Diesel Fumes Threaten Bees' Ability to Find Flowers

Honey Bees
A new study found that many of the chemicals that make up floral odors are altered by exposure to NOX. Researchers hypothesize that this could impact bees' ability to find flowers for pollination. Chris Helgren/Reuters

Toxic nitrous oxide (NOx) from diesel exhausts is reducing bees' ability to locate pollen, a new study has found.

According to the study, published recently the Journal of Chemical Ecology, bees are finding it harder to distinguish floral odors because of all the fumes in the air. Researchers from the University of Southampton and the University of Reading exposed chemical compounds in flower odors to NOx that is found in diesel fumes. They discovered that five out of the 11 most common chemical compounds that make up floral odors were permanently altered in the process.

The work, funded by the Leverhulme Trust, furthers a 2013 study by the same researchers that discovered that pollution was confusing bees' sense of smell.

"Bees are worth millions to the British economy alone, but we know they have been in decline worldwide," said the study's lead author Robbie Girling, from the University of Reading's Center for Agri-Environmental Research, in a press release. "We don't think that air pollution from diesel vehicles is the main reason for this decline, but our latest work suggests that it may have a worse effect on the flower odors needed by bees than we initially thought.

Guy Poppy, a biologist at the University of Southampton and coauthor on the recent paper, says scientists already know that bees are at risk from a number of stresses. "Our research highlights that a further stress could be the increasing amounts of vehicle emissions affecting air quality. Whilst it is unlikely that these emissions by themselves could be affecting bee populations, combined with the other stresses, it could be the tipping point."

The pollination process is essential to the survival of both bees and plants, and integral for global food production. According to a 2011 United Nations report, 70 out of the 100 crop species that make up 90 percent of the world's food stock require pollination by bees.

"People rely on bees and pollinating insects for a large proportion of our food, yet humans have paid the bees back with habitat destruction, insecticides, climate change and air pollution," said Girling. Earlier this month, a study that looked at museum records spanning 110 years found that global warming is a major reason why bumblebee populations are declining in North America and Europe.