Organochlorine Pesticides Contamination and Health Risk Assessment of Herbal Teas in Abuja, Nigeria

Abstract

Aim: The purpose of this investigation was to quantify the amounts of organochlorine insecticide residues present in packaged herbal teas sold within the Federal Capital Territory (FCT), Abuja, Nigeria, and to assess the likely health risks connected with their consumption. Methodology: Twelve different brands of herbal tea products were procured from Abuja market stores. The tea samples were purposively selected to reflect variations in brand, plant composition, formulation, and geographic origin to ensure a representative consumer exposure assessment. Samples of herbal tea were extracted and cleaned up based on the QuEChERS-AOAC 2000 method, and organochlorine pesticides (OCPs). The Gas Chromatography Mass Spectrometer (GC-MS) was employed for quantification.  To measure health risks, the Estimated Daily Intake (EDI) and Hazard Quotient (HQ) for the 20 commonly monitored organochlorine pesticides (OCPs) were calculated. These residues are noted for their persistence and potential toxicity. The EDI was computed using an average body weight of an adult (60 kg) and a daily herbal tea intake of 0.0016 kg/day. The resulting HQ values were benchmarked against internationally accepted Acceptable Daily Intake (ADI) values and a threshold limit of 100%. HQ values exceeding 100% indicate potential health risks. Results: The lowest percentage recovery was 95.2% in δ-BHC, confirming the suitability and appropriateness of the extraction procedure and the GC-MS analyses employed. Every tea sample was tainted with the 20 OC insecticides, except for endosulfan sulphate in the Lipton tea. Among the tea samples, heptachlor concentration was the highest (1.641 mg kg-1), followed by Aldrin (0.802 mg kg-1), a cyclodiene among the banned insecticides worldwide. The concentration of alpha-BHC was notably higher in Mango, Lem-Gin, and Highland teas, reaching up to 0.356 mg kg-1, against the EU MRL of 0.005 mg kg-1. Delta. The HRI of residues of Alpha-BHC, p,p’-DDE, p,p’-DDD, Endosulfan II, p,p’-DDT, endosulfan sulphate, methoxychlor and endrin ketone HQ in the herbal teas were far above the threshold limit of 100. The OCPs that exhibited the lowest HRI were Endosulfan sulphate (7.337) and Methoxychlor.