Antarctica is one of the most pristine environments on Earth, but it’s wrestling with a pollution problem. And the very people who are working hardest to protect the continent are responsible.

Across Antarctica, wastewater from dozens of research bases, housing up to 5,000 people at a time, mostly scientists, is releasing nasty chemicals into the environment—and into penguins and other wildlife.

The most recent culprit: a toxic flame retardant called Hexabromocyclododecane, or HBCD.

It’s commonly used in insulation, building materials, thermoplastics, and research equipment, including computers.

Da Chen, an ecotoxicologist from Southern Illinois University, and some marine science colleagues recently tested for HBCD at the U.S. research base McMurdo Station, on the southern tip of Ross Island, and at a New Zealand base nearby, using samples from dust and sewage sludge.

The scientists also tested wildlife tissue as well as sediments from the area where wastewater from the two bases—water containing sewage, organic and inorganic material, toxins, silt, pathogens, pharmaceuticals—spills into McMurdo Sound.

HBCD was present everywhere the scientists looked: in dust from the stations, in the sediment, and in the tissue of the animals, which ranged from Adélie penguins and fish to sponges and marine worms.

Not surprisingly, the sediment nearest the wastewater source had the highest HBCD contamination. But what was unexpected is just how high the levels were—rivaling those in some rivers near highly urbanized areas in the U.S. and Europe.

The scientists reported their findings at the Society of Environmental Toxicology and Chemistry meeting late last year, but they’ve gotten little press coverage.

View Images Open year-round, McMurdo Station has labs, warehouses, a power plant, and three airfields. Photograph by Norbert Wu, Science Faction/ Corbis

How Big a Threat?

Though no one’s yet sure how much HBCD penguins and other Antarctic animals can tolerate or what it does to them, in rodents and in fish the chemical has been shown to disrupt thyroid hormones, which affect metabolism and brain development.

The levels found in the animals in the recent study don’t appear to have caused problems, but some scientists are concerned nonetheless.

“We suspect cold climate conditions may prevent HBCD from degrading,” Chen says, so the chemical may linger, presenting an ongoing environmental threat.

Andrea Kavanagh, who leads the Pew Charitable Trusts’ Global Penguin Conservation program, says it may be too early to judge the toll of the chemical on wildlife because of the way it acts in the body.

“Flame retardants in particular are deposited in fatty tissue, and they bioaccumulate,” she says, “meaning the chemical persists and continues to build up in the body faster than it is eliminated or broken down.”

Kavanagh says previous research had found other flame retardants—now-banned brominated compounds that were used in electronics and upholstered furniture—in wildlife near McMurdo Station's wastewater outflow.

“No protocol was established to prevent it from happening again,” she says.

An Overlooked Problem

More than 30 countries maintain some 70 research bases across Antarctica, housing anywhere from 1,000 to 5,000 residents. Tourists visit the bases too.

Wastewater treatment methods vary widely from station to station. Some don’t do any treatment at all. Many use a basic process known as maceration, which breaks large sediment (like human waste) into small bits that can be pumped out but does nothing to remove chemicals.

Some stations have implemented better systems in the past decade, though efforts have been focused more on killing microorganisms than on cleaning up chemicals.

And little is known about how long such things as pharmaceuticals and personal care products persist or how they affect wildlife.