The Arctic’s warming climate is accelerating the spread of disease

The Arctic is changing faster than anywhere else on Earth. Climate change, pollution and shifting ecosystems are interacting in powerful ways that increasingly affect both human and wildlife health. As MARIO ACQUARONE writes, bringing together science, Indigenous Knowledge and policy strengthens early warning, preparedness and community resilience.

Health in the Arctic is influenced by rapid warming, long-range pollution, and the close, enduring connections between people, wildlife and ecosystems. Within this changing context, infectious diseases, especially zoonoses (diseases shared between animals and humans), are a growing concern. Roughly three-quarters of human infectious diseases are zoonotic, and many are climate-sensitive. This means that warming temperatures, altered precipitation patterns, and ecosystem change can directly influence where and how these diseases spread.

A sink for contaminants

Arctic communities, particularly Indigenous ones, often face greater exposure and more severe consequences. Close contact with wildlife through subsistence hunting and food preparation—combined with reliance on traditional foods that may be consumed raw or minimally processed—can increase vulnerability. These realities are compounded by limited access to health care, diagnostics and public-health surveillance in remote areas as environmental change disrupts food security and food safety.

The Arctic has little local industry, yet it acts as a sink for contaminants transported from the industrialized lower latitudes by air and ocean currents. Persistent organic pollutants (POPs)—such as polychlorinated biphenyls (PCBs) and per‑ and polyfluoroalkyl substances (PFAS), often referred to as “forever chemicals”—accumulate far from their sources along with mercury and other heavy metals.

Making matters worse, the concentrations of these substances increase as they move up the food web. This means the highest levels are found in top predators, such as polar bears, seals, whales and the people who depend on them for food. In this way, pollution becomes not only an environmental issue, but a direct threat to both wildlife conservation and human health.

Causing harm on multiple fronts

Contaminants affect wildlife in multiple, interconnected ways. They can suppress immune systems, reducing the ability to fight infections. They can disrupt endocrine and reproductive systems, undermining population viability. And they can increase susceptibility to disease, especially when combined with the stress of a rapidly warming climate.

Animals that are already challenged by habitat loss and changing food availability are less resilient to these additional pressures.

As climate change forces wildlife to shift their ranges, diets and behaviours, their exposure to both contaminants and pathogens is changing as well. These shifts have been linked to an increased prevalence of brucellosis, toxoplasmosis, avian influenza and parasitic infections, among others.

At the same time, mass mortality events in birds and marine mammals are becoming more frequent. These are visible signals of ecosystems under strain. Across the Arctic, the resilience of already stressed populations to climate change and related pressures is being eroded.

For humans, especially Indigenous Peoples, contaminant exposure and disease risks intersect directly.

—Mario Acquarone, marine mammal ecologist, Deputy Secretary with the Arctic Monitoring and Assessment Programme

Chemical exposure, largely through the consumption of country foods, has been linked to immune effects, hormonal disruption and greater severity of infections. Food‑borne zoonoses, such as trichinellosis, toxoplasmosis, botulism and anthrax, are persistent risks, shaped by both traditional food practices and rapidly changing environmental conditions.

In some regions, thawing permafrost has re-exposed historic pathogens like anthrax, affecting not only wildlife (including reindeer), but the human communities that depend on them. This is forcing Arctic societies to navigate a dual challenge: they must safeguard culturally vital food systems while responding to emerging and evolving health risks.

In the Arctic, human, animal and environmental health are interconnected. Contaminants that weaken immune systems and climate change that reshapes ecosystems together amplify the risk that infectious disease will emerge and spread. Sentinel species, such as sled dogs and top predators, offer early warning signals critical for wildlife conservation and human well-being.

A One Health response

Current research points to the need for integrated One Health monitoring, more inclusion of local and Indigenous Knowledge, and coordinated observation of contaminants, wildlife disease and human health. Responding effectively requires collaboration across disciplines, sectors and borders.

Within this framework, the Arctic Monitoring and Assessment Programme (AMAP) serves as the Arctic Council’s scientific backbone. Through long‑term, circumpolar assessments, AMAP documents how contaminants, climate change and ecosystem disruption affect human and wildlife health, including how pollution and environmental stressors weaken immune systems, alter disease dynamics, and increase zoonotic risk.

There was a time when the Arctic was protected by its remoteness. Not anymore. Today, climate change and global pollution are converging to undermine wildlife and human health concurrently, outpacing our ability to monitor and respond. The region has become an early warning system for global health, teaching us that when pollution weakens immunity and climate change reshapes ecosystems, diseases emerge earlier, spread faster and hit harder.

Ultimately, this means a One Health approach is not optional—it is essential.