Dissipation kinetics and health risk assessment of selected pesticides in green chillies

Combined formulations of pesticides help in mitigating different pests with each of their unique mode of action and help in reducing application costs for farmers. However, studies on the evaluation of the dissipation pattern and consumer health risk for the combined formulations on chilli are limited. Hence, this study was conducted to study the distribution pattern of a co-formulation of thiamethoxam 12.6% + lambda-cyhalothrin 9.5% ZC and a chlorantraniliprole 18.5% SC under open-field conditions at recommended doses. Method validation results showed linearity with r² ≥ 0.99 and LOQ in the range of 0.01-0.05 mg kg^-1 in green chilli and soil. Average recovery (spiking at 0.05 mg kg^-1) in the range of 93.6 to 105.5%. The initial residue deposits on green chilli on 0 day (2 h after spray) were 0.37, 0.10, and 0.35 mg kg^-1 for thiamethoxam, chlorantraniliprole and lambda-cyhalothrin, respectively. Residues on field-collected chilli and soil samples fitted well with a single first-order equation and half-lives of the pesticides were in the range of 4.2-13.0 days. Consumer risk was evaluated at pre harvest intervals (PHI) revealing that the residues do not pose a health risk.