The effect of preparation methods on fenthion residues in sprayed quelea birds for human consumption

Abstract

The aim of this study was to assess the different local methods that are used by the communities to prepare quelea birds collected after spray with Queleatox for human consumption. It was conducted in order to compare their effects in reduction of fenthion residues. The assessment of various local preparation techniques was done through social survey where by a questionnaire was administered to enumerate 34 respondents and data was collected. This study was conducted at Ikonda village in Shinyanga region with coordinates 03o 54'.097''S and 27o.033'. 035'E' and at Basotu village in Arusha regions with 04° 31'.658''S and 036° 12'.921"E coordinates. Both areas are famous for the production of three common cereal crops of rice, wheat and barley in Tanzania where by aerial spray of Queleatox to control quelea birds are done as an annual event. This social survey was conducted two days before spray operations in both sites after which samples of sprayed birds were randomly collected for fenthion residues analysis in laboratory. Residues analysis was done in Tropical Pesticides Research Laboratory (TPRI) by using Gas Chromatography with Mass Spectrometry (GC-MS). Results from general social survey showed that the mostly used preparation methods are frying in oil, boiling and grilling after washing. Results from fenthion residues analysis showed washing and cooking had significant effects in reduction of residues to below detection limit by GC-MS compared to raw sprayed samples which demonstrated some residues content.