Monitoring and Surveillance of Pesticide Residues in Rice Products from Central Thailand

Abstract

Rice is one of the most important agricultural export commodities of Thailand. However, intensive pest management practices may lead to pesticide residue in rice, which can pose concerns for food safety and international trade. Therefore, monitoring pesticide residues in rice is essential to ensure consumer safety and compliance with maximum residue limits (MRLs). This study aimed to monitor pesticide residues in rice samples and investigate pesticide use in rice production systems in central Thailand by interviewing farmers about rice pests and diseases, including types of pesticides and the application period. Additionally, pesticide residues in 277, 263 and 259 rice samples collected during the planting seasons of 2022/23, 2023/24 and 2024/25 respectively, were analyzed using LC-MS/MS and GC-MS/MS. The results showed that 155 (56%), 89 (34%) and 90 (35%) rice samples from the 2022/23, 2023/24 and 2024/25 planting seasons, respectively, contained detectable pesticide residues including propiconazole, tricyclazole, tebuconazole, cypermethrin, ethiprole and carbendazim. Among these, propiconazole was the most frequently detected pesticide residue and exceeding the maximum residue limits (MRLs). These results corresponded to monitoring information that farmers applied these chemicals during the rice maturation stages. Among 334 samples with detected residue,102 samples exceeded the maximum residue limits (MRLs) established by the National Bureau of Agricultural Commodity and Food Standards (ACFS). In contrast, when evaluated according to the European Commission Maximum Residue Limits (EU MRLs), 123 rice samples exceeded the permitted limits. These findings indicate a relationship between pesticide use practices and residue occurrence in rice, highlighting the need for continuous monitoring to ensure consumer safety and improve the quality standard of Thai rice.