Pesticide Residue Analysis in Soil and Rice: A Case Study of Kishe Agro-Industry in Shebe Sombo, Jimma Zone, Southwest Ethiopia

Abstract

The main objective of this study is to determine the level and types of organochlorine pesticide residues in Rice (Oryza sativa L.) and soil samples from kishe agro-industries, Shebe Sombo woreda, Jimma zone, south west Ethiopia. Survey data analysis direct field observations and answers to a structured questionnaire from a random sample of 25 farming households and 2 DA showed that commonly used types of pesticides comprised most were combination of two or more, especially OPPs and OCPs (40.74%), OPPs (37.04%) and OCPs (18.52%). Of these, OCPs 88.89% and 11.11% of the farmers largely applied 2, 4-D herbicide and recent use of insecticide DDT respectively. For laboratory data all samples were collected and prepare following the Codex Alimentarius commission for residual analysis. A Newly modified QuEChERS procedure were used for extraction of the pesticides in Rice and Soxhlet methods were used for extraction of the pesticides in Soil samples and the quantitative determination were carried out by using GC-MS analysis. The methods were validated before application to the analysis of the pesticides. The limit of detection (LOD), Limit of quantification (LOQ), and percentage recovery were determined. Concentrations of organochlorine pesticides (OCPs) for∑ (23.7, 25.6 µg kg-1), ∑ (45.5, 62.8 µg kg-1), ∑ (18.3, 40.2 µg kg-1), ∑ (11.9, 10.6 µg kg-1), Aldrin (11.8, 6.8 µg kg-1), and Endrin aldehyde (5.4, 9.1 µg kg-1) in all soil and rice sample items were detected respectively. The concentrations analytes were compared with the acceptable international standard. The residual concentrations of most of the studied pesticides were below their MRLs set in EU and CA guideline. One-way ANOVA results (p ≤ 0.05) indicated the presence of significant variations in the concentrations of the detected pesticides among the sampling sites. Generally, the findings showed that regular monitoring of pesticide residues in agricultural products of the area is important.