Multivariate analysis of heavy metals content of beef from Soroti, Uganda

Abstract

Information about food hygiene and quality in the sub-Saharan African countries remains scarce at a time when many of their citizenry are beginning to acquire the much coveted middle income status. Compounding this are challenges linked to monitoring the safety of food produced by such lucrative industries as the beef industry on a continuous basis. The objective of the study was to begin somehow the process of encouraging changes to the status quo and showing by example how a start in that direction might look like. Using heavy metal contents of representative beef samples from butcheries in Soroti, Uganda typical of a sub-Saharan country, we demonstrate how relationships and common sources of metals could be identied among samples in a multivariate space. Beef samples from 40 sites were analyzed by atomic absorption spectrometry for iron (Fe), zinc (Zn), nickel (Ni), chromium (Cr), lead (Pb), copper (Cu), cobalt (Co) and cadmium (Cd). The study showed that all beef samples contained these metals, the extent of which were in the order: Fe > Zn > > Ni, Cr > Pb > Cu, Co > Cd. By correlation analysis, the pairs Ni and Cr, Cd and Co, Ni and Fe or Cr and Fe were most likely coming from the same sources. We also found that there are at least three distinct characteristics of beef consumed in Soroti, a distinction perhaps arising from three major categories of feedlots used to raise donor cattle. The incremental risk of children or adults developing cancer over a lifetime was estimated and found to fall into three categories, two of which are separately explained by the presence of Cr or Ni. The sources of these metals remain a matter of speculation on our part. More studies are needed to determine these sources and to understand the nature of cancer risk in the three categories of beef idenfied here. Keywords: Beef contamination, heavy metals, food safety, Soroti, Uganda