Revealing the bioaccumulation of heavy metals in honey plants and their translocation into apiproducts

This study quantifies the translocation factor (TF) for heavy metals transferred from wild honey plants to beekeeping products. The research area is located near the war zone, so its contamination with heavy metals is possible. Analysis of honey plants and bee products can make it possible to establish their safety. Field studies were conducted in July 2025 in the village of Stepanivka (Ukraine). The concentration of Cd, Pb, As, as well as the TF for these heavy metals transferred from wild honey plants to beekeeping products (bee pollen and honey), were determined using generally accepted methods. It was found that the concentration of Pb in wild honey plants is 1.64 ± 0.44 mg/kg, which exceeds the level permitted in Europe and Ukraine for plants by 5.5–8.2 times. However, in bee bread and honey, the concentration of Pb is within the normal range (0.15 ± 0.01 mg/kg and 0.09 ± 0.01 mg/kg, respectively). This indicates that pollen is less contaminated compared to vegetative parts of the plant, acting as a barrier for heavy metals, and bees have the ability to reduce the concentration of pollutants. This is also confirmed by the fact that the concentration of Pb in bee bread is higher than in honey, which may indicate the ability of bees to act as a biofilter. The same effect is observed with other toxins. The level of Cd in honey (0.007 ± 0.01 mg/kg) was lower than its concentration in bee bread (0.01 ± 0.05 mg/kg). The concentration of As in honey is also 0.1 mg/kg lower than its concentration in bee bread. At the same time, it was found that the concentration of As in wild honey plants (< 0.0001 mg/kg) is significantly lower than its concentration in beekeeping products. The highest bioaccumulation of Cd was registered in bee bread (TF = 0.13). Considering that the translocation factor of heavy metals does not exceed 1, honey and bee bread collected in the study area can be considered safe for consumption