Asian Journal of Applied Chemistry Research

Background: One of the major contaminants of concern in food products, such as spices, is organochlorine pesticides (OCPs). These insecticides have been extensively used to control insect pests in the field and post-harvest storage facilities due to their high effectiveness.

Aim: This study investigated the occurrence of organochlorine pesticide (OCP) residues in marketed and consumed spices in the Federal Capital Territory, Abuja, and assessed their human health risks.

Methodology: This study was conducted at the Chemistry Advanced Research Laboratory – in Sheda Science and Technology Complex (SHESTCO), Sheda-Abuja and Ebic Integrated Laboratory, Port Harcourt, Rivers State, Nigeria. The eleven sampled brands of spices procured from the Abuja markets were extracted and cleaned up using the Quick, Easy, Cheap, Efficient, Rugged, and Safe (QuEChERS) method. Organochlorine pesticide residue (OCPs) in the extracts were quantified using Gas Chromatography-Mass Spectrometry (GC-MS). Health risk assessment involved determining the Estimated Daily Intake (EDI) and Hazard Quotient (HQ).  The derived HQ values were compared to a threshold limit of 100%. Potential health hazards are indicated if the HQ values higher than 100%. The concentrations of OCPs in the samples were quantified using the external calibration method. 

Results: The r² values obtained from the plot of known concentrations of OCPs against their peak areas ranged between 0.9997 and 0.9999.The percentage recoveries of the organochlorine compounds ranged from 96.01% in Alpha-Chlordane to 99.15% in Endosulfan II) with a mean of 98.14 ± 0.67, confirming the appropriateness and suitability of the separation protocol and the GC-MS analyses used.  Nine out of the 11 samples (81.08%) were contaminated with the 20 OCPs, while nutmeg and chicken seasoning spices had 19 OCPs residue each, as the PP’ DDD residue was below the detected level in them. Residual concentration of Delta-BHC (2.009 µg kg⁻¹) was the highest in Nutmeg (exceeding the EU standard of 0.010 µg kg⁻¹). Aldrin residual concentration was 1.743 µg kg⁻¹, and that of Beta-BHC in yellow pepper (0.686 µg kg⁻¹) exceeded the EU MRL limits. Gamma-Chlordane showed high levels in chicken seasoning (0.79 µg kg⁻¹) exceeding the 0.05 µg kg⁻¹ EU limit. Health risk assessment indicated that the EDI and HQ values for all OCP residues remained below the individual Acceptable Daily Intake (ADI) and the HQ threshold of 100, respectively, suggesting no long-term consumption risk. However, the HQ values for Heptachlor (65.06) and Aldrin (63.34) were relatively high, thus requiring attention.

Conclusion: Regulatory agencies need to intensify close monitoring of food commodities in Abuja, Nigeria, to ensure food safety.