Toronto: Honey bees may help monitor pollution in cities and help pinpoint the exact sources of environmental pollutants such as lead, a first-of-its-kind study has found. The study analysed honey from urban beehives in six Metro Vancouver neighbourhoods. The researchers tested for miniscule levels of lead, zinc, copper and other elements and carried out lead isotope analyses — similar to fingerprinting — to identify where the lead came from.
“The good news is that the chemical composition of honey in Vancouver reflects its environment and is extremely clean,” said Kate E Smith, PhD candidate at the University of British Columbia in Canada. “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,” Smith said in a statement. Metro Vancouver honey is well below the worldwide average for heavy metals like lead, and an adult would have to consume more than 600 grammes, or two cups, of honey every day to exceed tolerable levels, researchers said.
They found the concentration of elements increased closer to areas with heavy traffic, higher urban density and industrial activity such as shipping ports. Places like the city of Delta showed elevated levels of manganese, which could be a result of agricultural activity and pesticide use in the area. The researchers also compared the lead fingerprints of the honey to those from other local environmental samples like lichen from around British Columbia, rock from the Garibaldi volcanic belt, sediment from the Fraser River and trees in Stanley Park.
They discovered that the lead fingerprints of the honey did not match any local, naturally-occurring lead. The trees in Stanley Park and the honeys from downtown displayed some striking similarities that pointed to potential manmade sources of lead. “We found they both had fingerprints similar to aerosols, ores and coals from Asian cities,” said Dominique Weis, senior author of the study.
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