Dissipation kinetics and consumer risk assessment of novaluron + lambda-cyhalothrin co-formulation in cabbage

• Main Authors: Krishan Kumar Sharma, Vandana Tripathy, Soudamini Mohapatra, Nagapooja Yogendraiah Matadha, Abdul Rashid Khan Pathan, Badri Narayan Sharma, Jatiender Kumar Dubey, Sapna Katna, Thomas George, Amol Tayade, Khushbu Sharma, Ruchi Gupta, Suresh Walia
• Format: Article
• Language: English
• Published: Elsevier 2021-01-01
• Series: Ecotoxicology and Environmental Safety
• Subjects: Pesticide residue; Novaluron; Lambda-cyhalothrin; Cabbage; OECD MRL calculator; Consumer risk assessment
• Online Access: http://www.sciencedirect.com/science/article/pii/S0147651320313312

Cabbage, one of the most popular vegetables in the world is infested by several insect-pests and diseases. Novaluron, a chitin synthesis inhibitor and lambda-cyhalothrin, a synthetic pyrethroid group insecticide are used to manage insect-pests on cabbage. The dissipation kinetics and risk assessment of combination formulation (novaluron 9.45% + lambda-cyhalothrin 1.9%) with different modes of action has not yet been investigated in cabbage. Multi–location supervised field trials were therefore, conducted in different agro-climatic regions of India for safety evaluation of the combination product. The co-formulation at the recommended (novaluron 750 g a.i. ha−1 + lambda-cyhalothrin 750 g a.i. ha−1) and double the recommended (novaluron 1500 g a.i. ha−1 + lambda-cyhalothrin 1500 g a.i. ha−1) dose was sprayed on the cabbage crop. The samples were extracted and cleaned up using a modified QuEChERS method, and the residues analyzed by GC–ECD and GC–MS. The half-life (t1/2) varied between 1.77 and 2.51 and 2.00–3.38 days for novaluron and 1.36–2.24 and 1.69–3.82 days for lambda-cyhalothrin in cabbage at respective doses. The Food Safety and Standards Authority of India (FSSAI) has set the MRL of 0.7 mg kg−1 for novaluron at PHI of 5 days, and no MRL is set for lambda-cyhalothrin in cabbage. On the basis of OECD MRL calculator, the MRLs of 0.6 and 1.5 mg kg−1 for novaluron and lambda-cyhalothrin, respectively were calculated at the respective doses at PHI of 3 days. Hazard quotient (HQ) <1, theoretical maximum daily intake (TMDI) < acceptable daily intake (ADI) and < maximum permissible intake (MPI), percent acute hazard index (% aHI) <1, and percent chronic hazard index (% cHI) <1 for both novaluron and lambda-cyhalothrin suggested that the combination formulation is safe and will not pose any dietary risk to the consumers. The study will be helpful to conduct risk assessment of other pesticides/combination pesticides on food crops on which their MRLs have not yet been fixed.