Relation between application measures and residues of azoxystrobin and risk assessment for dietary residue intake

ObjectiveDissipation dynamics and behavior of terminal residues of azoxystrobin in peanut plant, peanut, peanut shell and soil under field conditions were studied in order to determine whether azoxystrobin usage is safe under the recommended application methods. MethodThe correlation between spraying times, dosage and interval to harvest, and terminal residues of azoxystrobin in peanut plant, peanut, peanut shell and soil were analyzed. Meanwhile, risk assess-ment for dietary residue intake of azoxystrobin was eveluated. ResultThe half-lives of azoxystrobin in peanut plant and in soil were 7.24-12.07 d and 5.57-13.48 d respectively. The terminal residues at harvest in peanuts plant, peanut, peanut shell and soil were lower than 1.135, 0.154, 0.922 and 0.957 mg/kg respectively. The rank of residue levels were as fol-lows: peanut < peanut shell < soil < peanut plant. The supervised trial median residue(STMR) in peanut was 0.05 mg/kg, the international estimated daily intake(IEDI) of azoxystrobin was 0.418785 mg/kg, the percentage of acceptable daily intake (ADI%) was found to be 3.32%. When the interval to harvest was 21 or 28 d, under different spraying times, dosages and intervals to harvest, there was no significent difference(P>0.05) in terminal residues in peanut plant, peanut, peanut shell and soil. ConclusionThe potential health risk induced by azoxystrobin is not significant based on conventional ap-plication. When the preharvest intervals(PHI) is 14 d, the application rate and frequency may have had an effect on the terminal residues.