocimum viride	0.233 ± 0.004	0.253 ± 0.005	3.218 ± 0.002	0.024 ± 0.001	74.119 ± 0.003	2.411 ± 0.002	0.629 ± 0.003
PP	Paullinia pinnata	0.383 ± 0.004	1.34 ± 0.000	2.749 ± 0.004	0.024 ± 0.001	231.174 ± 0.001	3.013 ± 0.004	9.899 ± 0.001
TT	Tetrapleura tetraptera	0.474 ± 0.006	0.478 ± 0.004	2.406 ± 0.004	0.045 ± 0.001	29.994 ± 0.001	3.859 ± 0.002	2.277 ± 0.004
PG	Piper guineense	0.389 ± 0.001	0.709 ± 0.011	2.8 ± 0.001	0.013 ± 0.003	74.097 ± 0.001	1.679 ± 0.002	3.166 ± 0.003
GL	Gongronema latifolium	0.306 ± 0.001	0.602 ± 0.005	2.53 ± 0.004	0.010 ± 0.002	135.482 ± 0.003	2.439 ± 0.001	2.577 ± 0.001
MO2	Moringa oleifera	0.471 ± 0.003	0.553 ± 0.001	3.47 ± 0.001	0.018 ± 0.002	41.686 ± 0.002	3.116 ± 0.001	2.649 ± 0.003
AB2	Alstonia boonei	0.239 ± 0.002	0.416 ± 0.001	2.89 ± 0.004	0.010 ± 0.001	20.583 ± 0.003	3.354 ± 0.002	20.049 ± 0.002
CL	Citrus limon	0.493 ± 0.005	0.496 ± 0.005	2.39 ± 0.005	0.014 ± 0.001	36.546 ± 0.001	2.678 ± 0.001	1.728 ± 0.001
MC	Momordica charantia	0.206 ± 0.003	0.634 ± 0.005	2.56 ± 0.003	0.005 ± 0.001	36.968 ± 0.003	4.529 ± 0.003	5.823 ± 0.003
NL	Newbouldia laevis	1.04 ± 0.006	0.699 ± 0.002	6.60 ± 0.002	0.008 ± 0.001	39.795 ± 0.001	4.279 ± 0.003	4.333 ± 0.004
Mean		0.45	0.62	3.15	0.02	74.01	3.31	6.14
Max		1.09	1.34	6.60	0.045	282.0	4.67	26.4
Min		0.206	0.253	2.005	0.001	20.6	1.68	0.629
Range (max-min)		0.89	1.09	4.59	0.044	262.0	2.99	25.8
WHO MPL		3.0	0.3	1.30	0.5	44.6	10.0	10.0

SD, standard deviation.