Bull. Environ. Contam. Toxicol. (1999) 62:30-33
© 1999 Springer-Verlag New York Inc.
Lead and Cadmium in Ethiopian Vegetables
S. I. Rahlenbeck,
R. D. Zimmermann
Gondar College of Medical Sciences, Gondar, Ethiopia
University of Applied Sciences, Department of Environmental Protection,
Berlinstrasse 109, 55411 Bingen, Germany
Received: 20 July 1998/Accepted: 17 November 1998
Pollution of the environment by heavy metals, such as lead and cadmium has
become recognized as a world-wide public health hazard. The occurrence of
environmental contaminants has therefore widely been studied over the last
decades, particularly in industrialized regions. Data from developing countries,
especially those in Africa, are, however, very scarce (Tumbo-Oeri 1988; Ukhun et
al 1990; Nriagu 1992). In Ethiopia, one of the poorest countries in sub-Saharan
Africa, relevant information is not available at all.
Environmental lead pollution occurs in Africa primarily through traffic emissions.
Lead contents in gasoline sold in African countries remained high and are now
among the highest world-wide (Nriagu et al 1996). Emission of cadmium into the
environment can result from incineration of metal scrap, but in African countries,
use of phosphate fertilizers, metal plating activities and abrasion from automobile
tyres are likely to constitute the main sources. It is well known that vegetables
absorb these metals from the soil and atmosphere by dusts deposited on their
surfaces (Ndiokwere 1984; Tumbo-Oeri 1988).
The objective of this study was to investigate the lead and cadmium contents of
vegetables sold on markets in two Ethiopian cities, the capital Addis Abeba and
Gondar in the Nortwestern highlands.
MATERIAL AND METHODS
Fresh vegetables (4 leafy species and carrots; each 5 samples) were purchased
ostensibly for consumption from various fruit sellers in the capital Addis Abeba
(2.5 million inhabitants), as well as in Gondar, the third largest city (165.000
inhabitants) of Ethiopia. Gondar is situated in the northwestern highlands in an
area without industrial activities and very low automobile traffic. The species
collected constitute those consumed by the local population. Samples were taken
June and July 1994. Vegetables were rinsed twice with tap water, and the outer 3-
5 leaves were peeled. Samples were dried in the oven for 36 hours at 95°C. The
material was ground and shipped to the lab at the University of Applied Sciences,
Bingen, Germany where all analyses were done. Samples were again dried at
95°C and 200 mg of the samples were digested with 5 ml of 0.65% nitric acid
Correspondence to: R. D. Zimmermann