Monitoring of Pesticides in the Cultivation of Nopal Vegetable ( Opuntia ficus-indica (L.)) Mill, Morelos, México

The presence of pesticide residues in vegetable and fruit products, as a consequence of inappropriate application in some cases, constitutes a risk to the health of the exposed population. In Mexico, the official norm, NOM-003-STPS-1999, only allows the use of pesticides with the phytosanitary registry, the responsible state commission for the control of the process and use of pesticides and toxic substances, which recommends doses and permitted crops. Despite the above, it is still common to find pesticide residues in some vegetable products. In this study, the following were detected: Chlorpyriphos, Dimetomorph I, Malathion, Omethoate, Carbendazim, and Imidacloprid in Nopal. The study was carried out in two collection centers located in the state of Morelos. In total, sixty samples were taken, thirty for each collection center, for a period of 10 months. To determine the pesticide residues, the analytical methodology was used, according to the guide, SANTE/11945/2015; in a laboratory accredited by the Mexican Accreditation Entity A. C. in the norm, NMX-EC-17025-IMNC-2006. The procedure for extracting analytes was carried out using the method, QuEChERS. The highest concentration of the pesticides detected in the samples obtained from the non-Certified Supply Center were Chlorpyrifos 0.309 mg/kg (MRL 0.01), Dimetomorf I 0.029 mg/kg (MRL 0.01), Malathion 0.155 mg/kg (MRL 0.01), Omethoate 0.032 (MRL 0.01), Carbendazim 0.090 mg/kg (MRL 0.01), and Imidacloprid 0.058 mg/kg (MRL 0.01). Thirty percent of the samples analyzed showed pesticide residues; the most frequent were Carbendazim. The results for the estimated daily intake (EDI) oscillated between 6.5 × 10 −5 and 1.3 × 10 −4 mg/kg body weight for the vegetable, Nopal. In principle, it could be concluded that the consumption of Nopal with pesticide residues does not represent any toxicological risk for human health, however, the risk cannot be ruled out due to the intake of other vegetables and fruits that are cultivated in the Mexican Republic, which probably present pesticide residues, which together would raise potential risks to human health.