A hive of activity: Using honeybees to measure urban pollution

Bees are startlingly intelligent creatures who form an essential part of the planet’s ecosystem, and now a new study shows they could help us understand urban pollution as well. A team from the Pacific Centre for Isotopic and Geochemical Research (PCIGR) at the University of British Columbia has found an innovative way to measure the level of source of pollution in urban environments: by analyzing honey.

The team analyzed honey collected from urban hives in Vancouver and found the tiny amounts of lead isotopes in the honey were distinctive and could be used as a “fingerprint” to identify where the lead originated from. This meant the team could track the relationship between the location of a hive and sources of pollution such as traffic or industrial activity very closely.

“The instruments at PCIGR are very sensitive and measure these elements in parts per billion, or the equivalent of one drop of water in an Olympic-sized swimming pool,” Dominique Weis, the paper’s senior author and director of PCIGR, explained in a statement.

“The good news is that the chemical composition of honey in Vancouver reflects its environment and is extremely clean,” Kate E. Smith, lead author of the study and Ph.D. candidate at PCIGR, said. “We also found that the concentration of elements increased the closer you got to downtown Vancouver, and by fingerprinting the lead we can tell it largely comes from manmade sources.”

The team also compared the fingerprints of the honey from Vancouver to other locations in the British Columbia area. They saw that the lead in urban locations was not from a local source of naturally occurring lead, suggesting it originated elsewhere. “We found [honeys from downtown Vancouver] had fingerprints similar to aerosols, ores, and coals from large Asian cities,” said Weis. “Given that more than 70 per cent of cargo ships entering the Port of Vancouver originate from Asian ports, it’s possible they are one source contributing to elevated lead levels in downtown Vancouver.”

The scientists gathered data in partnership with Hives for Humanity, a non-profit which promotes urban beekeeping, and they see potential for citizen scientists in other locations to collect honey samples too. Next they want to investigate how honey sampling can complement other environmental monitoring techniques like air and soil monitoring.

The study is published in the journal Nature Sustainability.