Verification of Aspergillus Niger   as a Myco-remediation Agent of Lambda-Cyhalothrin and Associated Heavy Metals in Lactuca Sativa   (L.) Leaf

Pesticide residue constitutes a danger to soil micro and macro fauna and flora and to humans. This study assessed the impact of the application of Aspergillus niger as a pesticide remediating agent on Lambda-cyhalothrin and some of its associated heavy metals translocated to the leaves of Lactuca sativa. A Complete Randomized Design (CRD) experiment using three Treatments was conducted. Lambda-cyhalothrin was extracted from the Samples using the multiple residue technique and its residue determined using Gas Chromatography with Pulsed Flame Photometric Detector (PFPD). The associated heavy metals were determined using the Atomic Absorption Spectrophotometric method. Data so generated were means from five replicates, and were subjected to a one way analysis of variance - ANOVA with Tukey HSD Test for differences between means at 99% confidence interval (P≤0.01). The results show that the highest mean value of Lambda-cyhalotrhrin residue in L. sativa leaves was found in Treatment A (1.50 mg/kg), a value which was significantly higher (P≤0.01) than the residue found in Treatments B (1.0 mg/kg) and C(0.02 mg/kg). Mean Lambda-cyhalothrin residue in Treatment A alone was above the Maximum Residue Level (MRL) of 1.0 mg/kg in vegetable set in the legal EU regulation.The application of A. niger also precipitated a significant reduction (P≤0.01) in the level of all the heavy metals evaluated except Arsenic. All the heavy metals evaluated were however below the WHO/FAO safe limit. The result from this study posits A. niger as a promising mycoremediation agent of pesticide pollution.

Keywords
pesticide residue; mycoremediation; lettuce; Heavy metals; Lambda-cyhalothrin