Products from Apis mellifera have long been considered theoretically ideal bioindicators since foraging worker bees naturally interact with all environmental domains: soil, air, water, and vegetation.
The average foraging radius of a worker bee is 3 km and depends on several factors, including the quality of nearby pollen and nectar, and the concentration of hives in a given neighbourhood. The bees’ unique collection mechanism includes direct uptake of pollen grains (5 to 1,000 μm diameter), and the passive collection of aerosol particulates during flight and from depositions on surfaces on which the bees land. Thus, when bees forage, transfer of major and trace elements occurs, including certain heavy metals (e.g., Pb, Zn, Cu, Cd, Mn) of which elevated levels in the environment are directly related to human activities. The resulting honey in a single beehive is thus a pooled sample from all of the foraging worker bees and will have a distinctive geochemical fingerprint of the local area.
Research questions include:
- How sensitive are bees as biomonitors of trace metal levels in the environment?
- Do lead isotopes and trace element concentrations in honey reflect proximity to different types of urban land use and pollution point sources?
- What dominant metal transfer mechanisms in the environment (e.g., direct aerosol deposition or indirect plant uptake) are represented in the metal content measured in pollen or honey bee tissue?
- Can we adapt the honey biomonitor method developed in Vancouver (Smith et al., 2019) for use in other major metropolitan centres that have a history of trade and industry (e.g., New York City, Paris, Brussels), or in isolated and low-popluation areas (e.g., Kaui Island, Hawaii)?