HONEY BEES AS BIOINDICATORS OF ENVIRONMENTAL POLLUTION

Bees and their products have long been considered a conceptually “ideal” bioindicator since foraging honey bees have a very specific and limited sampling area (~3 km radius) and naturally inhabit all environmental domains: soil, air, water, and vegetation. A non-profit organization, Hives-for-Humanity, installed beehives in various locations in the city of Vancouver (BC), including the Downtown Eastside, and suburban neighborhoods. We investigated the safety for human consumption of honey from beehives throughout Vancouver (BC), the Lower Mainland and through time (2014-16), by characterizing their chemical and isotopic compositions, and by comparing these results to commercial honeys from various parts of Canada and more remote areas such as Hawaii and Afghanistan. The project involves determining the concentrations of trace metals (Pb, Zn, As, Cu, Cd, among others) and Pb isotopic signatures to fingerprint the source of the metal in the honey. While trace metal concentrations in honeys are all below recommended limits and entirely safe for human consumption, distribution maps show clear patterns of elemental concentration and Pb isotopic variations within the city that directly reflect the proximity of major anthropogenic areas, such as Vancouver Ports, ferry terminals, and highways. These results simultaneously help us demonstrate the efficacy of isotopic characterization of honey and other bee products as a new bio-geochemical tool to assess the impact of urban activities. Carbon isotopes show limited variations so far, but can potentially identify adulterated versus pure honey, or honey from different plants. Other bee products (such as propolis and honeycomb), nectar, as well as environmental factors such as soil profiles, air and water quality, vegetation, and tree rings will also be investigated to refine the distribution maps, and to unambiguously fingerprint the source(s) of metals. This data will help define an environmental baseline against which potential increases in metal concentrations can be compared. The project also serves as a case study that can be used as a model in other cities worldwide for monitoring urban ecosystems, environmental conditions, and pollution dynamics.