Honey could be used to monitor air pollution

Beehives could act as a sensitive and cost-effective – if rather improbable – air pollution warning system, a new study has suggested.

A survey published in Nature Sustainability has shown that honey in urban beehives around Vancouver contained minute amounts of lead, iron, zinc and other substances not naturally present in the local environment and attributed by the researchers to human activity.

Bees foraging for pollen are already known to pick up trace amounts of metals, but the study by a team from the University of British Columbia has confirmed that tiny, non-harmful amounts make it into the bees’ honey.

Because a bee’s range typically covers no more than a 3.2km radius, the chemical profile of the honey directly reflects the air quality in a given area.

Scientists led by Kate Smith of the university’s Pacific Centre for Isotopic and Geochemical Research gathered samples from more than 20 hives across six Vancouver neighbourhoods.

The team established not only that the honey was safe for human consumption but also that its lead levels were below the global average for honey.

More intriguing, though, was the link between the honey’s chemistry and the immediate environment.

Volcanoes, river rocks, coal and other natural lead sources carry distinctive signatures because of their ratios of lead isotopes. Smith and her colleagues established that the ratios found in the honey did not match the local environment.

They attributed the lead profile of honey from hives near the port and close to the city centre to fuel burnt by ships and emissions from cars. They also found raised manganese in honey from near the edge of the city, which they linked to pesticide use.

The team now plans to explore how honey analysis can be used with established methods of pollution tracking.