Honeybees could be having a harder time finding flowers to forage due to diesel exhaust air pollutants, as it affects their ability to identify certain floral odors, according to a press release.

Honeybees rely on their ability to identify flowers for which they forage by sensing its odor. A common air pollutant found in diesel exhaust hampers their ability to detect these flowers using their sense of smell.

If honeybees cannot identify flowers for which they pollinate, global food security could face threatening consequences.

"Honeybee pollination can significantly increase the yield of crops and they are vital to the world's economy - £430 million a year to the UK alone," co-author Professor Guy Poppy said. "However to forage effectively they need to be able to learn and recognize the plants."

The research team, lead by the University of Southampton's Poppy and Dr. Tracey Newman, determined that diesel exhaust fumes changed the floral aroma's profile. For their study, published Thursday in the journal Scientific Reports, the team mixed eight chemicals found in the odor of all rapeseed flowers with clean air and with air tainted by diesel exhaust fumes.

"Honeybees have a sensitive sense of smell and an exceptional ability to learn and memorize new odors," Newman said. "NOx (nitric oxide and nitrogen dioxide) gases represent some of the most reactive gases produced from diesel combustion and other fossil fuels, but the emissions limits for nitrogen dioxide are regularly exceeded, especially in urban areas."

The odor chemicals were not affected at all by the clean air. However, two odor chemicals disappeared completely in the diesel exhaust fumes air and the other six reduced in volume, changing entirely the floral aroma's profile.

"Our results suggest that that diesel exhaust pollution alters the components of a synthetic floral odor blend, which affects the honeybee's recognition of the odor," Newman said. "This could have serious detrimental effects on the number of honeybee colonies and pollination activity."

When the researchers isolated NOx gasses in the same experiment, they saw the same results. The secondary results left the researchers to believe NOx gasses are what play a central role in altering the honeybees' ability to identify flowers' odor.

"The results indicate that NOx gases -- particularly nitrogen dioxide -- may be capable of disrupting the odor recognition process that honeybees rely on for locating floral food resources," Poppy said. "Honeybees use the whole range of chemicals found in a floral blend to discriminate between different blends, and the results suggest that some chemicals in a blend may be more important than others."