BANGOR – Between four and six tons of junk and debris – including 148 discarded shopping carts – were removed from Birch Stream on Friday as part of a daylong cleanup operation involving about 60 people.

Some of the carts had been there for 20 to 30 years, dating back to the days of King’s and Rich’s, two defunct department stores that once were part of the Airport Mall.

Other trash hauled out of the stream and from its banks included mattresses, sofas, waste metal, old car batteries, bicycles, carpets – and three used hypodermic needles, which were disposed of in a special container for biohazards, according to Tony Caruso, assistant director of Bangor International Airport.

According to Caruso, who organized the project, participants included personnel from the Maine Air National Guard, the Department of Environmental Protection, several city departments and BIA as well as volunteers from the community.

The cleanup was prompted by DEP’s findings noting that Birch Stream suffers from a significant amount of refuse that adversely affects the stream’s quality.

The stream and the area around it have been the subject of an in-depth study of contamination, some of which has been linked to runoff from de-icing procedures at BIA involving commercial and military aircraft.

The study began after residents of nearby Griffin Park, an apartment complex operated by the Bangor Housing Authority, in April complained about a “yeasty” odor they believed was causing headaches and other ailments.

The odor was found to have come from propylene glycol antifreeze used to remove ice from airplanes.

In response, BIA installed a $300,000 de-icer runoff collection system that directs runoff into the municipal sewer system. About 90 percent of the project was funded by a federal grant.

The Air Guard is installing a similar system for its aircraft, but will use the city’s until its system is finished next month.

“The airport is a significant presence in the region, especially to our neighbors,” said BIA Director Rebecca Hupp. “It is very important that we achieve the proper balance between conducting a successful commercial operation and preserving the quality of life of our neighbors.”

Although the source of the trash is not known, she said, “It is incumbent upon all of us to protect and preserve our environment.”

Ann Birmingham, who has served as a spokeswoman for Griffin Park residents, said that the cleanup was a step in the right direction, but that more needed to be done to rid the stream of chemicals residents believe are causing a variety of illnesses.

Though residents of Griffin Park were invited to participate, none did because they did not want to risk exposure to substances in the stream, Birmingham said.

Health and building surveys also are being developed in conjunction with the state Bureau of Health, with assistance from the state toxicologist and environmental health unit. The surveys will look at other environmental issues that may be causing some of the illnesses at Griffin Park, such as mold, excess moisture, and whether improper building techniques or materials were used in constructing the complex.