Pesticide contamination and effects of peeling on pesticide residues in tomatoes from the markets : a case study of Iringa Municipality

Dissertation

Tomato is the most consumed horticultural crop in the world due to its economic and nutritional benefits. The crop is very susceptible to pest infestation making the use of pesticides during production inevitable. Consumption of tomatoes contaminated with pesticide residues has been associated with both chronic and acute health risks to human. This study was aimed at assessing awareness and pesticide residues in tomatoes from selected markets in Iringa region of Tanzania together with assessing effects of peeling on reduction of pesticides. Seven pesticides (Profenofose, Chlorpyrifose, Cypermethrine, Hexaconazole, Lambda cyhalothrin, Endosulfan and Chlorothalonil) were analyzed in tomatoes by a using Gas Chromatography tandem mass-mass with time of fight (GC- MSMS-TOF) after extraction with quick, easy, cheap, effective, rugged and safe (QuEChERS) methodologies. The results showed that all sellers were aware on pesticides contamination in tomatoes and none of them applied pesticides prior to sell. Peeling tomatoes reduced pesticide contamination by 35—100% depending on the type of pesticides and the original pesticide levels before peeling. Thirty-four percent (34%) of samples didn’t comply with EU MRLs on ʎ- Cyhalothrin, (28%) chloripyrifos, (25%) hexaconazole and (22%) chlorothalonil. All the samples had lower health risk index, however cumulatively continuing using tomatoes with low level of pesticides will lead to increased concentration in the system. Therefore, the proper use of pesticides is encouraged to minimize residues in the agricultural products that will reduce health risks upon their consumption.

Director General of Tanzania Medicine and Medical Devices Authority (TMDA)