A survey of multiple pesticide residues on litchi: A special fruit

Litchi is a kind of fruit with high nutritional value and delicious flavor. The presence of pesticides has become the main risk factors affecting the safety and quality of litchi, and their potential risk to consumers have generated much public concern. We therefore sought to investigate the multiple residues, and dietary risk assessment of pesticide in litchi. 37 pesticide residues in 268 litchi samples were monitored during May 2019 to August 2020, as well as chronic dietary exposure assessment for consumers. Of 268 samples (100%) that contained pesticide residues, up to 11 pesticides were positive simultaneously (only accounted for 0.4% of all), and at least 1 pesticide (accounted for 3.6%) in one individual litchi sample. Concerning the most frequently detected pesticide residues, pyraclostrobin was found in 76.1% of the samples analyzed. Nine fungicides were detected in 252 samples (94.0%) at levels ranging from detectable to 1412 mu g/kg, and 92.9% of the samples tested contained thirteen insecticides at levels ranging from detectable to 2030 mu g/kg. Residue of eight pesticides in 19.8% of the total samples exceeded their MRLs, indicating indiscriminate use of these pesiticides. One non-authorized pesticides, imidacloprid was found in 5.2% of the total samples. The dietary risk of exposure to 23 detected pesticides through litchi, based on ADI% ranged from 0% to 36.8%. The results show that despite a high occurrence of pesticide residues in litchi, it could not be considered a serious public health problem. Nevertheless, routine monitoring of pesticide residues in litchi is necessary to decrease the MRL-exceeding rate of the pesticide residues and ensure the quality and safety of litchi.