That buzz in the air

Airports in Germany have come up with an unusual approach to monitoring air quality. The Dusseldorf International Airport and seven other airports are using bees as “biodetectives,” their honey regularly tested for toxins. “Air quality at and around the airport is excellent,” said Peter Nengelken, the airport’s community liaison.

The first batch of this year’s harvested honey from some 200,000 bees was tested in early June, he said, and indicates toxins are far below official limits, consistent with results since 2006 when the airport began working with bees. Beekeepers from the local neighbourhood club keep the bees. The honey, ‘Dusseldorf Natural,’ is bottled and given away as gifts. Biomonitoring, or the use of living organisms to test environmental health, does not replace traditional monitoring, said Martin Bunkowski, an environmental engineer for the Association of German Airports.

Volker Liebig, a chemist for Orga Lab who analyses honey samples twice a year for the Dusseldorf and six other German airports, said results showed the absence of substances that the lab tested for, like certain hydrocarbons and heavy metals and “was comparable to honey produced in areas without any industrial activity.”  

Promising results
A much larger data sampling over more time is needed for a definitive conclusion, he said, but preliminary results are promising. Could bees be modern-day sentinels like the canaries that once were used as early warning signals of toxic gases in coal mines? Assessing environmental health using bees as “terrestrial bioindicators” is a fairly new undertaking, said Jamie Ellis, assistant professor of entomology at the Honey Bee Research and Extension Laboratory, University of Florida in Gainesville. “We all believe it can be done, but translating the results into real-world solutions or answers may be a little premature.” Still, similar work with insects to gauge water quality has long been successful.

Many experts say aircraft are not the only, or even main, source of pollution at airports. Cars, taxis, buses and ground activities as well as local industry are often major polluters. Not surprisingly, Nancy Young, vice president of environmental affairs at the Air Transport Association of America, an airline trade group, defended the air quality at airports. “Airports are not significant contributors” to local air pollution, she said, adding that aviation emissions represent “less than 1 percent of the nation’s inventory and typically only a few percentage points in any given metropolitan area with a major airport.” She said the US had improved the air quality at its airports through more stringent standards and improved monitoring techniques.

Improvement from the 1960s
Internationally, there have been similar improvements, said Steven Lott, a spokesman for the International Air Transport Association. Since the 1960s, carbon monoxide, unburned hydrocarbons, smoke and nitrogen-oxide emissions have been substantially reduced, Lott said. Standards for most of them are set by the International Civil Aviation Organization, a United Nations body. “It’s a challenge for an industry that continues to grow,” Lott said. But the industry has invested in developing cleaner aircraft engines and ground-support equipment and vehicles as well as improvements in how equipment is operated.

Initiatives like its Green Teams, for example, allow industry consultants to visit airlines to identify and share ways to reduce fuel burn and emissions. More than 105 airlines have participated, he said. Still, some community groups are not persuaded that air quality at airports has improved. “It’s way worse than people think,” said Debi Wagner, a board member of Citizens Aviation Watch USA, who lives in Seattle. Some emissions are not adequately sampled and measured, Wagner said, and other potentially dangerous ones are not monitored at all. She said she was concerned particularly about the health of people living within three miles of commercial airports.

Two recent studies also raise questions about the quality of air at airports. Both focus on small general aviation airports, like the one in Santa Monica, Calif., which was studied in both reports. “The traditional pollutants did not seem to be a local issue,” said Philip Fine, atmospheric measurements manager for the South Coast Air Quality Management District, an air quality regulatory agency for most of Southern California. “However, there were issues for ultrafine particles and lead.” Fine, who oversees a network of more than 35 air-monitoring stations, was a lead researcher on a study financed by the Environmental Protection Agency. The lead levels from non-jet aircraft emissions did not exceed federal limits, but were significantly elevated, Fine said. Elevated levels of ultrafine particles, primarily from jet aircraft, were also a concern. The particles are short-lived, but because they are in high concentration down wind during takeoff, they are particularly worrisome for people who live close to small airports or who are repeatedly exposed, Fine said. Most large airports are farther from residential communities, and also have buffer zones separating them. The health implications of ultrafine particles are not yet known, but some medical research suggests they could pose a serious risk because the extremely fine particles pass through cell walls easily and are able to penetrate far into the brain and circulatory system.

Epidemiological studies have shown there are health risks from elevated levels of these particles emitted by cars and trucks, a concern for people who live near or frequently travel on busy highways, said Suzanne E Paulson, professor of atmospheric sciences at UCLA.  

‘Good honey’
She was a lead researcher on another study, published late last year in the journal Environmental Science & Technology. Paulson said ultrafine particles “are being watched very carefully” by the EPA and others. The federal government sets standards for air pollutants like ozone and particulate matter, Fine said, “but ultrafine particles are not currently regulated.” Europe has governmental limits on ultrafine particles from vehicle emissions, Fine said. Emanuel Fleuti, head of environment services for Zurich Airport, said there were concerns in Europe as well. Meanwhile, he said, he is confident about the biomonitoring work the German airports are doing, as the results are consistent with traditional air quality monitoring in Europe. Some airports in France, Sweden and Israel have recently begun working with bees also.“If you look at the honey, it’s perfectly fine,” Fleuti said, adding that he often gets jars of it when he visits Germany. “It’s good honey.”
 New York Times News Service