Levels of heavy metals in the raw and processed Ethiopian tobacco leaves

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Table 4 Comparison of metal concentration (μg/g dry mass) in the Ethiopian processed tobacco leaves (present study) with literature data (Zhang et al. 2005; Moulin et al. 2006; Ei-Amri et al. 1989)

Metals	Ethiopia (mean, present study)	Ethiopia (Nyala, present study)	UK	France	Belgium	Italy	Germany	Japan	References
Cd	1.67	1.55	1.62	1.59	1.22	1.96	1.96	1.04	Zhang et al. (2005)
Ni	2.27	4.70	5.62	8.91	9.44	8.60	9.11	3.24	Zhang et al. (2005)
Pb	ND	ND	14.3	15.6	14.7	22.0	17.2	NR	Zhang et al. (2005)
Cr	1.70	1.62	0.11	0.05	0.06	0.07	0.07	NR	Zhang et al. (2005)
Zn	92.7	79.3	NR	NR	NR	NR	NR	75.8	Zhang et al. (2005)

Metal	Ethiopia (present study)	Cameroun	France	Germany	Switzerland	UK	USA		Reference
Cd	1.45–1.90	1.30	2.30	1.80	1.27	1.34	1.60		Moulin et al. (2006)

Metals	Ethiopia (present study)	Libya	India	USA	Iran	Yugoslavia	References
Cr	1.62–1.75	4.55–4.85	3.0–8.2	0.24–6.3	4.3–6.2	NR	Ei-Amri et al. (1989)
Cu	8.95–12.8	32.8–41.1	NR	NR	NR	18.9	Ei-Amri et al. (1989)
Zn	79.3–101	63.5–95.8	15–31	4.1–54	51–56	51	Ei-Amri et al. (1989)