Air pollution interferes with the ability of bees and other insects to follow the scent of flowers to their source, undermining the essential process of pollination, a study by three University of Virginia researchers suggests.
Their findings may help unlock part of the mystery surrounding the current pollination crisis that is affecting a wide variety of crops. Scientists are seeking to determine why honeybees and bumblebees are dying off in the United States and in other countries, and the new study indicates that emissions from power plants and automobiles may play a part in the insects' demise.
Scientists already knew that scent-bearing hydrocarbon molecules released by flowers can be destroyed when they come into contact with ozone and other pollutants. Environmental sciences professor Jose D. Fuentes at the University of Virginia -- working with graduate students Quinn S. McFrederick and James C. Kathilankal -- used a mathematical model to determine how flowers' scents travel with the wind and how quickly they come into contact with pollutants that can destroy them. They described their results in the March issue of the journal Atmospheric Environment.
In the prevailing conditions before the 1800s, the researchers calculated that a flower's scent could travel between 3,280 feet and 4,000 feet, Fuentes said in an interview, but today, that scent might travel 650 feet to 1,000 feet in highly polluted areas such as the District of Columbia, Los Angeles or Houston.
"That's where we basically have all the problems," Fuentes said, adding that ozone levels are particularly high during summer. "The impacts of pollution on pollinator activity are pronounced during the summer months."