Beeswax as a Bioindicator of Heavy Metal and Pesticide Residues in Selected Apiaries

Abstract

Beeswax serves as a valuable raw ingredient in phar­maceuticals, cosmetics, medicinal formulations, and modern beekeeping practices. It serves as a veritable tool for assessing environmental contaminants owing to its fat-based chemical composition. This study assessed beeswax as a bioindicator of heavy metal and pesticide residues in selected apiaries. Beeswax samples were obtained after processing honey harvested from apiaries in Awka, Amizi, Ezzamgbo and Saki. The beeswax samples were transported to the laboratory for heavy metal and pesticide residue analysis using Atomic Absorption Spectrophotometer (AAS) and GC-FID respectively. The findings of this study showed that beeswax sampled from Awka had the highest concentration of cadmium (1.211 mg/kg) and iron (0.193 mg/kg), while those from Saki had the highest concentration of zinc (2.215 mg/kg) and chromium (0.034 mg/kg). Ezzamgbo had the least concentration of all the heavy metals analysed. The total concentrations of all heavy metals sampled were significantly different (P<0.05) from the values recommended by FAO/WHO, except for cadmium (P>0.05). The pesticide residue concentrations of beeswax from Ezzamgbo recorded the highest values of Chlorophyrifos (0.108 mg/kg), Dichlorovos (0.464 mg/kg), Dicophol (0.282 mg/kg), Dieldrin (0.064 mg/kg), Profeneros (0.321 mg/kg) and T-nonachlor (0.103 mg/kg). Beeswax sampled from Saki had the highest values of Dianzinon (0.003 mg/kg) and Endosulfan (0.032 mg/kg) while 2_4 DDT (0.243 mg/kg), Heptachlor (0.321 mg/kg) and Lindane (0.318 mg/kg) were highest in Amizi. There was a significant difference in the levels of the pesticide residue components recovered from the beeswax sampled in the various locations at P<0.05, except for g-chlordane and Profeneros (P>0.05). All concentrations of the various components of the pesticide residues were below the recommended limit by FAO except for 2_4 DDT, Carbofuran, Dichlorovos, Dicophol, Heptachlor and Lindane. The findings of this study revealed that while beeswax from Awka and Saki had the highest heavy metal concentrations while Ezzamgbo and Amizi were more contaminated with pesticide residue. Based on the presence of contaminants in honey samples in this study, the need to regulate the use of pesticides by beekeepers and farmers in apiaries and its environment was strongly recommended.