Dithiocarbamates Residues Level in Selected Vegetables from Bukavu, Democratic Republic of Congo

This study involved a survey on the use of dithiocarbamates in agriculture practices in Bukavu Region and the determination of their residues in vegetables (tomatoes and cabbages) from five main sites supplying Bukavu town with vegetables. A total of 75 vegetable samples from different fields were analysed using an HPLC-UV method developed by the Codex Committee on Pesticide Residues. Mancozeb, traded under the name Dithan-45 has been found to be widely used in Bukavu region especially in the protection tomato crops against pests. The analysis of extracts from tomato samples showed that they contained  dithiocarbamate residues. The concentration of the residues in tomatoes varied (in mg.kg-1) from no detectable (ND) to 1.33 for Kamanyola,  ND to 1.87 for Nyangezi,  1.44 to 3.99 for Katana, 1.54 to 4.06 for Miti and  ND to 4.65 for Mudaka samples. The average values ± SD  in mg.kg-1 for the five study sites were 0.89 ± 0.35, 1.31 ± 0.44, 2.48 ± 1.02, 2.71 ± 0.82  and 3.25 ± 1.25 respectively.  The results further show that 24 % of the tomato samples had Mancozeb residue values above the MRLs of European Food Safety Authority and 33 % above the MRLs set by EPA, while 73 % were not good for consumption with regards to the maximum permitted level for dithiocarbamates in tomatoes (1 mg.kg-1) in Germany. On the other hand, 83% of cabbage samples from all sites had no detectable Mancozeb residue levels and the rest had less than 0.1 mg.kg-1.