From drinking water to distant wildlife, the disruptive legacy of PFAS—per- and polyfluoroalkyl substances—has infiltrated every corner of our planet. Known as « forever chemicals » for their extreme persistence in the environment, PFAS are increasingly under scrutiny not just for the human health risks they pose, but also for the biodiversity crises they may be fueling in silence. While much attention has centered on toxic exposures to people, the impact of these contaminants on ecosystems and species diversity is an unfolding story—and it’s deeply alarming.
The invisible hand of PFAS in ecosystem decline
Biodiversity forms the bedrock of healthy ecosystems. Every species plays a role—some visible and charismatic, others subtle but indispensable. In recent decades, global biodiversity has been under immense pressure from habitat destruction, climate change, invasive species, and pollution. PFAS can be a stealth contributor to this decline, acting as both a toxin and a disruptor of ecological balance.
But how exactly do these synthetic chemicals threaten biodiversity? The answer lies in the unique properties of PFAS themselves: they resist degradation, accumulate in living tissue, and spread easily through water, air, and soil. Their impacts are insidious, affecting reproduction, development, immune function, and behavior in wildlife species. Because PFAS don’t break down, they linger—and their effects compound across generations and food chains.
From fish to falcons: tracing PFAS through the food web
One of the clearest windows into PFAS’s ecological reach is the food web. Aquatic environments—rivers, lakes, wetlands, and oceans—act as major sinks for PFAS, making aquatic animals especially vulnerable. Fish, amphibians, and benthic organisms (those living at the bottom of water bodies) readily absorb PFAS from contaminated water and sediment.
Take, for instance, the smallmouth bass in the U.S. state of Michigan. A 2021 study found alarmingly high PFAS concentrations—particularly PFOS, a notorious legacy PFAS—in their livers and blood. The same fish are a food source for birds like eagles and ospreys, which then accumulate even higher levels of PFAS through biomagnification. This pattern has been echoed globally—from Arctic foxes to Australian platypuses, and even in whale populations.
In birds, PFAS exposure has been linked to decreased hatching success, developmental abnormalities, immune suppression, and hormonal disruption. For species already on the brink—like seabirds battling plastic ingestion and overfishing—PFAS may be the tipping point.
Sublethal effects: the silent Saboteurs
What makes PFAS particularly dangerous in terms of biodiversity is their ability to create “sublethal” effects—damage that might not immediately kill an organism, but that slowly destabilizes populations. These include:
- Endocrine disruption: PFAS can mimic or interfere with hormone systems, affecting growth, development, and reproduction across a range of species.
- Immunotoxicity: Exposed animals may have weakened immune responses, making them more susceptible to disease and less able to survive environmental stressors.
- Behavioral changes: Altered feeding, migration, or mating behaviors have been observed in fish and birds exposed to PFAS, which directly impacts their fitness and survival rates.
Individually, these impacts may seem subtle. Collectively, they create ripple effects throughout ecosystems—undermining reproductive success, weakening population resiliency, and pushing species toward local extinction.
Soil and terrestrial contamination: underappreciated pathways
While water contamination often commands headlines, terrestrial ecosystems are no safer. PFAS can persist in soils for decades, with contamination stemming from firefighting foams, industrial discharges, and biosolids used as fertilizer. Once in the soil, PFAS are taken up by plants and consumed by herbivores, working their way up the food chain just as they do in aquatic systems.
In a 2023 study, earthworms exposed to PFAS-contaminated soil accumulated high concentrations of the chemicals, leading to reduced reproductive capacities and slower growth rates. Since earthworms play a key role in soil health and nutrient cycling, their decline ripples through the ecosystem—affecting everything from soil fertility to bird populations that rely on them for food.
In forest environments near airports or military installations (both common sources of PFAS), researchers have found PFAS in deer, coyotes, and even fungi. This suggests that terrestrial bioaccumulation is more widespread—and more troubling—than previously understood.
Why biodiversity loss matters—for all of us
It’s easy to dismiss biodiversity as an abstract concern—something for conservationists and ecologists to ponder. But the collapse of biodiversity isn’t just a tragedy for wildlife—it’s a direct threat to human survival. Ecosystem services such as pollination, water purification, pest control, and climate regulation all depend on robust, diverse biological systems.
Disrupting the intricate relationships between species weakens the overall resilience of our ecosystems. When keystone species—those crucial to ecosystem function—are compromised by contaminants like PFAS, the results can cascade far beyond the immediate environment. Insect populations drop, birds vanish, and plant growth stalls. And ultimately, it’s the human food supply, water security, and health that suffer.
It’s a stark reminder that chemical pollution is not just a local issue. PFAS are already found in polar bears in the Arctic and penguins in Antarctica—proof that no corner of Earth is untouched. The loss of any species, no matter how small or remote, leaves the whole web of life more fragile.
Regulatory blind spots and scientific uncertainty
Despite mounting evidence, many environmental risk assessments and chemical regulations are slow to account for the cumulative and long-term effects of PFAS on biodiversity. Part of the challenge lies in the sheer complexity of PFAS as a chemical class—there are over 12,000 known compounds, and most have never been fully tested for ecological toxicity.
Current legal thresholds in water and soil often focus on human health endpoints, not wildlife impacts. Moreover, PFAS toxicity can vary drastically between species, making it difficult to establish one-size-fits-all safety limits. This lack of ecological consideration in policymaking is a dangerous blind spot.
Encouragingly, some nations are beginning to revise their frameworks. For example, the European Union is pushing for a group-wide restriction of PFAS under REACH, citing not just drinking water concerns but also the chemicals’ persistence, bioaccumulation, and ecotoxicity. However, comprehensive ecosystem protection remains an uphill battle.
What can be done?
Awareness is the first step—but action must follow. Here are some key strategies that researchers, regulators, and individuals can pursue to reduce the biodiversity risks of PFAS:
- Expand ecological monitoring: Long-term, wildlife-centered studies are essential to understand how PFAS affect non-human species over time and across ecosystems.
- Adopt class-based regulation: Instead of restricting PFAS one by one, regulators should address them as a class to prevent regrettable substitutions.
- Promote safer chemistry: Innovation in material science must prioritize environmental compatibility from the design stage. PFAS-free alternatives already exist—especially in textiles, packaging, and firefighting agents.
- Support restoration efforts: Wetland rehabilitation, soil remediation, and wildlife reintroductions can rebuild biodiversity in PFAS-impacted areas—with long-term community and ecological benefits.
- Strengthen consumer advocacy: Demand transparency. By choosing PFAS-free products and supporting brands committed to sustainability, consumers can help shift market demand.
Ultimately, the fight for biodiversity and the fight against chemical pollution are two sides of the same coin. As we continue to unravel the biological cost of PFAS, the urgency becomes clear: safeguarding wildlife is not just about ethics or aesthetics. It’s about ensuring the stability of the very systems we rely on—clean water, fertile soil, and a climate that sustains life.
We can’t afford to ignore the warning signs any longer. Biodiversity is our planet’s life insurance—and PFAS are quietly shredding the policy.