More than 53 million travelers and over 2 million tons of cargo passed through Frankfurt Airport last year, and passenger travel is expected to grow up to 7 percent this year. That makes it Germany's most used and Europe's third biggest airport.

But it also means there are a lot of planes, cars, buses and trucks emitting chemicals, particles and fumes into the air.

In a cargo area a few hundred feet from the runways, however, the smoke is being produced by master beekeeper Matthias Ullmann. He holds a metal canister filled with smoldering bits of egg carton and dried apple pulp, and pumps it near the opening of one the 12 hives that are stacked on top of each other.

Ullman is part of a team of researchers from the Institute for Apiculture at the Goethe University Frankfurt am Main that has run a bio-monitoring study here since 2006.

"We assume that bees are very good indicators for pollution," said Bernd Grünewald, who oversees the project. "An individual hive covers some 50 square kilometers (19 square miles). From this area they are collecting pollen and nectar. And if we take the honey, we can get a measure of how polluted an area is."

Happy, healthy bees

The research team said the bees are healthy and happy here. The untamed land in the area offers a nutritious mix of fruits and plants, and while bees are disturbed by ground vibrations, they aren't bothered by noise, one of the biggest issues for the airport.

Bees aren't disturbed by the noise around Frankfurt Airport

Since a noise study began in 2002, the airport's operator, Fraport, has spent 50 million euros ($71 million) to give nearby residents sound insulation and will spend another 100 million euros for the same thing over the next two years. But the winged residents of the hives don't need such measures, said Ullmannm, a third generation beekeeper.

"One of these beehives has up to 150,000 take-offs and landings a day, and it doesn't affect the airport," he said. "On the other side, it's the same thing. The airport and the bees function in harmony."

About 300,000 bees collect up to 38 kilograms (84 pounds) of nectar a day from around the airport. That's enough to provide a large range of data for a bio-monitoring study as well as material to sample for toxins like lead, copper, zinc and cadmium, Grünewald said.

Grünewald's study is a small part of the environmental monitoring that occurs near Frankfurt Airport, but it's the one that has attracted the most attention, according to Peter Marx, vice president for environmental management for Fraport.

"Airports and bees are somehow connected," he said. "We have the big birds, and they are, shall we say, the small birds."

Part of a larger process

In its efforts to reduce its carbon dioxide emissions by 30 percent, Fraport obtained a permit to produce hydroelectricity and installed numerous instruments around the airport to check on air quality, ground water, sewage, and noise.

Scientists are confused that planes don't impact local honey

Fraport has published the results of its monitoring program since 2005, but the data - listed in tons, kilograms and micrograms - is difficult to relate to everyday life, Marx said. The bee program, however, is much easier to grasp.

"Bio-monitoring is something which is really, really close to peoples' minds," he said. "They understand that flowers are dying, or why flowers are not dying.”

The bee study was not that cost-effective as a research tool, but it's a boon for public relations, Marx added.

"It might be less costly than monitoring stations, but with monitoring stations you have hard facts," he said. "Bees are always an add-on. Sure, it's for the public, but also a good collection of data. You can show the impact of air quality all over the airport."

Good honey proof of low pollution?

And, they do get honey out of the deal. Grünewald and his colleagues collect almost 300 kilograms a year of the sticky stuff from various sample sites, including one on a mountain, and another near a busy highway. The findings seem to show that pollution is nominal.

Grünewald, left, and Ullmann regularly check on the bees

"The residues in the honey and in the pollen are very low," Grünewald said, adding that the measurements were in the parts per billion range. "Much lower than, for instance, in ham or in water. We were puzzled by that because we assumed at least at a highway we would have a greater concentration of these substances. But we didn't."

That may have confused scientists - but it sounds sweet to Fraport.

"If the honey from the airport is of good quality, then we can say the air quality at the airport in general is fine," Marx said. "The pollution people are often talking about at airports is not really at the airport."

As Grünewald and his team look for new ways to get more information from the bees, Marx and his team are bottling the results.

Frankfurt airport is taking its honey, along with some more from around the region, putting the Fraport label on it, and getting it ready as Christmas gifts for the airports 13,000 employees.

Author: Susan Stone

Editor: Sean Sinico