Tuesday, June 29, 2010
At German Airports, Bees Help Monitor Air Quality
Airports in Germany have come up with an unusual approach to monitoring air quality. The Düsseldorf 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 indicated that toxins were far below official limits, consistent with results since 2006 when the airport began working with bees.
Beekeepers from the local neighborhood club keep the bees. The honey, “Düsseldorf 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. But “it’s a very clear message for the public because it is easy to understand,” he added.
Volker Liebig, a chemist for Orga Lab, who analyzes honey samples twice a year for the Düsseldorf and six other German airports, said results showed the absence of substances that the lab tested for, like certain hydrocarbons and heavy metals, and the honey “was comparable to honey produced in areas without any industrial activity.” 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 once used as 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 United States had improved the air quality at its airports through more stringent standards and improved monitoring techniques.
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, he 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,” Mr. 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, Ms. 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.”
Dr. Fine, who oversees a network of air-monitoring stations, was a lead researcher on a study financed by the Environmental Protection Agency that is to be released in the next few weeks.
The lead levels from non-jet aircraft emissions did not exceed federal limits, but were significantly elevated, Dr. 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, he 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 the University of California, Los Angeles. But “we know next to nothing about the health effects of aircraft emissions” of these particles, Dr. Paulson said. She was a lead researcher on another study, published late last year in the journal Environmental Science & Technology.
The federal government sets standards for pollutants like ozone and particulate matter, Dr. Fine said, “but ultrafine particles are not currently regulated.”
Europe has limits on ultrafine particles from vehicle emissions, Dr. Fine said. But 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 with bees, as the results are consistent with traditional air quality monitoring in Europe.
“If you look at the honey, it’s perfectly fine,” Mr. Fleuti said, adding that he often gets jars of it when he visits Germany. “It’s good honey.”
A version of this article appeared in print on June 29, 2010, on page B6 of the New York edition.