Metal Content in Honey, Propolis, Wax, and Bee Pollen and Implications for Metal Pollution Monitoring

We studied the concentrations of Cd, Ni, Pb, Fe, Mg, and Zn in multi-floral honey, propolis, bee pollen, and wax coming from apiaries situated in different locations in Małopolska Voivodeship in southern Poland. Honey contained the lowest concentrations of all the tested metals, with Cd and Pb concentrations well below allowable levels. Other products showed much higher contamination by Cd and Pb. Propolis and pollen from certain areas were significantly contaminated with Pb. High metal contents occurred in beeswax. Moreover, positive correlations between metals occurred in wax: i.e. Cd vs. Ni, Cd vs. Fe, Ni vs. Fe, Ni vs. Mg, Pb vs. Fe, and Fe vs. Mg. Interestingly, metal contents in honey were not correlated with metal contents in other tested products. Correlations between Fe concentrations in honey and wax and between Mg concentrations in bee pollen and propolis were exceptional. This suggests that honeybee products may be useful in monitoring environmental contamination by metals, although complex studies of all bee products give sufficient information.