Assessment of the Potential of Honeybees (Apis mellifera L.) in Biomonitoring of Air Pollution by Cadmium, Lead and Vanadium

The aim of our study was to explore whether honeybees (Apis mellifera L.) could be used as a reliable alternative to the standard mechanical devices for monitoring of air quality, in particular with respect to the concentration of the heavy metals cadmium (Cd), lead (Pb) and vanadium (V). We therefore tested whether the concentrations of these metals in adult honeybees and in ambient air were positively correlated, and whether differences in concentration between locations were similar for bees and air. On the basis of our measurements, conducted over a two-month period at three distinct locations in the Netherlands with each three replicate honeybee colonies placed next to mechanical monitoring devices, we concluded that a significant positive relationship between the concentrations in bees and in air could only be established for V. Also, only in the case of V, the differences between the three locations in mean concentration were similar for bees and air. Both outcomes were probably due to the relatively large range over which the concentrations of V varied, both in bees and in air, as compared to Cd and Pb. However, for V, as well as for Cd and Pb, the concentrations in ambient air were about two orders of magnitude below the established air quality standards. We therefore conclude that in the Netherlands, both variation and levels of the atmospheric concentrations of these metals are too low to establish a relationship between the concentration in bees and in air that is useful to present honeybees as an alternative to mechanical devices in monitoring of air pollution. However, in countries with larger variation and higher levels of the atmospheric concentrations of these metals, further exploration of the potential of honeybees in biomonitoring of air pollution may be worthwhile