QAANAAQ, Greenland -- Pitching a makeshift tent on the sea ice, where the Arctic Ocean meets the North Atlantic, brothers Mamarut and Gedion Kristiansen are ready to savor their favorite meal.
Nearby lies the carcass of a narwhal, a reclusive beast with an ivory tusk like a unicorn's. Mamarut slices off a piece of muktuk, the whale's raw pink blubber and mottled gray skin, as a snack.
"Peqqinnartoq," he says in Greenlandic. Healthy food.
Mamarut's wife, Tukummeq Peary, a descendant of famed North Pole explorer Admiral Robert E. Peary, is boiling the main entree on a camp stove. The family dips hunting knives into the kettle, pulling out steaming ribs of freshly killed ringed seal and devouring the hearty meat with some hot black tea.
Living closer to the North Pole than to any city, factory, or farm, the Kristiansens appear unscathed by any industrial-age ills. They live much as their ancestors did, relying on foods harvested from the sea and skills honed by generations of Inuit.
But as northbound winds carry toxic remnants of faraway lands to their hunting grounds in extraordinary amounts, their close connection to the environment and their ancestral diet of marine mammals have left the Arctic's indigenous people vulnerable to the pollutants of modern society. About 200 hazardous compounds, which migrate from industrialized regions and accumulate in ocean-dwelling animals, have been detected in the inhabitants of the far north.
The bodies of Arctic people, particularly Greenland's Inuit, contain the highest human concentrations of industrial chemicals and pesticides found anywhere on Earth -- levels so extreme that the breast milk and tissues of some Greenlanders could be classified as hazardous waste.
Nearly all Inuit tested in Greenland and more than half in Canada have levels of PCBs and mercury exceeding international health guidelines.
Studies of infants in Greenland and Arctic Canada who have been exposed in the womb and through breast milk suggest that the chemicals are harming children. Babies suffer greater rates of infections because their immune systems seem to be impaired, and their brain development is altered, slightly reducing their intelligence and memory skills. Scientists say the immune suppression could be responsible, at least in part, for the Arctic's inordinate number of sick babies. They believe the neurological damage to newborns is similar in scope to the harm done if the mothers drank moderate amounts of alcohol while pregnant.
The tragedy for the Inuit is that they have few, if any, ways to protect themselves. Many Arctic natives say abandoning traditional foods would destroy a 4,000-year-old society rooted in hunting.
In this hostile and isolated expanse of glacier-carved bedrock and frozen sea, survival means that people live as marine mammals live, hunting like they do, wearing their skins. No factory-engineered fleece compares with the warmth of a sealskin parka, mittens, and boots. No motorboat sneaks up on a whale like a handmade kayak latched together with rope. No snowmobile flexes with the ice like a dog-pulled sledge crafted of driftwood.
And no imported food nourishes their bodies, warms their spirit, and strengthens their hearts like the flesh they slice from the flanks of a whale or seal.
"Our foods do more than nourish our bodies. They feed our souls," said the late Ingmar Egede, a Greenlandic educator who promoted the rights of indigenous peoples.
"When I eat Inuit foods, I know who I am." In 1987, Dr. Eric Dewailly, an epidemiologist at Laval University in Quebec, was surveying contaminants in breast milk of mothers near the industrialized, heavily polluted Gulf of St. Lawrence when he met a midwife from Nunavik, the Arctic portion of Quebec. She asked whether he wanted to gather milk samples from women there. Dewailly reluctantly agreed, thinking it might be useful as "blanks," samples with nondetectable pollution levels.
A few months later, the first batch of samples from Nunavik arrived by air mail at the lab.
Dewailly soon got a phone call from the lab director. Something was wrong with the Arctic milk. The chemical concentrations were off the charts. The peaks overloaded the lab's equipment, running off the page.
Upon checking more breast milk, the scientists soon realized that the peaks were accurate: The Arctic mothers had seven times more PCBs in their milk than mothers in Canada's biggest cities.
"Breast milk is supposed to be a gift," said Dewailly, who today is among the world's leading experts on the human health effects of contaminants. "It isn't supposed to be a poison."
From ice-clinging algae to polar bears, the Arctic has a long and intricate ladder of life. An estimated 650,000 indigenous people inhabit the top rung, and their population is steadily growing. About 90,000 of them are the Inuit of eastern Canada and Greenland -- a territory of Denmark under its own home-rule government. Others, spread across eight nations and speaking dozens of languages, include the 350,000 Yakuts of Siberian Russia, Alaska's Inupiat and Yup'ik, and Scandinavia's Saami. The chemicals, such as polychlorinated biphenyls, or PCBs, originate in the cities of North America, Europe, and Asia. They travel thousands of miles north via winds, ocean currents and rivers. In the Arctic, the sea is a deep-freeze archive, storing contaminants that are slow to break down in cold temperatures and low sunlight. Ingested first by zooplankton, the chemicals spread through the food web as one species consumes another.
Most urban dwellers consume food from a host of sources, eating comparatively limited amounts of seafood and no marine mammals or other top predators high on the food web. Instead, they consume mostly land-raised foods with low contaminant levels.
lnuit, by contrast, eat much like a polar bear does, consuming the blubber and meat of fish-eating whales, seals, walruses, and seabirds four or five links up the marine food chain. Contaminants, which accumulate in animals' fat, magnify in concentration with each step up, from plankton to people.
In newborns' umbilical cord blood and mothers' breast milk, average PCB and mercury levels are 20 to 50 times higher in remote villages of Greenland than in urban areas of the United States and Europe, according to a 2003 report by the Arctic Monitoring and Assessment Programme, or AMAP, a scientific consortium created by the eight Arctic nations, including the United States.
In far northern villages such as Qaanaaq, where the Kristiansens live, one of every six adults tested exceeds 200 parts per billion of mercury in the blood, a dose known to cause acute symptoms of mercury poisoning, according to a 2003 United Nations report.
PCBs and DDT, the so-called legacy chemicals banned three decades ago in most developed nations, peaked in the Arctic in the 1990s and since then have declined, although they remain at substantially higher levels in people there than elsewhere.