Assessment of pesticide residue patterns and multiple residue occurrence in Egyptian medicinal and aromatic plants: a comprehensive market screening

This study investigated the prevalence of 430 pesticide residues in 9963 samples representing 20 types of medicinal and aromatic plants (MAPs) from Egyptian markets using GC-MS/MS and LC-MS/MS. Pesticide-free samples ranged from a high of 68.33% in rosemary and 64.52% in hibiscus to a low of 9.70% in sage and 9.43% in calendula. Compliance with EU maximum residue limits (MRLs) was highest in calendula (84.18%), thyme (81.09%), and oregano (79.23%), but lowest in rosemary (31.38%) and hibiscus (34.66%). Exceedances of MRLs were most notable in sage (10.97%), moringa (8.57%), and cumin (7.80%). Chlorpyrifos dominated as the most frequently detected pesticide across all plants, with detection rates of 16-88%, followed by metalaxyl (detected in 14 plants with detection rates from 1.84% to 36.55%) and pendimethalin (found in 13 plants with detection rates from 2.27% to 19.91%). Single residue prevalence was highest in calendula (59.93%), camomile (57.05%) and dill (52.30%), whereas multiple residues were more common in oregano (50.77%), marjoram (49.52%) and sage (48.95%). The most common co-occurring pesticide combinations were chlorpyrifos with profenofos (16 out of 20 plant types), metalaxyl (15 out of 20 plant types) or atrazine (11 out of 20 plant types). These findings underscore the need for stricter pesticide monitoring, regulation, and sustainable agricultural practices to ensure the safety of these widely consumed plants.