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Researchers are surprised that these chemicals have skyrocketed in Svalbard

Svalbard reindeer live in a place so remote that they have actually evolved into their own subspecies. But that remoteness isn’t enough to protect them from contaminants.

Researcher sitting on tundra collecting reindeer droppings with reindeer grazing in the background.

If you want to study contaminants in Svalbard reindeer, you have to be willing to find and collect reindeer poop, as Malin Andersson Stavridis did.

(Photo: Arthur Garreau / NTNU)

Nancy Bazilchuk Nancy Bazilchuk COMMUNICATIONS ADVISER

Presented by: Presented by: NTNU - Norwegian University of Science and Technology

Published 19 June 2026 - 00:01

Researchers have long known that heavy metals and organic pollutants such as DDT accumulate in the Arctic.

This is especially true for predators at the top of the food chain, such as polar bears.

But what happens to animals like Svalbard’s reindeer, which graze on arctic plants?

How contaminated are these animals? How do they compare to other reindeer species, such as caribou, across the Arctic? What effects might those contaminants have?

And since people eat Svalbard reindeer, should they limit their consumption?

This knowledge gap led Malin Andersson Stavridis to spend four years in the northern archipelago of Svalbard, searching for answers.

A bull Svalbard reindeer lying in grass with large antlers in a tundra landscape. — A male Svalbard reindeer. Female reindeer also grow antlers, but they are typically smaller than the male’s.

She found that levels of toxic metals such as cadmium, lead, and mercury have been relatively stable for the last decade.

"What the heck?"

But what really shocked her was that levels of so-called forever chemicals, PFAS, have skyrocketed during that same period.

The increase was so dramatic that the researcher initially thought the results had to be wrong.

“To see that the concentrations are so high, maybe even the highest measured in reindeer, that was a not an ah-ha moment, but more like ‘what the heck?’” says Stavridis.

From poop and fur to more comprehensive sampling

One of the challenges Stavridis faced was how to measure contaminant levels in a meaningful way. Earlier studies had relied on testing reindeer faeces and fur. These samples are easy and non-invasive to collect.

But these sampling methods don’t necessarily give a full picture of how pollutants may be affecting the animals.

“I was asking myself, can we say anything about the contaminants inside? Can we determine the contaminants in liver or soft tissues just based on what’s in the fur? And I felt like that link was missing, especially since Svalbard reindeer are also consumed by people living on the island,” she says.

Two field researchers use binoculars to look across a tundra landscape, with gear on their backpacks. — Malin Stavridis at work, looking for reindeer to collect fresh reindeer droppings. Note the rifle on her backpack. It’s required equipment, along with a flare gun, to scare away any polar bears that might cross their paths.

She was given the opportunity to participate in a major international research project in which 68 female reindeer were culled over a three-year period. In October 2021, she collected samples from the animals’ brains, kidneys, livers, faeces, and thighs.

Over the next two years, she also analysed fur, faeces, muscle tissue, and liver samples to determine contamination levels.

Wanted to establish a baseline

Mercury in the Arctic comes both from natural sources such as wildfires and volcanoes and from the burning of fossil fuels. It can be transported northwards by wind or through the food chain.

Plants can absorb mercury from the air through their leaves. As a result, Arctic permafrost contains large amounts of the metal.

“Permafrost soils are just old plants that have been slowly building up over time. So that’s how we have this very big accumulation of mercury in Arctic soils,” the researcher says.

As permafrost thaws due to global warming, mercury may become more available within the ecosystem.

Faecal samples provided good answers

“So in that context, I just wanted to lay the foreground for how we can determine whether mercury concentrations are becoming bioavailable. How will we know what's happening to the mercury in the Arctic if we don’t know what levels look like now?” she asks.

Bioavailability describes the extent to which a substance – such as a nutrient, medicine, or metal – is absorbed in the intestine and made available for uptake and use by the body’s cells.

In the end, Stavridis was able to confirm that faeces could be used to monitor mercury levels in the animals. This is good news because it means animals do not need to be culled in order to track changes over time.

Some toxins are decreasing

Stavridis didn’t just want to take a snapshot of contaminants in Svalbard reindeer, she also wanted to know how these levels changed throughout the summer as reindeer build up fat reserves for winter.

Researcher kneels on a grassy slope holding reindeer droppings in gloved hands. — Sometimes you get lucky when it comes to collecting reindeer poop. And in this case, reindeer droppings proved to be a good way to keep tabs on mercury levels in the animals.

She found that contaminants such as mercury, cadmium, and PFAS were higher in October than in August.

But levels of two other toxic metals, cadmium and lead, had decreased compared to levels reported in the 1980s.

The PFAS mystery

Most of these contaminants were similar to, or lower than what has been found in other reindeer subspecies across the Arctic. But not PFAS levels, according to Stavridis.

These levels were among the highest ever recorded. They had increased by more than 900 per cent in ten years, from about 0.6 to 5.48 nanograms per gram.

Earlier studies suggested that the source was firefighting exercises in Longyearbyen. However, the new measurements revealed a different chemical 'fingerprint.'

“Now we see a profile that’s dominated by another type of PFAS. The concentrations are so high, maybe even the highest measured in reindeer,” she says.

The reason for the increase remains a mystery.

“I only have my samples from the reindeer to go from. I can say that there's something that has affected their exposure. It could be as simple as they have a different diet. But even if they have a different diet, the levels shouldn't change that much in 10 years,” she says.

Hints of biological effects

Stavridis also examined 20 genes to determine whether they were being upregulated, meaning that they might produce more of the substances they play a role in making, or downregulated, meaning that they would produce less.

Many of the genes she studied were related to the ability to convert fat into energy. This process appeared to be downregulated as contamination increased.

“Building fat and using fat is very important for these animals because they undergo such large fluctuations in body mass throughout the year,” she says.

Similar effects have been observed in polar bears and orcas.

The results suggest that even though each individual substance is present at a low level, the combination of multiple substances may affect biological processes.

The researcher has both good news and bad news

Each of the individual contaminant concentrations are below current wildlife toxicity thresholds.

Nevertheless, the gene analyses suggest that the combined exposure may still have effects. She also found that the meat can be eaten, but with limitations.

"If a person wants to eat Svalbard reindeer, they can only consume 11.5 grams of liver per week over a year so as to not exceed the PFAS threshold,” she says.

Svalbard reindeer live far away from most human activity.

“They're out there, wild, in the middle of nowhere. You would assume this would be completely safe. And yet here we are,” the researcher says.

Reference:

Stavridis et al. Seasonal Shift in Exposure and Accumulation of PFAS and Heavy Metals in High Arctic Reindeer, Environmental Science & Technology, 2026. DOI: 10.1021/acs.est.5c11066

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Read the Norwegian version of this article on forskning.no