Biomonitoring of heavy metal pollution by pollen in the urban and agricultural environments

Heavy metals such as Fe, Cu, Zn, and Mn are essential for nutrition, however the presence of metals such as Cd, Pb, Cu and Ni in high quantities in pollen when consumed can be toxic to the living organisms including important pollinators. It can be speculated that the apiary products maintained near urban areas could have varying degree of bioaccumulation of trace metals (As, Pb, Ni, Cd, Fe, Al, Cu) compared to those in agricultural environment. Therefore, we have characterized heavy metal composition and quantities in pollen collected from urban and agricultural environments. Toxic metals such as Cd, As, Fe, Zn, and Al were predominantly found in pollen samples collected from beehives in agricultural landscapes, urban landscapes contained high concentrations of Cu, Ni, and Pb, compared to conserved regions. These findings shed light on the use of pollen as bioindicator of heavy metal pollution for human-consumption and can also help designing targeted habitat restoration protocols by connecting bee-specific nutritional requirements to pollen quality of host-plant species.