Mineral Content in Honeybee Wax Combs as a Measurement of the Impact of Environmental Factors

Environmental pollution from metals needs to be constantly monitored due to their predominantly negative impacts on living organisms. As apian products stored in hives are considered useful bioindicators, the objective of this study was to: (a) investigate and compare the essential and toxic metal concentrations in freshly constructed combs (light combs, LC) and old combs (dark combs, DC) in use for two to three beekeeping seasons, and (b) compare the mineral content of beeswax combs from apiaries exposed to different levels of environmental pollution using the energy dispersive x-ray fluorescence method. Concentrations of ten elements (Cr, Pb, Cu, Ni, Fe, Zn, Mn, Sr, Rb, Ca) were determined in 18 honeybee wax comb samples from three apiaries in continental Croatia. The results showed that the influence of comb age and/or geographical origin (representing varying levels of environmental pollution exposure) on the elemental composition of beeswax was evident for the toxic elements Cr, Pb, Cu and Ni, and for the essential elements Fe, Zn, Mn and Sr, but not Rb. In addition to monitoring the environmental element content, wax combs can be used to determine contamination levels. Additionally, in-time analysis results can enable beekeepers to adjust management practices, such as moving apiaries to better positions. They can also be useful in the creation of policies on acceptable limits for toxic metal levels in particular geographical areas.