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.

Essential and toxic element concentrations in monofloral honeys from southern Croatia.

The concentrations of 24 elements in seven honey types (multifloral, heather, common heather, bearberry, sage, mandarin orange-blossom and honeydew) collected in southern Mediterranean regions of Croatia were determined using ICP-MS. Significant differences were found in the concentrations of Ag, As, Ba, Cu, Co, Fe, K, Mg, Mn, Mo, Na, Ni, Se, Sb, U and Th (p<0.05, all) among honeys. The highest element concentrations were determined in honeydew honeys, with the exception of multifloral (Ca, Cr, Mo, Se), common heather (Mg, Na), bearberry (Ba, Fe, Pb) and sage (Ag) honeys. Among the floral honeys, the highest concentrations were found in multifloral honey (Al, As, Be, Ca, Cr, Mn, Mo, Ni, Se, Th and U), common heather (Co, K, Mg, Na, V), sage (Ag, Cd, Cu), and bearberry (Ba, Fe, Pb, Sb, Zn). The results contribute to the evidence supporting the role of botanical origin on the elemental composition of honey.

Variations in lead, cadmium, arsenic, and mercury concentrations during honeybee wax processing using casting technology.

Beeswax foundations are a necessary material in intensive modern beekeeping. Heavy metals can accumulate in these foundations for decades, as it is a common beekeeping practice to recycle wax. Beeswax samples were analysed using GFAAS for As, Cd, Pb, and Hg concentrations during the production of beeswax foundations using casting technology with a prolonged cooling and sedimentation phase. Significant differences were determined in the concentrations of As, Cd, Pb (p<0.01, all), and Hg (p<0.05) between the three levels of wax in a double-walled steel casting container and comb foundations (CF) during the processing stage. Concentrations (mg kg-1) of the examined metals in comb foundations as the final product ranged as follows: As 0.01-0.88; Cd 1.26-3.55; Pb 82.5-171, and Hg 0.29-1.46. All examined element concentrations demonstrated similar distribution and ratio in different layers, ranging from the lowest concentrations in layers from which wax material is used for comb foundations as the final product, to the highest concentrations in sedimented layer, which represents waste. The obtained results suggest that the described method could effectively eliminate a significant amount of heavy metals from the initial material used for the production of new beeswax foundations.