Honey as a bioindicator of environmental organochlorine insecticides contamination.

M Attaullah,B Ahmad,A Hazrat,I Ullah,H Ali,S Ullah,Z Ullah,S Khwaja,R Ullah,M A Nawaz,I Ilahi,T Jan

doi:10.1590/1519-6984.250373

Abstract

Honey is a suitable matrix for the evaluation of environmental contaminants including organochlorine insecticides. The present study was conducted to evaluate residues of fifteen organochlorine insecticides in honey samples of unifloral and multifloral origins from Dir, Pakistan. Honey samples (5 g each) were extracted with GC grade organic solvents and then subjected to Rotary Evaporator till dryness. The extracts were then mixed with n-Hexane (5 ml) and purified through Column Chromatography. Purified extracts (1μl each) were processed through Gas Chromatograph coupled with Electron Capture Detector (GC-ECD) for identification and quantification of the insecticides. Of the 15 insecticides tested, 46.7% were detected while 53.3% were not detected in the honey samples. Heptachlor was the most prevalent insecticide with a mean level of 0.0018 mg/kg detected in 80% of the samples followed by β-HCH with a mean level of 0.0016 mg/kg detected in 71.4% of the honey samples. Honey samples from Acacia modesta Wall. were 100% positive for Heptachlor with a mean level of 0.0048 mg/kg followed by β-HCH with a mean level of 0.003 mg/kg and frequency of 83.3%. Minimum levels of the tested insecticides were detected in the unifloral honey from Ziziphus jujuba Mill. Methoxychlor, Endosulfan, Endrin and metabolites of DDT were not detected in the studied honey samples. Some of the tested insecticides are banned in Pakistan but are still detected in honey samples indicating their use in the study area. The detected levels of all insecticides were below the Maximum Residue Levels (MRLs) and safe for consumers. However, the levels detected can cause mortality in insect fauna. The use of banned insecticides is one of the main factors responsible for the declining populations of important insect pollinators including honeybees.

Highlights

Honey is a complex matrix of at least 181 constituents used worldwide for nutritional and therapeutic purposes (Alvarez-Suarez et al, 2010)
Honey samples of different floral origins locally available in the study area were evaluated for the presence of fifteen organochlorine pesticides including HCB, α-HCH, β-HCH, γ-HCH, Heptachlor, Aldrin, Heptachlor exo-epoxide, Heptachlor endo-epoxide, Dieldrin, Endrin, Endosulfan, DDD, DDE, DDT and Methoxychlor
Of the tested organochlorine insecticides including α-HCH, γ-HCH, Endrin, Endosulfan, DDD, DDE, DDT and Methoxychlor were not detected in the honey samples

Summary

Introduction

Honey is a complex matrix of at least 181 constituents used worldwide for nutritional and therapeutic purposes (Alvarez-Suarez et al, 2010). Determination of insecticide residues in bee products is necessary for ensuring safety to consumers and bee populations (Fernández et al, 2002). Honeybees and their products can be effectively used as bioindicators of environmental pollution from miticides (Fell and Cobb, 2009), trace and heavy metals and metalloids (Zhelyazkova, 2012; Yaqub et al, 2020; Lazarus et al, 2021), polychlorinated biphenyls (Santos et al, 2021), DDT (Cervera‐Chiner et al, 2020; Freitas et al, 2021) and various pesticides (Alghamdi et al, 2020; Choi et al, 2020; Bramlitt, 2021; Rodríguez-Martínez et al, 2021). Sublethal doses of pesticides in honeybees affect their behavior and immune system (Desneux et al, 2007), reproduction and learning (Wu et al, 2011; Williamson and Wright, 2013), locomotion (Tosi and Nieh, 2017), and homing flight (Tosi et al, 2017)

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Conclusion