April 29, 2026 | PloS one | Zhang
This study conducted by Haikou Customs District, Haikou, Hainan, China investigated the occurrence of unconventional pesticide residues in fruits and vegetables produced in Hainan Province, one of China’s major tropical agricultural regions. Although routine monitoring programs focus on commonly regulated pesticides, many unconventional pesticides are not systematically monitored and lack established residue standards, creating potential gaps in food safety oversight.
The researchers analyzed 216 fruit and vegetable samples collected from eastern, central, and western Hainan using the QuEChERS extraction method combined with gas chromatography–tandem mass spectrometry (GC-MS/MS). A total of 117 unconventional pesticides were screened. Results showed that pesticide residues were detected in 23 samples, representing 10.6% of all samples analyzed. Notably, 78.3% of the contaminated samples contained pesticides that were not covered by existing national residue limit regulations. Peppers and Chinese cabbage exhibited the highest detection frequencies. Eleven pesticide types were identified, with tetramethrin being the most frequently detected and isoprocarb showing the highest recorded concentration.
The study also developed a correlation model to identify factors influencing pesticide residue levels. Geographic and climatic conditions, crop characteristics, and pesticide properties were found to be the major contributing factors. The findings provide important baseline data on unconventional pesticide contamination in tropical agriculture and support the improvement of monitoring programs, regulatory standards, and food safety management systems in Hainan.
